Anatomy and Physiology II Lecture Exam 1 Review - Endocrine System PDF

**[Lecture Exam 1 Review:]** **[Endocrine System ]** [Chapter 16: Endocrine System ] [HYDROPHILIC HORMONS BINE OUTSIDE TO EXTRACELLULAR RECEPTER] Know the major functions of the endocrine system - Hormones - interact with specific target cells and influence their functions in order to mai...

**[Lecture Exam 1 Review:]** **[Endocrine System ]** [Chapter 16: Endocrine System ] [HYDROPHILIC HORMONS BINE OUTSIDE TO EXTRACELLULAR RECEPTER] Know the major functions of the endocrine system - Hormones - interact with specific target cells and influence their functions in order to maintain fluid, electrolyte, and acid-base homeostasis, promote growth, and regulate metabolic reactions Define Hormone, endocrine gland/tissue, target cell, and receptor - Hormones - interact with specific target cells and influence their functions in order to maintain fluid, electrolyte, and acid-base homeostasis, promote growth, and regulate metabolic reactions. - Endocrine gland/tissues- uses hormones to transport hormone via the blood stream. - Target call-hormones interacts with specific cells known as target cells - Receptor - target have specific receptor to which the hormones can BIND, leading to changes in the cells function Know how hormones travel throughout the body **PAGE 585 TRAVEL THROUGH BLOODSTREAM AND ONLY BIND TO CERTAIN RECEPTORS!!!!** - Chemical messengers secreted by endocrine glands; regulate other cells - Circulate in bloodstream - Amount of a particular hormone in blood at a given moment depends. - Are able to affect only particular cells called target cells; contain specific protein receptors to which hormones bind: - Three-dimensional shapes are highly specific for hormone molecule that they bind - Can be either embedded in plasma membrane or reside within cytosol or nucleus of a target cell Know what tropic hormones are - tropic hormones - control secretion of other endocrine glands Know the major differences between how the nervous system and the endocrine system (ie. Response time, duration, and how they use chemical messengers to communicate throughout the body) Know the difference between primary and secondary endocrine organs/glands, as well as which endocrine glands/organs are classified as such **THIS A CHOOSE ALL THAT APPLY QUESTION** - Primary endocrine organs are as follows: - Anterior pituitary gland -- in sphenoid bone of skull - Thyroid gland -- in anterior neck - Parathyroid gland -- on posterior side of thyroid gland - Adrenal cortices -- on superior side of each kidney - Secondary organs range from heart, kidneys, and small intestines to testes and ovaries - Pancreas -- digestion - Thymus -- immunity - Hypothalamus, Posterior Pituitary, adrenal medulla, and Pineal glands -- neural Know the different receptors (intracellular and extracellular) and which types of hormones interact with them (hydrophobic/steroid hormones & hydrophilic/amino acid hormones) - Receptor location largely depends on chemical structure of hormone itself: - Hydrophilic hormones cannot readily cross plasma membrane so generally interact with extracellular receptors found embedded in target cell's plasma membrane - Amino-acid hormones -- consist of one or more amino acids ranging in size; generally hydrophilic = bind to plasma membrane receptors (few are hydrophobic\*) - Hydrophobic hormones are able to cross through plasma membrane so generally interact with intracellular receptors - Steroid hormones -- derived from cholesterol; hydrophobic hormones that bind to receptors in cytosol or nucleus Know the differences between endocrine, paracrine, and autocrine - Hormones and neurotransmitters represent only a few of chemical signals used by body; three basic types of chemical signals include: - Paracrine -- chemicals are secreted & affect nearby but different types of cells - Example: ACh in neural stimulation of muscle cells - Autocrine -- chemicals are secreted & effects same cell or cell type - Used by many immune system cells - Endocrine -- use hormones and blood stream to affect near or far cells If given an example, know what kind of stimulus is causing a hormone to be secreted (hormonal, humoral, and neural) - What stimulates hormones to be released? - Hormonal stimuli -- (WHEN A HORMONE CAUSES THE RELEASE OF ANOTHER HORMONE)hormones secretion is increased or decreased in response to other hormones - Humoral stimuli - ( WHEN THE BLOOD CAUSES THE RELEASE OF A HORMONE) hormones secretion is incr eased or decreased in response to certain molecules in the blood - Neural stimuli - (WHEN THE NERVOUS SYSTEM CAUSES A RELEASE OF A HORMONE). hormones secretion is increased or decreased in response to signals form the nervous system Know the difference between positive and negative feedback loops - Negative feed back loop: An disruption in homeostasis is detected by a receptor, sends a message to a control center to elicit a response or effect. That effect then corrects until homeostasis is regained...thus shutting off the response as it is no longer necessary - Positive feed back loop: disruption in homsostasis, detected by a receptor results in a response that in effect amplifies itself Be able to identify antagonist and synergist hormones if given an example - Hormone interactions -- maintenance of homeostasis requires multiple hormones: - Many hormones have complementary actions; each hormone interacts with a different target cell in order to accomplish a common goal - Some hormones (synergists) can act on same target cell to exert same effect; effect is more pronounced with interaction of multiple hormones than any one individual hormone by itself - Some hormones called antagonists act on same cells but have opposite effects Define releasing hormones and inhibiting hormones - Hypothalamus produces and releases tropic hormones that either stimulate (releasing hormones), - inhibit (inhibiting hormones) the release of hormones from anterior pituitary Define tropic hormones and hormone cascades Know the special blood supply pathway that hormones use to get form the hypothalamus to the pituitary gland - Hypothalamic-hypophyseal portal system --specialized blood supply; allows both hypothalamus and pituitary to deliver their hormones directly to their target cells 1. What endocrine gland produces it 2. What organ, gland, or tissue it stimulates (if applicable) 3. The effect the hormone causes or produces 4. Be able to predict what will happen within the body if a drastic fluctuation occurs of that hormone Antidiuretic hormone (ADH) (vasopressin) (MAKDE BY HOPOTHALMUS AND STORED IN POSTERIOR PITUARTY GLAND) ACTS ON KIDNEYS AND CAUSES WATER RETENTION THAT INTURN CAUSE INCREASE IN BP - Antidiuretic hormone (ADH) aka vasopressin - [Water retention] controls maintenance of water in the blood\...effecting blood pressure - ADH allows for insertion of water channels (aquaporins) into plasma membranes of cells of kidney tubules - Promoting water uptake into the blood rather than the kidney tubules - Diabetes insipidus -- disease caused by lack of ADH secretion or activity; causes extreme thirst and signs of dehydration because body is unable to conserve most water consumed Oxytocin - **MADE IN HYPOTHALUMS AND STORE IN POSTERION PITUARY GLAND. ACTS ON UTERIUS TO CAUSE CONTRACTIONS AND CAUSE MAMMARY GLAND TO RELEASE IN ORDER TO BREATS FEED**. - Oxytocin -- produced by hypothalamus and stored in axon terminals of posterior pituitary gland - Target cells are in mammary glands and smooth muscle of uterus - In nursing mother, suckling stimulates oxytocin release; causes mammary glands to contract resulting in milk ejection - During labor it promotes contractions of the smooth muscle of the uterus - Rare example of a positive feed back loop Thyroid stimulating hormone (TSH) - **STIMULATES THYROID. MADE IN ANTERIOR PITUITARY GLAND. Acts on thyroid and effects: cause release of thyroid hormone** - Thyroid-stimulating hormone (TSH, thyrotropin) -- stimulates development of thyroid gland and its secretions Adrenocorticotropic hormone (ACTH) - **MADE IN ANTERIOR PITUITARY GLADE AND ACTS ON ADRENAL GLAD CAUSES ADRENAL GLAND TO RELEASE HORMONES** - Adrenocorticotropic hormone (ACTH, corticotropin) -- stimulates development of adrenal gland and synthesis of various steroid hormones Prolactin (PRL) - **MADE IN ANTERIOR PITUIARY GLAND AND CAUSE MILK PRODUCTION** - Prolactin (PRL) -- stimulates growth of mammary gland tissue, initiates milk production after childbirth, and maintains milk production for duration of breastfeeding - Stimulated by hormone prolactin-releasing hormone; inhibited by prolactin-inhibiting factor (known to be dopamine) Luteinizing hormone (LH) - **MALES- ACTS ON TESTES. FEMALE- ACTS ON OVARIES AND STIMULATES TESTERONE IN MALES OR STIMULATES RELEASE OF ESTROGEN AND PROGESTRONE IN FEMALES** - Luteinizing hormone (LH; gonadotropin) -- acts on the gonads to stimulate sex hormones: testosterone estrogen, progesterone Follicle stimulating hormone (FSH) - Follicle-stimulating hormone (FSH; gonadotropin) - Male -- stimulates cells of testes to produce chemicals that bind and concentrate testosterone - Female -- FSH and LH together trigger production of estrogen; FSH also triggers maturation of ovarian follicles Growth hormone (GH) **NON TROPIC.** - Growth hormone (GH; somatotropin) -- produced and secreted by anterior pituitary - Release GH periodically throughout day, with peak secretion occurring during sleep - Main function is to **regulate growth** of various target tissues including skeletal and cardiac muscle, adipose, liver, cartilage and bone; can be either short or long-term effects - Growth hormone is regulated by two hypothalamic hormones: - Growth hormone-releasing hormone (GHRH) stimulates release of GH; secretion increases during exercise, fasting, and stress, and after ingestion of a protein-rich meal - GH release is inhibited by hypothalamic hormone somatostatin. Thyroid hormone (TH) (thyroxin & triiodothyronine) **REGUALTES METABOLISM** - Thyroid gland -- secretes thyroid hormone and calcitonin. - Thyroid hormone: - Inactive form = Thyroxine (T4) -- produced by thyroid - Active form = triiodothyronine (T3) -- T4 is converted to T3 in/at the tissues or organs where needed esp. in the liver - Regulation of metabolic rate - set basal metabolic rate - Promotion of growth and development --bone & muscle growth, and nervous system development - Affects regulation of blood pressure, heart rate, and other sympathetic activities -- via receptors for sympathetic neurotransmitters. Calcitonin. - Thyroid gland -- secretes thyroid hormone and calcitonin - Parafollicular cells in the thyroid secrete calcitonin, - Each on has an opposing effect on calcium ion concentration in blood - Keeps this vital ion within a normal range - **[Calcitonin (produced by thyroid parafollicular cells)]** --released when calcium ion level in blood increases above normal: - Primary target is osteoclast cells in bone; osteoclast activity is inhibited by presence of calcitonin; allows osteoblast activity. - Unopposed osteoblast activity reduces blood calcium ion levels as these ions are incorporated into bone matrix - **OSTEROCLAST BREAKDOWN BONE AND RELEASE CALCIUM IN BLOOD** - **OSTEOBLAST USE CALIUM TO BUILD BONE** Parathyroid hormone (PTH) - Parathyroid hormone (PTH) -- secreted in response to declining calcium ion levels in blood; triggers following effects: - Increases release of calcium ions from bone by stimulating osteoclast activity. - Increases absorption of dietary calcium ions by small intestine. - STIMULATES OSTEOCLAST TO BREAKDOWN BONE TO RELEASE CALCIUM Aldosterone (mineralocorticoids) - **RELEASED BY ADRENAL GLAND. ACTS ON KIDNEYS. REGULATES SODIUM AND POTASSIUM IN THE BLOOD** - Aldosterone a mineralocorticoid hormone that regulates concentration of certain minerals in body - Maintains concentrations of extracellular sodium and potassium ions within their normal ranges - Regulates extracellular fluid volume - because water follows... - Increases blood pressure -- will make more sense in Ch. 18 - \*\*Hyperaldosteronism can lead to hypokalemia (low blood potassium ion level), hypernatremia (high blood sodium ion level), and hypertension (high blood pressure) Cortisol (glucocorticoids) **MADE IN ADRENAL GLAND**. **THIS IS A STRESS HORMONE AND HELPS RELIEVE STRESS.** **\*\*\*LONG TERM SECREATIONS CAUSE MEMORY LOSS\*\*** - Cortisol (hydrocortisone) -- most potent glucocorticoid who's main role is to help mediate body's response to stress - Cortisol Stress response (series of events that maintains homeostasis when body is faced with a stressor -- distress or eustress - involves regulation of blood glucose levels - Chronic elevation can interfere with learning and memory, lower immune function and bone density, increase weight gain, blood pressure, cholesterol, heart disease, increase risk for depression, mental illness, and lower life expectancy. - Cortisol disorders, involve either over secretion of cortisol or long-term administration of corticosteroids - Cushing's disease -- over secretion from adrenal cortex, usually from a tumor - Iatrogenic Cushing's syndrome -- caused by long-term administration of glucocorticoid-containing products - Regardless of cause, symptoms of cortisol excess are: - Lipolysis releases fatty acids from upper and lower limbs, which become slim and are deposited in adipose tissue in the face, trunk, and back of neck Dopamine, Epinephrine, & Norepinephrine **STRESS HORMONES (SHORT TERM STRESS) RELEASED BY ADRENAL GLAND. ACTS ON EVERYTHING "FIGHT OR FLIGHT"** - Epinephrine, norepinephrine and dopamine; mediate immediate responses to a stressor: - Increase rate and force of heart contraction and dilate bronchioles in lung - Constrict blood vessels supplying skin, digestive organs, and urinary organs (increasing blood pressure) - Dilate blood vessels supplying skeletal muscles - Dilate pupils - Decrease digestive and urinary functions Androgenic steroids - **MADE IN ADRENAL GLAND.** **ACTS ON TESTES OR OVARIES. CAUSES ESTROGEN TO CONVERT TO TESTOSTERONE AND VICE VERSA** - Androgenic steroids -- steroid sex hormones that affect reproductive organs (gonads) as well as other tissues - Adrenal cortex synthesizes these hormones in small quantities in both genders; largely byproducts of cortisol synthesis pathway - Same general effects as those made by gonads - Can be converted in circulation to androgen testosterone or female hormone estrogen Glucagon - Glucagon and insulin regulate concentration of glucose in blood - Glucagon --increase levels of glucose by: - Breakdown of glycogen, fats, & proteins to form glucose Insulin - Glucagon and insulin regulate concentration of glucose in blood - Insulin -- primary antagonist of glucagon; lowers blood glucose levels by: - Promotes uptake and storage of ingested nutrients - Synthesis of glycogen in liver; synthesis of fat from lipids and carbohydrates - Promotes satiety (feeling of fullness) - Hypoglycemia -- condition where blood glucose levels are too low; can be caused by elevated insulin levels - Symptoms -- weakness, dizziness, rapid breathing, nausea, and sweating - Severe hypoglycemia can lead to confusion, hallucinations, seizures, coma, and death; ensues as brain is deprived of adequate glucose (primary fuel for its metabolic reactions) - Hyperglycemia -- condition where blood glucose levels are too high; common causes of chronic hyperglycemia: - Type I diabetes mellitus (insulin-dependent diabetes mellitus) -- disease caused by destruction of beta islet cells that produce and secrete insulin - Target cells are unable to take in circulating glucose; Glucose is overproduced in liver - Type II diabetes mellitus -- disease in which insulin's target tissues become insensitive to insulin and target cells do not initiate proper responses to increases in blood glucose concentration (insulin resistance) Melatonin - Pineal gland -- posterior region of diencephalon of brain - Secretes neurohormone melatonin, appears to be related to light and dark cycles; secretion increases in dark Testosterone - Primary male and female reproductive organs or gonads = testes or ovaries - Responsible for production of gametes (sperm or ova) - Produce sex steroid hormones responsible for gamete production and other functions - Testes produce testosterone (females make testosterone in adrenal glands) - Testes produce testosterone (females make testosterone in adrenal glands) - Cells of ovary produce female sex hormones, estrogen and progesterone Estrogen & Progesterone - Cells of ovary produce female sex hormones, estrogen and progesterone Atrial Natriuretic Peptide - Specific cardiac muscle cells contain stretch-sensitive ion channels that open more widely when blood volume inside heart increases; simulates cardiac muscle\ cells to secrete atrial natriuretic peptide (ANP): - Triggers relaxation of smooth muscle cells in blood vessels; increases vessel diameter (vasodilation) - Enhances excretion of sodium ions from kidneys, an effect called natriuresis; enhances water excretion from kidneys; creates a concentration gradient that water follows into kidney fluid by osmosis; example of - Both vasodilation and natriuresis decrease blood volume and lower blood pressure Erythropoietin - Kidneys serve following roles involving endocrine functions: - Erythropoietin (EPO) -- secreted by specific kidney cells in response to decreased blood oxygen levels; acts on red bone marrow to stimulate development of new erythrocytes (erythropoiesis); increases oxygen-carrying capacity of blood - Specific kidney cells secrete renin; converts plasma protein angiotensinogen to angiotensin I; vital component of renin-angiotensin-aldosterone system, which maintains blood pressure Thymosin - Thymus -- found in mediastinum - Where T lymphocytes mature - Secretes hormones thymosin and thymopoietin; function mainly as paracrine signals that assist in T lymphocyte maturation Leptin - Adipocytes produce protein hormone leptin; able to cross blood-brain barrier where it interacts with neurons in hypothalamus - Action of leptin is to communicate to the brain that you either: - Have enough energy stored in adipose that you can maintain normal activity -- brain tells you that you are satiated - Do not have enough energy stored in fat -- brain tells you that you are in starvation mode - Leptin production is closely related to adipose tissue quantity - Once a threshold is surpassed (genetically determined) leptin resistance occurs Gastrin - Hormone produced by the stomach - Gastrin is a peptide hormone that stimulates secretion of gastric acid by the parietal cells of the stomach and aids in gastric motility. - It is released by G cells in the pyloric antrum of the stomach, duodenum, and the pancreas. STEROID HORMONES ARE LIPID BASED WHICH ARE HYDROPHOBIC AMINO ACID (PROTEINS) ARE HYDROPHILIC   **[Lecture Exam 1 Review:]** **[Cardiovascular system I: The Heart ]** **[Chapter 17: The Heart]** - autorhythmicity, meaning it sets its own rhythm without a need for input from nervous system - myocardial infarction (MI), or heart attack - CAD decreases blood flow to myocardium; results in inadequate oxygenation of myocardium, a condition known as myocardial ischemia. - anastomoses (systems of channels formed between blood vessels) - Cardiac dysrhythmias = Disturbances in heart rate/ rhythm - Bradycardia -- is a heart rate under 60 beats per minute. - Tachycardia -- is a heart rate over 100 beats per minute; sinus tachycardia is a regular, fast rhythm. - Stroke volume (SV) = the volume of blood pumped in one heartbeat - Cardiac output (CO) = volume of blood pumped into pulmonary and systemic circuits in 1 minute - Heart undergoes an average of 60--80 cardiac cycles or beats per minute (bpm) = heart rate (HR) - rate at which SA node generates action potentials - Heart failure is defined as any condition that reduces heart's ability to function effectively as a pump: - Cardiomyopathy -- disease of the heart muscle - Pulmonary congestion -- blood backs up in pulmonary circuit d/t left ventricular failure, causing pulmonary edema - Systemic congestion -- blood backs up in both or the right ventricle, causing peripheral edema Know in which direction veins and arteries carry blood (in relation to the heart) -  - Cardiovascular system -- consists of heart, blood vessels, and blood; heart pumps blood into blood vessels - Pulmonary circuit -- carries blood to the lungs for gas exchange and then returns oxygenated blood back to the heart - Systemic circuit -- supplies oxygenated blood to the entire body Be able to answer questions about the pulmonary and systemic circuits in regard to where blood is going and coming back from (direction and target) as well as compare the pressure within each circuit, as well as where in each circuit the blood is oxygenated and deoxygenated SEE ABOVE - Heart is divided functionally into right and left sides - Right side (right atrium and ventricle) is the pulmonary pump b/c it pumps blood into the pulmonary circuit - a series of blood vessels leading to and within lungs - Pulmonary arteries of pulmonary circuit deliver oxygen-poor and carbon dioxide-rich, or deoxygenated, blood to lungs - Pulmonary capillaries -- in tiny air sacs in lung (alveoli) are the site of gas exchange in the lungs - Pulmonary veins - delivers this oxygen-rich (oxygenated) blood to left side of heart - Left side (left atria and left ventricle) is systemic pump; b/c it pumps it into the systemic circuit - blood vessels that serve rest of body - Systemic arteries - deliver oxygenated blood to smallest blood vessels - Systemic Capillaries -- deliver oxygen to tissues in the body while picking up the waste product carbon dioxide - Systemic veins -- return the deoxygenated blood back to the heart so that the carbon dioxide can be exhaled from body Know the layers of the pericardium and their function (fibrous pericardium, serous pericardium, parietal pericardium, visceral pericardium, pericardial cavity) - Pericardium -- double- walled membranous structure surrounding heart; composed of following structures: - Fibrous pericardium -- outer layer -- connective tissue - Collagen bundles make it tough and enable it to anchor heart to structures such as diaphragm and great vessels-helps to prevent chambers of heart from overfilling with blood - Serous pericardium -- thin inner serous membrane that produces serous fluid: - Parietal pericardium -- fused to fibrous pericardium; encases heart like a sac, but when it reaches great vessels, it folds under itself and forms the visceral pericardium - Pericardial cavity -- found between parietal and visceral pericardia; contains a very thin layer of serous fluid (pericardial fluid); acts as a lubricant, decreasing friction as heart moves - Visceral pericardium -- innermost layer; also known as epicardium Know the layers of the heart tissue and their function (endocardium, myocardium, and epicardium) - Epicardium = visceral pericardium - Myocardium -- middle layer; has two components: - Cardiac muscle cells (myocytes or cardiocytes) - Fibrous skeleton; composed of dense irregular collagenous connective tissue act as an insulator for heart's electrical activity - Endocardium -- innermost epithelial layer that is continuous with the blood vessel endothelium Know the SPECIFIC function of each of the heart valves (just 'to prevent backflow' is not enough....to prevent backflow from 'where' to 'where') - **Valves prevent backflow of blood** - Semilunar valves prevent backflow into the ventricles - AV valves prevent backflow into the atria - consist of flaps, called cusps; composed of endocardium overlying a core of collagenous connective tissue - Chordae tendineae -- fibrous, tendon-like structures attached to inferior end of each cusp; attach to papillary muscles that contract just before ventricles begin ejecting blood; creates tension on chordae tendineae keeping valves closed Know the function of papillary muscles - Papillary muscles attach by tendon-like cords called chordae tendineae to valves to open and close them Know the coronary blood vessels we went over in class and what parts of the heart they supply or drain - Know the functions of pacemaker and contractile cells - Pacemaker cells undergo rhythmic, spontaneous depolarizations that lead to action potentials (MAKE YOUR HEART BEAT/CONTRACT) 1% OF CELLS ARE PACEMAKER CELLS IN THE HEART - Action potentials are transmitted from pacemaker cells to contractile cells through intercalated discs that unite them - Gap junctions in these discs allow electrical activity generated by pacemaker cells to rapidly spread to all cardiac muscle cells via electrical synapses - Contractile cells make up great majority (99%) of cardiac muscle cells (CONTRACT) - An action potential in a contractile cardiac muscle cell results from a reversal in membrane potential (from negative to positive) - These changes happen because of voltage-gated ion channels in sarcolemma and because of unequal concentrations of sodium and potassium ions on either side of membrane that drives those ions in or out of cell through channels Know the three main sets of pacemaker cells (especially which one is the most primary) - Pacemaker cells make up only about 1% of total number of cardiac muscle cells - There are three populations of these cells in heart that are capable of spontaneously generating action potentials, thereby setting pace of heart - Sinoatrial node (SA node) - Atrioventricular node (AV node).... bundle of His - Purkinje fibers = AV bundle & right and left bundle branches - These three cell populations are collectively called the cardiac conduction system Know what causes the heart beat sounds ('lub -- dub' ) sounds you hear - S1, or "lub," is heard when AV valves close - S2, "dub," is heard when semilunar valves close; S1 is typically longer and louder than S2 If given stroke volume and heart rate, be able to calculate cardiac output - Heart undergoes an average of 60--80 cardiac cycles or beats per minute (bpm) = heart rate (HR) - rate at which SA node generates action potentials - Stroke volume (SV) = the volume(amount) of blood pumped in one heartbeat - Cardiac output (CO) = volume(amount) of blood pumped into pulmonary and systemic circuits in 1 minute **\*\*\*\*CO = HR x SV\*\*\*\*** - **Resting cardiac output averages about 5 liters/min;** - **Normal adult blood volume is about 5 liters, so entire supply of blood passes through heart every minute** For the section on membrane potential and how the heart muscles communicate to contract: Know what is meant by 'polarized' in terms of charge across a membrane PACEMAKER CELLS 1. Slow initial depolarization phase in a pacemaker cell occurs much more slowly; because of nonspecific cation channels that are unique to pacemaker cells. Let cations in AND out of the cell 2. Full depolarization phase -- when membrane reaches threshold, voltage-gated calcium ion channels open, allowing calcium ions to enter cell and thereby causing membrane to fully depolarize 3. Repolarization phase -- recall that calcium ion channels are time-gated for closing, so after a certain time (about 100--150 msec), they close; at same time, voltage-gated potassium ion channels begin to open; allows potassium ions to exit cell, and membrane begins to repolarize 4. Minimum potential phase -- potassium ion channels remain open until membrane reaches its minimum potential; when this happens, membrane is hyperpolarized, which opens nonspecific cation channels, and cycle begins again CONTRACTILE CELLS 1. Rapid depolarization phase -- in response to pacemaker cell action potentials that cause voltage changes in adjacent cells, voltage-gated sodium ion channels in sarcolemma are activated; causes a rapid and massive influx of sodium ions; leads to rapid membrane depolarization 2. Initial repolarization phase -- there is a small, initial repolarization immediately after depolarization spike; due to abrupt inactivation of sodium ion channels and to a very small outflow of potassium ions through selected potassium ion channels that are open only briefly 3. Plateau phase -- depolarization is sustained at about\ 0 mV; known as plateau phase; this critically important phase is mostly due to slow opening of calcium ion channels and resulting influx of calcium ions 4. Repolarization phase -- final phase; both sodium and calcium ion channels return to their resting states and most of potassium ion channels open; allows positively charged potassium ions to exit cardiac muscle cell; membrane potential returns to its resting value of about --85 mV Know the major differences & similarities between pacemaker cells and contractile cells - Pace maker cells: Slow and rapid depolarization in pacemaker cells \-\-- which ion causes it and in what direction it is moving across the membrane (in or out of cell) - Slow initial depolarization phase in a pacemaker cell occurs much more slowly; because of nonspecific cation channels that are unique to pacemaker cells. Let cations in AND out of the cell Repolarization in pacemaker cells \-\-- and which ion causes it and in what direction it is moving across the membrane (in or out of cell) - Repolarization phase -- recall that calcium ion channels are time-gated for closing, so after a certain time (about 100--150 msec), they close; at same time, voltage-gated potassium ion channels begin to open; allows potassium ions to exit cell, and membrane begins to repolarize Contractile cells: Rapid depolarization \-\-- which ion causes it and in what direction it is moving across the membrane (in or out of cell) - Rapid depolarization phase -- in response to pacemaker cell action potentials that cause voltage changes in adjacent cells, voltage-gated sodium ion channels in sarcolemma are activated; causes a rapid and massive influx of sodium ions; leads to rapid membrane depolarization - Plateau phase -- depolarization is sustained at about\ 0 mV; known as plateau phase; this critically important phase is mostly due to slow opening of calcium ion channels and resulting influx of calcium ions - Repolarization phase -- final phase; both sodium and calcium ion channels return to their resting states and most of potassium ion channels open; allows positively charged potassium ions to exit cardiac muscle cell; membrane potential returns to its resting value of about --85 mV Know what the P wave, T wave, QRS complex, and R-R interval represent on an ECG - A diagram of ecg and heart rate Description automatically generated -  Know what is occurring and how to treat atrial fibrillation, ventricular fibrillation, and asystole - Fibrillation, electrical activity in heart essentially goes haywire, causing parts of heart to depolarize and contract while others are repolarizing and not contracting - Atrial fibrillation is generally not life threatening because normal atrial contractions aren't necessary for ventricular filling - Ventricular fibrillation immediately life-threatening and manifests on ECG with chaotic activity - Treated with defibrillation; depolarizes all ventricular muscle cells simultaneously - Ideally, SA node will resume pacing heart after shock is delivered Know the steps of the cardiac cycle and what is occurring in each in regard to systolic and diastolic pressures and valve position - Cardiac cycle -- when each chamber has successfully contracted (systole) and relaxed (diastole) - Blood flows in response to pressure gradients - Pressure gradients, systole, and diastole cause the valves to open and close Know and be able to differentiate the factors that control/ influence C.O. - Although heart is autorhythmic, it still requires regulation to ensure that cardiac output meets body's needs at all times - Regulated primarily by nervous and endocrine systems, which influence both heart rate and stroke volume - Two branches of autonomic nervous system (ANS) regulate our automatic functions - Sympathetic -- activates fight or flight response - Parasympathetic -- rest or digest response - Hormonal regulation of cardiac output occurs in various forms - Adrenal medulla is activated by sympathetic nervous system, and in response it secretes hormones epinephrine and norepinephrine into bloodstream - Aldosterone & antidiuretic hormone -- increase the amount of water in the blood and this increase blood volume & blood pressure - Atrial natriuretic peptide, decreases blood volume and preload, and therefore reduces cardiac output - Other factors that influence cardiac output - Concentration of certain electrolytes in extracellular fluid plays a large role in determining length and magnitude of an action potential and cardiac output - Body temperature influences CO; SA node fires more rapidly at higher body temperatures and more slowly at lower body temperatures - Age and physical fitness influence heart rate and cardiac output; younger children and elderly often have a higher resting heart rate, whereas trained athletes often have a much lower resting heart rate - Exercise increases stroke volume, so for body to maintain a constant cardiac output, heart rate must decrease The essay / short answer: detailed description of tracing blood flow through the heart. Must the pathway IN SEQUENTIAL ORDER, of NAMED chambers (left and right), named valves, NAMED blood vessels, where blood is oxygenated/deoxygenated, as well as when systolic and diastolic pressures occur in one heart beat. Right Side of the Heart - Goal: to get the blood RIGHT to the lungs so it can become oxygenated. 1\. The un-oxygenated blood (this is blood that has been "used up" by your body and needs to be resupplied with oxygen) enters the heart through the SUPERIOR AND INFERIOR VENA CAVA. 2\. Blood enters into the RIGHT ATRIUM 3\. Then it is squeezed through the TRICUSPID VALVE 4\. Blood then enters into the RIGHT VENTRICLE 5\. Then it is squeezed into the PULMONIC VALVE 6\. Blood is then shot up through the PULMONARY ARTERY and then enters into the lungs for some oxygen - Left Side of the Heart 7\. Blood enters from the lungs through the PULMONARY VEIN 8\. Blood then enters into the LEFT ATRIUM 9\. Down through the BICUSPID VALVE (also called mitral valve) 10\. Then blood is squeezed into the LEFT VENTRICLE 11\. Up through the AORTIC VALVE 12\. Lastly up through the AORTA, where it pumped throughout the body - A diagram of a heart Description automatically generated - RIGHT ATRIA - RIGHT VENTRICLE - Left ATRIA - LEFT VENTRICLE - TRUCUSPID VALVE - BISCUPID (MITRIAL) VALVE - PULMONIC VALVE - AORTIC VALVE - VENA CAVA'PULMONARY ARTERY - PULMONARY VEIN - AORTIC - \+ OXYGENATED - \+ DEOXYGENATED - \+ SYSTOILS - \+ DIASTOLIC **[Lecture Exam 1 Review:]** **[Cardiovascular System II: Blood Vessels ]** **[\*\*\*\*\*ARTERIES ARE UNDER THE MOST PRESSUE, THEN CAPILLIARIES ARE UNDER THE MIDDLE PRESSURE AND VEINS ARE UNDER THE LEAST AMOUNT OF PRESSURE\*\*\*\*\*\*\*]** [Chapter 18: Blood Vessels ] - Anastomoses-the location of several converging arteries or veins that provide alternate pathways to a capillary bed. Allows blood to enter a capillary bed by more than one route - Vasodilation- relaxation that increases diameter - Vasoconstriction- contraction that narrows diameter - Blood flow = C.O.= amount or volume of blood that flows per minute - Blood pressure- outward force that blood exerts on walls of blood vessels. - Resistance- any impedance to blood flow (slows blood flow) - Edema- condition characterized by an excessive amount of water in interstitial fluid - Hydrostatic pressure- force that a fluid exerts on wall of its container = blood pressure - Osmotic pressure- Osmosis involves movement of water from a high concentration to a low concentration (ie: water follows solutes/salt) - Fenestrations- small pores - Skeletal muscle pumps- skeletal muscles surrounding deeper veins of upper and lower limbs squeeze blood in veins and propel it upward (toward heart) as they contract and relax - Venous valves- prevent backward flow in some veins Know the primary functions of blood vessels - Blood vessels - Regulate blood flow to tissues - Control blood pressure - Secrete a variety of chemicals - Transport blood Know the three major types of blood vessels and their function in terms of transport to/from heart and tissues - Types of blood vessels - Arteries- transport blood from heart to tissues - Capillaries- where gases, nutrients, and wastes are exchanged - Veins - transport blood back to heart (a majority (\~65%) of blood resides in veins at any given time) Know the layers of a blood vessel (tunica intima, tunica media, tunica externa) and the major function of each layer - Innermost tunica intima -endothelium; continuous with inner lining of heart (endocardium); provide a smooth surface with a minimum of friction and turbulence. Other 3 layer anchor endothelium in place and allow for some level of stretch - Tunica media; composed primarily of Smooth muscle cells which control the diameter of the blood vessel and therefore amount of blood that flows to organs. The other layer is again for stretchability - Outermost tunica externa (aka tunica adventitia) is composed connective tissue; supports blood vessel and prevents it from overstretching. Vaso vasora are tiny vessels supplying tunica media and tunica external. Supply oxygen and nutrients to outer layers of larger blood vessels, whose cells are too far away from lumen to receive oxygen and nutrients by diffusion alone Know the function of the vaso vasora and vasomotor nerves - Smooth muscle cells of tunica media are innervated by sympathetic (autonomic) nervous system vasomotor nerves - Vaso vasora are tiny vessels supplying tunica media and tunica external. Supply oxygen and nutrients to outer layers of larger blood vessels, whose cells are too far away from lumen to receive oxygen and nutrients by diffusion alone Know what baroreceptors and chemoreceptors 'sense' in the blood vessels - Baroreceptors in common carotid artery and aorta detect and monitor blood pressure - Also in carotid artery (carotid bodies) and aorta (aortic bodies) are groups of chemoreceptors; detect blood oxygen, carbon dioxide, and hydrogen ion concentrations Know the different types of arteries (including arterioles) and their relative sizes (largest to smallest) - Elastic / Conducting arteries -- lgst, highest pressure, closest to the heart - Muscular / Distributing arteries -- intmd, arteries that supply organs - Arterioles - smallest arteries, lead to the capillary beds - metarterioles; directly feed capillary beds in most tissues Know the different types of capillaries and what makes them different - Capillaries -- classified by their appearance - Continuous capillaries -- smooth and entire only small hydrophobic molecules pass through (diffuse) - Fenestrated capillaries -- contain fenestrations or filtration pores (20 -- 100nm) allow larger molecules across - Sinusoids -- specialized; found in blood filled cavities in lymphoid tissue and the liver Know the difference between veins, venules, and venous sinuses - Veins (like arteries) can be classified by their size: - Venules -- smallest veins; drain blood from capillary beds - Veins (medium and large based on diameter of lumen) - Can also have unique function: - Venous sinuses -- specialized non constricting veins located in the heart and brain Know the differences between the different circulatory routes (Simple, Portal, Arteriovenous shunt, and anastomoses) - Portal System Pathway/Route - Blood flows through 2 capillary beds before returning to the heart - Example: veins in your intestines travel to the liver before returning to the heart - Arteriovenous Shunt - Blood is re-routed to completely bypass a capillary bed - Can be found in skin, but dangerous anywhere else - Anastomoses - the location of several converging arteries or veins that provide alternate pathways to a capillary bed - Allows blood to enter a capillary bed by more than one route Know the factors that affect blood pressure and the effect those factors have -  Know the 4 factors that affect resistance (diameter, viscosity, length, and obstruction) - Peripheral Resistance -- at it increases, blood pressure also increases and is determined by: - Blood vessel radius -- as a radius increases (vasodilation), resistance decreases and thus the pressure decreases and v/v - Blood viscosity -- increase in viscosity means an increase in resistance and thus increase in blood pressure - Determined by hematocrit, plasma contents, and RBC aggregation - Blood vessel length -- the longer the blood vessel the greater the resistance; thus the more pressure and v/v - Physical Obstructions -- obstructions increase resistance and thus increase blood pressure - Atherosclerosis -- deposit of fatty plaques in the blood vessels Know the relationship between resistance and blood pressure (ie. As one increases the other increases) - as resistance increases, blood pressure increases and flow decreases. - As resistance decreases blood pressure decreases and flow increases Know the relationship between Cardiac output and blood pressure (as one increases the other increases) - Cardiac output (CO) -- amount of blood pumped by the heart per minute - When cardiac output increases, blood pressure increases and vice versa Know the relationship between blood volume and blood pressure (as one increases the other increases) - Blood Volume - the volume of blood in the body - Directly linked to amount of water in blood - When blood contains more water, blood volume increases: as blood volume increases, blood pressure increases and vice versa Know the relative amount of pressure found in the types of blood vessels (highest, mid, and lowest) - A table with text and numbers Description automatically generated Know the difference between hydrostatic pressure and osmotic pressure in capillaries - hydrostatic pressure and osmotic pressure; promote movement in opposite directions--- - hydrostatic pressure drives water out of the capillary - osmotic pressure generally draws fluid into capillary Know where the pressures are highest and lowest within a capillary bed (arteriole or venule side) - Arterioles- 80-35 mmHg - Venules -- 15-5 mm Hg Know which way water is moving (in or out of the capillary) in regard to hydrostatic pressure and osmotic pressure - **hydrostatic pressure and osmotic pressure; promote movement in opposite direction** - hydrostatic pressure drives water out of the capillary and into tissues **(causes water filtration)** - osmotic pressure generally draws fluid into capillary **(causes water absorption)** - Hydrostatic pressure in a capillary changes from its arteriolar end, where it measures about 35 mm Hg, to its venular end, where it measures about 15 mm Hg; hydrostatic pressure of interstitial fluid is so low that it is functionally 0 mm Hg Know how veins are able to move blood back to the heart given low pressure and going against gravity VENOUS VALVES **[PREVENT]** BACKFLOW IN SOME VEINS SKELETAL MUCLES PUMPS SQUEEZE SKELTAL MUSCLES TO MOVE BLOOD BACK TO HEART - For veins to pump blood uphill against gravity, there needs to be movement. This movement is supplied by the movement of the leg muscles during walking or exercise. During movement, the muscles push on the veins, "squashing" them and squirting blood up and out of the veins. This results in the blood getting forced upwards into the pelvis against gravity. Know the functions of the major VEINS and ARTERIES that we go over in class Arteries: (SUPPLY) Veins: (DRAIN) Carotid artery-supplies head/brain with blood juggler drains head and brain blood Gastric-supplies stomach with blood gastric vein-drains stomach blood and goes back to heart Hepatic-supplies liver with blood hepatic vein-drains livers blood Renal -- supplies kidneys with blood Renal vein-drains kidneys blood Splenetic-supplies spleen with blood Splenetic veins-drains spleen blood Mesenteric-supplies intestines with blood Mesenteric-drains intestines blood