Final Exam Study Guide #2 PDF

Practice Exam I Part A. Multiple Choice (2 pts each; 40 points total on real test) 1. Serosae (aka mesothelia) are found in the lining of the: a) marrow cavity b) integument c) mucosa d) body cavities Mucosae are found in the lining of the: → Oral Cavity...

Practice Exam I Part A. Multiple Choice (2 pts each; 40 points total on real test) 1. Serosae (aka mesothelia) are found in the lining of the: a) marrow cavity b) integument c) mucosa d) body cavities Mucosae are found in the lining of the: → Oral Cavity Serous membranes (aka serosa and mesothelia) line the surfaces of the body cavities and their resident organs o Pericardial cavity o Pleural cavity o Peritoneal cavity (abdominal cavity) Mucous membranes (mucosa) line the surface of hollow organs that open into an internal lumen o Oral cavity o Traches and lungs o Stomach and intestines o Ureters, urethra, and urinary bladder Cutaneous membrane (the skin) is the largest membrane in the body. Mostly for protection o The epidermis and dermis make up the cutaneous membrane a. Marrow cavity is lined by endosteum. - Endosteum is a layer of thin connective tissue lining internal bone surfaces - Lines compact bone surrounding the marrow cavity - Lines canals within compact bone osteons - Lines every spicule in cancellous bone b. The integument is a cutaneous membrane, which is made up of two layers epidermis and dermis. c. Mucous membranes (mucosa) line the surface of hollow organs that open into an internal lumen. d. Serous membranes (aka serosa and mesothelia) line the surfaces of the body cavities and their resident organs 2. A cutaneous membrane will never have which of the following? a) an apical surface b) keratinized stratified squamous epithelium c) tactile cells d) adipocytes e) elastin f ) blood vessels A mucous membrane will never have which of the following components? → simple squamous epithelia because it is in serous membranes Membranes have both epithelia and connective tissue Cutaneous membranes consist of:  o (a) an apical surface o (b) Keratinized stratified squamous epithelium and Simple squamous epithelium o (c) tactile cells o (d) does NOT contain adipocytes (adipose tissue is in the hypodermis) ▪ The hypodermis is not apart of the cutaneous membrane o (e) elastin o (f) blood vessels (in papillary dermis → areolar CT) o Cells of the epidermis: keratinocytes, stem cells, melanocytes, tactile cells, dendric cells o Layers of the epidermis: stratum corneum, stratum lucidum, stratum granulosum, stratum basale o Layers of the dermis: papillary layer (areolar connective tissue) and reticular layer (dense irregular connective tissue) Serous membranes consist of: o an apical surface o Keratinized stratified squamous epithelium o tactile cells o elastin o blood vessels o serous fluid o squamous cells o areolar tissue o smooth muscle o Does NOT contain adipocytes Mucous membranes consist of o an apical surface o ciliated pseudostratified epithelium o goblet cells o collagen and elastic fibers o blood vessels o muscularis mucosae 3. Which of these is NOT true of connective tissues? a) most cells are in direct contact with extracellular protein fibers b) ground substance is more abundant than in epithelial tissues c) most have a lower cells:matrix ratio compared to epithelial tissues d) protein fibers are usually present in the extracellular matrix  e) frequently found superficial to epithelial tissue layers Which of these is true of connective tissues? → ground substance is more abundant than in epithelial tissue a. In CT, cells are in direct contact with EC protein fibers - Cells being in direct contact with each other is a property of epithelial tissue b. Ground substance is more abundant in CT than epithelial tissue c. Connective tissue has a lower cell:matrix ratio than epithelial tissue d. Protein fibers are present in EC matrix e. Connective tissue is NOT found superficial to epithelial tissue. CT is located below epithelial tissue. In connective tissue, fibers are more abundant than in epithelial tissue 4. Which of the following is a characteristic of positive feedback? a) a self-amplifying cycle b) more common than negative c) maintains steady state d) occurs only in non-human primates e) always unhealthy Which of the following is a characteristic of negative feedback? → promotes a steady state of equilibrium Positive feedback is a self-amplifying cycle that occurs in response to a stimulus (amplifying stimulus). o A positive feedback loop is repeated → change produces more of that change. o Produces rapid changes in some appropriately healthy situations ▪ Ex: childbirth, blood clotting, fever o Positive feedback is more rare than negative feedback a. Positive feedback is a self-amplifying cycle b. Positive feedback is NOT more common than negative feedback c. Positive feedback disrupt the steady state and alters set point for steady state d. Positive feedback occurs in humans e. Positive feedback can be healthy (in childbirth, blood clotting, and the mineralization of bone tissue) or life-threatening (unhealthy) Negative feedback is a self-attenuating cycle that maintains or restores steady state o A self-attenuating cycle and promotes steady state o It keeps variable close to the set point o Loss of negative feedback (loss of homeostatic control can cause illness or death 5. Which of the following is formed from ectoderm? a) serosae b) brain cells c) mucosae d) dermis e) blood Which of the following is formed from endoderm? → goblet cells in mucus membrane 3 primary germ layers: o Ectoderm (outer): gives rise to epidermis and nervous system ▪ Keratinized stratified squamous epithelium is derived from the ectoderm o Mesoderm (middle): gives rise to muscle, bone, blood, adipose, cartilage, serous membrane, dermis ▪ The mesoderm becomes a gelatinous tissue called mesenchyme o Endoderm (inner): gives rise to mucus membrane lining digestive and respiratory tracts, digestive and endocrine glands, and mucosal epithelium ▪ Non-keratinized stratified squamous epithelium, simple cuboidal, and simple columnar are derived from the endoderm a. Serosae/mesothelium is formed from the mesoderm b. Brain cells are formed from the ectoderm c. Mucosae / mucosal epithelium are formed from the endoderm d. Dermis is formed from the mesoderm e. Blood and muscle tissue are formed from the mesoderm 6. Accumulation of the pigment bilirubin, notably visible in the whites of the eyes, is called? a) pallor b) jaundice c) cyanosis d) melanization e) erythema Which of the following may present on the skin during respiratory arrest? → cyanosis a. Pallor: pale or ashen color that occurs when there is little blood flow through the skin Result from a stroke b. Jaundice: yellowing of the skin and whites of the eyes from high levels of bilirubin in the blood Result from liver failure c. Cyanosis: blueness of the skin from a deficiency of oxygen in the circulating blood Result from anemia or cardiac arrest Cyanosis is caused by condition such as cardiac arrest or airway obstruction that lead to depletion of oxygen from the blood. d. Melanization is the process that produces melanin, which protects the skin from UV rays e. Erythema: abnormal redness of the skin Albinism: genetic lack of melanin 7. Which of the following hair follicle structures is furthest from the integument surface? a) hair matrix b) hair root c) hair shaft d) dermal papilla Which of the following hair structures extends from the skin surface? → hair shaft a. Hair matrix is the hair’s growth center. Located right above the dermal papilla. b. Hair root is the remainder of the hair in the follicle. Located in the epidermis/dermis c. Hair shaft is the portion above the skin’s surface d. Dermal papilla is a bud of vascular connective tissue encased by the bulb. Located below the hair matrix. It nourishes the hair. Hair bulb is a swelling at the base where the hair originates in the dermis or hypodermis o Only living hair cells are in or near the bulb; nourished by a dermal papilla 8. In the intestine, __________________ ensure(s) that most digested nutrients pass through the epithelial cells via membrane transport and not between the cells of the epithelial layer. a) tight junctions b) hemidesmosomes c) connexons d) desmosomes In the intestine, desmosomes ensure(s) that keratinocytes of the stratum spinosum hold together against mechanical stress. a. Tight junctions (occluding junctions) form a zone that completely seals off lateral intercellular spaces near the apical side of the membrane. - Tight junctions force larger solutes to pass through the cells if they want to be absorbed into the body and not pass between the cells - Tight junctions make it possible for most substances to pass between cells - Most (not all) epithelia have tight junctions - Tight junctions ensure that most digested nutrients pass through the epithelial cells via membrane transport b. Hemidesmosomes (type of desmosome) latch the basal surface of epithelium to the basal lamina. Resists epithelial layer delamination (dividing) from underlying tissues - Hemidesmosomes are located between cells in the basement membrane c. Connexons form a pore for a gap junction between the cytoplasm of two adjacent cells. - Connexons are the proteins involved in forming gap junctions and allow solutes to pass between two adjacent cells d. Desmosomes (anchoring junctions) patches that hold cells together and resists mechanical stress. Gap or communicating junctions are pores that equilibrate internal conditions between cells of an epithelial tissue. o Allows for free diffusion of ions, glucose, and amino acids through the cytoplasm  o In bone tissue, communicating (gap) junctions ensure that osteocytes further from the blood supply can maintain homeostasis with adequate nutrition and sanitization. 9. Which of the following cellular flow processes is the most readily saturable? a) Water diffusion through membrane channels with the concentration gradient b) Pumped potassium against the concentration gradient c) Gated sodium diffusion with the concentration gradient d) Diffusion of a steroid through the plasma membrane by simple means Which of the following would have the highest cellular transport maximum value? → ungated potassium diffusion with the concentration gradient Order of saturability (least to most saturable): o Simple diffusion → highest transport max o Ungated facilitated diffusion (passive transport) o Gated facilitated diffusion (passive transport) o Active transport → lowest transport max Highest transport maximum value: water diffusion through membrane channels with the concentration gradient Transport maximum is the saturation point Solute concentration can only increase up to the transport maximum o Active transport has a slower rate than passive facilitated diffusion o Active transport is also more saturable than passive transport a. Water diffusion through membrane channels with the concentration gradient requires ungated facilitated diffusion b. Potassium being pumped against the concentration gradient requires active transport, which makes this the most saturable and have the lowest transport max c. Gated sodium diffusion with the concentration gradient requires ungated facilitated diffusion d. Diffusion of a steroid / lipid through the membrane by simple means is the least saturable and has the highest transport max 10. Matrix synthesis during osteoblast activity involves: a) seed crystal precipitation b) mineral resorption c) inhibition of osteoblasts d) decreased osteocyte activity e) apoptosis (death) of osteoblasts Interstitial growth during bone elongation involves: chondrocyte multiplication  Ossification: mineralization process in which calcium phosphate and other ions are taken from the blood plasma and deposited in osteoid tissue as crystallized salts o (a) As minerals accumulate, crystals precipitate from solution and encrust collagen fibers serving as seed crystals for the continuing deposition of more inbound calcium phosphate crystals (positive feedback) Osteoblasts synthesize the matrix and become osteocytes that become apart of bone tissue (b) Mineral resorption is taking minerals out of the matrix and putting them in the blood o Osteoclasts activity (mineral resorption) involves the breakdown of collagen Matrix resorption during osteoclast activity involves enzymatic degradation of collagen. (c) inhibition of osteoblasts stops matrix synthesis (d) osteocytes are not involved in matrix synthesis; they are involved in maintaining the matrix (e) death of osteoblasts would not contribute to matrix synthesis 11. An abnormal posterior exaggeration of the lumbar curvature is called: a) acromegaly b) kyphosis c) lordosis d) scoliosis An abnormal lateral exaggeration of the thoracolumbar portions of the column is called: scoliosis a. Acromegaly: enlarged hands and feet b. Kyphosis: abnormal anterior exaggeration of the lumbar curvature (hunchback) c. Lordosis: abnormal posterior exaggeration of the lumbar curvature (swayback) d. Scoliosis: abnormal lateral deviation of the thoracolumbar curvature 12. ___________ are abundant in osseous tissue within both compact and cancellous bone portions. a) Circumferential lamellae b) Sharpey’s fibers c) Canaliculi d) Trabecular endosteum e) Osteogenic cells Central canals are only found in osseous tissue of compact, but not cancellous bone portions. a. Circumferential lamellae are ONLY found in compact bone b. Sharpey’s fibers are ONLY found in compact bone - Sharpey’s fibers only are in the periosteum and the periosteum always covers the outside of compact bone c. Canaliculi are found in BOTH compact and spongy bone d. Trabecular endosteum are ONLY found in spongy bone e. Osteogenic cells are found in the endosteum and periosteum membranes Osteons with central canals are found in compact bone Lacunae are found in BOTH compact and spongy bone (NOT only found in compact bone)  Circumferential lamellae, Sharpey’s fibers, Central canals, and perforating canals are ONLY found in compact bone. 13. Blood vessels in the _________ provide a hair with its sole source of nutrition/sanitation. a) bulb b) root c) shaft d) dermal papilla e) medulla Cells in the bulb provide a hair with its sole source of mitotic growth. a. Hair bulb is a swelling at the base where the hair originates in the dermis or hypodermis - Only living hair cells are in or near the bulb; nourished by a dermal papilla b. Hair root is the remainder of the hair in the follicle. Located in the epidermis/dermis c. Hair shaft is the portion above the skin’s surface d. Dermal papilla is a bud of vascular connective tissue encased by the bulb and it is the hair’s source of nutrition and sanitation e. The medulla of the hair is the inner layer of the hair shaft. Hair matrix is the hair’s growth center. Located right above the dermal papilla. 14. Which of the following is true regarding osteosarcoma? a) caused by tumor growths in bone b) called osteomalacia in adults c) causes ectopic calcification of soft tissues d) caused by infection & inflammation Which of the following is true regarding osteomyelitis? → caused by infection and inflammation a. Osteosarcoma: caused by tumor growths in bone and it is the most common and deadly form of bone cancer. o It occurs most often in the tibia, femur, and humerus of males between the ages of 10 and 25. In 10% of cases, it metastasizes to the lungs or other organs; if untreated, death typically occurs within 1 year. b. Osteomalacia in adults and rickettsia in children is a result of a lack of Vitamin D o Vitamin D is essential for adequate retrieval of dietary calcium and phosphate c. Ectopic calcification of soft tissues happens when you have too much calcium in the blood d. Osteomyelitis: Inflammation of osseous tissue and bone marrow as a result of bacterial infection. This disease was often fatal before the discovery of antibiotics and is still very difficult to treat. Osteogenesis imperfecta: caused by collagen deficits. A defect in collagen deposition that renders bones exceptionally brittle, resulting in fractures present at birth or occurring with extraordinary frequency during childhood; also causing tooth deformity, and hearing loss due to deformity of middle ear bones.  Paget disease: excessive proliferation of osteoclasts and resorption of excess bone, with osteoblasts attempting to compensate by depositing extra bone. This results in rapid, disorderly bone remodeling and weak, deformed bones. Usually passes unnoticed, but in some cases it causes pain, disfiguration, and fractures. It is most common in males over the age of 55 15. Mature bones can grow throughout life by employing a) intramembranous ossification. b) endochondral ossification. c) interstitial growth. d) appositional growth. e) metaphyseal growth. When mature bones grow throughout life, the mineralized layer of new osseous growth around the entire cortical (outer) surface of the bone are referred to as? → circumferential lamellae. An increase in bone width due to layers of growth around the outer surface a. Intramembranous ossification: produces flat bones, has no cartilage template, forms in fibrous connective tissue (bones develop from inside out) b. Endochondral ossification: produces most bones and has hyaline cartilage template calcified into osseous tissue c. Interstitial growth: elongation of bones and elongation only occurs up to early 20s d. Appositional growth: thickening or widening of bones and it can occur throughout life - Appositional growth is a form of intramembranous ossification, so A and D are both correct e. metaphyseal growth the transition from cartilage to bone 16. When ____________ become enclosed in ________, they become cells called _____________. a) osteogenic cells; lacunae; osteoblasts b) osteoblasts; canaliculi; osteoclasts c) osteoblasts; lacunae; osteocytes d) osteocytes; canaliculi; osteoblasts e) osteogenic cells; canaliculi; osteocytes When stem cells in bone marrow fuse to form multinucleate osteoclasts, they become capable of mineral resorption. Osteogenic cells are stem cells that develop from embryonic mesenchyme and multiply continuously to produce new osteoblasts Osteoblasts: bone forming cells that synthesize the organic matter of the bone and then promote it mineralization o Line up in a layer with endosteum and periosteum Osteocytes: former osteoblasts that have become trapped in the matrix they deposited. They reside in tiny cavities called lacunae, which are interconnected by slender channels called canaliculi o Osteocytes are connected by gap junctions  o Osteocytes contribute to the homeostatic maintenance of bone density and blood concentrations of calcium and phosphate ▪ Capable of mineral deposition Osteoclasts: bone dissolving cells on the surface of bone o Osteoclasts have an independent origin o The side of the osteoclast facing the bone surface has a ruffled border and they reside in resorption bays Osteogenic cells → osteoblasts → osteocytes 17. Wolff's law of bone explains the effect of a) different diets on bone elongation. b) mechanical stress on bone remodeling. c) temperature on bone growth. d) age on bone thickening. Wolff's law of bone explains the effect of: compression/tension forces on trabecular architecture Wolff’s law of bone explains the architecture of bone is determined by the mechanical stress placed on it (the effect of bone usage on bone strength and vise versa) o Wolff’s law of bone explains the effect of mechanical stress on bone remodeling 18. During metaphyseal growth, chondrocytes die within the zone of __________ a) calcification b) cell hypertrophy c) cell proliferation d) bone deposition e) reserve cartilage f) bone resorption Prior to growth stimulation, chondrocytes in the metaphysis remain dormant within the zone of reserve cartilage. 1. Zone of reserve cartilage: histology resting of hyaline cartilage - In the metaphysis of a long bone, interstitial growth elongates the bone. A person can no longer grow in height after the zone of reserve cartilage is depleted. 2. Zone of cell proliferation: chondrocytes multiplying and lining up in rows of small flattened lacunae 3. Zone of cell hypertrophy: cessation of mitosis; enlargement of chondrocytes and thinning of lacuna walls 4. Zone of calcification: temporary calcification of cartilage matrix between columns of lacunae 5. Zone of bone deposition: breakdown of lacuna walls, leaving open channels; death of chondrocytes; bone deposition by osteoblasts, forming trabeculae of spongy bone 19. Which of these accurately describes an interaction between skeletal physiology & another body system? a) The skeletal system is protected by blood pumped from the heart as blood surrounds bones and serves as a hydraulic cushion against skeletal trauma b) The skeletal system contains minerals that can be used in excitation of muscle c) Respiratory system provides CO2 to use in the mineralization of osseous tissue d) Skeletal system contains proteins that can be used to synthesize minerals for digestion Which of these accurately describes an interaction between skeletal physiology & another body system? → The skeletal system contains minerals that can be used in neuronal signaling Calcium is needed in neuron communication, muscle excitation/contraction, blood clotting, and exocytosis Calcium and phosphate are used for much more than bone structure Phosphate is a component of DNA, RNA, ATP, phospholipids, and biological pH buffers 20. Which of these is a symptom of osteoporosis? a) osteosarcoma b) Increased appetite c) osteomyelitis d) hip fractures e) hypocalcemia f) decreased calcitonin Which of these is the safest long term treatment for osteoporosis once diagnosed? → Actonel/Fosamax Osteoporosis is the severe loss of bone mineral density (most common bone disease) Bones lose mass and become brittle due to loss of organic matrix and minerals o Affects spongy bone the most a. Osteosarcoma: caused by tumor growths in bone (not a direct symptom of osteoporosis) b. Increased appetite is not a symptom; decreased appetite is a symptom of osteoporosis c. Osteomyelitis: Inflammation of osseous tissue and bone marrow as a result of bacterial infection - Not a direct symptom of osteoporosis d. Pathological fractures of hip, wrist, and vertebral column are the most common with osteoporosis e. Hypocalcemia is caused by vitamin D deficiency, diarrhea, thyroid tumors, underactive parathyroid, and pregnancy and lactation - Not a symptom of osteoporosis f. Decreased calcitonin is not a symptom of osteoporosis Loss of estrogen can lead to osteoporosis and can lead to fractures o Estrogen maintains density in both sexes and inhibits osteoclast activity o Women have rapid bone loss after menopause o Estrogen replacement therapy can increase bone density  Only treatment for osteoporosis that can increase bone density later in life: estrogen replacement therapy Part B. Choose all that apply (0.5-1 pts per letter; 3 pts per question; 33 points on real test) 21. Which of the following examples involve endocytosis? a) phagocytosis b) neurotransmitter release c) pinocytosis d) sodium influx from the ECM e) sweat excretion f) melanosome uptake by keratinocytes Which of the following examples involve exocytosis? → Neurotransmitter release and sweat excretion Endocytosis: vesicular transport of particles into a cell o Phagocytosis o Pinocytosis o Melanosome uptake by keratinocytes Exocytosis: expelling particles out of a cell by way of a vesicle o Neurotransmitter release o Secretion of ECM o Exocrine sweat excretion Phagocytosis: cell-eating; engulfing a particle Pinocytosis: cell-drinking; membrane pinches off small vesicles containing fluid Receptor mediated endocytosis: phagocytosis/pinocytosis in which receptors bind to the membrane and into the cell vesicle a. Phagocytosis is a form of endocytosis in which a phagocytic cell takes up debris or foreign invaders and then packages it into a vesicle and starts to digest it. b. NT release is exocytosis because it is going out of the cell. c. Pinocytosis is basically cell drinking aka cell will take up a decent size portion of extracellular fluid or general solvent. A way the cell can take up parts of the matrix in mass. d. Sodium influx from ECM would happen through a channel protein which isn’t considered to be endocytosis. Plus, sodium is a small ion so it wouldn’t count either way e. Sweat excretion (both glands do merocrine secretion) but this is going out of the cell so its an example of exocytosis f. Uptake of melanosomes is something that is going inside. Melanin is a big particle. Uptake of those melanosomes by keratinocytes is an example of endocytosis 22. These are all types of cells found in the epidermis except… a) melanocytes. b) fibroblasts. c) stem cells. d) tactile (Merkel) cells. e) dendritic cells. f) erythrocytes. These are all types of cells in the dermis except: melanocytes, chondrocytes, and keratinocytes Both the fibroblasts and erythrocytes are found in the dermis and not in the epidermis. o Epidermis is avascular (no vasculature means cant have erythrocytes). o Dermis has fibroblasts which make collagen and elastin (which have nothing to do with the epidermis). Epidermis does contain: melanocytes, stem cells, tactile cells, and dendritic cells. o Epidermis does NOT contain: fibroblasts and erythrocytes Dermis does contain: macrophages, fibroblasts, leukocytes, erythrocytes, and dendritic cells o Dermis does NOT contain: melanocytes and tactile cells 23. Which of the following structures does not contain mesoderm derivatives? a) lamina propria b) integument c) mucous membranes d) nervous tissue e) blood f) thyroid glandular cells Which of the following structures contain ectoderm derivatives? → nervous tissue and epidermis 3 primary germ layers: o Ectoderm (outer): gives rise to epidermis and nervous system ▪ Keratinized stratified squamous epithelium is derived from the ectoderm o Mesoderm (middle): gives rise to muscle, bone, blood, adipose, cartilage, serous membrane, dermis ▪ Lamina propria (layer of connective tissue proper) contains mesoderm derivatives ▪ Integument contains mesoderm derivates because the dermis has connective tissues ▪ All membranes have epithelial and connective tissues which means this would contain mesoderm derivatives (same with the serous and cutaneous membranes) ▪ Heart muscles, parietal pericardium, and menisci of the knee are mesoderm derivatives o Endoderm (inner): gives rise to mucus membrane lining digestive and respiratory tracts, digestive and endocrine glands, and mucosal epithelium ▪ Non-keratinized stratified squamous epithelium, simple cuboidal, and simple columnar are derived from the endoderm ▪ thyroid glandular cells come from endoderm  ▪ tracheal, gastric, and vaginal mucosa are endoderm derivatives 24. Characteristics/features of epithelial tissues include… a) rich blood supply b) absence of a basal lamina c) hyaluronic acid in matrix d) resting upon lamina propria e) extensive extracellular matrix f) tightly packed cells Characteristics/features of lamina propria (CT Proper) connective tissues include: - lower cell:matrix ratio than epithelial tissues - type I and III collagen in matrix - lack of a basement membrane - fibroblasts and leukocytes are main cell types a. epithelial tissues are avascular which means no blood supply could get to them b. epithelial tissues all have a basal lamina (which is a fancy word for basement membrane) c. epithelial tissues do NOT have hyaluronic acid in the matrix; CT does have hyaluronic acid in the matrix d. Lamina propria is connective tissue proper and usually epithelial tissue are resting on this layer of connective tissue proper (and usually that connective tissue is areolar connective tissue because it’s a good source of microvasculature) e. epithelial tissue has a high cells to matrix ratio which means very little ECM f. epithelial tissues are characterized by many cells and not much space (not much matrix) between them Features of cartilaginous tissues: o Chondroitin sulfate and type II collagen in matrix o Presence of lacunae ▪ Cells begin as chondroblasts and become chondrocytes as they mature and trap themselves in lacunae o Extensive EC matrix 25. Which skin features secrete products by a holocrine mechanism? a) sudoriferous glands b) sebaceous glands c) melanocytes d) mammary glands e) ceruminous glands f) tarsal glands Which of these secrete products by a merocrine mechanism? - apocrine sudoriferous glands - melanocytes - eccrine glands - endocrine glands Merocrine secretion: o Sudoriferous glands (sweat glands) and apocrine sudoriferous glands o Melanocytes  o Tear glands o Pancreatic glands o Goblet cells o All endocrine glands Apocrine secretion: o Ceruminous glands o Mammary glands Holocrine secretion: o Sebaceous glands o Tarsal (oil) glands 26. Which of the following is NOT a bone forming part of the borders of the orbits? a) vomer b) temporal c) lacrimal d) nasal e) ethmoid f) maxilla Which of the following bones form part of the walls of the orbits? - sphenoid - maxilla - ethmoid Bones that surround the orbit: o Sphenoid o Frontal o Zygomatic o Ethmoid o Lacrimal o Maxilla o Palatine Bones that contain a paranasal sinus: o Frontal o Maxilla o Ethmoid o sphenoid 27. Which of these tissues contain significant amounts of type II collagen? a) areolar CT b) stratified squamous epithelium c) hyaline cartilage CT d) pseudostratified columnar epithelium e) fibrocartilage CT f) dense irregular CT Which of these tissues contain significant amounts of type III collagen? - reticular CT Type I collagen: o Dense irregular CT (reticular dermis) o Areolar CT (papillary dermis) o Fibrocartilage CT Type II collagen: o Hyaline cartilage CT o Fibrocartilage CT Type III collagen: o Reticular CT 28. The process of bone elongation includes: a) intramembranous ossification b) endochondral ossification c) hyperplasia d) interstitial growth e) resorption of mineral matrix f) hypertrophy The process of bone resorption includes: - collagen digestion - osteoclast activity - hydrogen ion pumps Bone elongation: o Endochondral ossification o Interstitial growth o Hyperplasia → chondrocytes go through hyperplasia during growth o Hypertrophy → chondrocytes go through hypertrophy during growth o Involves deposition of mineral matrix Bone thickening: o Appositional growth → Flat bones don’t elongate they thicken o Intramembranous ossification Bone resorption: (by osteoclasts) → dissolving bone minerals to release into bloodstream o Collagen digestion o Osteoclast activity o Hydrogen ion pumps 29. If skin were completely impermeable to UV, what risks would likely decrease? a) risk of skin cancer b) risk of Paget’s disease c) risk of rickettsia d) risk of psoriasis e) risk of osteoporosis f) risk of osteogenesis imperfecta If skin were completely impermeable to UV, what risks would likely increase? - risk of osteoporosis a. No UV rays would decrease the risk of skin cancer b. Paget’s disease is not affected by UV light c. Rickettsia is a vitamin D deficiency disorder, so no UV rays would increase the risk of it d. Psoriasis is abnormal exfoliation, which is not affected e. Osteoporosis is a vitamin D deficiency disorder, so no UV rays would increase the risk of it f. Osteogenesis imperfecta is a genetic defect in collagen, which is not affected by UV rays 30. Which of the following are associated with intramembranous ossification? a) Chondroblast differentiation b) Bony collar synthesis c) Condensation of mesenchyme d) Conversion of deep cancellous bone to compact e) Replacement of cartilage with bone f) Vascular invasion of mesenchyme Which of the following are associated with endochondral ossification? - bony collar formation - formation of separate marrow cavities Intramembranous is the one that occurs directly in the mesenchyme and involves the laying down of osteoid template, the blood vessels that invade them, spongey bone occurs, diploe layer in center of the bone, outer layer of compact bone, deep cancellous bone in the middle Associated with endochondral ossification: o Ossification centers o Bony collar synthesis o Chondrocyte apoptosis o Vascular invasion of cartilaginous tissue 31. Which of the following are typical sites where red bone marrow can be found in adults? a) Pelvic girdle b) Marrow cavity of tibia c) Central Canals d) Within the Diploe layer e) Proximal epiphysis of the humerus f) Frontal bone Which of the following are typical sites where red bone marrow can be found in adults? - temporal bone - proximal epiphysis of the femur - sternum Red bone marrow (myeloid tissue): o Children: in every bone  o Adults: axial skeleton, skull, vertebra, ribs, sternum, os coxae, proximal heads of humerus and femur ▪ Pelvic girdle ▪ Frontal bone ▪ Sternum ▪ Coxal bones ▪ vertebrae Yellow marrow: Adults: appendicular skeleton Part C. Matching (1 pt each; 10 points total) Match the description on the left with the corresponding major tissue type from the choices on the right. Note: Some answers may be used twice; some answers may not be used at all. (1 pt ea) 32. tendon H Ligament → Dense regular CT 33. knee menisci I Knee meniscus → Fibrocartilage CT 34. papillary dermis E Reticular dermis → Dense irregular CT 35. vaginal lining D Esophagus lining → Non-keratinized stratified 36. stroma of spleen F squamous epithelium 37. alveoli in lungs A Stroma of lymph node → Reticular CT 38. small intestine mucosa B Blood vessel lining → Simple squamous 39. epidermis C epithelium 40. reticular dermis G Serosa → Simple squamous epithelium 41. articular cartilages J Mucosa → Non-keratinized stratified squamous a. simple squamous epithelium epithelium b. simple columnar epithelium Bronchioles → Simple cuboidal epithelium c. stratified squamous Articular cartilages → Hyaline cartilage CT (keratinized) d. stratified squamous (non- keratinized) e. areolar connective tissue f. reticular connective tissue g. dense irregular conn. tissue h. dense regular conn. tissue i. fibrocartilage j. hyaline cartilage  Simple Squamous epithelium (thin, flat, plate-like cells) o Thin layer permits rapid diffusion or selective transport, may secrete lubricating substances o Located in: ▪ Mesothelia/Serosa/Serous membranes (Visceral and Parietal layers) ▪ Endothelium (luminal lining of blood vessels) ▪ Glomerular capsule, inner layer (filtration structure in kidneys) ▪ Alveoli (air sacs in lungs) Simple Cuboidal epithelium (squarish or rounded cells) o Balanced absorption and secretion, more selective layer than squamous epithelium o Located in: ▪ Renal (Kidney) ducts and tubules ▪ Hepatic (Liver) ductules for bile secretion ▪ Thyroid follicles ▪ Pancreatic ducts ▪ Mammary gland ducts ▪ Bronchioles Simple Columnar epithelium (tall, narrow, stalk-like cells) o Bulk Absorption and bulk secretion, highly selective o Secretions usually have a very high mucus content o Often contain apical microvilli (brush border) and varying amounts of interspersed goblet cells o Located in: ▪ Luminal Lining of most of the GI tract ▪ Gastric mucosa (not oral/esophageal) ▪ Small intestine mucosa ▪ Colonic mucosa ▪ Rectal mucosa (not anal) Pseudostratified, Ciliated Columnar epithelium (PSCCE) o Secrete and propel mucus along surface, limited absorption, mostly barrier functions o Considered a single (simple) layer of cells (one layer) o Appears multi-layered but all cells touch basement membrane o Ciliated on apical surface with a few interspersed goblet cells o Located in: ▪ Most of respiratory mucosa ▪ Nasal to bronchial mucosa Keratinized Stratified Squamous Epithelium o Abrasion protection, prevent infections, minimize fluid losses o Keratin-filled flat cells on surface (dead, no nucleus) o Flake off and are replaced by deeper layers (exfoliation/desquamation) o Found only in the Epidermis Non-Keratinized Stratified Squamous Epithelium o Mild abrasion resistance, barrier to pathogens, must be constantly moistened o No dead, keratinized surface cells o Cells do not flake off en masse o Located in:  ▪ Oral, Esophageal, Anal, Vaginal mucosa Transitional epithelium o “Stretchy” epithelium with cells of different shapes and sizes indicative of distension to fill/recoil bladder wall o Highly localized to urinary system: Ureteral, Urinary bladder, Proximal urethral mucosa Areolar tissue (loose CT) o Loosely-organized fibers, abundant blood vessels, and a lot of ground substance o Nearly every epithelial layer rests on a layer of areolar tissue (upper/papillary dermis) Reticular connective tissue (loose CT) o Made of type III collagen reticular fibers o Located in: spleen and lymph nodes Dense regular connective tissue o Located in: all tendons and ligaments Dense irregular connective tissue o Located in: deep/reticular dermis Hyaline cartilage (most abundant) o Flexibility eases joint movement and allows for some expansion/constriction o Rigidity maintains a patent airway and gives shape to facial features o Located in: ▪ Articular cartilages (joint surfaces at ends of long bones) ▪ Respiratory tract: tracheal rings, bronchial plates, laryngeal cartilages, nasal cartilages Elastic cartilage o Modified hyaline cartilage with additional elastin secreted into the cartilage matrix o More flexible cartilage due to elastic fibers o Able to stretch and recoil to original shape o Limited locations: ▪ external ear and epiglottis of the larynx Fibrocartilage o Modified hyaline with coarse bundles of type I collagen secreted into cartilage matrix More fibrous appearance, chondrocytes often form linearized rows o Resists compression, absorbs shock but has very limited flexibility o Does not regenerate due to lack of perichondrium o Located in: ▪ interpubic disc ▪ knee menisci ▪ articular disc of the jaw  ▪ intervertebral discs Negative Feedback: Positive Feedback: Bone resorption in response to low Faster, stronger uterine contractions in blood calcium response to oxytocin release as a Melanin production in response to consequence of uterine cervical increased UV exposure stimulation/pressure by the fetus Compensatory response to a low Coagulation of blood following the temperature environmental change laceration of a blood vessel Mineralization of osteoid tissue during osteoblast activity Practice Exam II Part A. Multiple Choice (2 pts each; 40 points total on real test) 1. Which term refers to the cumulative effect of simultaneous PSPs on membrane potential? a) facilitation b) spatial summation c) convergence d) divergence e) temporal summation f) inhibition Which term refers to the cumulative effect of successive PSPs over time on membrane potential? → temporal summation A post-synaptic potential (PSP) is a local/graded potential generated in the postsynaptic neuron due to neurotransmitter release from the presynaptic neuron o PSPs can stimulate (EPSP) or inhibit (IPSP) downstream neurons a. Facilitation is a process in which a facilitating interneuron forms an axoaxonic synapse to enhance neurotransmitter release from a presynaptic neuron. Increases or boosts synaptic transmission b. Spatial summation occurs when EPSPs from several different synapses add up to threshold at an axon hillock. Simultaneous → spatial summation o Occurs when multiple presynaptic neurons release neurotransmitters together to fire an action potential in the postsynaptic neuron. o Spatial involves multiple neurons firing at the same time (collaboration) o Spatial summation refers to the cumulative effect of simultaneous PSPs on membrane potential. c. Convergence: fewer downstream targets than upstream targets d. Divergence: fewer upstream targets than downstream targets e. Temporal summation (wave summation) occurs when a single synapse generates EPSPs so quickly that each is generated before the previous stimulus has dissipated. Allows EPSPs to add up over time to a threshold voltage that triggers an action potential Succession or overtime → Temporal summation Occurs when one presynaptic neuron releases neurotransmitters over a period of time to fire an action potential Temporal involves one neuron firing quickly in succession (reinforcement) Temporal summation refers to the cumulative effects PSPs in rapid succession originating from the same synapse on membrane potential. o Cumulative effect of successive PSPs over time on membrane potential. f. Inhibition is a process in which an inhibitory interneuron forms an axoaxonic synapse to suppresses neurotransmitter release from a presynaptic neuron. Reduces or halts synaptic transmission 2. Which disease is an inflammation of joints due to autoimmune attack of joint tissues? a) osteomyelitis b) rigor mortis c) meningitis d) rheumatoid arthritis Which disease is an inflammation of joints due to wear and tear on joint tissues as one ages? → osteoarthritis a. Osteoarthritis: most common form of arthritis, articular cartilages degenerate, and bone spurs develop on exposed bone tissue causing pain Osteoarthritis: inflammation of joints due to wear and tear on joint tissues as one ages Accompanied by crackling sounds called crepitus b. Rigor mortis: stiffening of the joints and muscles of a body a few hours after death c. Meningitis: inflammation (swelling) of the protective membranes (meninges) covering the brain and spinal cord. d. Rheumatoid arthritis: autoimmune attack of joint tissues. Misguided antibodies (rheumatoid factor) attack synovial membrane, enzymes in synovial fluid degrade articular cartilage, joint begins to ossify into bony tissue Arthritis: a broad term for pain and inflammation of a joint. Most common crippling disease in the United States 3. An enveloped cluster of neurosomas not found in the brain or spinal cord is called a: a) ganglion b) nerve c) nucleus d) tract An enveloped cluster of neurosomas found in the brain or spinal cord is called a: nucleus a. Ganglion (PNS): a knot-like swelling in a nerve where neuron cell bodies are concentrated b. Nerve (PNS): a bundle of nerve fibers (axons) wrapped in fibrous connective tissue c. An enveloped cluster of neurosomas found in the brain is called a nucleus (CNS). d. Tract (CNS): bundle of axons is a tract In the CNS, a bundle of axons is a tract and a bundle of soma is a nucleus. In the PNS, a bundle of axons is a nerve and a bundle of soma is a ganglion. 4. The interphalangeal joints are an example of ________________ joints. a) ball and socket b) condylar c) hinge d) saddle e) pivot The metacarpophalangeal joints are an example of condylar joints. Synovial Joints Ball and socket joints: Smooth, hemi-spherical head fits in a cup-like socket o Multiaxial joints o Coxal joints (aka Femoroacetabular) joints o Humeroscapular (aka Glenohumeral) joints Condylar joints: Oval convex surface of one bone fits into a complementary-shaped depression on another o Biaxial joints (movement in two planes: x,y) o Radiocarpal (SLT) & all 5 metacarpophalangeal joints (not interphalangeal or carpometacarpal joints!) o Temporomandibular joints o Atlanto-occipital joint Saddle joints: Both bones have an articular surface that is shaped like a saddle, concave in one direction and convex in the other (only 2) o Biaxial Joint o Trapeziometacarpal joint o Sternoclavicular joint Plane joints: Flat articular surfaces in which bones slide over each other with relatively limited movement o Biaxial Joints o Intercarpals of wrist and Intertarsals of ankle  o Carpometacarpal joints of digits II - V o Sternocostal joints of ribs 2-7 o Costovertebral joints of all ribs o Intervertebral facet joints Hinge joints: One bone with convex surface that fits into a concave depression on other bone (similar to saddle/condyloid but more restrictive) o Monoaxial joint (large ~180O movement but in 1 restricted axis) o Hyperextensions result in injury to joint tissues o Humeroulnar joints (elbows) o Tibiofemoral joints (knees) o Talocrural joints (ankles) o Interphalangeal joints (intersegmental joints of digits) Pivot joints: One bone has a process encircled by a ring-like (annular) ligament attached to another bone (only 3) o Mono-axial joint o Atlantoaxial joint (axis with atlas) o Proximal radioulnar joints 5. Which connective tissue membrane, also known as “deep fascia”, surrounds the muscle’s belly? a) endomysium b) epimysium c) perimysium d) sarcolemma a. Endomysium is a CT membrane that surrounds each muscle fiber. b. Epimysium is a fibrous layer that surrounds each muscle. c. Perimysium is a CT membrane that surrounds a fascicle of muscle fibers (surround and separates muscle fascicles from one another). d. Sarcolemma: excitable plasma membrane of a muscle fiber o It is a muscle fiber membrane where in an indented portion forma the synaptic cleft in the junction between a motor nerve fiber and a muscle fiber o This area contains receptors responsive to neurotransmitter from the motor nerve fiber 6. In response to neurotransmitter release and binding, efflux of potassium across the postsynaptic membrane would cause a(n): a) absolute refractory period b) EPSP c) IPSP d) threshold a. Absolute refractory period: No stimulus of any strength will trigger an AP as long as Na+ gates are open or inactivated o Voltage-gated mechanism not a response to NT release and binding b. Excitatory postsynaptic potential (EPSP): Any voltage change in the direction of threshold that makes a postsynaptic neuron more likely to fire o In response to neurotransmitter release and binding, influx of sodium across the postsynaptic membrane would cause EPSP. c. Inhibitory postsynaptic potential (IPSP): Any voltage change away from threshold making a neuron less likely to fire o In response to neurotransmitter release and binding, influx of chloride or efflux of potassium across the postsynaptic membrane would cause an IPSP. d. Threshold: critical voltage to which local potentials must depolarize the membrane in order to open voltage-gated sodium channels (-55 mV) Relative refractory period: Only strong stimuli will trigger another AP o Some K+ gates still leaking (more than at “rest”) o Any effect of incoming Na+ is partially nullified by leaking K+ (cell is hyperpolarized) 7. The glial cells that line the ventricles of the brain and secrete cerebrospinal fluid are called: a) astrocytes b) satellite cells c) Schwann cells d) oligodendrocytes e) ependymal cells f) microglia Neuroglia or Glial cells: Support and protect neurons Types of Glial cells in CNS: Microglia: Small, wandering phagocytes that remove debris Oligodendrocytes: Arm-like processes form myelin sheaths around axons in CNS Ependymal cells: o Line brain spaces; circulate cerebrospinal fluid (CSF) o Clear liquid that bathes the CNS (fluidic vehicle of brain similar to blood plasma) Astrocytes: o Most abundant glial cell in CNS; have many functions o Form a supportive framework of nervous tissue o Have extensions (perivascular feet) that contact blood capillaries that stimulate them to form a tight seal called the blood–brain barrier o Convert blood glucose to lactate & supply to neurons for nourishment Types of Glial cells in PNS: Schwann cells (~CNS Analog: Oligodendrocyte) o Envelop nerve fibers (axons) of PNS neurons o Produce a myelin sheath similar to oligodendrocyte myelin sheaths in CNS o Assist in regeneration of damaged PNS fibers o Schwann cells are regenerative glial cells that myelinate peripheral nerve fibers Satellite cells (~CNS Analog: Astrocyte…kinda) o Surround the neurosomas in ganglia of the PNS o Provide electrical insulation around soma o Regulate the chemical environment of the neurosomas 8. The integrative functions of the nervous system are performed mainly by: a) association neurons b) motor neurons c) sensory neurons d) neuroglia Functional Classes of neurons: Sensory or Afferent neurons o Most are unipolar o Specialized to detect stimuli from receptors & transmit to CNS o Begin in almost every organ in the body and terminate in CNS o The sensory information of the nervous system is relayed mainly by the afferent neurons. Motor or Efferent neurons o Most are multipolar o Send signals out from CNS to effector organs (i.e. muscles, organs, & glands) Interneurons or Association neurons o Most are multipolar o Lie entirely within CNS o Integrate information from many neuronal paths, organize and process information (decision-making) o Can store and retrieve information o Determines complex responses to stimuli o Relay between sensory and motor Structural Classes of neurons: Multipolar neuron (Most common neuron structure/structural class) o Motor/efferent neurons and interneurons/association neurons  o One axon and more than one dendritic poles off soma o Most neurons within the brain and spinal cord are multipolar o The motor functions of the nervous system are relayed mainly by the multipolar neurons. Bipolar neuron o One axon and one dendritic pole o Least common neuron structure o Olfactory cells, retina, inner ear → Smell, vision, hearing (Sensory/afferent neurons) Unipolar (pseudounipolar) neuron o Sensory/afferent neurons o Single pole (projection) from the soma o This projection bifurcates into a peripheral branch and central branch o 2nd most common neuron structure 9. If one additional nerve stimulus arrives at a muscle fiber so soon that tension in the fiber has only partially subsided from the previous twitch-inducing stimulus, the most likely result will be a) fatigue b) treppe c) incomplete tetanus d) complete tetanus e) paralysis a. Muscle fatigue is a progressive weakening and loss of contractility (twitch strength) from prolonged use of muscle b. 10–20 stimuli per second produces treppe (staircase) phenomenon with progressive increases in tension o Treppe → Full subsiding of tension / full relaxation o Muscle still recovers fully between twitches, but each twitch develops more tension than the one before o Stimuli arrive so rapidly that the SR does not have time between stimuli to completely pump back all of the released calcium o Full subsiding of tension / full relaxation, but there is an increase in tension with progressive twitches → treppe o If additional nerve stimuli arrives at a muscle fiber so soon that tension has fully subsided, but SR calcium re-uptake is incomplete from previous twitch-inducing stimuli, the most likely result will be treppe. c. 20–40 stimuli per second produces incomplete tetanus → partially subsided o Twitch summation: results from higher stimulus frequency close enough to not permit a full relaxation → sarcomeres still partially contracted o Partial subsidy (relief) → incomplete tetanus d. 40–50 stimuli per second produces complete tetanus → not subsided o Muscle has no/zero time to relax between stimuli  o Twitches fuse to a smooth, prolonged contraction o Does not occur in the body; only occurs in a laboratory o If one additional nerve stimulus arrives at a muscle fiber so soon that tension in the fiber has not subsided at all from the previous twitch-inducing stimulus, the most likely result will be complete tetanus. e. If nerve connections to muscle are severed or poisoned, a muscle is effectively paralyzed. Chronic muscle paralysis leads to Denervation atrophy 10. The sarcolemma of a resting muscle fiber is most permeable to: a) calcium b) potassium c) chloride d) sodium e) magnesium Sarcolemma—excitable plasma membrane of a muscle fiber o Muscle and nerve fibers have the same properties at rest Potassium ions have the greatest influence on resting membrane potential (RMP) o At rest, plasma membrane is more permeable to K+ than other ions The greater the permeability of the plasma membrane for a given ion, the greater the tendency for that ion to drive the membrane potential toward the ion’s own equilibrium potential. At rest, the membrane is more permeable to K+ than to Na+, so resting membrane potential is closer to the K+ equilibrium potential “Permeable” refers to # open channels, which is much greater for potassium than sodium at rest Plasma membrane at rest is much less permeable to high concentration of sodium found outside the cell The axolemma of the axon’s trigger zone at rest is most permeable to sodium. o The axolemma of a resting nerve fiber is most permeable to sodium. o Axolemma → plasma membrane of the axon 11. Which of the following is true concerning isometric contraction? a) muscle shortens, tension remains constant b) muscle lengthens, tension remains constant c) muscle tension increases, muscle shortens d) muscle tension increases, length unchanged e) muscle tension decreases, muscle lengthens Isometric contraction: contraction without change in length o the muscle is tense but there is no movement (ex. Flexing) Isotonic contraction: contraction with a change in length but no change in tension o begins when internal tension builds to the point that it overcomes the resistance o isotonic concentric contraction: a muscle shortens as it maintains tension  o isotonic eccentric contraction: a muscle lengthens a it maintains tension o concentric = shortens o eccentric = lengthens 12. Athletes who train at high altitudes increase their red blood cell count to promote physical endurance. An increase in the number of hemoglobin-containing red blood cells results in: a) increased glycolysis b) increased use of myokinase c) increased ATP production d) increased fermentation e) reduced ATP consumption An increase in hemoglobin containing red blood cells results in increased ATP production A reason for oxygen depletion: is due to phospagens must be replenished o Why does heavy breathing continue after strenuous exercise? ▪ Oxygen reserves need to be repleted ▪ Phosphagen systems need to be replenished ▪ Lactate needs to be removed and recycled ▪ Lingering elevation in metabolic rate uses more than basal rates of oxygen consumption NOT a reason for oxygen debt: glycolytic muscles borrow oxygen from oxidative muscles 13. A crackling sound called crepitus indicating worn cartilage commonly occurs due to: a) Tay-Sach’s disease b) rheumatoid arthritis c) osteoarthritis d) multiple sclerosis a. Tay-Sachs disease is caused by the absence of an enzyme that helps break down fatty substances. These fatty substances, called gangliosides, build up to toxic levels in the brain and spinal cord and affect the function of the nerve cells. b. Rheumatoid arthritis: autoimmune attack of joint tissues. Misguided antibodies (rheumatoid factor) attack synovial membrane, enzymes in synovial fluid degrade articular cartilage, joint begins to ossify into bony tissue o A fused form of synotoses known as ankylosis commonly occur due to rheumatoid arthritis c. Osteoarthritis: most common form of arthritis, articular cartilages degenerate, and bone spurs develop on exposed bone tissue causing pain o Accompanied by crackling sounds called crepitus o Osteoarthritis: inflammation of joints due to wear and tear on joint tissues as one ages d. Multiple sclerosis is a disease in which the immune system eats away at the protective covering (myelin sheath) of nerves  Arthritis: a broad term for pain and inflammation of a joint. Most common crippling disease in the United States 14. Opening of gated sodium channels typically leads to a) repolarization of the plasma membrane b) hyperpolarization of the plasma membrane c) depolarization of the plasma membrane d) more negative membrane potential e) plasma membrane voltage returning to resting membrane potential Depolarization of membrane: sodium influx (opening of VG sodium channels) o Closing of gated chloride channels at Vm = -65 mV leads to depolarization of membrane Repolarization of membrane: rapid potassium efflux (all VG potassium channels are open) Hyperpolarization of membrane: slow potassium efflux (VG potassium channels are slowly closing) o Opening of gated potassium or chloride channels leads to hyperpolarization of membrane Less negative membrane potential: sodium influx (opening of VG sodium channels) Membrane voltage returning to resting membrane potential: all channels are closed Depolarization: 1. Stimulatory local potentials trigger Sodium influx that diffuses to the trigger zone 2. A threshold is reached when membrane has depolarized from rest (-70 mV) to -55 mV…At this point, VG Na+ channels open A rapid flurry of sodium influx occurs further depolarizing the membrane 3. At >0mV VG Na+ channels begin to close and VG K+ channels begin to open Peak: 4. All VG Na+ channels are closed and all VG K+ channels are open Repolarization: 5. A rapid flurry of potassium efflux occurs repolarizing the membrane Hyperpolarization: 6. Some potassium channels are “sluggish” and close slowly allowing for K+ leak and hyperpolarization following an action potential 7. Channel closing and actions of special cells called astrocytes restore membrane potential to -70 mV (the resting value) 15. Which of the following is NOT a typical characteristic of neurotransmitters? a) synthesized by a presynaptic neuron b) released in response to voltage-gated Ca2+ influx c) released into the bloodstream d) bind to specific receptors on the postsynaptic cell e) alter the membrane potential of the postsynaptic cell Characteristics of neurotransmitters: o Synthesized by a presynaptic neuron o Released in response to voltage-gated Ca influx o Bind to specific receptors on the postsynaptic cell o Alter the membrane potential of the postsynaptic cell NOT Characteristics of neurotransmitters: o Synthesized by a postsynaptic neuron o Released in response to voltage-gated K influx o Bind to non-specific receptors on the post-synaptic cell o Do not alter the membrane potential of the postsynaptic cell o Released into blood stream o Always lead to action potential conduction along the postsynaptic target cell’s membrane 16. Which of these is NOT a characteristic of local potentials? a) are variable in magnitude b) can be caused by opening ligand-gated ion channels c) are reversible d) are decremental e) always begin with depolarization Local Potentials: o Graded: vary in magnitude with stimulus strength (often called graded potentials for this reason) ▪ Stronger, more frequent stimuli can open more Na+ channels o Decremental: gets weaker as it spreads from point of stimulation ▪ Voltage shift caused by Na+ inflow diminishes over distance as sodium dilutes through diffusion o Non-refractory: graded potentials can be produced at any time ▪ There is no time period where graded potentials are impossible to produce or more difficult to produce than other times  o Can be excitatory or inhibitory: some trigger hyperpolarization instead of depolarization ▪ Local potentials can be hyperpolarizing or depolarizing ▪ If a graded potential is caused by potassium efflux or chloride influx, neurons are inhibited and therefore require greater stimulation to activate (conversely, sodium influx is excitatory) o Reversible: when stimulation ceases or is interrupted, permeability values change ▪ If cessation, resting permeability values electrochemical gradients return the cell to RMP ▪ If interrupted by a stimulus of opposing effect, permeability values change according to stimulus and gradients will drive MP corresponding to the effect o Local potentials can be caused by opening ligand-gated ion channels Action Potentials: o Requires a threshold voltage for initiation o Follows the all-or-none law ▪ Non-graded ▪ If threshold is reached, neuron fires at max voltage ▪ If threshold is not reached, neuron does not fire o Nondecremental: doesn’t get weaker with distance o Irreversible: once started goes to completion and cannot be stopped o Refractory: AP event cannot be superseded by other action potentials and is more difficult to re-stimulate immediately following an AP o Do not vary in magnitude o Actions potentials always begin with depolarization 17. Which of the following would increase action potential conduction velocity along the axon? a) smaller diameter b) larger diameter c) presence of myelin sheaths d) more microtubules in axoplasm e) a and c f) a and d g) b and c h) b and d Speed at which a nerve signal travels along a fiber depends on two factors o Diameter of fiber → larger diameter; faster conduction o Presence or absence of myelin → presence of myelin; faster conduction Presence of myelin sheaths increase action potential conduction velocity along the axon The type of NT released from terminals has no effect on action potential conduction velocity along the axon 18. When aspartate binds to a particular receptor, which is coupled to a G protein, it initiates the synthesis of intracellular cAMP. This receptor is, therefore, an example of a(n): a) ionotropic receptor b) ligand-gated ion channel c) metabotropic receptor d) inhibitory receptor e) voltage-gated ion channel f) hormone receptor Ionotropic receptors o Produce excitatory or inhibitory local potentials on that cell through ligand-gated ion channels (faster, but have shorter effects) o When neurotransmitter binds to a particular receptor, which is coupled potassium ion channels, it initiates the efflux of potassium. The receptor is therefore, an example of a inotropic receptor, ligand-gated ion channel, and inhibitory receptor. ▪ Coupled to an ion channel (Na or K channel) → inotropic receptor and ligand-gated ion channel NOT a voltage-gated ion channel Metabotropic receptors o Activate second messenger systems; slower but with longer-lasting effects on membrane potential (slower, but have longer effects) o When glutamate or asparate binds to a particular receptor, which is coupled to a G protein, it initiates the synthesis of intracellular cAMP. The receptor is therefore, an example of a metabotropic receptor. ▪ G protein causes second messenger system → metabotropic receptor Indirectly changes ion flow ▪ Glutamate or asparate are excitatory NT Neurotransmitters o Acetylcholine ▪ In a class by itself (oddball) o Amino acids ▪ Excitatory NT: glutamate and aspartate ▪ When glutamate or asparate binds to a particular receptor, which is coupled to a G protein, it initiates the synthesis of intracellular cAMP. The receptor is therefore, an example of a metabotropic receptor. ▪ Inhibitory NT: γ-aminobutyric acid (GABA) and glycine GABA opens chloride channels Glycine opens potassium channels o Monoamines (amino acid derivatives) ▪ Removed carboxyl (–COOH) group while retaining amino (–NH2) group  ▪ Major monoamines Epinephrine, norepinephrine, dopamine (aka catecholamines) Histamine and serotonin o Neuropeptides ▪ Neuropeptides are chains of 2 to 40 amino acids o Beta-endorphin, substance P, CCK, and Enkephalins Glutamate is the primary excitatory brain neurotransmitter that produce EPSPs o Glutamate receptors trigger ligand-gated Na+ influx producing a graded depolarization GABA (gamma-amino butyric acid) and Glycine are the primary inhibitory neurotransmitters that produce IPSPs o GABA receptors hyperpolarize the postsynaptic cell by triggering a ligand-gated influx of chloride o Glycine receptors hyperpolarize the postsynaptic cell by triggering a ligand-gated efflux of potassium Some neurotransmitters can be excitatory or inhibitory depending upon the location o Acetylcholine (ACh) and norepinephrine (NE) are excitatory to some cells and inhibitory to others ▪ Depending on type of receptors on target cell ▪ For example, ACh excites all skeletal muscle, but inhibits cardiac muscle due to the different types of ACh receptors 19. What event is involved in the excitation phase in active skeletal muscles? a) Actin-myosin cross bridge formations within the sarcomeres of a myofibril b) Acetyl choline release into the synapse and generation of an end-plate potential (EPP) c) T tubule excitation triggering SR Ca2+ efflux into the sarcoplasm for binding troponin d) Myosin hydrolysis of ATP to “cock” the myosin head into a high energy state Excitation Phase: Acetyl choline release into the synapse and generation of an end-plate potential (EPP) Excitation-contraction coupling: T tubule excitation triggering SR Ca2+ efflux into the sarcoplasm for binding troponin Contraction: Myosin hydrolysis of ATP to “cock” the myosin head into a high energy state and Actin-myosin cross bridge formations within the sarcomeres of a myofibril Relaxation: ATP-dependent sequestration of Ca into the sarcoplasmic reticulum o Excitation ▪ The process in which nerve stimulation lead to muscle stimulation ▪ Electrical nerve signal arrival opens voltage-gated calcium channels in synaptic knob Calcium in the synaptic knob triggers vesciular exocytosis of ACh ▪ ACh is released into the synaptic cleft Initiates a wave of electrical current called an action potential that spreads along the sarcolemma o Excitation–contraction coupling ▪ Events that link the stimulation on the sarcolemma motor end plate to activation of the myofilaments in sarcomeres, thereby preparing them to contract ▪ Action potential wave spreads through the connected T tubules to the adjacent terminal cisternae, and along the SR ▪ Voltage-gated Calcium channels in the SR open and efflux calcium stores into the sarcoplasm dramatically increasing concentration ▪ Calcium diffuses throughout sarcoplasm to myofilaments ▪ Calcium binds to troponin on thin filaments ▪ Troponin–tropomyosin complex changes shape and exposes active sites on actin for myosin to bind o Contraction ▪ Step in which the muscle fiber develops tension and usually shortens ▪ Cross bridge cycling occurs (in 4 steps) 1. ATP is used to move Myosin heads into an actin binding position (“cocked”) 2. Cross bridges form between actin and myosin 3. A power stroke (de-cocking) pulls on the thin filament 4. Cross bridges are terminated by binding of a new ATP molecule o Each myosin head cycles at ~ 5 times/second & uses 1 ATP/cycle ▪ Contraction and sliding filaments Step One: Preparation of myosin o Before contraction begins, myosin heads are “pre-loaded” with molecules of bound ATP o Myosin head contains enzymatic subunit with ATPase activity which hydrolyzes bound ATP o Hydrolysis of ATP changes the shape of myosin → “cocking” Step Two: Actin-myosin cross bridging  o In the presence of calcium, troponin shifts tropomyosin to expose binding sites for myosin on actin thin filaments o “Cocked” myosin heads of thick filaments bind to exposed actin sites ▪ ATP-bound myosin heads have low actin binding affinity ▪ ADP-bound heads have high actin binding affinity Step Three: Power stroke o ADP is released ▪ Affinity is not greatly reduced by this release o Cocked head is “de-cocked” while still bound ▪ Cross bridge pulling of thin filament is referred to as the power stroke Step Four: Cross bridge release o Free ATP binds myosin head o Myosin head loses affinity for actin and the cross bridge is separated o As long as there’s calcium+ATP, cycling continues o Relaxation ▪ When its work is done, a muscle fiber relaxes and returns to its resting length ▪ When nerve stimulation stops, ACh release stops AChE breaks down Ach; fragments reabsorbed into synaptic knob ▪ When ACh stimulation stops, the action potential wave ceases Sarcolemma and T Tubules are no longer stimulated ▪ pumped (actively) along with the free floating calcium back into SR ▪ Muscle fiber loses tension and sarcomeres return to resting length ATP binding to myosin heads triggers their release of actin Tropomyosin shifts back to reblock free myosin-binding sites on actin Recoil of elastic components aids in restoration 20. Below threshold for the firing of an action potential, what event would produce an EPSP? a) opening of ligand-gated sodium channels b) Release of γ-amino butyric acid c) opening of ligand-gated potassium channels d) opening of voltage-gated sodium channels Excitatory postsynaptic potential (EPSP) o Any voltage change in the direction of threshold that makes a postsynaptic neuron more likely to fire o Glutamate is the primary excitatory brain neurotransmitter that produce EPSPs o Glutamate receptors trigger ligand-gated Na+ influx producing a graded depolarization  Inhibitory postsynaptic potential (IPSP) o Any voltage changes away from threshold making a neuron less likely to fire o GABA (gamma-amino butyric acid) and Glycine are the primary inhibitory neurotransmitters that produce IPSPs ▪ GABA receptors hyperpolarize the postsynaptic cell by triggering a ligand-gated influx of chloride ▪ Glycine receptors hyperpolarize the postsynaptic cell by triggering a ligand-gated efflux of potassium Below threshold for the firing of an action potential, opening of ligand-gated sodium channels would produce an EPSP. o Voltage-gated sodium channels do NOT open below threshold o Voltage-gated sodium channels open above threshold and produce an action potential Below threshold for the firing of an action potential, Na efflux and K influx via the Na-K pump uses ATP and contributes approximately -3mV to resting membrane potential. Below threshold for the firing of an action potential, release of gamma (y)-amino butyric acid would produce an IPSP. Part B. Choose all that apply (0.5-1 pts per letter choice; 3 pts per question; 33 points total) 21. Which of these would increase strength and/or duration of a muscle contraction? a) Inhibition of ACh release b) Inhibition of acetyl cholinesterase activity c) Increased potassium efflux d) Inhibition of Ca2+ reuptake into sarcoplasmic reticulum Strength and duration are roughly synonymous in this case. What will prolong the mechanical phase stronger or longer. A) Inhibition of ACh release will decrease because it prevents excitation. Incorrect. B) Inhibition of AChE activity prolongs the time the acetyl choline is in the synapse, if we prolong this activity then we increase the duration. Correct. C) Increased potassium efflux is a hyperpolarizing stimulus. By hyperpolarizing the cell, we are certainly not creating more action potentials, which will not increase strength/duration. Incorrect. D) Inhibition of Ca reuptake into the sarcoplasmic reticulum means more calcium is available to bind to troponin and open those binding cites for cross bridge cycling. Correct. Increase strength or duration of a muscle contraction is caused by: o Decreased AChE activity o Decreased Ca reuptake into SR  o Increased Ca efflux from the SR o Increased Ca efflux from stores into an active muscle’s sarcoplasm Stronger muscle contractions are produced by the stimulation of a greater number of muscle fibers 22. With neural/electrical excitatory stimuli of varying magnitude (frequency unchanged), which of these is capable of a variable response? a) one muscle b) one bone c) one motor unit d) one muscle fiber e) one fibroblast f) one nerve When you exciting something with electrical stimuli you cause variation in the nerves which will lead to variation in the muscle. You can vary the magnitude of the stimulus to either muscle or nerve and thereby vary the response of that unit. You cannot vary the strength in the building blocks because just one of those small individual units won’t result in much change. BUT if you had multiple motor units or multiple of the building blocks then yes you will create the variable response. Bone and fibroblasts are not even types of excitable cells only muscle cells and neurons are excitable cells and the have very unique ways that they work. They operate within the bounds of a single action potential and in strength, one cell. If we recruit multiple of those cells within the organ we can make a variable response. With neural/electrical excitatory stimuli of varying magnitude (frequency unchanged), which of these is capable of a variable electrical or chemical response? o One muscle fiber and one motor unit 23. If Na+ were the only ion affecting membrane potential, it would confer a membrane potential: a) at or near the potassium equilibrium potential b) at or near the sodium equilibrium potential c) of about +60 mV d) of about +35 mV e) of about -70 mV f) of about -90mV If sodium is the only one affecting potential and there is nothing else to counteract it then it will drift towards its equilibrium potential (+60 mV). The Nernst/equilibrium potential (Ex) of an ion is the membrane potential at which there is no net movement of the ion across the plasma membrane o ENa = +60 mV o ECl = -70 mV o EK = -90 mV  If chloride were the only ion affecting membrane potential, it would give a membrane potential: o At or near the chloride equilibrium potential o Of about -70 mV 24. Which of these contain overlapping thin and thick filaments? a) A-band b) I-band c) H-band/zone d) Z disc e) sarcomeres f) myofibrils A band is the darkest part that contains overlapping thin (actin) and thick (myosin) filaments I band only contain thin filaments and Z discs so does not have overlapping myosin and actin filaments H band is only thick filaments so no overlap Z disc no thick filaments (contains thin filaments and titin) Sarcomere has contains overlapping thin and thick filaments Myofibril made of sarcomeres, so it has overlapping thick and thin filaments too Which of these are part of thick filaments? o Myosin/myosin heads Which of these are part of thin filaments? o G actin and F actin o Troponin and tropomyosin are located on the thin filaments Which of these are part of elastic filaments? o Titin 25. Which of the following do NOT CHANGE during skeletal muscle activity? a) the width of the actin strands b) the width of the H-band/zone c) the width of the I-band d) the distance between the z-discs e) the thickness of the thick filaments f) the calcium binding status of troponin Activity means the contractions of the skeletal fibers. Filaments themselves don’t change width. Changes during skeletal muscle activity/contraction: o Width of the H band (width decreases) o Width of I band (width decreases) o Distance between the Z discs o The calcium binding status of troponin o Muscle cells shorten during contraction due to sarcomeres shortening Does NOT change during skeletal muscle activity/contraction: o Width/thickness of actin strands (thin filaments)  o Width/thickness of myosin (thick filaments) Which of the following have ATPase activity? o SR calcium pumps during muscle relaxation o Sodium/potassium pumps 26. _______________ joint is a multi-axial joint. a) the proximal radioulnar b) the metatarsophalangeal c) the humeroulnar d) the glenohumeral e) the gomphosis f) the costosternal (of rib 1) Multi-axial → ball and socket joinys o Glenohumeral joint and hip joint Bi-axial → plane, saddle, condylar joints o Metatarsophalangeal joint o Proximal radioulnar joint o Trapeziometacarpal o Radiocarpal o Atlanto-occipital Monoaxial → hinge and pivot joints o Humeroulnar joint o Pubic symphysis A) Pivot joint and is a biaxial joint B) Condylar joint and is biaxial C) Hinge joint and is monoaxial D) Multiaxial E) Gomphosis → Synanthropic joint (no axes) F) Costosternal → Not a movable joint (Synchondroses) 27. Which of the following actions or structures always confers a mechanical advantage > 1.0? a) Mandible elevation b) Antebrachial flexion c) 1st class levers nd rd d) 2 class levers e) 3 class levers f) a longer effort arm than resistance arm First-class lever o First class levers: MA above or below 1.0 based E/R arm lengths o Rarest class in body o Fulcrum lies between effort and resistance arms (R-F-E) o Example: Atlanto–occipital condyloid joint  Second-class lever o Second class levers: always have MA > 1.0 o Also less common than 3rd class o Resistance lies between fulcrum and effort (F-R-E) ▪ Longer effort arm than resistance arm o Example: Temporomandibular condyloid (gliding hinge) joint ▪ Depression/elevation of the mandible ▪ Standing on one’s toes Third-class lever o Third class levers: always have MA < 1.0 o Most joints of the body are third class o Effort lies between the resistance and the fulcrum (R-E-F) o Longer resistance arm than effort arm o Example: Humeroulnar hinge joint ▪ flexion of the antebrachium MA > 1.0: system produces more power with less effort but moves an object slowly (or only a short distance) MA < 1.0: system moves an object rapidly (or traverses a longer distance quickly) but with considerably greater effort Has to be a second class lever so the effort arm is longer than resistance If asked less than one it would be B, E, first class lever consistently never do either or the other bc it depends bc the fulcrum is in the middle. 28. Which of these are true of fibrous joints (according to the textbook)? a) All types contain collagen b) All types contain Sharpey’s fibers between 2 bones c) Only type where collagen is found d) All are considered synarthrotic e) All are considered mono-axial f) Includes interosseous membranes All fibrous joints are synarthrotic, all contain collagen fibers, those collagen fibers are a type of sharpeys fiber, not only type because other connective tissues like dense regular and dense irregular tissues and synovial joins and cartilaginous joints also have collagen. Not freely movable so not monoaxial, includes interosseous/ syndesmoses membranes which included gomphoses and sutures as well Bony Joints (synostoses): formed by ossification in the gaps and residing tissues between two bones, the bones then become, in effect, a single bone  o Absolutely no movement o Can occur in either fibrous or cartilaginous joints but not synovial joints o Frontal bone fusion & Fontanel closures in childhood o Epiphyseal lines through adolescent growth Fibrous Joints (synarthroses): little to no movement o Bound by collagen (type 1) fibers that cross the space between and penetrate the other bone o Three types: ▪ Sutures Closely bind the bones of the joint to each other through extensions of Sharpey’s fibers Fetal/infant sutures more flexible ▪ Gomphoses: attachment of a tooth to its socket Fastened tightly to oral mucosa and mandible by fibrous periodontal ligaments o Dense regular type I collagen (sharpey’s fibers) tether tooth securely ▪ Syndesmoses: fibrous joint at which two bones are bound by longer collagenous fibers than in sutures or gomphoses Most moveable fibrous joints Interosseus membranes (flat collagenous sheet between parallel bones) Only three total: o Antebrachial Interosseus membrane o Crural interosseeus membrane o Interspinous membranes (ligaments along adjacent vertebral spinous processes) Cartilaginous joints: Amphiarthroses → slight movement o two bones are linked by cartilage (mostly hyaline, a few locations with fibrocartilage) o Two types of cartilaginous joints ▪ Synchondroses: bones are directly bound by hyaline cartilage No fibrocartilage in a synchondrosis Very little, if any, movement Epiphyseal growth plates o Temporary synchondrosis joints in youth Costosternal joint of Rib 1 (only Rib 1)  ▪ Symphyses: bones are joined by fibrocartilage sandwiched between outer layers of hyaline cartilage Intervertebral disc joints (between vertebral bodies) o Very modest movements between adjacent vertebrae o Collective effect of all 23 discs gives the vertebral column considerable flexibility Pubic symphysis o Right and left pubic bones joined by interpubic disc Symphyses are considered more flexible than Synchondroses o Which of these are true of cartilaginous joints? ▪ Some contain fibrocartilage ▪ All contain hyaline cartilage ▪ Includes pubic symphysis ▪ Includes epiphyseal plates 29. The near-immediate energy needed for myofilaments to slide across each other during short bursts (