Physiology Notes T2 PDF

Mod 1 - Cells, Tissues and Homeostasis Basic Chemistry - Levels of Structure Explain the difference between an atom and an Ion Atoms are ultramicroscopic building blocks of matter. They contain a nucleus (protons and neutrons) and surrounding electrons. The number of protons and electrons are equ...

Mod 1 - Cells, Tissues and Homeostasis Basic Chemistry - Levels of Structure Explain the difference between an atom and an Ion Atoms are ultramicroscopic building blocks of matter. They contain a nucleus (protons and neutrons) and surrounding electrons. The number of protons and electrons are equal. An Ion is an atom with an unequal number of protons and electrons Define a molecule, a compound, an element, and a free radical Molecules are when two or more atoms bond to form a stable structure Element is a substance made entirely of the same atoms. For example oxygen. The 4 elements oxygen, hydrogen, carbon and nitrogen make up 96% of the body’s mass Compound is a substance made of different atoms. For example, oxygen + hydrogen = water molecule H2O Free radical is an atom or molecule with an unpaired electron Metabolism Define metabolism, and describe what are the two types of metabolism and explain the processes Metabolism is the sum of all chemical reactions in the body. Includes: Anabolism which is the building phase of metabolism, molecules use energy to combine and make more complex ones Catabolism which is the process of producing/releasing energy. Complex molecules are broken down into simpler ones, you also break down food to reform ATP Explain ATP Also known as Adenosine TriphosphateIs basically energy currency, energy used by all cells. This energy stored is spent to perform many body functions including muscle contraction, cell division, movement of substances across cell membranes. Energy needed to reform ATP is gained by breaking down food (catabolizing) Define Cellular Preference Depending on the cell, demand for energy, and energy substrate available, different substrates will be used. E.g. when going for a short walk, the demand for energy is less and longer duration whereas when working out, using muscles, you will dip more in fats in energy substrates Define Cellular respiration, and describe what are the two types of cellular respiration and explain the processes and give one example for each Cellular respiration refers to the different pathways to access energy and molecules. Aerobic cellular respiration happens with oxygen present. For example when you are sitting on the couch in a relaxed state, you are taking in oxygen. Anaerobic cellular respiration happens without oxygen present/being used. For example when you are doing high intensity exercises, you run out of breath, you won't be able to breathe in fast enough to get energy into the muscles. Identify and explain the metabolic processes of each energy substrate Carbohydrate (Glucose) Metabolism is the main energy substrate, you get ATP quickly but only a very little amount. It is the preferred energy substrate. It can break down glucose to get energy with or without oxygen. Glycolysis is the breakdown of glucose. The stored form of glucose is glycogen Fat metabolism is not preferred because it is only taken in aerobically, it is more complex and takes longer. However you get more ATP out of it. Lipolysis is the breakdown of stored fat. Storage form of fat is called triglycerides Protein metabolism is also not preferred, proteins are broken down into amino acids and using amino acids to generate ATP takes longer and produces extra waste. Happens when the body is very low on fats and carbs. For example, chemotherapy Define Pyruvic Acid Breaking down glucose becomes 2 molecules of pyruvic acid and 2 ATP What happens to pyruvic acid during aerobic vs anaerobic cellular respiration? In aerobic cellular respiration, pyruvic acid enters the mitochondria and you may ATP out of it, quickly but not a lot. This would be in relaxed states In anaerobic cellular respiration. Pyruvic acid DOES NOT go into the mitochondria, but gets converted into lactic acid, which converts to lactate which diffuses out of the cell and circulates around the blood, liver, heart, brain. It is the feeling of the burn you get during a high intensity exercise Key Cellular Substances Define what are nutrients Substances needed for body structure and function Define and describe the two main types of compounds within a cell Organic compounds contain carbon, include ATP, carbs, fats, proteins and nucleic acids Inorganic compounds which contain no carbon, include water which account for 65% of the body’s weight and acid, bases and salts Define dissociation Dissociation is the separation of inorganic acids, bases and salts into ions in a solution Define what is an acid, base and salt Acid is a substance that dissociates into one or more hydrogen ions (H+) Base is a substance that dissociates into one or more hydroxide ions (OH-) Salt is a substance that dissociates into positive and negative ions (no H+ or OH-) Explain what does the pH scale do and give one example pH scale measures how acidic or how alkaline an object is. Objects that are not very acidic are called basic. The scale has values ranging from zero (most acidic) to 14 (most basic). The more hydrogen ions (H+) dissolved in a solution, the more acidic it is. The more hydroxide ions (OH-) dissolved in solution, the more basic (alkaline) it is. For example, pure water which has a pH value of 7, this value is considered neutral which is neither acidic or basic. For example, milk is a 6, so it's fairly neutral leaning towards acidic. Bleach is a 13 so extremely alkaline and Gastric juice is 1.2-3.0 which makes it extremely acidic _____ What is needed for a cell to survive? Needs nutrients, substances, and oxygen for body structure and function Explain the difference between Solute, Solvent and Solution A solute is a dissolvable substance, a solvent is a substance in which a solute is dissolved. A solution is what you get when you dissolve a substance into another substance a solution is formed. What are the two different types of Nucleic Acids? DeoxyRibonucleic Acid - a molecule that contains the genetic code that is unique in every individual, controls most cell activities Ribonucleic Acid (RNA) relays genetic instructions to guide protein synthesis ____ Define what is a cell Smallest unit of life responsible for all of life’s processes, makes up all living organisms and tissues of the body. Consists of a cell membrane, nucleus and cytoplasm What is the difference between Tissue and Organ? Tissues are a group of cells that perform a similar function, whereas organs are part of the body composed of at least two kinds of different tissue. Define an organ system and give two examples An organ system are a group of organs related to each other that perform functions together, for example the respiratory system and digestive and excretory system What are the four major types of Tissue ? Epithelial Tissue which includes body surfaces, lines, hollow organs and form glands Connective tissue which provides structure and connects Muscular tissue where cells that use ATP generate force for tension and contraction Nervous tissue which are tissues that make up the nervous system Homeostasis Define and explain Homeostasis A self regulating process by which an organism can maintain internal stability while adjusting to changing external conditions Define and explain the main components of a feedback system/loop* Feedback system/loop is a cycle in which the internal environment is monitored, evaluated, changed, and re-evaluated. This process requires ATP. The main components include -A stimulus which can be internal or external and disrupts or changes the controlled condition -A controlled condition which is the variable being monitored -A sensor/receptor which is a structure that monitors the changes in a controlled condition and sends information to the control via transmission pathway -A control center comprises the nervous and endocrine systems (gland and organ systems). Received information from sensors/receptors, sets the range values in which the controlled condition should be maintained, evaluates the body’s response to change in the controlled condition and sends commands to the effector via transmission pathways -An effector is the structure that produces the response to a given stimulus. It receives commands from the control center and produces the response that will change the controlled condition Explain how a negative feedback system works and give one example Negative feedback system reverses changes in the internal environment. A stable process and the most common feedback system. For example, when body temperature increases, your receptors will monitor the change, send a signal to the brain, your brain sets the ranges for what is the correct temperature, and send a command to the effector via transmission pathways which would cause your skin in this case to sweat. As your body temperature gets back to normal, the receptor will monitor and send a signal back to the brain to determine if it is the correct temperature. Explain how a positive feedback system works and give one example Positive feedback system intensifies a change in the body’s physiological condition rather than reversing it. Positive feedback is supposed to have an end point in its delivery. For example, in contractions of labor (stimulus) the baby is pushed towards the cervix which contains stretch-sensitive cells (sensors) that monitor the degree of stretching. These nerve cells send messages to the brain (control center), which causes the pituitary gland at the base of the brain to release hormone oxytocin into the bloodstream. Oxytocin causes stronger contractions of the smooth muscles (effectors) in the uterus, pushing the baby further down the birth canal, causing even greater stretching of the cervix. The cycle of stretching, oxytocin release, and increasingly more forceful contractions stops only when the baby is born. At this point stretching of the cervix halts stopping the release of oxytocin What is the difference between adaptation and compensation? Adaptation is an adjustment of an organism to its environment for good reason. For example if you decide to become more active, you will become more physically active Compensation on the other hand is an adjustment of an organism to counterbalance a defect, so it will not be for a good reason. For example, in a heart attack, the heart will be compromised and your kidneys will try to compensate for the extra workload. Although it will be adjusted to it’s function, the reason is not a good one because it was a heart attack Cell structures Define the plasma membrane * A flexible, sturdy barrier that surrounds the cell’s contents. Also contains membrane proteins and microvilli Define membrane proteins and explain their 3 functions Membrane protein identifies the cell, strengthens its membrane and moves substances in and out of the cell. It is also selectively permeable (allows which substances can come in and out). Also involved in communication between cells and other cells and their environment Define Microvilli Finger-like projections of the plasma membrane that increase surface area through wrinkling. For example in order to absorb more nutrients from the gastrointestinal system Define Cytoplasm The contents of the cell (everything inside the plasma membrane but outside the nucleus), includes the intracellular fluid and everything inside the fluid (organelles), metabolism occurs in the cytoplasm. Define and explain the 5 roles of a Cytoskeleton Cytoskeleton is a network of protein filaments within the cytosol. Is critically important for muscle contraction, provides a structural framework for cell shape, organization and movement and anchoring of cell organelles What's the difference between intracellular fluid and extracellular fluid and interstitial fluid? Intracellular fluid (cytosol) refers to fluid inside the cell whereas extracellular fluid are fluids outside the cell, which include fluid in blood vessels (plasma), fluid surrounding the brain and spinal cord (cerebrospinal fluid). Interstitial fluid is part of extracellular fluid referring to fluid between the cells What are the organelles and what function does each have inside of a cell? Nucleus - rounded or elongated structure near the center of the cell, actively involved in maintaining its own homeostasis (at a cellular level). Acts as a control center for the cell, responsible for the cell's metabolism, growth, reproduction. Is present in all human cells except red blood cells. Mitochondria - the powerplant of the cell, transforms organic compounds into energy (ATP) Golgi Complex - is like a post office, that processes, sorts, packages and delivers molecules to the plasma membrane or around the cell Lysosomes - is like a garbage truck, cleans things up, breaks down substances that the cell has taken in or normal parts of the cell that are damaged. E.g. bacteria that gets in gets killed and cleaned up by Lysosomes Ribosomes - a site of protein synthesis (where proteins are assembled), floats around separately Rough Endoplasmic Reticulum (rER) - also a site of protein synthesis, covered in ribosomes Smooth Endoplasmic Reticulum (sER) - makes lipid molecules, NOT covered in ribosomes, regulates calcium and metabolism within the cell * Cillia - short hair like projections extending from surface of the cell, their movement causes steady movement of fluid/particles along the cell surface e.g. respiratory system has a lot of cilia that move away dust Flagella - similar to cilia but longer. They move the entire cell. Only known cell is the sperm cell Define membrane transport Cells transport material across the plasma membrane in and out via the membrane proteins. Explain what is a concentration gradient Concentration gradient is the difference in concentration of a chemical from one place to another (from the inside to the outside of the plasma membrane). In moving substances in and out and IN being selectively permeable, concentration gradients can be formed Explain what is the difference between passive and active transport Passive transport has two processes: For Passive transport, no energy is needed to move substance Diffusion which is when substances move down in a concentration gradient from high concentration to low concentration. For example, oxygen in inhaled air diffuses through the lungs and into the bloodstream. Oxygen is then transported throughout the body Osmosis which is the passive movement of water across a semi permeable plasma membrane from an area of high water concentration to low. Water always moves from an area of higher water concentration to one of lower concentration. The plasma membrane prevents the solute from moving. For example, when you have a sore throat, drinking salt water bathes your throat cells with a concentration of salt water. The water passes through but the plasma membrane prevents the salt from passing through. The salt draws water out of bacteria by osmosis and if you draw enough, you kill the bacteria. Active transport has two processes: For Active transport, energy is needed Active transport which is the movement of a substance across a membrane AGAINST a concentration gradient. Energy is needed to pump it in or out of the cell Transport in Vesicles (which includes 3 types) A vesicle is a small sphericals sac Endocytosis - where extracellular materials are brought into a cell in a vesicle formed by the plasma membrane. It is also done in greater volume than normal in mass quantities Phagocytosis (a form of endocytosis) where the cell engulfs large solid particles like bacteria and viruses and have the lysosomes come in and break it down, kill and clean it Exocytosis - where vesicles formed in a cell fuse with the plasma membrane and release materials out of the cell. The golgi would package it, fuse it with the plasma membrane, export and release materials out via a vesicle Identify and briefly describe the three main types of Cell Junctions Tight Junctions - prevent the passage of substances between cells. E.g. cells line the bladder, preventing materials in the bladder from leaking and circulating into the body Anchoring Junctions - anchors cells to one another e.g. creates a point of contact between two cell membranes. If you twist it they will maintain the same relationship and revert back to the original contact. E.g. twisting skin cells Gap Junctions - provides channels to allow substances to pass between cells for rapid communication. Gap junctions are small holes. E.g. the cells in the chambers of your heart beat together. Those cells talk to each other and have gap junctions that contract at the same time Epithelial Tissues Describe what are Epithelial Tissues and give two examples of where they are found Epithelial tissues are tissues that cover the body surfaces, line the hollow organs, and form glands. They function as selective barriers. Found on the skin, gastrointestinal tract etc. What are the key features of the structure and blood supply in epithelial tissue? Epithelial tissue is free/apical (not in contact with another cell), lateral (connects with other epithelial cells) and contains basal surfaces (connected to connective tissue, holding the epithelial tissue in place) avascular which means it has no blood supply. Define and explain the function of a basement membrane Basement membrane is a thin layer that anchors the epithelial cells to the underlying connective tissue. Gives directions for cells for wound healing, holds vasculature of cell, acts as base for cells for growth Identify and describe the ways we classify Epithelial Tissue We classify epithelial tissue through layering and shape Layering Simple - means one layer Pseudostratified - single layer, but not every cell has a free surface Stratified - more than one layer. Bacteria would have to go through multiple defenses. Found in lungs and skin. Shape Squamous - flat and thin rapid movement of substances (simple), protection (stratified). E.g. gas exchange in lungs is simple squamous epithelial. Cuboidal - cube or hexagon shaped, free surface may have microvilli, good for secretion or absorption e.g. the GI Tract Columnar - similar to cuboidal but has more substances, taller and wider, free surface may have cilia or microvilli, good for secretion or absorption. Define what is a gland One or more cells that make and secrete a particular product What is the difference between the exocrine and endocrine glands? Give one example for each Exocrine glands are free surface glands secrete their products into ducts that empty onto the epithelial surface. For example, sweat, salivary and oil Endocrine glands secrete their products into interstitial fluid and diffuse directly into the bloodstream without flowing through a duct. For example, pituitary, thyroid and adrenals Connective Tissues Define the extracellular matrix and what does it consist of?* Extracellular matrix is the material between the cells which is plasma, has a good blood supply and has a nerve supply. Contains scaffolding like protein fibers (different types of protein), ground substances (fluidish environment in which the fibers exist). Identify and explain what are the three types of Protein Fibers? Collagen Fibers - white, very strong, resist tensile (pulling). Found in the tendon. Fiber arrangement is determined by forces acting on the fibers based on Wolff's law. If collagen fiber breaks, scar tissue fixes it up with a scar mess (prone to retearing). What we do in therapy is to prevent reinjury with gentle movements before scar tissue comes in. Reticular Fibers - thin, fine collagen fibers that form branching networks, and form mesh like structures. Found in lymph nodes and spleen which filters blood. Elastin Fibers - yellow, smaller than collagen, strong but stretchy. Found in lungs and the skin. For example breath recoil comes from elastin when you breath in/out Define a ground substance * Ground substance of an extracellular matrix is a fluid, gel-like or calcified, that supports cells and fills the space between fibers and cells. Substances are exchanged between blood and cells Explain what is Wolff’s law and give one example that applies to the law Wolff’s law is when the arrangement of fibers is based on the forces acting on the fibers - page 28 Technical term - Wolff’s law is the idea that natural healthy bones will adapt and change to adapt to the stress that it is subjected to. For example, if the bones are subjected to heavier and heavier loads, they will naturally reconstruct themselves to accommodate that weight. This is how bones respond to stress Identify the 5 types of Connective Tissue Cells Fibroblasts - present in all connective tissue, they produce protein fibers, elastin and ground substance* Macrophages - eats bacteria and cellular debris Plasma cells - secrete antibodies (part of immune response)* Mast cells - make histamine (part of an inflammatory response) Adipocytes - cells that store fat Identify and explain 5 types of of Connective Tissue and their subtypes Loose (areolar, adipose, reticular) - contains more cells, fewer fibers, loosely intertwined -areolar: found everywhere/most widely distributed, provide strength, elasticity support -adipose: found beneath skin and around some organs like kidney, heart, behind eye. Provides thermoregulation, support and protection -reticular: found in liver, spleen, lymph nodes, basement membrane, around blood vessels and muscles. Forms supporting network of organs, binds smooth muscles, filters and removes old blood cells and microbes Dense (regular, irregular, elastic) - have greater density of collagen fibers and fewer cells -regular: collagen is arranged in parallel patterns. Found in tendons and ligaments. Very strong, but act as pliable structural connections e.g. muscle contraction -irregular: collagen is arranged in random/irregular patterns, found in areas of structure and support. Provides tensibility (pulling strength in many directions). For example, joint capsules are dense irregular tissues, fibers in shoulder joints go in all sorts of directions. Or any joint that is capable of circumduction movements -elastic: high elastic content, found in lung tissue, arteries, ligaments between vertebrae. Provides stretch and recoil. For example, the artery squeezes blood which goes through the aorta. Aorta has elastin fibers which makes it recoil and go back to its original shape thereby pushing blood along Bone/Osseous tissue - fewer cells with large amounts of collagen fibers. Matrix filled with calcium phosphate salts which make it VERY hard. Provide protection, support and movement Cartilage (hyaline, fibrocartilage, elastic) -hyaline: most common cartilage, blue white appearance, found on ends of bones, parts of the ribs, tip of nose, parts of throat and lungs, fetal skeleton. Provide flexibility, support, friction reduction and shock absorption -fibrocartilage: has a little more cartilage than hyaline. found between vertebrae (intervertebral discs), public symphysis, menisci. Provides support -elastic cartilage: contains elastin fibers, found in the external ear, epiglottis, provides support and flexibility while maintaining shape. For example helps air go into lungs, food down the throat Liquid (blood, lymph) -blood: cells include red blood cells, white blood cells and platelets. Acts as a transport system -lymph: plasma-like fluid in lymphatic vessels. Provides immunity, transportation and fluid regulation Identify and explain the 3 types of Muscle Tissues Skeletals (striated, voluntary, compartmentalized, attached to skeleton cylindrical, movement, heat) - are compartmentalized by CT, they are attached to the skeleton and some are attached to the skin. The cell structure is cylindrical and can be quite long. Its role is to include movement and for heat production. Cardiac (striated, involuntary, branches, bloods flow and propulsion) - The cell structure is branched striated fibers that fit tightly together, they are found ONLY in the heart and we have involuntary control of them. Their purpose is for blood flow and propulsion e.g. structure is like a tree and its branches, branches connect and communicate, chambers of heart contract at the same time, gap junction stuff Smooth (not striated, involuntary, spindled, constrict tubes, movement of substance) - It is *spindle shaped, found in the walls of hollow tubes (lungs, blood vessels, stomach, intestines. We have involuntary control and they serve to constrict tubes, movement of substances through these tubes e.g. when tubes are tensed they constrict, when tubes are relaxed they expand, e.g. esophagus transitions down from skeletal to smooth Identify the 2 types of Nervous Tissue and their subtypes Neuroglia (glia means glue) supports, nourishes and protects the nervous system. They support the neurons Neurons are nerve cells and have 3 subtypes: Dendrite (input) are single or multiple extensions off the cell body. Its function is to input information in a portion of the neuron (?) Cell body/soma/perikaryon (control) - contains a nucleus and other organelles. This is where the cell processes begin e.g. protein synthesis Axon (output) - a thin cylindrical process off the cell body, its function is to output information from a portion of the neuron (?) ***black arrows tell you the direction of communication on a quiz Mod 2 - Fascia Describe the two definitions of Fascia? Anatomical Definition (identification of fascia - cadaveric dissection, imaging, tissue sampling for pathology) - a fascia is a sheath, or any other dissectible aggregation of connective tissue that forms BENEATH the skin to attach, enclose and separate muscle and other internal organs Functional Definition (describe functions/systems/nets) - Fascial system consists of a 3-dimensional continuum of soft, collagen-containing loose and dense fibrous connective tissues that permeate the body. The fascial system surrounds, interweaves between and interpenetrates all organs, muscles, bones and nerve fibers, endowing the body with a functional structure, and providing an environment that enables all body systems to operate in an integrated manner. Identify the three types of Fascia? Superficial fascia (below skin) - connective tissue that is often referred to as adipose - beneath the skin, e.g. loose adipose connective tissue just below skin you could call it superficial fascia Visceral/Subserous fascia (organs) - connective tissue that suspends the organs within their cavities and wraps them in layers of connective tissue membranes Deep fascia (muscle) - dense irregular connective tissue that gives form and support for underlying organs, can have areolar connective tissue continuous with it What are the 4 main purposes of Fascia? Fascia provides support and definition (shape), compartmentalization, acts as a force transmission (contraction, cytoskeleton in the deep fascia), and connection (lungs and heart, arteries and vein, everything is interconnected) Define compartment syndrome Discomfort from muscles contracting pressing on nerves and blood vessels Explain the difference between Tensegrity and Biotensegrity of Fascia Tensegrity is the support and structures that muscles and fascia give to the body that enables posture and therefore function. e.g The musculoskeletal system is strengthened by the unison of tensioned muscles, connective tissue and compressed bone parts Biotensegrity is the forces that our bodies are subjected to throughout the day that require continuous shifts in tension. e.g inappropriate changes in the tension of muscle and fascia will negatively affect the overall structure and function. The correct tension in muscle and fascia will positively affect the overall structure and function. For example, when you stretch something, something else shortens, if you create compression here, you’ll get tension elsewhere. By correcting the strength, you can maintain tension. If you have tightness from the front, you are lengthening your back, observation would see to it that you are not short, but in a shortened position. Adaptive Qualities of Fascia Define Thixotropy and briefly explain its pros and cons Thixotropy is the property of gels or fluids becoming fluid when stirred or shaken and more solid when at rest. In a massage therapy setting, preparing fascia prior to treatment makes our treatment more effective Pros - fascia is in a more appropriate less-viscous (relative thickness) state when warmed and/or with movement. It becomes more adaptable, durable and healthier. Because its healthier it recovers faster, gets in more nutrients Cons - we will become less active, assume postures that encourage gel-like state. With disuse, fascia will gradually lose its pliability, tissue is not as healthy and age has a similar effect lol Define Bonding and briefly explain its pros and cons First, bonds between molecules are what help make a collagen fiber, fibers bond together to give tissue structure and strength Pros - connections are beneficial, good for wound healing, tissue strength and tissue adaptation Cons - over time collagen fibers will pack more tightly and form more bonds. Areas thicken, stiffen and lose their ability to move and thereby limit function. Happens more readily in areas of high stress and compression in areas of disuse, also happens with dehydration Clinical Implications of Fascia What are 4 ways in which Fascia can be negatively affected? Immobilization - where tissue is fragile and adhesions form decreasing function Inactivity - will weaken the tissue, and activity strengthens the tissue Age - tensile strength decreases with age, adaptive qualities decrease as well Medications - can lead to locally and/or systemically weakened tissue Some Interesting tidbits of Fascia Fascia needs to be challenged to effect a change, restrictions in one segment of fascia can affect other segments. Site of dysfunction is not necessarily the source of dysfunction. Mod 3 - Membranes Identify and describe the 4 different types of membranes Mucous Membrane - lines a body cavity that opens directly to the exterior. It protects and provides absorption Serous Membrane (2 layers) - lines a body cavity that DOES NOT open directly to the exterior, also covers organs within the cavity e.g. thoracic and abdominal cavities -parietal layer - lines the cavity wall. Serous membrane is bound to the cavity wall. For example, abdominal cavity made up of the spine in the back, muscles from the front and side. -visceral layer - covers and adheres the organs in the cavity - bound to the organ itself Cutaneous Membrane - made up of the epidermis and dermis, has epithelial tissue. There is fatty tissue from a fascial perspective called superficial fascia, and if looking at fascia from a holistic perspective (cellular), its called loose adipose fascia Synovial Membrane - these line freely movable joint cavities and is made up of a layer of synoviocytes with a connective tissue base. The synovial fluid lubes and nourishes joint cartilage and contains macrophages that help fight infections and clean up within the joint cavity. DOES NOT open to the exterior. Has no epithelial tissue. Synovial fluid is made by synoviocytes Integumentary system (skin system) Identify the main features of the integumentary system Structure - is from superficial to deep Epidermis - most superficial layer of skin Dermis - inner thickest layer of skin Subcutaneous tissue/superficial fascia/loose adipose connective tissue/hypodermis Describe and explain the 4 main functions of the skin* Protection - provides barrier, cushioning, monitoring, UV protection, thermoregulation Blood reservoir - blood needs to move around the body, when doing nothing blood is put in the skin as a blood reservoir Excretion - done through production of sweat by sweat glands Vitamin synthesis - process of making vitamin d, , starts in the skin Explain the difference between the Epidermis and Dermis The Epidermis is the superficial layer of the skin. Squamous epithelial tissue is avascular whereas the Dermis is a thicker layer, made up of loose areolar, and dense irregular connective tissue. Deeper to the epidermis and superficial to the loose adipose layer. Provides a lot of strength to the skin Identify and describe the 4 Epidermal Cells Keratinocytes are the majority of the epidermal cells. They produce keratin. The deeper cells constantly divide Melanocytes produce melanin which is a protein made up by melanocytes. Its a pigment that gives us the color of our skin. Melanin comes out of arm like structures of melanocytes and are secreted into skin Langerhans Cells are responsible for recognizing foreign and harmful antigens and helping remove them. For example, for viruses that try to get into the bloodstream, Langerhan cells will locate, report it to the nervous system and assist in destroying bacteria/viruses Merkel Cells are receptors detecting the sensation of light touch. They have wriggly arms. A sensory neuron is attached to a merkel cell and that cell has capacity when it is squashed to send communication along sensory neurons that goes to the brain. For example, they tell the brain somebody’s touching the back of their hand. Identify and describe the 5 Epidermal layers from deepest to superficial Stratum Basale - is the base layer consisting of single row keratinocytes anchored to the basement of the membrane. The keratinocytes are constantly dividing under continuous mitosis in order to replenish your skin. It has the best access to blood supply which is next to the dermis Stratum Spinosum - stuff between the keratinocytes. It provides strength and flexibility, have a whole bunch of anchoring junctions, tension on those anchoring junctions there will be a sharp spiny appearance Stratum Granulosum - these cells are dying because they need access to a blood supply. Compromised ability to get rid of waste. They clump together they look like granules Stratum Lucidum - flat dead keratinocytes (extra layer of skin like palm of hands and on the sole of the foot, epidermis will be a little thicker. Structure of rough ER and mitochondria are broken down, nothing is left, they are clear. Stratum Corneum - most superficial layer, are flat dead keratinocytes (really dead as mentioned by Peter) that are shed. Even anchoring junctions are breaking down, you lose connection between cells so you get a cell that is curled alongside another cell which look like horns Identify and describe what the Dermis consist of (5 things) Blood vessels/nerves Free nerve endings - most common nerve endings which extend into the middle of the epidermis that transmit pain and temperature to the brain Sweat and Oil glands and Hair - are also embedded in the dermis and continue through to the epidermis Meissner corpuscles - are touch receptors which are structures designed for a deeper level of touch Pacinian Corpuscles - receptors that transmit pressure, vibration to the brain Identify and explain the types of skin color there are based on the function of melanin Skin color is a function of genetics. We can use coloring of the skin to determine if there is a recent or old injury yellow/orange - carotene, for example eating too much orange and yellow vegetables makes your hands yellow/orange red/pink - hemoglobin, for example, a protein that allows you to carry oxygen. Oxygen + hemoglobin makes the red color redness - inflammatory response blue - cyanosis - NOT GOOD. For example, if you see it on the lips, call 911. It means that person is not getting enough oxygen. blue/black - new bruising yellow/green - old bruising yellow - Jaundice - for example, means the liver is damaged if you see yellow in the eye. Appendages of the Skin Identify the 3 appendages of the skin Hair, Glands, Nails Identify and describe the 6 components of Hair Hair functions to protect the scalp, eyelashes, filtration, thermoregulation and sensation Root - is the part of the hair deep to the shaft that penetrates into the dermis Shaft - portion of the hair the projects beyond the skin surface Follicle - tube-like structure that surrounds the root and strand of the hair Arrector pili muscle - when it contracts, it pulls hair from bent position to vertical position, helps shaft extend farther out, you can see more, it traps air close to the skin. For example, contraction for thermoregulation, hairs sticking out for warding off predators and goosebumps Sebaceous glands - makes oil, the oil is secreted onto hair and some onto skin. Lubricates the hair and helps prevent it from becoming brittle Hair Color - function of melanin which is a function of your genetics. Describe and explain the arrector pili muscle The arrector pili muscle is a small band of smooth muscle that connects the hair follicle to the connective tissue of the basement membrane. It mediates thermoregulation by contracting to increase air-trapping Identify and explain the 3 types of Glands in the Appendages of Skin Sebaceous glands (sebum/oil) - secrete sebum which is an oily waxy substance. Found all over the skin EXCEPT palms and soles of your feet. Sebum keeps the skin moist, prevents hair from becoming dry/brittle and kills surface bacteria Sudoriferous glands (sweat) - sweat is released through pores and sometimes hair follicles. Functions as a means of thermoregulation. Ceruminous glands (ear) - found in external ear, produce cerumen (ear wax), which prevents foreign bodies from entering the air Describe what Nails consist of and their function Nails contain hardened plates of tightly packed, hard and dead keratinized epidermal cells which function as protection, small object manipulation, scratching, and also show the health status information of a person. The base of the nail is part of the epidermis, and the ends are stratum corneum dead keratinocytes. What do you call the area underneath the nail where bacteria gets trapped? Keep your nails short as a RMT because the hyponychium which is the area underneath the nail is where bacteria gets trapped. Describe 3 ways the Sun can damage the Skin Acute overexposure - overexposure to UV radiation can weaken the immune system, reducing the skin’s ability to protect against invaders. For example, Sunburn is a type of radiation burn that affects skin due to overexposure of solar UVR. It is characterized by erythema, a well-known acute cutaneous response to UVR (redness of the skin via inflammation reaction DNA damage - Long term UV exposure precipitates genetic alterations in skin cells, encouraging benign and malignant neoplastic growth (abnormal mass of tissue that forms when cells grow and divide more than they should or do not die when they should. Malignant being cancer). Collagen and elastin fiber damage - prolonged exposure in the sun gives off poor health appearance in skin Describe 4 ways in which Aging can damage the Skin Collagen fibers decrease in number and are not as functional Elastin loses its elasticity Fibroblasts decrease in number Skin becomes thinner Mod 4 - Skeletal System Define a long bone A bone that has a shaft and 2 ends that is longer than it is wide. Long bones have a thick outside layer of compact bone and an inner medullary cavity containing bone marrow. The ends of long bone contain spongy bone and an epiphyseal line. Includes humerus, ulna, radius, femur, tibia, fibula, phalanges, metatarsals, metacarpals and clavicles Identify the 3 regions in the bone and their main features (draw out) Diaphysis -medullary cavity (space that contains red (blood cell formation) and yellow marrow (fat storage)) Epiphyses -articular cartilage (hyaline cartilage covering epiphysis) Metaphyses -EGP (cartilaginous area of a growing bone), epiphyseal line (where metaphysis turns into epiphyses) What is the connective tissue layer that surrounds the outer layer of bone? Periosteum Which part of the bone contains yellow marrow? Long bones - shin, NOT hip ribs, skull Generic Long Bone stuff Periosteum surround bone up to articular cartilage Bone is CT, and is 25% water/ 25% collagen/ 50% mineral salts Long bones lengthen at EPG, thicken by osteoblasts in periosteum Long bone is constantly in a state Identify the 4 types of bone cells Osteoprogenitor/Osteogenic - active during normal growth, healing, cyclical bone replacement Osteoblasts - bone building cells Osteocytes - mature bone cells Osteoclasts - bone eating cells Identify the 2 types of Bone Compact Spongy Identify the 6 structures in compact bone (draw out) Osteon - cylindrical shape, go along lines of stress Central Canal - hole through osteon through which blood and lymphatic vessels run Concentric Lamellae - rings of hard, calcified bone matrix around the central canal like the rings of a tree Lacunae - spaces between the concentric lamellae rings. Inside are osteocytes Canaliculi - channels between rings of calcified bone in all directions. Filled with extracellular fluid. Osteocytes send their extensions and communicate through gap junctions in order to maintain homeostasis Volkmann’s Canals - holes which run transversely to connect inner and outer portions of the bone Identify the 4 main features of Spongy bone -trabeculae which contain osteocytes in lacunae connected by canaliculi -lighter than compact bone -spaces can contain red bone marrow -designed for lower stresses or stressors from different directions (dense irregular CT) Describe the Bone blood supply -vascularized -metaphyseal arteries supply metaphysis -epiphyseal arteries supply epiphysis -periosteal arteries enter diaphysis at multiple points to supply periosteum and outer compact bone -nutrient arteries enter diaphysis via nutrient foramen to supply inner compact bone Describe the effects of Aging on Bone growth* -from birth to adolescence, bone growth is greater than bone loss -young adults bone growth is equal to bone loss -middle age, bone loss exceeds bone growth (age 25, systems drop off) Mod 5 - Nervous System What are the 2 types of Nervous Systems and what do they each contain? Central Nervous System - brain, spinal cord Peripheral Nervous System - nervous tissue outside of CNS, e.g. cranial and spinal nerves, ganglia, enteric plexuses in small intestine, sensory receptors in skin What are the 3 functions of the Nervous System Sensory (towards) - input Integrative (within) - processing, storing, decision making Motor (away) - output Identify the 2 types of nervous tissue cells and their subtypes Neuroglia - supports, nourishes and protects Neurons -dendrites -body/soma/perikaryon -axon Describe the main features of an Axon (draw out) axon terminals: end of axon divides into many fine processes called axon terminals. synaptic end bulb: swollen ends of axon terminals myelin: some axons are a lipid protein wrapping called myelin. Myelin speeds up communication via electricity action potential: one shot of electricity is an action potential. Travels along the cell membrane of a neuron. Travel speed depends on whether they have myelin. Describe Myelination myelin is a multilayered lipid and protein covering of the axon that speeds up signal (actional potential) conduction - myelinated axons. Identify and explain the 3 Structural Classifications of Neurons Unipolar - sensory neurons (periphery axon has sensory receptors) Bipolar - neuron with one main dendrite and one axon (uncommon, found in the eye) Multipolar - motor neurons, and interneurons (several dendrites and one axon) we Identify and explain the 3 Functional Classifications of Neurons Sensory (afferent) - towards CNS from receptors Motor (efferent) - away from CNS to effectors Interneurons (association) - primarily in CNS between sensory and motor Identify describe the 2 types of Synapses (draw out) Electrical - APs conduct directly between plasma membranes of adjacent cells through gap junctions Chemical - when AP reaches the end of the presynaptic neuron (neuron sending the signal), it causes the release of a neurotransmitter that diffuses across the synaptic cleft (space between communicating neurons), binds to the postsynaptic neuron (neuron receiving the signal) Presynaptic converts electrical signal into chemical -> postsynaptic converts chemical back into electrical Explain the difference between an excitatory and inhibitory neurotransmitter -if neurotransmitter is excitatory, continuation of the AP is more likely -if neurotransmitter is inhibitory, continuation of the AP is less likely Neurotransmitter definition - chemical released by the presynaptic neuron to affect (excite or inhibit) the post-synaptic neurons or effector Identify the 4 common neurotransmitters and their function Acetylcholine (ACh) - CNS/PNS, excitatory at neuromuscular junction Gamma aminobutyric acid (GABA) - CNS, inhibitory Dopamine - excitatory or inhibitory (depending on receptor), emotional responses, addictive behaviors, skeletal muscle tone Serotonin - excitatory or inhibitory (depending on receptor), sensory perception, temp regulation, mood, sleep, appetite Identify the 4 types of neuroglia of the CNS Astrocytes - helps form bbb, provide nutrients to neurons Oligodendrocytes - form/maintains the myelin sheath of CNS neurons Microglia - phagocytic cells which remove debris, phagocytize microbes Ependymal cells - line cavities of brain and spinal cord, produce and assist circulation of CSF, protects brain and spinal cord from injury Identify the 1 type of neuroglia of the PNS Schwann cells - encircle axons in PNS, form myelin sheath of PNS axons, regen of PNS axons Define the following terms Nucleus - cluster of neuronal cell bodies in the CNS Ganglion - a cluster of neuronal cell bodies in the PNS Tract - a bundle of axons in the CNS Nerve - a bundle of axons in the PNS Grey matter - collections of cell bodies and UNMYELINATED nerve fibers in the CNS White matter - collections of MYELINATED axons in the CNS Explain the structure of the spinal cord and its 3 main spinal regions (draw out) -Spinal cord is encased in the vertebrae and extends from the bottom part of the brainstem to the 2nd lumbar vertebrae (L2). -At L2, it tapes into a structure called the conus medullaris -Cauda equina are the roots below the conus medullaris (technically peripheral nervous system) Cervical Spine - C1-C7 Thoracic Spine - T1-T12 Lumbar Spine - L1-L5 Identify and describe the 3 horns in the region of gray matter in a spinal cord (draw out) Posterior (dorsal) horn - axons of incoming sensory neurons and interneurons Anterior (ventral) horn - motor nuclei out going Lateral horn - sympathetic nuclei (upper lumbar, sacral portion) Identify and describe the 2 features in the region of white matter in a spinal cord (draw out) 3 regional columns - anterior, posterior, lateral Columns - bundles of axons (tracts) that have a common origin or destination -Sensory (ascending) tracts consist of axons that conduct AP toward the brain -Motor (descending) tracts consist of axons that conduct ap away from the brain Briefly explain the difference between anterior median fissure and posterior median sulcus Anterior median fissure is the anterior slit-like opening in the spinal cord, and posterior median sulcus is the posterior back end slit. Identify the 4 structures of the Brain and their subtypes (draw out) Brain Stem (4) Medulla oblongata - heart rate, blood pressure, breathing, swallowing and vomiting Pons - control of breathing Midbrain - hearing, reflex visual activities, contains substantia nigra (neurons that make dopamine extend from it) Reticular formation - contains reticular activating system (consciousness, maintaining attention, prevent sensory overload, regulate muscle tone) Cerebellum -smooths and coordinates skeletal muscle contraction, regulates posture and balance Diencephalon (3) Hypothalamus - homeostasis, controls ANS, hormone production, emotion and behavior, eating, drinking, body temp, circadian rhythm Thalamus - major relay for most sensory input to cerebral cortex Epithalamus - contains pineal gland (smelling, emotional response to smelling) Cerebrum (3) Cerebral cortex - sensory areas involved in perception, motor areas involved in execution of voluntary movements (gray matter) Association areas (white matter) - memory, emotions, reasoning, will, judgment, personality traits, intelligence Basal Ganglia - start/stop movements, helps control subconscious contraction of skeletal muscles, helps suppress unwanted movement, set resting muscle tone, basal ganglia are linked to substantia nigra (gray matter) Identify the 2 structures the limbic system consists of Limbic system - emotion, smelling, memory Hippocampus - functions in memory (encoding, consolidation, retrieval), converts short term to long term memory Amygdala - important in emotional function, esp fear In the Connective Tissues of the CNS what are the 3 types of Meninges (brain and sc)? Dura Mater - outer layer, bound to skull Arachnoid membrane - middle layer, space in between Pia mater - inner layer, right on spinal cord What are the 4 types of Nervous Tissue outside of the CNS? (PNS) Cranial Nerves - nerves connect brain to periphery Spinal Nerves - nerves connect the spinal cord to the periphery Ganglia - cluster of neuronal cell bodies in the PNS Sensory Receptors Explain the structure of spinal nerves -1st pair of cervical nerves emerge from SC between base of skull and 1st cervical vertebra -c1-c7 exit the spine above corresponding vertebra -c8 exits between c7 and t1 vertebrae -T1-L5 exit below their corresponding vertebra -not all are aligned with their corresponding vertebra - e.g. lumbar, sacral, and coccygeal nerves descend from L2 to their respective levels Define the following terms for spinal nerve roots (axons) Nerve root - two bundles of axons that connect the spinal nerve to SC Anterior (ventral) root - a bundle of motor axons Posterior (dorsal) root - a bundle of sensory axons posterior/dorsal root ganglion - a swelling in the posterior root containing cell bodies of sensory (unipolar, primary afferent) neurons of the PNS Identify the 3 types of connective tissues of a spinal nerve Epineurium - outermost layer, covers spinal nerve Perineurium - middle layer, covers fascicles (bundle of axons) Endoneurium - innermost, covers axon (whether myelinated or not) Perineurium and epineurium are highly vascularized Identify and describe the 2 subdivisions of the Peripheral Nervous System and their subtypes Somatic Nervous System (voluntary) - sensory neurons convey info to CNS, motor neurons conduct impulses from CNS to SKELETAL MUSCLES ONLY Autonomic Nervous System (2 divisions) (involuntary) - monitors (sensory) and controls (motor) body activities automatically Sympathetic Nervous System (fight or flight or freeze) - responding to physical threat, pupil dilation, increased heart rate, bp, pupil and airway dilation, vasodilation of skeletal and cardiac, glucose release, vasoconstriction in kidneys and digestive tract Parasympathetic Nervous System (rest and digest) - conserves and restore energy systems, increased digestive and urinary functions Explain the difference between autonomic tone and autonomic control Autonomic Tone -balance between sympathetic and parasympathetic nervous systems, for normal function there needs to be a balance. -effects of sympathetic stimulation last longer and are more widespread than the effects of parasympathetic stimulation Autonomic Control -is a major control and integration center for ANS is the hypothalamus Describe the Enteric Nervous System (autonomic nervous system, but recently is its own system) -sensory neurons that monitor chemical changes within GI tract and stretching of its wall - “brain of the gut” -motor neurons control contract of GI tract, its smooth muscles, and secretions of GI organs Identify and describe 2 main types of processing for input and output in the spinal cord Sensory input (3) -axon extends into white matter and travels up brain (same side) -axon enters dorsal horn and synapses with interneuron, crosses over to white matter and goes up brain (opposite side) -axon enters dorsal horn and synapses with interneuron, which then synapses with a somatic motor neuron in the ventral horn as part of a spinal reflex pathway Motor output (2) Somatic - axons from motor tract synapse with somatic motor neurons in ventral horn on contralateral side - (voluntary, skeletal muscle tissues) Autonomic - axons of autonomic motor neurons synapse with another group of autonomic motor neurons, innervating cardiac, smooth muscles and glands. - (involuntary, cardiac, smooth muscle tissues) Briefly describe the metabolic requirements for nervous tissue -only use glucose as an energy substrate, but cannot store glycogen -can only be obtained through the bloodstream or neuroglia cells Briefly describe regen and repair of nervous tissues -although nervous tissue can readily adapt, it has limited ability to regen -in the PNS, damage to dendrites and myelination can be repaired if the cell body is intact and schwann cells are active -in the CNS, little or no repair of damaged neurons occur Mod 6 - Muscle Identify and explain the 4 characteristics of Muscle Tissue (4) Electrical excitability - the ability to respond to certain stimuli by producing electrical signals. These signals are called Action Potentials (AP) Contractility - ability of muscle tissue to generate tension (force) when stimulated by an AP Extensibility - ability of muscle to stretch (lengthen) without being damaged. Muscle can still contract when stretched Elasticity - ability of muscle to return to its original shape after contraction Describe the hierarchy of skeletal muscle (4) Muscle - which subdivide into bundles of fascicles Fascicle - which is made up of many muscle fibers Muscle Fiber - cylindrical in shape and have lots of mitochondria, are multinucleated and filled with myofibrils Myofibril - specialized contractile organelles of the muscle cell, they extend the length of the muscle fiber/cell. Myofibrils are held in place by cytoskeletal proteins. Myofibrils are composed of a number of sarcomeres arranged in series (end-to-end) Sarcomere - basic contractile unit of muscle fiber Other Structures include Sarcolemma - cell (plasma) membrane of the muscle cell Transverse Tubules - tiny invaginations that tunnel in from the sarcolemma towards the center of the muscle fiber Sarcoplasm - cytoplasm of the muscle fibers which contain lots of glycogen Myoglobin - protein that binds oxygen that has diffused into the muscle fiber and delivers it into the mitochondria Sarcoplasmic reticulum - fluid filled tubes and sacs running along and surrounding each myofibrils which store and release calcium into the cell (when needed) Describe a Sarcomere and Identify its 2 contractile proteins (2) Actin - thin filaments Myosin - thick filaments Actin are thin filaments and Myosin are thick filaments. These overlap and their interaction is what generates force/contraction. The overlap also creates light and dark strips which gives skeletal muscle its striated appearance. Explain how tension is generated through chemical synapses and the sliding filament mechanism. Stimulation from motor neuron -> NMJ to sarcolemma First, skeletal muscle cells must be stimulated by a nerve signal from a motor neuron. The axon connects with the muscle when it reaches the muscle and branches out into a number of axon terminals. Each axon terminal forms a junction called the Neuromuscular Junction (NMJ) with the sarcolemma of a number of different muscle cells. Signal arrives, neurotransmitter released -> crosses synaptic cleft The axon terminal and sarcolemma never actually touch - there is a gap between them called the synaptic cleft. When the signal arrives, it releases a neurotransmitter (ACh) which crosses the synaptic cleft. Signal stimulates sarcolemma and muscle fibers, travels down t-tubules and stimulates SR to release calcium When the signal crosses the synaptic cleft, it stimulates the sarcolemma (cell membrane). The signal is then continued by the muscle fibers (electrical excitability) and spreads out across the sarcolemma. The signal then travels down the transverse tubules and stimulates the sarcoplasmic reticulum to release calcium Calcium released -> sliding filament mechanism Calcium release allows myosin (thick filaments) to connect with actin (thin filaments). With repetition, it shortens the sarcomere, myofibril, and muscle fiber and the entire muscle. In order to disengage the pull, ATP is used. When APs stop, SR takes back calcium (using ATP). Without sufficient calcium, thick filaments cannot continue pulling thin filaments and tension generation stops. Explain the difference between a motor neuron and a motor unit A motor neuron is a neuron/nerve cell that conducts Action Potentials to muscle cells whereas a motor unit includes the motor neuron and all the skeletal muscle fibers it innervates. Identify and describe the 3 ways Muscle fibers reforms ATP (3) Creatine Phosphate (phosphocreatine, ATP-PCr, anaerobic alactic) stores high amounts of energy in its chemical bonds. When PCr is split by an enzyme, energy is released to reform ATP. This happens very fast therefore PCr is considered the first source of energy used when muscle contraction begins. -provides 3-15 seconds of maximal contraction -NO oxygen needed (anaerobic) -no lactic acid produced (alactic) Anaerobic glycolysis (anaerobic lactic) - when muscle activity continues and PCr is depleted, glucose is used to make ATP. cells break down glycogen stored in their cytoplasm/sarcoplasm or glucose from the blood and the energy release in breaking them down is used to reform ADP + Pi. Lactic acid diffuses out of the cell into the blood. Glycolysis - process of making ATP from glucose occurs in the cell cytoplasm. A molecule of glucose is broken into 2 molecules of pyruvic acid and 2-3 ATP. Anaerobic - during heavy exercise/demand, not enough oxygen is available Anaerobic lactic - no oxygen required and producing lactic acid Lactic Acid/Lactate - a metabolic by-product of anaerobic glycolysis. At lower levels of activity, any lactate produced is consumed by other muscle fibers, less active nearby muscles and the heart so lactate does not accumulate. It is also converted back into a glucose/glycogen in the liver (Cori Cycle). Lactic has a half life of 15-25 minutes and is cleared in a matter of hours -capable of supplying energy for 30-40 seconds Aerobic cellular respiration - Pyruvic acid enters the mitochondria when it undergoes a series of reactions (that require oxygen). This pathway is active when you are able to get oxygen into the cells (at rest or at low moderate intensity exercise). Oxygen is delivered by myoglobin or from oxygen diffusing from the blood. In the presence of oxygen, pyruvic acid enters the mitochondria in a series of reactions (that use oxygen), producing much more ATP (much more than glycolysis). At rest, cells of the body use aerobic metabolism to generate their ATP. -carbohydrates yield relatively little ATP -fats yield a lot of ATP -proteins aren’t used readily (often not even included) -in activities that last longer than 10 mins, most (90%) of the ATP generated comes from aerobic system Identify and describe the 3 skeletal muscle fiber types (3) Slow Oxidative (SO) fibers (type 1 - fatigue resistant) -used in endurance type functions (maintaining posture, running marathon) -LOTS of mitochondria, myoglobin, capillaries -generate ATP via aerobic cellular respiration (oxygen is available) -with immobilization, atrophy faster (than type 2 fibers) Fast Oxidative-Glycolytic (FOG) fibers (2a - moderately high resistance to fatigue) -used in endurance and shorter duration functions (walking and sprinting) -intermediate mitochondria, myoglobin, capillaries -generate ATP via aerobic and anaerobic energy pathways Fast Glycolytic (FG) fibers (type 2x - low resistance to fatigue) -used in high intensity, short duration activities (weight lifting, sprinting) -relatively low amounts of mitochondria, myoglobin, capillaries -generate ATP via anaerobic energy pathways (glycolysis) Explain muscle fiber and motor unit recruitment in relation to fine and large movements (2)* (key concept) When AP travels down the motor neuron the muscle fibers (motor unit), all fibers in that motor unit will generate force. Are all motor units recruited with every contraction? Not all motor units are recruited with every contraction, and all motor units recruited for a given action do not contract at the same time. Smallest/weakest motor units (SO) are recruited first Fine Movements Precise movements require small changes in muscle contraction. And muscles that perform fine movements will be made up of small motor units (few muscle fibers/motor units) Large movements Large (imprecise) movements don't require small changes in muscle contraction - they typically require large amounts of tension. Muscles that perform gross movements will be made up of large motor units (many muscle fibers/motor unit) Describe the gradation of force To increase the amount of force generated, we can increase the number of motor units recruited and increase the frequency of neuronal AP firing (wave summation)  Explain the length-tension relationship (3) The forcefulness of contraction (ability to generate force) depends on the length of the sarcomeres within a muscle before the contraction begins. Optimal overlap (resting length) - greatest ability to generate tension Minimal overlap (lengthened) - decreased ability to generate tension Excessive overlap - decreased ability to generate tension Identify and briefly describe the 6 types of muscle contractions (6) Isotonic - muscle contraction through a range against a resistance that is not changing concentric - a shortening contraction eccentric - a lengthening contraction Isometric - muscle contraction in which the length of the muscle does not visibly change Isokinetic - muscle contraction through a range in which the equipment keeps the velocity of movement constant Variable resistance - muscle contraction through a range in which the equipment varies the resistance to match the strength curve Describe the following muscle-related terminology Muscle tone - a small amount of tension being generated in the muscle, not strong enough to produce movement. Twitch Contraction - a brief contraction of all muscle fibers in a motor unit in response Flaccidity - a lack of tone from the nerve being damaged or cut Hypertrophy - increase in muscle size Atrophy - decrease in muscle size Fatigue (neurological and CNS fatigue) - inability of a muscle to function at a required level via energy substrate depletion, metabolic by products. E.g. Neurological -> inappropriately training everyday for marathons. CNS -> depression, motivation, lack of will to do exercise Identify the 3 types of connective tissue in muscle (3) Epimysium - surrounds the entire muscle Perimysium - surrounds the fascicles Endomysium - surrounds the muscle fibers Explain the difference between Musculotendinous Junction and Tenoperiosteal Junction MTJ is the transition from muscle to tendon, whereas TPJ is the transition from tendon to periosteum (bone) Briefly explain the role of Satellite cells Satellite cells are undifferentiated muscle cells that are actively involved in muscle repair and regeneration. Their capacity is limited. Explain the structure and role of cardiac muscles Cardiac muscles have the same actin/myosin arrangement as skeletal muscles, although are involuntary based. Fibers are branched - its ends fit tightly together with neighboring fibers at junctions called intercalated discs (connect where one cell fits into another cell). Have lots of gap and anchoring junctions that hold the cells together and allow them to communicate quickly and perform a function together. Explain autorhythmicity There are specialized cells within the heart that can generate their own electrical signals and act as a pacemaker. The cardiac cells change shape and function (resembling nervous system cells) and have the capacity to take on Action Potentials of their own, making it so that the heart can beat on its own. Explain the structure of smooth muscles These are involuntary muscles, and their contractions start slower and last longer. When smooth muscle contracts it contracts in response to being stretched. They have gap junctions, are spindle shaped and are found in the walls of hollow tubes Describe the effect of aging on muscle tissue Capacity for skeletal strength progressively decreases after 25 years. A greater portion is lost at 50. Exercise is beneficial at any age. This is where muscle function converts to strength, and an increase in functional independence. People who are stronger live longer. The adaptation to exercise however is lower and balance can become an issue later in life. Mod 7 - Respiratory System Identify the describe the 4 types of respiration and their subtypes Pulmonary ventilation (2) Inhalation - the flow of air into the LUNGS Exhalation - the flow of air out of the LUNGS Pulmonary respiration - exchange of gasses across the respiratory membrane (barrier between air and blood) Tissue respiration - exchange of gasses between the blood and tissue cells Cellular respiration - the metabolic reactions that consume oxygen and release carbon dioxide in the production of ATP Identify the 2 structural divisions of the respiratory system - draw out Upper respiratory system - nose, pharynx (throat) Lower respiratory system - larynx (voicebox), trachea (windpipe), bronchi, lungs Identify the 2 functional divisions of the respiratory system - draw out Conducting zone (no gas exchange) Includes the nose, pharynx (throat), larynx (voicebox), trachea (windpipe), bronchi, bronchioles (air goes in left and right tubes and continue dividing into smaller and smaller tubes), terminal bronchioles (last part of the conducting zone, after that it divides into the respiratory zone). The role of the conduction zone is to filter air, warms and moistens air before conducting it into the lungs (contains a lot of ciliated cells). It also receives olfactory (smell) stimuli and sound generation for speech (noise are vibrations set up by breathing) Respiratory zone Includes the respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli (grape shaped structures where pulmonary respiration happens) The role of the respiratory zone is the gas exchange inside each of the Alveoli (grape shaped structures) -> oxygen going in, carbon dioxide going out - for gas exchange to happen you need to get air inside alveolus, oxygen then gets diffused in the blood vessels that surround the alveoli Describe the 6 structures of the respiratory system - draw out Nose - has a rich blood supply, houses olfactory receptors, and has sticky mucous which traps particulates Pharynx (throat) - funnel shaped tube behind the nasal cavity and above the larynx. Provides a passageway for air and food, and acts as a resonating chamber for sounds and as housing for the tonsils. On the inferior end, it opens the esophagus (posteriorly) and larynx (anteriorly) Larynx (voicebox) - is inferior to where the pharynx divides. The epiglottis protects the top of the larynx. Provides voice production (vocal folds) and connects to the trachea (inferiorly) Trachea (windpipe) - is anterior to the esophagus. Has fairly rigid c-shaped rings of hyaline cartilage that reinforces and supports its shape and prevents the trachea from collapsing from its “vacuum tube”.Has a VERY IMPORTANT REGION called the mucociliary elevator which acts as a primary site for trapping articulate like dust. Has lots of mucous membrane and ciliated cells. The cilia sweep particulate out of the trachea to the throat for coughing or digestion Bronchi - located at the 5th thoracic vertebra, divides the right and left primary bronchi which travel to the right and left lungs. The carina is an internal ridge where the trachea divides (most sensitive areas of trachea and larynx for triggering cough reflex). Good for tapotement for drainage Lungs - are 2 organs separated by the heart and other structures in the mediastinum (region in the thoracic cavity between the lungs - extends rom the sternum to the vertebrae and from the 1st rib to the diaphragm). If one collapses, the other can still maintain pressure. Within each lung, each bronchus subdivides into smaller and smaller units - secondary, tertiary, bronchioles, and terminal bronchioles. As smooth muscle increases, cartilage decreases. Terminal bronchioles divide further until you get alveoli. Alveoli are cup shaped outpouching lined with simple squamous epithelium supported by a thin elastic basement membrane. Briefly describe Alveolar cells These cells are used for gas exchange (simple squamous epithelium - thin basement membrane which acts as a minimal barrier between substance from one side to another and has a stretchiness to it. Contains surfactant which reduces surface tension of fluid which reduces the tendency of alveoli to collapse. The alveolar macrophages remove dust, fibroblasts make reticular and elastic fibers. Briefly describe the blood supply to the lungs (respiratory membrane) The alveoli are surrounded by capillaries. Gas exchanges happen through simple diffusion across the alveolar and capillary walls which together form the respiratory membrane. The respiratory membrane contains the alveolar epithelium and its underlying basement membrane, and the blood vessel endothelium and its basement membrane. Basement membrane is the peanut butter. Endothelium is the simple squamous epithelium of blood vessel Identify and describe the two types of gas transport (2)* (key concept) Oxygen - carried from lungs to the body tissues bound to hemoglobin part of red blood cells. When oxygen is bound to hemoglobin it turns red (oxygenated blood). For example, having not enough red blood cell concentration can lead to decrease in oxygen carrying capacity and therefore the person will get tired because they cannot make enough ATP through aerobic cellular respiration. Carbon dioxide - carried in the blood in the form of bicarbonate (HC02). Some are carried attached to carboxyhemoglobin. Little is dissolved in the blood and released at the lungs and exhaled. Identify the two types of pleural membranes (2) First of all, each lung is enclosed in, and protected by a double layered serous membrane called the pleural membrane. The pleural cavity, is a space between the visceral and parietal pleura which contains lubricating fluid Explain the 2 types of Ventilation* - ask peter Inhalation - contraction expands the lungs and thoracic cage. As thoracic volume increases, pressure decreases. Air rushes to normalize the pressure Exhalation - a passive process when at rest. Muscles relax, and elastic recoil at the thoracic cage, thoracic volume decreases Visceral pleura - layer of the pleural membrane that covers the lungs Parietal pleura - layer of the pleural membrane that covers the inside of the thoracic cavity Explain the difference between Forced Vital Capacity (FVC) and Forced Expiratory Volume (FEV) and Tidal Volume (TV) FVC is the largest volume of air that can be brought into the lungs FEV is the volume of air that can be exhaled in 1 second (after maximal inhalation) TV is the volume of air in one regular breath Identify and explain the 2 types of control of the respiratory system Central control - respiratory control center that controls the rhythm and rate of breathing, MO, and pons Peripheral chemoreceptors - detect rising concentration of CO2 and H and respond by increasing ventilation Describe the effects of aging on the respiratory system Airways and tissues become less elastic, the chest wall becomes more rigid resulting in decreased lung capacity. Alveolar macrophages are less functional/active and cilia are less functional. This increases the risk of certain respiratory infections such as pneumonia and bronchitis