Anaphy 12 Stem Quarter 1 Notes PDF

**ANAPHY 12 STEM\| Quarter 1** ANATOMY - from a **Greek word "ANATOME"** means **to dissect** - it is concerned with the **structure of parts** PHYSIOLOGY - concerned with the **function of the parts** TYPES OF ANATOMY SYSTEMIC - studies **body systems** REGIONAL - studies **body...

**ANAPHY 12 STEM\| Quarter 1** ANATOMY - from a **Greek word "ANATOME"** means **to dissect** - it is concerned with the **structure of parts** PHYSIOLOGY - concerned with the **function of the parts** TYPES OF ANATOMY SYSTEMIC - studies **body systems** REGIONAL - studies **body regions** SURFACE - studies **external features** ORGANIZATION OF HUMAN BODY 1. ATOM - **basic unit of matter** - submicroscopic particle 2. MOLECULE - **two or more atoms** held together by chemical forces 3. MACROMOLECULE - **large molecules** that are essential for biological processes 4. ORGANELLES - **system or part of the cell** that perform metabolic synthetic, energy generating and energy requiring functions 5. CELL - **basic unit of organism** 6. TISSUE - an **aggregation of cells** that function together and have a similar structure - with extracellular matrices 7. ORGAN - composed of several type of tissues and perform a particular function 8. ORGAN SYSTEM - a group of organs that works together to perform a complex function - we have 11 organ system 9. ORGANISM - an individual life forms HOMEOSTASIS - a relative **constancy of the body's internal environment** - a **state of balance** among all the body systems needed for the body to survive and function correctly - example: body temperature, blood pressure, heart rate, breathing rate, water level, testosterone rate, sugar level COMPONENTS THAT INTERACT TO MAINTAIN HOMEOTASIS STIMULUS - it is a **factor or variable that influences** the behavior of an organism SENSOR - monitor change or detects stress through **senses** - ex: free nerve ending in the skin CONTROL - receives information from the receptor and sends a message to the effector - ex: brain EFFECTOR - a body structure that **receives output** from the control center and produces a response or effect that changes the controlled condition - ex: muscle or gland NEGATIVE FEEDBACK - it is a mechanism that maintains homeostasis by **reducing any changes** to keep a variable within the normal range thereby keeping the body stable POSITIVE FEEDBACK - it is a mechanism that **increases the rate of the process** - the effector produces a response that enhances or reinforces the initial change in controlled condition ANATOMICAL TERMS - ANATOMICAL POSITION - person standing erect with face and palms forward SUPINE - if the anatomical position is **placed face-up**, it is in the supine position PRONE - if the anatomical position is placed **face-down**, it is in the prone position DIRECTIONAL TERMS ANTERIOR OR VENTRAL - refers to something located **towards the front or the belly side** - ex: the breastbone is anterior to the spin kneecap is located at the anterior side of the leg POSTERIOR OR DORSAL - refers to something located **towards the back** - ex: the shoulder blades are located on the posterior side of the body the spine is posterior to the breastbone SUPERIOR - refers to something located **uppermost or above** - ex: the head is superior to the neck the nose is superior to the mouth INFERIOR OR CAUDAL - refers to something located **below or towards the feet/tail** - ex: the chin is inferior to the mouth the neck is inferior to the head MEDIAL - body part is **nearer than another part to an imaginary midline of the body** - ex: nose is in the medial position on the face the nose is medial to the eyes LATERAL - refers to something located **towards the side of the body part** or the **farther away from the midline** - ex: the ears are lateral to the eyes the shoulder is lateral to the neck PROXIMAL - refers to something **closer to the point of attachment** or **closer to the trunk of the body** - ex: knee is proximal to the ankle ankle is proximal to the toes DISTAL - body part is **farther from the point of attachment or farther from the trunk or torso** - ex: a finger is distal to the wrist wrist is distal to the elbow elbow is distal to the shoulder SUPERFICIAL (EXTERNAL) - body part is located **near/closer the surface** - ex: skin is superficial to the bone the cornea is on the superficial surface of the eye DEEP (INTERNAL) - body part is **farther to the surface of the body** - ex: brain is deep to the skull bones are deep to the muscles CENTRAL - body part is **situated at the center of the body** or an organ PERIPHERAL - body part is situated **away from the center** of the body or an organ BODY PLANES - are **hypothetical geometric planes** used to **divide the body into sections** SAGITTAL (MEDIAN) - plane extends **lengthwise** and divides the body into **right and left portions** MIDSAGITTAL PLANE - passes exactly through the midline of the body - divides the body into **equal right and left parts** FRONTAL (CORONAL) - plane also extends lengthwise, but it is perpendicular to a sagittal plane and divides the body or an organ into **anterior and posterior portions** - the thoracic TRANSVERSE (HORIZONTAL) - the plane is perpendicular to the body's long axis and therefore **divides the body horizontally** to produce a cross section - dividing the body into **superior and inferior portions** BODY REGION UPPER LIMBS - upper arm, forearm, wrist, hand LOWER LIMBS - thigh, lower leg, ankle, foot CENTRAL - head, neck, trunk TRUNK - thoracic (chest), abdomen, pelvis BODY CAVITIES - is any **space or compartment**, or potential space in the animal body - cavities accommodate organs and other structure - two largest human body cavities are the **ventral cavity, and the dorsal cavity** DORSAL CAVITY - it **contains organs of the nervous system** that coordinate the body's functions - cranial cavity contains the brain - spinal or vertebral cavity contains the spinal cord VENTRAL CAVITY - it **contains organs that are involved in maintaining homeostasis** or a constant internal environment within small ranges of deviation THORACIC CAVITY - it contains the heart, thymus gland, lymph and blood vessels, trachea, esophagus, lungs and nerves PERICARDIAL CAVITY - around **heart** PLEURAL CAVITY - around **lungs** PEROTONEAL CAVITY - around **abdominopelvic cavity** MEDIASTINUM - divides **thoracic cavity into left and right** ABDOMINAL CAVITY - stomach, intestines, liver, spleen, pancreas PELVIC CAVITY - urinary bladder, reproductive organs, part of large intestine MEMBRANES MESENTERY - **double-layered membrane** that covers organs and **anchors them to body wall** SEROUS MEMBRANE - cover **organs and line cavity walls** VISCERAL MEMBRANE - **cover organs** PARIETAL MEMBRANE - **lines the cavity wall** TISSUE - came from **the latin word "texere**" which means **weave** - are **aggregates or groups of cells**, organized (with addition to extra cellular matrix or substances) to perform one or more specific functions 4 MAJOR ANIMAL TISSUES EPITHELIAL/EPITHELIUM TISSUE - is **a sheet of cells that covers a body surface** or line a body cavity and forms glands CONNECTIVE TISSUE - **underlies or supports the other three basic tissues**, both structurally and functionally MUSCLE TISSUE - is **made up of contractile cells** and is responsible for **movement** NERVE TISSUE - **receives, transmits, and integrates information** from outside and inside the body **to control the activities of the body** FUNCTION AND LOCATION OF EPITHELIAL TISSUE (PDAS) PROTECT/ACT AS A BARRIER - exterior body surfaces and line internal closed cavities (including vascular system) - protects us from the harmful rays of the sun and certain chemicals - ex: skin keeps bacteria out, lining in digestive tract DIFFUSION AND FILTRATION - **all glands are made of epithelial tissues** - ex: lungs and kidneys SECRETION - the secretory portion (parenchyma) of glands and their ducts - sweat glands excrete waste products such as urea - ex: glands and mucus glands ABSORPTION - the lining of the small intestine, nutrients from our digested food enter blood capillaries and get carried to the cells of our body - ex: small intestine \*receptors for the special senses (smell, taste, hearing, and vision) CLASSIFICATION OF EPITHELIAL TISSUE - each epithelial tissues are given **two names** - the first name indicates the **number of cell layers present** and the second **describes the shape of its cells** SIMPLE - **one cell layer thick** STRATIFIED - **two or more cell layers** SQUAMOUS SIMPLE SQUAMOUS - structure: **1 layer of flat, tile-like cells​** - function: **diffusion and filtration​** - location: blood vessels, lungs, heart, kidneys​ STRATIFIED SQUAMOUS - structure: **many layers of flat, tile-like cells** - function: **protect and acts as a barrier** - location: skin, mouth, throat, esophagus CUBOIDAL - when the **cells function in secretion**, microvilli (tiny extensions from the cells) increase the surface area of cells SIMPLE CUBOIDAL - structure: 1 layer of square-shaped cells attached to a basement membrane - function: **for secretion** - location: **glands**, such as salivary glands, thyroid gland, and pancreas - also covers the ovaries and lines most of the kidney tubules; in one part it absorbs substances from the tubule, and in another part, it secretes substances into the tubule STRATIFIED CUBOIDAL - mostly **found lining the larger ducts** of certain glands, such as the **mammary glands and the salivary glands** - this tissue often has only **two layers** COLUMNAR EPITHELIUM SIMPLE COLUMNAR - structure: **1 layer of tall, narrow cells** - function: secrete mucus and absorption - location: stomach, intestines, respiratory tract, uterine tubes, and male urethra STRATIFIED COLUMNAR - it is **not very common** but does **exist in parts of the pharynx and the male urethra** TRANSITIONAL EPITHELIUM - structure: **cuboidal (relaxed) & squamous (compressed)** - function: physically **able to slide in relation to one another** while at the same time **forming a barrier** - location: bladder CONNECTIVE TISSUE - comprises a **diverse group of cells** within a tissue-specific extracellular matrix - function: provides support and protection, fills spaces, produced blood cells, and stores fat EXTRACELLULAR MATRIX - composed of an **organic ground substance** that contains fibers and varies in consistency from solid (bone to semi fluid and cartilage to fluid (blood)) TYPES OF FIBERS WHITE FIBERS - contain **collagen**, occur in **bundles and are strong and flexible** YELLOW FIBERS - contain **elastin**, form a highly elastic network that returns to its original length after stretching RETICULATED FIBERS - **highly branched, collagenous fibers** that form delicate supporting networks CELLS - fibroblast, histocytes, phagocytic, mast cell LOOSE CONNECTIVE TISSUE - sometimes **called areolar tissue** - located between organs, muscles, glands, skin - structure: **collagen fibers far apart** - function: support and protect - cells: fibroblast DENSE CONNECTIVE TISSUE - **located in tendons, ligaments, skin** - structure: **collagen fibers packed close together** - function: connect and can withstand pulling forces - types: regular and irregular ADIPOSE TISSUE - **located under the skin and around organs** - structure: collagen and elastic fibers, cells filled with lipids - function: storage, insulate cushion, and hormone production - types: brown adipose tissue (multilocular) - white adipose tissue (unilocular) CARTILAGE - **composed of cells called chondrocytes** and a highly specialized extracellular matrix - chondrocytes are specialized cells that produce and maintain the extracellular matrix - contains collagen - can **withstand compression** - **provides support, flexibility, strength** HYALINE CARTILAGE - from the Greek work hyalos, glassy - location: covers ends of bones - structure: glycoproteins and some collagen fibers - function: reduces friction (cushion) provides a model for the developing skeleton of the fetus - hyaline cartilage matrix is highly hydrated to provide resilience and diffusion of small metabolites TYPES OF LAYERS SUPERFICIAL (TANGENTIAL) ZONE - a **pressure-resistant region** closest to the articular surface - it contains numerous elongated and flattened chondrocytes surrounded by a collagen fibrils that are arranged in fascicles parallel to the free surface INTERMEDIATE (TRANSITIONAL) ZONE - lies **below the superficial zone** and contains **round chondrocytes** DEEP (RADICAL) ZONE - characterized by **small, round chondrocytes** that are arranged in **short columns perpendicular** to the free surface of the cartilage - the collagen fibrils are positioned between columns parallel to the long axis of the bone ELASTIC CARTILAGE - **located in ear and tip of nose** - structure: elastic fibers - function: **can recoil** FIBROCARTILAGE - located between vertebrae - structure: lots of collagen and fibers - function: can withstand compression BONE TISSUE - characterized by **a mineralized (calcium phosphate) extracellular matrix** - classified as either compact (dense) or spongy (cancellous) CELL TYPES ASSOCIATED WITH BONE OSTEOPROGENITOR CELLS - are **cells derived from mesenchymal stem cells**; they **give rise to osteoblasts** OSTEOBLASTS - **cells that secrete the extracellular matrix** of bone; once the cell is **surrounded with its secreted matrix, it is referred to as an osteocyte** BONE-LINING CELLS - cells that **remain on the bone surface when there is no active growth** - they are derived from those osteoblasts that remain after bone deposition ceases OSTEOCLASTS - are **bone-resorbing cells** present on bone surfaces where **bone is being removed or remodeled** (reorganized) or where bone has been damaged COMPACT BONE (DENSE) - present in the **outer layer of long bones** SPONGY BONE (CANCELLOUS) - present in the **middle of the long bones** BLOOD - composed of **cells suspended in a liquid matrix called plasma**, that circulates through the cardiovascular system FUNCTION OF BLOOD - delivery of nutrients and oxygen directly or indirectly to cells - transport of wastes and carbon dioxide away from cells - delivery of hormones and other regulatory substance to and from cells and tissues - maintenance of homeostasis by acting as a buffer and participating in coagulation and thermoregulation - transport of humoral agents and cells of the immune system that protect the body from pathogenic agents, foreign proteins, and transformed cells (cancer cells) TYPES OF BLOOD RED BLOOD CELLS - also known as **erythrocytes**, which **carry oxygen** WHITE BLOOD CELLS - also known as **leukocytes**, which **aid in fighting infection** PLATELETS - important to the **initiation of blood clotting** - are not complete cells; rather they are **fragments of giant cells found in bone marrow** MUSCLE TISSUE - **responsible for movement of the body** and its parts and for changes in the size and shape of internal organs - composed of **contractile cell called myocyte** STRIATED MUSCLE - the **cells exhibit cross striations** - ex: skeletal muscle and cardiac muscle SMOOTH MUSCLE - which the **cells do not exhibit cross striations** SKELETAL TISSUE - responsible for movement of the axial and appendicular skeleton - maintenance of body position and posture - help maintain a constant body temperature - help protect internal organs and stabilize joints - characteristics: tubular, multinucleated, and striated; longest of muscle type; voluntary CARDIAC MUSCLE - heart - 1 centrally located nucleus/cell - striated - rich in mitochondria - intercalated disks: special cell junctions that allow cells to act as a unit SMOOTH MUSCLE - found on organs - 1 centrally located nucleus/cell - not striated - less actin and myosin - under involuntary control NERVOUS TISSUE - consist of **neurons or nerve cells** - found in brain, spinal cord, and peripheral nerves - controls and coordinates body movements - includes axons, dendrites, and cell bodies GLANDS - consists of one or more cells that **produce and secrete a product** - **most glands are composed primarily of epithelium** - mucus-secreting goblet cells withing the columnar epithelium lining the digestive tract are single cells TYPE OF GLANDS EXOCRINE GLANDS - glands with ducts **that secrete their product onto the outer surface or into a cavity** - ex: sweat glands and mammary glands, and pancreas - ducts can be simple or compound ENDOCRINE GLAND - glands that **no longer have a duct** are appropriately known as the **ductless glands** BASAL DOMAIN OF EPITHELIAL CELLS BASEMENT MEMBRANE - a specialized structure **located next to the basal domain of epithelial cells** and the underlying connective tissue stroma CELL-TO-EXTRACELLULAR MATRIX JUNCTIONS - anchor the cell to the extracellular matrix - they are represented by focal adhesions and hemidesmosomes BASAL LAMINA - the **structural attachment site** for overlying epithelial cells and underlying connective tissue. - in **non-epithelial cells is referred to as the external lamina​** - contains molecules (glycoprotein and collagen) that come together to form a sheet-like structure.​ TIGHT JUNCTION OCCLUDING JUNCTION - **impermeable and allow epithelial cells** to function as **a barrier** - primary intercellular diffusion barrier between adjacent cells​ - limiting the movement of water and other molecules through the intercellular space, they maintain physicochemical separation of tissue compartments​ - prevent the migration of lipids and specialized membrane proteins between the apical and lateral surfaces. - recruit various signaling molecules to the cell surface and link them to the actin filaments of the cell cytoskeleton. ANCHORING JUNCTION - provide **mechanical stability to epithelial cells** by linking the cytoskeleton of one cell to the cytoskeleton of an adjacent cell - creating and maintaining the structural unity of the epithelium by interacting with both actin and intermediate filaments​ - types:​ desmosomes (Lateral)​ and hemidesmosomes (Basal) COMMUNICATING JUNCTION - allow **direct communication between adjacent cells** by diffusion of small molecules (e.g., ions, amino acids, sugars, nucleotides, second messengers, metabolites) ​ - permits the coordinated cellular activity that is important for maintaining organ homeostasis.​ SKIN - surface area of an adult body is covered with **3000 square inches​** - weighs about **6 to 9 pounds or 3 to 5 kilos of the body weight​** - receives about 1/3 of the blood circulating through the body​ - flexible and can repair and regenerate itself under normal conditions​ - almost entirely waterproof​ FUNCTION OF SKIN - protection: water loss, microbes, UV light - sensation: hot, cold, pain, pressure - temperature regulation: helps maintain homeostasis - excretion: remove waste - vitamin D production: UV light stimulates production SKIN - cutaneous membrane or the integument - components: - hair follicles and hair - sweat (sudoriferous) glands - sebaceous glands - nails and mammary glands LAYERS OF THE SKIN EPIDERMIS - composed of **a keratinized stratified squamous epithelium** that grows continuously but maintains its normal thickness by the process of desquamation DERMIS - composed of a **dense connective tissue** that imparts **mechanical support, strength, and thickness** of the skin HYPODERMIS - a **subcutaneous tissue** is found between the skin and any underlying structures such as muscle STRATIFIED SQUAMOUS EPITHELIUM STRATUM BASALE - also called the **stratum germinativum** - **deepest layer of epidermis** - single layer of cells that are capable of mitosis - give rise to all the cells of the upper layers - contain melanocytes that extend up to the other layers - produce melanin pigments STRATUM SPINOSUM - also called the **spinous layer or prickle cell layer** because of the characteristic light microscopic appearance of short processes extending from cell to cell - **many layers of prickly or spiny polyhedral cells** - desmosomes still prevalent STRATUM GRANULOSM - contains **numerous intensely staining granules** - **3 to 5 layers of flattened cells** - cells lose nuclei and become compact and brittle - contain lamellar granules that release lipid and repels water - contain keratohyalin granules that converts to keratin STRATUM LUCIDUM - which is **limited to thick skin** - lies beneath stratum corneum - only **1 to 2 layers thick** - cells are transparent and flat - **found only in thick skin like palms and soles of feet** STRATUM CORNEUM - **composed of keratinized cells** - **20-30 layers of dead squamous cells** filled with keratin DESQUAMATION - a process by which **cells are sloughed off** - dandruff results from shedding of cells of stratum corneum from the scalp - **callus**- forms when stratum corneum has frequent **friction** - **corns**- form from **abrasions on the bony prominences** of the foot CELLS OF THE EPIDERMIS KERATINOCYTES - **separation of the organism from its external environment** - they account for **85% of the cells in the epidermis** MELANOCYTES - the **pigment-producing cells** of the epidermis - they account for approximately **5% of the cells in the epidermis** LANGERHANS' CELLS - the **antigen-presenting cells** involved in signaling in the immune system - they account for approximately **2% to 5% of the cells in the epidermis** MERKEL'S CELLS - the **sensitive mechanoreceptor cells** associated with **sensory nerve endings** - they account for approximately **6% to 10% of the cells in the epidermis** DERMIS - **dense connective tissue** - contains **collagen and elastic fibers** - contains fibroblasts, nerve endings, smooth muscle, glands, blood vessels, and hair follicles CLEAVAGE LINES - area where skin is **most resistant to stretching** - due to orientation of collagen fibers - **important in scarring** - the orientation of collagen fibers produces cleavage lines, or tension lines in the skin - **langer's lines sometimes called cleavage lines** PAPILLARY LAYER - made of **areolar loose connective tissue layer** - contains blood vessels highly vascularized DERMAL PAPILLAE/RIDGES - provide blood supply to the epidermis - remove waste on hands and feet (fingerprints and footprints) - **pattern is genetically determined** RETICULAR LAYER - **lies deep to the papillary layer** - thickness varies in different parts of the body - less cellular than the papillary layer - contains collagen and elastic fibers - deepest layer of the dermis - account for **80% of dermis** - made of dense irregular connective tissue HYPODERMIS - below dermis - **foundation of skin** - attaches skin to underlying muscle and bone - contains **loose and adipose tissue** - contains ½ of body's fat - body fat for females 20-23% and males 13-25% NERVE SUPPLY - **free nerve ending** in the epidermis terminate in the stratum granulosum - the endings are "free" in that **they lack a connective tissue or schwann cell** ENCAPSULATED NERVE ENDINGS PACINIAN CORPUSCLES - detect **pressure changes and vibrations** applied on the skin surface MEISSNER'S CORPUSCLES - responsible for **sensitivity to light touch** RUFFINI'S CORPUSCLES - **sensitive to skin stretch and torque** ACCESSORY STRUCTURE OF THE SKIN HAIR/SHAFT - flexible strands of keratinized cells ROOT - below skin (scalp) HAIR BULB - base of root and where hair is produced HAIR FOLLICLE - group of cells that surround root and bulb and gives hair different shapes INFUNDIBULUM - extends from the surface opening of the follicle to the level of the opening of its sebaceous gland - a part of the pilosebaceous canal, which is used as a route for the discharge of the oily substance sebum ISTHMUS - extends from the infundibulum to the level of insertion of the arrector pili muscle - arrector pili: smooth muscle that surrounds each hair follicle. contracts and hair stand on end (goose bumps) HOW HAIR IS PRODUCED - hair is produced in hair bulb; hair bulb rests on blood vessels to supply it with nutrients - hair grows longer as cells are added to base of hair bulb - **testosterone and good nutrition promote hair growth** - growth occurs in cycles: active and resting - scalp hair grows for 3 years and rests for 1 year - eyelashes grow for 30 days and rest for 105 days - **we lose about 90 scalp hairs/day** - **grey hair is the loss or fading of melanin** - male pattern baldness is from the loss of the hair follicle - attaches to nail and is distal to nail matrix GLAND - the glands in the skin are **groups of cell specialized to produce and secrete a substance into ducts** - sweat glands are classified on the bases of their structure and the nature of their secretion - eccrine sweat gland and apocrine sweat glands are limited to the axilla, areola, and nipple of the mammary gland; skin around the anus; and the external genitalia ECCRINE GLAND - are **distributed over the entire body surface** except for the **lips and part of the externa; genitalia** - temperature regulation through the cooling that results from the evaporation of water from sweat on the body surface - clear cell, dark cell, myoepithelial cell APOCRINE GLAND - produce **a secretion that contains protein, carbohydrate, ammonia, lipid, and certain organic compounds** that may color the secretion SEBACEOUS GLAND - secrete **sebum that coats the hair and skin surface** EFFECTS OF AGING - blood flow decreases and skin becomes thinner due to decreased amounts of collagen - decreased activity of sebaceous and sweat glands make temperature regulation more difficult - loss of elastic fibers cause skin to sag and wrinkle BURNS 1^st^ DEGREE - damages only epidermis redness, slight swelling, pain heals within 2-3days (usually no scar) includes sunburns or exposure to cold 2^nd^ DEGREE - damages epidermis and upper dermis redness, swelling, pain, blisters heal in 2 weeks with some scarring 3^rd^ DEGREE - destroys epidermis and dermis burned areas are cherry red to black nerve endings are destroyed skin graft might be necessary MUSCULAR SYSTEM - its function is for movement, maintain posture, respiration, production of body heat, communication, heartbeat, contraction of organs and vessels MUSCLE TISSUE - composed of contractile cell called myocyte CLASSIFIED ACCORDING TO THEIR APPERANCE STRIATED MUSCLE - which the cells exhibit cross striation - ex: skeletal and cardiac muscle SMOOTH MUSCLE - cells do not exhibit cross striations CONNECTIVE TISSUE ENDOMYSIUM - **layer of reticular fibers** that immediately **surrounds individual muscle fibers** PERIMYSIUM - **connective tissue layer** that surrounds a group of fibers **to form a bundle or fascicle** FASCICLES - **are functional units of muscle fibers** that tend to work together to perform a specific function - muscle itself is covered by connective tissue layer call epimysium CHARACTERISTICS OF SKELETAL MUSCLE - tubular, multinucleated, and striated - longest of muscle types - voluntary MYOBLAST - **mononucleate precursor cells** of skeletal muscle, can differentiate to form multinucleated muscle fibers capable of muscle contraction MUSCLE FIBER - contains the usual cellular components, but special names have been assigned SARCOLEMMA - refers to the **membrane of the skeletal muscle** SARCOPLASM - refers to the **cytoplasm of the muscle cell** - also contains glycogen which provides stored energy for muscle contraction and red pigment myoglobin which binds oxygen until it is needed for muscle contraction SARCOPLASMIC RETICULUM - **smooth endoplasmic reticulum of the myocyte** - calcium storage sites T (TRANSVERSE) SYSTEM - the sarcolemma forms T tubules that penetrate, or dip down, into the cell so that they come into contract but do not fuse with expanded portions of the sarcoplasmic reticulum MYOFIBRILS - **thread-like proteins** that make up muscle fibers - the contractile portions of the muscle fibers - composed of bundles of myofilaments 2 TYPES OF PROTEIN MYOFILAMENTS THICK FILAMENTS - composed primarily of the **protein myosin II** - resemble golf clubs THIN FILAMENTS - consists of **two intertwining strands of the protein actin** - resemble 2 strands of pearls - two other proteins called tropomyosin and troponin are also present SARCOMERES - the placement of myofilaments within units of myofibrils - contractile unit - a sarcomere extends between two dark lines called the Z line Z DISK - protein fibers that form attachment site for actin H ZONE - center of sarcomere - contains only myosin I BAND - contains only actin A BAND - where actin and myosin overlap M LINE - where myosin is anchored MEMBRANE POTENTIALS - the nervous system stimulates muscles to contract through electrical signals called action potentials - plasma membranes are polarized which means there is a charge difference (resting membrane potential) across the plasma membrane - the inside of the plasma membrane is negative as compared to the outside in a resting cell - electricity - an action potential is a reversal of the resting membrane potential - so that the inside of the plasma membrane becomes positive - stimulus that causes rapid depolarization and repolarization - causes muscle to contract MUSCLE RESPONSE THRESHOLD - **weakest stimulus** needed to produce a response ALL OR NONE LAW - **muscle contracts or doesn't (no in between)** TWITCH - **rapid contraction and relaxation** of a muscle TETANUS - muscle **remains contracted** TYPE I - fibers or slow oxidative fibers slow twitch, fatigue-resistant motor units (a twitch is a single, brief contraction of the muscle) - contains more myoglobin and mitochondria - found in the limb muscles of mammal's long erector spinae muscles of the back in humans where they are particularly adapted to the long, slow contraction needed to maintain erect posture - a high percentage of these fibers make up the muscles of high endurance athletes such as marathon runners TYPE IIa FIBERS OR FAST OXIDATIVE GLYCOLYTIC FIBERS - many mitochondria and high myoglobin content - contain large amounts of glycogen and are capable of anaerobic glycolysis - they make up fast-twitch, fatigue resistant motor units that generate high peal muscle tension TYPE IIb FIBERS OR FAST GLYCOYTIC FIBERS - are large fibers that appear light pink and contain less myoglobin and fewer mitochondria than type I and type IIa fibers - exhibit high anaerobic enzyme activity and store a considerable amount of glycogen - fatigue-prone motor units and generate high peal muscle-tension ATROPHY - the **wasting or thinning of your muscle mass** HYPERTROPHY OR MUSCLE GROWTH - refers to an **increase in muscle mass** ISOMETRIC - amount of **tension increases (weight)** ISOTONIC - **number of repetitions increases** TONE - **constant tension over a long period** of time SPASMS AND INJURIES SPASM - **sudden and involuntary muscular contractions**, most often accompanied by pain STRAIN - **overstretching** of a muscle near a joint SPRAIN - the **twisting of a joint**, leading to swelling and to injury not only of muscles but also of ligaments, tendons, blood vessels, and nerves MYALGIA - refers to **inflammation of muscle tissue** TENDINITIS - **inflammation of a tendon** due to the strain of repeated athletic activity SKELETON - consist of two types of connective tissue - there are **206 bones in adults and cartilage** JOINTS - the **point where two bones come together** LIGAMENTS - **formed of fibrous connective tissue** which join the bones TENDONS - **connect muscle to bones** FUNCTION OF SKELETON - support the body - protects soft body parts - produces blood cells - stores minerals and fat - contains calcium phosphate, a source of calcium ions and phosphate ions in the blood; fat is stored in yellow bone marrow - along with the muscles permit flexible body movement BONE - characterized by a mineralized (calcium phosphate) extracellular matrix - classified as either compact (dense) or spongy (cancellous) CELL ASSOCIATED WITH BONE OSTEOPROGENITOR CELL - cells derived from mesenchymal stem cells - they give rise to osteoblasts OSTEOBLASTS - cells that secrete the extracellular matrix of bone - one the cell is surrounded with its secreted matrix; it is referred to as an osteocyte BONE-LINING CELLS - cells that remain on the bone surface when there is no active growth - derived from those osteoblasts that remain after bone deposition ceases OSTEOCLASTS - bone-resorbing cells present on bone surfaces where bone is being removed or remodeled (reorganized) or where bone has been damaged CLASSIFICATION OF BONES LONG BONES - longer than they are wide SHORT BONES - cube shaped; their lengths and widths are about equal FLAT BONES - platelike and have broad surfaces IRREGULAR BONES - varied shapes with many places for connections with other bones ROUND BONES - it is circular ANATOMY OF A LONG BONE DIAPHYSIS - the **shaft or main portion of the bone** - has a **large medullary cavity** which composed of compact bone - it is lined with a thin vascular membrane (the endosteum) and is filled with yellow bone marrow which stores fat EPIPHYSIS - **expanded region at the end of a long bone** - **composed largely of spongy bone** that contains red bone marrow where blood cells are made METAPHYSIS - contain the **epiphyseal plate**, a region of cartilage that allows for bone growth PERIOSTEUM - **layer of fibrous connective tissue** covered the long bone is completely - contains blood vessels, lymphatic vessels, and nerves ANATOMY OF COMPACT BONE - compact or dense bone - contains many cylinder-shaped units called osteons which contain osteocytes LACUNAE - **tiny chambers** arranged in concentric circles around a central canal that occur between concentric layers of matrix called lamellae - the matrix contains collagenous protein fibers and mineral deposits, primarily of calcium and phosphorus salts CANALICULI - **tiny canals** that run through the matrix - these canaliculi connect the lacunae with one another and with the central canal ANATOMY OF SPONGY BONE - also known as cancellous bone - contains numerous thin plates called trabeculae - red blood cell formation called hematopoiesis, occurs in the spongy bone of the skill, ribs, sternum (breastbone) and vertebrae and in the end of the long bones BONE DEVELOPMENT AND GROWTH OSSIFICATION - refers to the **formation of bone** INTRAMEMBRANOUS OSSIFICATION - bone develops between sheets of fibrous connective tissue - cells derived from connective tissue become osteoblasts that form a matrix resembling the trabeculae of spongy bone - other osteoblasts associated with a periosteum lay down compact bone over the surface of the spongy bone ENDOCHONDRAL OSSIFICATION - bone replaces the cartilaginous (hyaline) models of the bones FRACTURES - complete if the bone is broken clear through - incomplete if the bone is not separated into two parts - simple if it does not pierce the skin - compound if it does pierce the skin - impacted means that the broken ends are wedged into each other - spiral fracture occurs when the break is ragged due to twisting of a bone AXIAL SKELETON - lies in the midline of the body - consists of the skull, hyoid bone, vertebral column, and rib cage SKULL FRONTAL BONE - one frontal bone forms the forehead, a portion of the nose, and the superior portions of the orbits (bony sockets of the eyes) PARIETAL BONES - two parietal bones are just posterior to the frontal bone - they form the roof of the cranium and also help form its sides OCCIPITAL BONE - one occipital bone forms the most posterior part of the skill and the base of the cranium