Physiology Exam 1 Study Guide PDF

# Study Guide ## Cardiovascular System (Week 4) ### General cardiac anatomy and its relation to function 1. Trace the path of a drop of blood as it travels from the vena cava through the heart and into the aorta. This should include the chambers, and the valves it passes through. - Right Atrium...

# Study Guide ## Cardiovascular System (Week 4) ### General cardiac anatomy and its relation to function 1. Trace the path of a drop of blood as it travels from the vena cava through the heart and into the aorta. This should include the chambers, and the valves it passes through. - Right Atrium - Tricuspid Valve - Right Ventricle - Pulmonary Valve (Semilunar) - Pulmonary Artery - Lungs - Pulmonary Vein - Left Atrium - Mitral Valve - Left Ventricle - Aortic Valve (Semilunar) - Aorta 2. Compare and contrast the histology of cardiac muscle to skeletal muscle - Both are striated with actin and myosin - Cardiac muscle has intercalated discs - Cardiac muscle has splitting, syncytial arrangement 3. Describe the function of intercalated discs in relation to electrical conduction within the heart - Communication between cells (rapid diffusion of ions) 4. Describe the function of the papillary muscles and chordae tendinae - Papillary muscles attach to AV valves by chordae tendinae - Prevent bulging towards atria to prevent regurgitation 5. Compare the properties to the semilunar valves and the AV valves, and relate them to their function - AV valves are thin, semilunar valves are built stronger - Faster velocity through semilunar valves - Semilunar valves have more mechanical abrasion - Semilunar valves function passively (high pressure in arteries) without the need for chordae tendinae ### Briefly Describe Blood Flow Distribution at Rest - ~15% to Brain - Absolute volume remains constant - Percentage decreases during exercise - ~5% to Coronary Arteries - Absolute volume increases proportionately during exercise - Myocardium is working harder, so it needs more blood - Percentage remains at 5% during exercise - ~25% to Kidneys ## Cardiovascular System (Week 5) ### Sections 5A (Fluid Compartments) and 5B (Filtration and Reabsorption) #### Fluid volumes and compartments 1. Organize the body's fluid into compartments, and rank the volume within each compartment - Intracellular fluid (MOST FLUID IN BODY) - Extracellular Fluid - Vascular Compartment (THIRD LARGEST FLUID COMPARTMENT) - Plasma is the fluid in this compartment - 99% of plasma is water - Electrolytes are dissolved in this water - Remaining 1% is proteins ("plasma proteins") - Albumin (most abundant) - Transports various hormones and drugs - Globulins - Incudes immunoglobulins (like IgG) - Fibrinogen - For blood clotting - Interstitial Fluids (SECOND LARGEST FLUID COMPARTMENT - DETAILS IN NEXT SECTION) - Water and dissolved electrolytes #### Interstitium 1. Define interstitium, interstitial fluid, and tissue gel - Interstitium - Space between cells - Interstitial fluid - Fluid in the interstitium - Tissue gel - Combination of proteoglycans and the fluid trapped within them 2. Describe the role of proteoglycans in the interstitial space - Provide structure to the interstitum, along with collagen - Interact with water molecules to create a gel - Slow diffusion of water molecules rather than rapid movement 3. Compare free fluid concentration in normal tissue versus edematous tissue - Normal tissue or mild edema - Very little free fluid - Most of fluid is in the form of tissue gel - Moderate to severe edema - Considerable free flowing fluid, not trapped between proteoglycans ## Cardiovascular System (Week 6) ### Neural Control of Blood Pressure #### Reflexes 1. Describe the basic anatomy of a reflex arc (this is not just for the cardiovascular system, but true for ANY reflex) - Afferent component: An input signal, usually from a specialized receptor - Specialized receptor sends signal along afferent nerve, back to CNS - CNS component: The central nervous system (brain and/or spinal cord) interprets the afferent information - Efferent component: An output signal, which travels from the CNS to a target site, and produces a physiologic response 2. Remember - a reflex happens automatically. HOWEVER, higher brain centers can over-ride the reflex - Examples - Knee jerk reflex: - Afferent component - patellar tendon being stretched out by a clinician tapping on it with a specialized hammer - CNS-interpretation is that the tendon is being rapidly stretched, so we must shorten it to prevent injury. So, we send and efferent signal for the quadriceps to contract - Efferent component - the signal telling the quadriceps to contract - OVERRIDE - if you consciously try to stop your quadriceps from contracting, you can do so (pre-motor cortex and motor cortex will send a signal which overrides the efferent component). - Cough/sneeze reflex (to be covered in detail separately): - Think about a time where you have been in a situation where you suddenly need to sneeze or cough, but for whatever reason (usually a social purpose) you fight the urge to do so. That is an example of overriding a reflex with higher brain centers #### Baroreceptor Basics 1. Briefly describe what a baroreceptor is - Specialized receptors which detect changes in blood pressure - Important to recognize they are best at identifying CHANGES in pressure, not what the absolute pressure is - Baroreceptors are CRITICAL for maintaining SHORT-TERM homeostasis of blood pressure - Respond rapidly - not instantaneous, but less than 1 second ## Tissue Types and Cell Injury / Adaptation / Death ### Tissue Types 1. Briefly describe the hierarchy of tissue organization - Chemical level - Atoms combine to form molecules - Cellular level - Cells - Composed of lots of different molecules - Tissue level - Composed of cells AND the extracellular matrix they produce - System level - Composed of lots of different tissue types - For example, our skin includes all of the following tissue types - Epithelial tissue - The "skin cells" (i.e., the epidermis) and their extracellular matrix - Blood vessels - Connective tissue - Loose connective tissue which fills space (i.e., the dermis) and its extracellular matrix, such as areolar tissue - Extracellular matrix includes collagen, elastin, proteoglycans to "glue" all of the cells together - Blood, which supplies nutrients to the skin cells - Nervous tissue - Receptors and nerves, which give us sensation 2. Briefly describe the concept of the extracellular matrix - Fluids and molecules secreted by cells - Influences the structure and function of that tissue type - For example: - The extracellular matrix secreted by bone cells makes bone tissue is hard and rigid - The extracellular matrix secreted by tendon cells makes tendon tissue stretchy (like a rubber band) 3. Briefly describe the most common molecules in the extracellular matrix - Collagen - Provides structure and strength - Triple helix structure - Elastin - Provides elasticity (stretchiness) - Proteoglycans - Fill space - Attract water - this determines how "soft" a tissue will be - Example - Cartilage has lots of proteoglycans, so it can provide some "cushioning" to joints ## Connective Tissue - Bone ### Describe the general structure of bone 1. Cortical bone (also known as Compact Bone) - Tough outer layer - Majority of bone in the body - Covered by periosteum on superficial surface - This contains blood vessels 2. Cancellous Bone (also known as Trabecular Bone or Spongy Bone) - Spongy, mesh plates - In contact with bone marrow ### Describe the cellular and non-cellular components of bone 1. Cellular Component - Osteoblasts - Immature bone cells - Secrete extra-cellular matrix to give bone its material properties - Eventually can: - Become osteocytes (see below) - Become bone lining cells - Die via apoptosis - Osteocytes - Mature bone cells - Maintain extracellular matrix - Response to mechanical loading - Response to hormones - Osteoclasts - Break down extracellular matrix - Releases minerals into the blood stream - Provides space for osteoblasts to secrete new extracellular matrix - Bone Lining Cells 2. Non-cellular Component (extracellular matrix, secreted by osteoblasts) - Non-mineralized - Osteoid is the main non-mineralized component - Collagen is main protein in osteoid - Mineralized - Hydroxyapatite is main mineralized component ### Differentiate between the two classifications of bone based on the tissue's maturity level 1. Immature bone = woven bone - Also known as "primary bone" - Found during fracture repair process (and also in fetal growth) - Weaker than mature bone - Irregular collagen structure ## Hypersensitivity ### Define hypersensitivity 1. Increased immune response to the presence of an antigen which produces undesirable clinical effects 2. Note that the four types of hypersensitivity reactions do not necessarily occur in isolation ### Describe the four types of hypersensitivity, including the time course of each 1. Type I-Immediate Hypersensitivity, Atopy - IgE is produced instead of IgG - Mast cell degranulation - Histamine released - Response to allergens - Normally harmless substances which cause an allergic response - Examples include: - Shellfish - Pet dander - Dust mites - Peanuts - Latex - Insect venom - Anaphylaxis = systemic Type I response 2. Type II - Cytotoxic reactions to self-antigens - Immune response to one's own tissues - Complement activation, agglutination, phagocytosis - Examples: - Hemolytic diseases of newborn - Myasthenia gravis - Cross-reaction between exogenous and endogenous body tissues - Examples: - Hemolytic streptococci / mitral valve disease - Guillian-Barre syndrome 3. Type III - Immune Complex Diseases - Antigen-antibody complexes depositing around small blood vessels - Complement cascade, acute inflammation, tissue injury - Examples: - Rheumatoid arthritis - Nephritis - Pericarditis - Vasculitis - Systemic lupus erythematosus (cell nucleus is antigen) 4. Type IV-Cell-mediated immunity - Delayed reaction to allergen, usually 48-72 hours - Based on macrophage to T-cell interactions which take time to occur ## Metabolism (Week 3) ### State the fates for the energy released from breaking the phosphate bonds in ATP 1. Energy to drive chemical reactions 2. Heat ### State the general pathways by which ATP can be produced 1. Combusion of carbohydrates - Glycolysis - Citric acid cycle 2. Combustion of fatty acids - Beta-oxidation 3. Combustion of proteins (after being broken down into amino acids) ### Describe the role of phosphocreatine for energy transfer 1. Reversible reaction used to generate ATP 2. Phosphocreatine + ADP → ATP + Creatine - Moves rightward whenever ATP levels become ever so slightly depleted - Maintains high ATP levels in cell - Acts as ATP "buffer" - Moves to the left when ATP demand is low - Phosphocreatine is resynthesized 3. "Immediate" source of chemical energy 4. Also known as "creatine phosphate" ### State the end products of glycolysis 1. 2 molecules of pyruvate 2. ATP - 2 ATP if glucose is used - 3 ATP if glycogen is used - Thus, glycogen is a better source of energy than glucose! ### State the sources of anaerobic ATP availability/production, and how long they can sustain exercise independently of oxidative metabolism 1. Existing ATP in cell - ~1 second 2. Phosphocreatine - 5-10 seconds 3. Glycolysis - ~30-60 seconds ### Rank and briefly describe the amount of energy sources in the body 1. Most = fat mass 2. Glycogen = storage form of glucose - Found in liver, skeletal muscle, and kidney 3. Glucose = found in blood stream 4. [Protein = abundant, but not typically used for ATP production ### Briefly describe blood glucose regulation 1. Glycogen production of glycogen from glucose - Turned on by insulin ## Metabolism (Week 4) ### Briefly explain the concept of basal metabolic rate (BMR), and name factors which influence it 1. Minimum energy required to exist (at complete rest) 2. Muscle mass - More muscle mass requires more energy to maintain it 3. Various hormones - Growth hormone, testosterone, and thyroxine all increase metabolic rate 4. Fever (increased metabolic rate) 5. Sleep (decreases metabolic rate) 6. Malnutrition (decreases metabolic rate - think of the body being more "efficient") 7. Sex and age - Females and older individuals have lower BMR - Dependent upon numerous factors, but... - Differences in muscle mass and adipose tissue have major influence - Sex hormone differences vary by sex and age ### Briefly explain how the body produces heat 1. About one third of energy released by ATP hydrolysis is heat 2. Friction at microscopic levels also produces heat - Blood flow - Friction from movement within musculoskeletal system ### State the range of oral temperatures for a healthy person under resting, exercise, and cold conditions, and how this differs than rectal temperature 1. APPROXIMATE temperatures - Rest: 97 to 99.5°F - Exercise: 101 to 104°F - Cold: <96°F 2. Rectal is about 1°F greater than oral temperature 3. Fluctuation is normal throughout the day 4. Skin temperature varies considerably from core temperature - Skin and subcutanaeous tissues insulate core from outside surroundings - Thus, skin temperature approaches temperature of surroundings ### State the two principle factors which determine heat loss and how this relates to blood flow 1. Factors - Speed at which heat can conducted from core to the skin - Speed at which heat can be transferred from skin to surroundings 2. Blood flow - Greater blood flow yields greater speed of transmission for both of these - Varies from nearly 0 to 30% of cardiac output ### Describe the mechanisms used to detect temperature in the body 1. Hypothalamus - Heat-sensitive and cold-sensitive neurons ## Inflammation ### Name the four signs of inflammation and relate them to the precipitating events (Table 6-3) 1. Erythema (redness) - Vasodilation and increased blood flow 2. Heat-Vasodilation and increased blood flow 3. Edema - Increased vascular permeability and hydrostatic pressure, causing filtration into interstitial spaces 4. Pain-Multiple causes - Direct trauma - Edema causing pressure - Nerve endings swelling - Chemical mediation ### Differentiate acute vs. chronic inflammation 1. Acute - Chiefly edema (including fluid and plasma proteins) and neutrophilic migration 2. Chronic - Includes lymphocytes, plasma cells, and macrophage infiltration - Attracted by chemotaxis from other cells - Promote growth of endothelial cells and fibroblasts - Granulation tissue forms - Angiogenesis / Neovascularization - Fibrosis - Tissue destruction ### Provide examples of conditions that would cause acute and chronic inflammation 1. Acute - Infections - Tissue necrosis - Foreign bodies - Immune Reactions 2. Chronic - Extensive necrosis - Sites where regeneration of tissue parenchyma is not possible - Heart - CNS - PNS - Underlying cause is not addressed - Persistent injurious agent - Repeated episodes of acute inflammation ### Briefly describe granulomatous inflammation 1. Aggregate of macrophages and lymphocytes ### Differentiate exudate, transudate, and effusion 1. Exudate is high protein fluid with high cellular content - Dependent upon increased vascular permeability ## Immune System ### Compare the functions of innate immunity vs. adaptive immunity 1. Innate immunity - Innate immunity is non-specific to a given pathogen - Eliminate pathogen rapidly - Mediate initiation and development of adaptive immunity - Work with adaptive immune response to eliminate pathogen 2. Adaptive immunity - Specific to different pathogens, and develops a "memory" to fight them in the future - Specific response to a given pathogen - Pre-activation required - Days to weeks - Re-activated if a high enough threat is sustained (activation threshold) - Continually develops throughout life ### Name the key components of innate immunity (Table 7-2) 1. Exterior defenses - Epithelial barriers - Mucosa - Secretions 2. Cellular components / Phagocytes (leukocytes) - Natural killer cells - Neutrophils - Monocytes/Macrophages - Neutrophils, Eosinophils, Basophils - Mast Cells and platelets 3. Soluble mediators - Complement - A system of proteins which induces the acute inflammatory response - Damage microbial membranes to kill cells and aid in phagocytosis - Cytokines - Proteins/glycoproteins which modify cellular behavior ### Describe the key types of cytokines 1. Chemokines - Small cytokines that cause chemically-induced migration of leukocytes to enhance inflammation - Increase vascular permeability - Activate vascular epithelial tissue - Change blood flow 2. Interferons - Produced by cells infected with viruses - Increase resistance to viral replication 3. Acute phase proteins ## Skeletal Muscle Injury Repair ### Describe the process of repair following a muscle strain or contusion 1. Hemostasis and hematoma formation 2. Degeneration - Necrosis - Neutrophils are the first on the scene - Chemotactic agents released to attract inflammatory mediators 3. Inflammation - Begins within 24-48 hours following injury - Phagocytosis of cellular debris - Macrophages cause stimulation of satellite cells - Migrate to the region - Differentiate - Various cytokines released (see Point C) - T-lymphocytes dominate after macrophages wane - Various cytokines released (see Point C) 4. Regeneration - 6-8 weeks after injury - Remodeling occurs after regeneration 5. Fibrosis may occur (but not necessarily) - Less functional ### Describe the role of the basement membrane in muscle healing 1. Basement membrane must remain intact for regeneration to occur - Division of satellite cells maintain this - Combine with other myogenic cells - Fuse with remaining muscle fibers - If basement membrane is not intact, fibrosis results - Maintains structural integrity of muscle - Lacks functional capacity - Increased risk of re-injury ### State the five effects that cytokines can have on satellite cells / muscle cells during repair 1. Enhanced resistance to oxidative stress - Cell survival 2. Block myofibrogenesis - Improved muscle healing 3. Proliferation - Cell division 4. Differentiation - Fusion to myofibers 5. Angiogenesis - Vascular supply to new muscle cells