A&P Exam #1 learning objectives

discuss the types, causes, and effects of leukocyte excesses and deficiencies

-Normal WBC count is 5,000-10,000 WBCs/uL. -Differential WBC count- identifies what percentage of the total WBC count consists of each type of leukocyte. Leukopenia- low WBC count. seen in lead, arsenic, and mercury poisoning; radiation sickness; and such infectious diseases as measles, mumps, chickenpox, polio, influenza, typhoid fever, and AIDS. Presents an elevated risk of infection and cancer. Leukocytosis- High WBC count. Usually indicates infection, allergy, or other diseases but can also occur in response to dehydration or emotional disturbances. Types: -Leukemia- Cancer of the hemopoietic tissues that produces extraordinarily high numbers of circulating leukocytes and their precursors. classified as Myeloid or Lymphoid, acute or chronic. Myeloid is marked by uncontrolled granulocyte production. Lymphoid involves uncontrolled lymphocyte or monocyte production. Acute appears suddenly, progresses rapidly, and causes death within a few months if not treated. Chronic develops slowly, and may go undetected for months. untreated, survival time is about 3 years. Effects: As leukemia cells proliferate, they replace normal bone marrow and a person suffers from a deficiency of normal granulocytes, erythrocytes, and platelets. The deficiency of competent WBCs leaves the patient vulnerable to opportunistic infection (the establishment of pathogenic organisms that usually cannot get a foothold in people with healthy immune systems. RBC deficiency > patient anemic and fatigued. Platelet deficiency > hemorrhaging and impaired blood clotting. powerpoint: Overproduction of abnormal, nonfunctioning WBCs Normal red bone marrow function is impaired because WBCs fill bone marrow Severe anemia and bleeding problems, fever, weight loss, bone pain, infections Acute leukemia - quickly advances, derived from stem cells, typically affect children Chronic leukemia - slowly advances, derived from later cell stages, typically affect elderly Treatment - radiation, drug therapy, bone marrow transplant Infectious Mononucleosis- Highly contagious, called the "kissing disease" Caused by Epstein-Barr virus Excessive, atypical agranulocytes Symptoms: tired, achy, sore throat, low-grade fever No cure, but recovery in a few weeks

name several organs of the endocrine system

-Pineal Gland -Hypothalamus -Pituitary Gland -Thyroid Gland -Thymus -Adrenal Gland -Pancreas -Parathyroid Glands -Gonads (ovary/testis)

explain what keeps blood from clotting in the absence of injury

-Platelet repulsion: Endothelial cells secrete antithrombic substances (prostacyclin) to prevent platelet adhesion -Dilution: At normal rates of blood flow, thrombin is diluted so quickly that a clot has little chance to form. -Anticoagulants present in plasma suppress thrombin formation. -Antithrombin secreted by liver deactivates thrombin before it can act on fibrinogen. -Heparin - natural anticoagulant in basophils and mast cells, on surface of endothelial cells -Inhibits with the formation of prothrombin activator -Inhibits intrinsic pathway

list the functions of platelets

-Secrete *SEROTONIN* vasoconstrictors, chemicals that stimulate spasmodic constriction of broken vessels and thereby help to reduce blood loss. ****Help stop blood loss by sticking together to form temporary platelet plugs that seal small breaks in injured blood vessels. -Secrete procoagulants, or clotting factors, which promote blood clotting. -Initiate the formation of a clot-dissolving enzyme that dissolves blood clots that have outlasted their usefulness. -Secrete chemicals that attract neutrophils and monocytes to sites of inflammation. -Internalize and destroy bacteria. -Secrete growth factors that stimulate mitosis in fibroblasts and smooth muscle and thereby help to maintain and repair blood vessels. Powerpoint: Release granules the promote clotting -Ca2+ -Serotonin (vasoconstrictor) -ADP (attracts platelets) -Thromboxane A2 (eicosanoid, platelet aggregation, degranulation, vasoconstriction) -Clotting factors -Enzymes, growth factors

contrast endocrine with exocrine glands

-The classical distinction between endocrine and exocrine glands has been the presence or absence of ducts. Exocrine glands secrete their products by way of a duct into body cavities or to the outer surface. Endocrine glands are ductless and release their secretions into the bloodstream/interstitial fluid around the cell. -exocrine glands have extracellular effects, whereas endocrine glands have intracellular effects. Liver cells act as both.

in more detail, describe the causes and pathology of diabetes mellitus

-can be defined as a disruption of carbohydrate, fat, and protein metabolism. -Due to hyposecretion (Type 1) or inaction (Type 2) of insulin -Blood glucose levels remain elevated (hyperglycemia) -Glycosuria (glucose in the urine) -ketonuria (ketones in the urine) -Ketoacidosis due to excessive breakdown of fatty acids -3 cardinal signs: polyuria- excessive urine output polydipsia-intense thirst polyphagia- ravenous hunger in a healthy person, the kidney tubules remove all glucose from the filtrate and return it to the blood, so there is little or no glucose in the urine. Water follows the glucose and other solutes by osmosis, so the tubules also reclaim most of the water in the filtrate. Because of the high blood glucose level in diabetes mellitus, glucose enters the kidney tubules so rapidly that it exceeds the maximum rate of reabsorption and the tubules can't reabsorb it fast enough. the excess passes through into the urine. Basement membrane of blood vessels is thickened, limiting nutrient/waste exchange Tissue degeneration Blindness (due to arterial degeneration) Renal failure (due to arterial degeneration) Diabetic neuropathy - nerve damage due to reduced blood flow (no pain felt) Circulation is poorest in the feet, and a lot of pressure is placed on them - frequently become gangrenous and need amputation

describe two reaction pathways that produce blood clots

2 Reaction pathways- Extrinsic Mechanism: Initiated by clotting factors released by the damaged blood vessel and perivascular tissues. Triggered by exposing blood to a factor found in tissues underneath damaged endothelium Extrinsic refers to the fact that these factors come from sources external to the blood itself. Faster- fewer steps. Intrinsic Mechanism: Uses only clotting factors found in the blood itself. Triggered by negatively charged surfaces - platelets, collagen, glass. Slower - many steps In most cases, intrinsic and extrinsic mechanisms work simultaneously and interact with each other to achieve hemostasis. Intrinsic and extrinsic pathways differ only in how they arrive at factor x. Extrinsic pathway to factor X (15 seconds): Damaged blood vessel and perivascular tissues release a lipoprotein mixture called tissue thromboplastin (factor III) > Factor III combines w/ factor VII to form a complex that, in the presence of Ca2+, activates factor X. Intrinsic pathway to factor X (3-6 minutes): Everything needed to initiate it is present in the plasma or platelets. Platelets degranulate > Platelets release factor XII. > through a cascade of reactions, this leads to activated factors XI, IX, and VIII in that order, each serving as an enzyme that catalyzes the next step > finally to factor X. This pathway also requires Ca2+ and PF3. Once factor x is intimated, the remaining events are identical in the intrinsic and extrinsic mechanisms. Thrombin has 2 positive feedback effects: -Accelerates formation of prothrombin activator -Thrombin activates platelets Clot formation remains localized because fibrin absorbs thrombin and clotting factor concentrations are low.

discuss how the body adapts to stress through its endocrine and sympathetic nervous systems

3 stages: 1. Fight or flight Sympathetic division brings in glucose 2. Resistance Hypothalamus releases CRH > ACTH > cortisol > gluconeogenesis, lipolysis, protein catabolism 3. Exhaustion Energy sources are depleted Continued exposure to cortisol leads to muscle wasting, immune suppression, disruption of body systems

describe the composition of blood plasma

90% water 8% plasma proteins 2% dissolved molecules & ions (mostly electrolytes) Because it contains proteins in the plasma, blood is considered a colloid.

Recognize the standard abbreviations for many hormones

ACTH- Adrenocorticotropic Hormone ADH- Antidiuretic hormone CRH- Corticotropin-releasing hormone DHEA- Dehydroepiandrosterone EPO- Erythropoietin FSH- Follicle stimulating hormone GH- Growth hormone GHRH- Growth hormone releasing hormone GnRH- Gonadotropin-releasing hormone IGFs- Insulin-like growth factors LH- Luteinizing hormone NE- Norepinephrine OT- Oxytocin PIH- Prolactin-inhibiting hormone PRL- Prolactin PTH- Parathyroid hormone T3- Triiodothyronine T4- Thyroxine TH- Thyroid hormone TRH- Thyrotropin-releasing hormone TSH- Thyroid-stimulating hormone

explain what eicosanoids are and how they are produced

Eicosanoids -have 20-carbon backbones derived from a polyunsaturated fatty acid called arachidonic acid. some peptide hormones and other stimuli liberate arachidonic acid from one of the phospholipids of the plasma membrane, and the following two enzymes then convert it to various eicosanoids. -they are Paracrine messengers -2 families of eicosanoids synthesized by arachidonic acid: -Prostaglandins affect smooth muscle contraction, blood flow, reproductive processes, platelet function, intensifying pain, etc. -Leukotrienes - stimulate chemotaxis of white blood cells, mediate inflammation

describe in general terms how blood is produced

Everyday, an adult typically produces 400 billion platelets, 200 billion RBCs, and 10 billion WBCs. Production of blood is called hemopoiesis. Red bone marrow produces all seven kinds of formed elements, while lymphocytes are also produced in the lymphatic tissues and organs. All formed elements trace their origins to a common type of hemopoietic stem cell in the bone marrow. HSCs multiply to maintain a small but persistent population in the bone marrow, but some one them go on to become a variety of more specialized cells called colony-forming units. powerpoint: Hemopoiesis or hematopoeisis in red bone marrow Formed elements must constantly be replaced Negative feedback systems regulate the total number of RBCs and platelets in circulation Number of various WBC types based on response to invading pathogens or foreign antigens Erythropoietin (EPO) is a growth factor that increases the number of RBC precursors Produced by the kidneys

explain what happens to blood clots when they are no longer needed

Fibrinolysis- The dissolution of a clot. -Clots need to be removed when vessel is healed -Plasmin: natural "clot buster", digests fibrin -Plasminogen - plasma protein -tPA - tissue plasminogen factor, secreted when clot is near

explain the function of leukocytes in general and the individual role of each leukocyte type

General Leukocytes: -Aka white blood cells -Have nuclei (retain their organelles throughout life unlike erythrocytes) have a complex internal structure -Classified as either granular or agranular -Have MHC antigen proteins protruding from plasma membrane - cell ID markers unique for each person -function: protection against infection and other diseases. Granulocytes- also have various kinds of specific granules that stain conspicuously and distinguish each cell type from the others. Agranulocytes- lack specific granules > inconspicuous to the light microscope, and therefore have relatively clear looking cytoplasm. types: Granulocytes 1. Neutrophils- Neutrophils and macrophages phagocytose; attracted by chemotaxis. Neutrophils respond most quickly to tissue damage by bacteria; Uses lysozymes, strong oxidants, defensins. Functions- phagocytize bacteria and release antimicrobial chemicals. 2. Eosinophils- Leave capillaries and enter tissue fluid; Attack parasitic worms (by releasing enzymes). Release histaminase, phagocytize antigen-antibody complexes. 3. Basophils- Leave capillaries and release granules containing heparin (an anticoagulant, which promotes mobility of other WBCs by preventing clotting), histamine (a vasodilator, which increases blood flow to a tissue) and serotonin, at sites of inflammation; Intensify inflammatory reaction, Involved in hypersensitivity reactions (allergies), Similar to mast cells . Agranulocytes 4. Lymphocytes- The major soldiers of the immune system. B cells destroy bacteria and inactivate their toxins. T cells attack viruses, fungi, transplanted cells, cancer cells and some bacteria. Natural Killer (NK) cells attack a wide variety of infectious microbes and certain tumor cells. 5. Monocytes- take longer to arrive but arrive in larger numbers and destroy more microbes. Enlarge and differentiate into macrophages

describe the body's mechanisms for controlling bleeding

Hemostasis -Sequence of steps to stop bleeding -Quick, localized, carefully controlled 3 mechanisms (happen in order): 1. Vascular spasm- prompt constriction of the broken vessel. smooth muscle contracts, causing vasoconstriction. lasts only a few minutes. Reduces blood loss. 2. Platelet plug formation- injury to lining of vessel exposes collagen fibers; platelets adhere. Platelets release chemicals that make nearby platelets sticky; platelet plug forms. (recap: platelet adhesion > platelet degranulation > platelet aggregation) 3. Coagulation (blood clotting)- fibrin forms a mesh that traps red blood cells and platelets, forming the clot. most effective defense against bleeding. powerpoint: Serum- blood plasma minus clotting proteins Clotting - series of chemical reactions that result in formation of fibrin threads Clotting factors - Ca2+, several inactive enzymes, various molecules associated with platelets or released by damaged tissues 3 stages of clotting: -Extrinsic or intrinsic pathways lead to formation of prothrombin activator (aka prothrombinase) -Prothrombinase converts prothrombin into thrombin -Thrombin converts fibrinogen (soluble) into fibrin (insoluble) forming the threads of the clot Hemorrhage - loss of a large amount of blood

Hemostasis vs homeostasis vs hemopoiesis

Hemostasis- Mechanism for controlling bleeding homeostasis- maintenance or regulation of stable body conditions. hemopoiesis- production of blood cells and platelets

describe how hormones are synthesized and transported to their target organs

Hormone synthesis: all hormones are made from either cholesterol or amino acids, with carbohydrate added in the case of glycoproteins. steroids- synthesized from cholesterol and differ mainly in the functional groups attached to the four-ringed steroid backbone peptides- synthesized the same way as any other protein. The gene for the hormone is transcribed to form a molecule of mRNA, and ribosomes translate the mRNA and assemble amino acids in the right order to make the peptide. Rough endoplasmic reticulum and golgi complex modify the peptide to form the mature hormone. Monoamines- melatonin is synthesized from the amino acid tryptophan and all others from the amino acid tyrosine. Transport: to get from an endocrine cell to a target cell, a hormone must travel in the blood, which is mostly water. Monoamines and peptides are mostly hydrophilic, so mixing with the blood plasma is no problem. steroids and TH, however, are hydrophobic. To travel in the watery bloodstream, they must bind to hydrophilic transport proteins- albumins and globulins synthesized by the liver. A hormone attached to a transport protein is called a bound hormone. one not attached is an unbound (free) hormone. only the unbound hormone can leave a blood capillary and get to a target cell. steroid hormones bind to globulins such as transcortin, the transport protein for cortisol. TH binds to 3 transport proteins in the blood: thyretin, albumin, and most of all, thyroxine-binding globulin.

describe how hormones stimulate their target cells

Hormones stimulate only those cells that have receptors for them- their target cells. the receptors are proteins or glycoproteins located on the plasma membrane, in the cytoplasm, or in the nucleus. They act like switches to turn certain metabolic pathways on or off when the hormones bind to them. specificity- the receptor for one hormone will not bind other hormones -Response depends on the hormone AND the target cell -Lipid-soluble hormones bind to receptors inside target cells -Water-soluble hormones bind to receptors on the plasma membrane -Activates second messenger system -Amplification of original small signal Adenylate Cyclase pathway (Fig 17.9a) -Hormone > receptor > activated G protein >AC converts ATP to cAMP> activates protein kinase Phospholipase C pathway (Fig 17.9b) -Hormone > receptor > activated G protein >Phospholipase C splits PIP2 > DAG & IP3 -DAG > activates protein kinase -IP3 > increases Ca2+concentration > activates protein kinase Target cell response depends on: Hormone concentration Concentration of receptors Affinity of receptor to hormone Influence exerted by other hormones Permissive, synergistic and antagonistic effects

list the hormones produced by the hypothalamus and each lobe of the pituitary, and identify the functions of each hormone

Hypothalamus: -Thyrotropin-releasing hormone (TRH)- Promotes secretion of thyroid-stimulating hormone and prolactin. -Corticotropin-releasing hormone (CRH)- Promotes secretion of adrenocorticotropic hormone. -Gonadotropin-releasing hormone (GnRH)- Promotes secretion of follicle stimulating hormone and luteinizing hormone. -Growth hormone-releasing hormone (GHRH)-Promotes secretion of growth hormone. -Prolactin-inhibiting hormone (PIH)- Inhibits secretion of prolactin. -Somatostatin- Inhibits secretion of growth hormone and thyroid stimulating hormone. Anterior pituitary: -Follicle stimulating hormone (FSH)- targets ovaries, testes. Effects male sperm production and female growth of ovarian follicle and estrogen secretion. -Luteinizing hormone (LH)- targets the ovaries and testes. Effects male testosterone secretion and female ovulation and the corpus luteum. -Adrenocorticotropic hormone (ACTH)- targets the adrenal cortex. effects growth of adrenal cortex and secretion of glucocorticoids. -Thyroid stimulating hormone (TSH)- Targets the thyroid gland. effects the growth of the thyroid and secretion of thyroid hormone. Prolactin(PRL)- Targets mammary glands. Effects milk synthesis. Growth hormone (hGh)- Targets liver, bone, cartilage, muscle, fat. Effects widespread tissue growth, especially in the stated tissues. Posterior Pituitary: ***Does not synthesize hormones, it stores and releases hormones*** -Antidiuretic Hormone (ADH)- Targets the kidneys. Effects water retention. -Oxytocin(OT)- Targets the uterus and mammary glands. Effects labor contractions, milk release; possibly involved in ejaculation, sperm transport, sexual affection, and mother-infant bonding.

describe the formation and life history of leukocytes

Leukopoiesis (production of white blood cells) begins with same hemopoietic stem cells as erythropoiesis. Some HSCs differentiate into distinct types of colony-forming units (CFUs) -Myeloblasts > granulocytes/Neutrophils, eosinophils, and basophils. -Monoblasts > monocytes -Lymphoblasts > all lymphocyte cells CFUs have receptors for colony-stimulating factors (CSFs). Mature lymphocytes and macrophages secrete several types of CSFs in response to infections and other immune challenges. Each CSF stimulates a different WBC type to develop in response to specific needs. Circulating leukocytes do not stay in the blood for very long. Granulocytes circulate for 4-8 hours and then migrate into the tissues, where they live another 4 or 5 days. Monocytes travel in blood for 10-20 hours, then transform into macrophages in the tissues and can live a few years. Lymphocytes survive from weeks to decades. they are continually recycled from blood to tissue fluid to lump and back to the blood. when leukocytes die, they are generally phagocytized and digested by macrophages. Dead neutrophils are responsible for the creamy color of pus, sometimes disposed of by the rupture of a blister.

describe the life history of erythrocytes

Life history from book: Any erythrocyte lives for an average of 120 days from the time it is produced in the red bone marrow until it dies and breaks up. Ina state of balance and stable RBC count, the birth and death of RBCs amount to nearly 100 billion cells per day, (1 million per second). powerpoint: RBC life cycle -RBCs undergo a lot of wear and tear and must be replaced continuously. -No nucleus = no synthesis of new parts -Old ruptured RBCs are removed and destroyed, new RBCs replace them Usually, rate of erythropoiesis = rate of RBC destruction -Negative feedback loop monitors this via oxygen level -Hypoxia - cellular oxygen deficiency Macrophages phagocytose old RBCs Globin & heme are split apart -Globin amino acids recycled -Iron removed from heme & attaches to transferrin Iron stored on ferritin or hemosiderin until needed ("free" iron is toxic) Iron + transferrin carried to red bone marrow Erythropoiesis occurs in red bone marrow

Define Hormone

Messenger molecule that binds to receptors elsewhere in the body.

discuss how hormones are removed from circulation after they have performed their roles

Most hormones are taken up and degraded by the liver and kidneys, and then excreted in the bile or urine. Some are degraded by their target cells. The rate of hormone removal is the metabolic clearance rate.

describe the appearance and relative abundance of each type of leukocyte

Neutrophils: Appearance- Nucleus usually with 3-5 lobes S or C shaped. Fine reddish to violet specific granules in cytoplasm. Abundance- 60-70% of WBCs/4,150 cells per uL Eosinophils: Appearance- Nucleus usually has two large lobes connected by thin strand. Large orange-pink specific granules in cytoplasm. Abundance- 2-4% of WBCs/165 cells per uL Basophils: Appearance- Nucleus large and U or S shaped, but typically pale and obscured from view. Coarse, abundant, dark violet specific granules in cytoplasm. Abundance- <0.5% of WBCs/44 cells per uL Lymphocytes: Appearance- Nucleus round, ovoid, or slightly dimpled on one side, of uniform or mottled dark violet color. In small lymphocytes, nucleus fills nearly all of the cell and leaves only a scanty rim of clear, light blue cytoplasm. In larger lymphocytes, cytoplasm is more abundant; may be hard to differentiate from monocytes. Abundance- 25-33% of WBCs/2,185 cells per uL Monocytes: Appearance- Nucleus ovoid, kidney shaped, or horseshoe-shaped; violet. Abundant cytoplasm with sparse, fine nonspecific granules. Sometimes very large with stellate or polygonal shapes. Abundance- 3%-8% of WBCs/456 cells per uL

list some blood groups other than ABO and Rh and explain how they may be useful

Other groups: MN, Duffy, Kell, Kidd, and Lewis. Useful for such legal purposes as paternity and criminal cases and for research in anthropology and population genetics.

describe some disorders of blood clotting

Patients at risk of forming blood clots may received anticoagulants like heparin or warfarin Warfarin is an antagonist to vitamin K blocks synthesis of clotting factors vitamin K deficiency: -Fat soluble vitamin absorbed through intestine into blood -Not involved in clot formation, but required for the synthesis of 4 clotting factors -Deficiency can cause uncontrolled bleeding. Thromboembolism (intravascular clotting): -Even though your body has anticoagulating mechanisms to dissolve small clots, sometimes they form anyway -Thromus - clot -Thrombosis - abnormal clotting in an unbroken vessel -Embolus - blood clot, air bubble, fat, or debris transported by the bloodstream -Pulmonary embolism - embolus in the lungs -more likely to occur in veins than arteries because blood flow is slower. Aspirin inhibits vasoconstriction and platelet aggregation by blocking thromboxane A2 synthesis -Reduces risk of transient ischemic attacks, strokes, heart attacks, artery blockage Thrombolytic agents dissolve blood clots -Activate plasminogen, which digests fibrin -Genetically engineered tPA treats heart attack and stroke victims

describe the structure and location of the remaining endocrine glands

Pineal Gland- Pine cone shape, attached to the roof of the third ventricle of the brain, beneath the posterior end of the corpus callosum. Thymus- A bilobed glad in the mediastinum superior to the heart, behind the sternal manubrium. Thyroid Gland- 2 lobes connected by isthmus, located inferior to larynx. Parathyroid Glands- ovoid glands, usually four in number, partially embedded in the posterior surface of the thyroid. Adrenal Glands- Sit on top of the kidneys 2 distinct regions - cortex & medulla Pancreatic islets- Located at first part of small intestine. Functions as an exocrine and endocrine gland

name the hormones these endocrine glands produce, what stimulates their secretion, and their functions

Pineal Gland: -melatonin- effects uncertain, may influence mood and sexual maturation. Secretion is stimulated at night. Thymus: -Thymopoietin, thymosin, thymulin- stimulate T lymphocyte development and activity. hormones stimulate development of other lymphatic organs and T cell activity. Thyroid Gland: -Thyroxine and Triiodothyronine- elevates metabolic rate and heat production; increase respiratory rate, heart rate, and strength of heart beat; stimulate appetite and accelerate breakdown of nutrients; promote alertness and quicken reflexes; stimulate growth hormone secretion and growth of skin, hair, nails, teeth, and fetal nervous system. thyroid hormone is secreted or inhibited in response to fluctuations in metabolic rate. Parathyroid Gland: -parathyroid hormone (PTH)- regulates blood calcium levels. Secrete PTH when the calcium level dips too low. Adrenal Medulla: -epinephrine, norepinephrine, dopamine- Intensifies sympathetic responses. stimulated by nerve fibers usually in a situation of fear, pain, or other stress. Adrenal cortex: -Mineralocorticoids: affect mineral homeostasis. Regulation of Na+ is very important - tied to other mineral & water levels. Aldosterone regulates Na+ & K+, is secreted when blood pressure falls. -Glucocorticoids: cortisol-regulates: Protein breakdown, Glucose formation & lipolysis, Stress resistance, Anti-inflammatory effects, Depression of immune responses. Secreted by the zone fasciculate and zone reticularis in response to ACTH from the pituitary. -Androgens: Dehydroepiandrosterone (DHEA) and estradiol are sex steroids. ACTH regulates androgen and cortisol secretion. Pancreatic islets: -Alpha cells secrete glucagon - raises blood sugar -Beta cells secrete insulin - lowers blood sugar -Delta cells secrete somatostatin - inhibits stomach acid secretion

distinguish between the anterior and posterior lobes of the pituitary

Pituitary Gland: -Anterior pituitary = adenohypophysis -Stimulated by hypothalamic releasing hormones or inhibiting hormones -Tropic hormones act on other endocrine glands -Posterior pituitary = neurohypophysis -Hypothalamic-hypophyseal tract - nerve bundle; connection between hypothalamus and pituitary -Hypophyseal portal system Pituitary Gland- suspended from the floor of the hypothalamus by a stalk and housed in a depression of the sphenoid bone, the sella turcica. Usually about 1.3 cm wide and roughly the size and shape of a kidney bean. composed of two structures, the anterior and posterior pituitary. The anterior pituitary arises from a pouch that grows upward from the embryonic pharynx, while the posterior pituitary arises as a bud growing downward from the brain. they come to lie side by side and are so closely joined that they look like a single gland. the anterior pituitary constitutes about 3/4 of the pituitary as a whole. has no nervous connection to the hypothalamus but is linked to it by a complex of blood vessels called the hypophyseal portal system. the posterior pituitary- hormones are made by certain neuroendocrine cells in the hypothalamus. their icons pass down the stalk as a bundle called the hypothalamo-hypophyseal tract and end in the posterior lobe.

describe the anatomical relationships between the hypothalamus and pituitary gland

Pituitary gland- "Master gland" Hypothalamus- controls pituitary and is the link between the nervous and endocrine systems. Hormones secreted from these 2 structures play roles in growth, development, metabolism, and homeostasis. Hypothalamus- shaped like a flattened funnel, forms the floor and walls of the third ventricle of the brain. Pituitary Gland- suspended from the floor of the hypothalamus by a stalk and housed in a depression of the sphenoid bone, the sella turcica. Usually about 1.3 cm wide and roughly the size and shape of a kidney bean. composed of two structures, the anterior and posterior pituitary. The anterior pituitary arises from a pouch that grows upward from the embryonic pharynx, while the posterior pituitary arises as a bud growing downward from the brain. they come to lie side by side and are so closely joined that they look like a single gland. the anterior pituitary constitutes about 3/4 of the pituitary as a whole. has no nervous connection to the hypothalamus but is linked to it by a complex of blood vessels called the hypophyseal portal system. the posterior pituitary- hormones are made by certain neuroendocrine cells in the hypothalamus. their icons pass down the stalk as a bundle called the hypothalamo-hypophyseal tract and end in the posterior lobe.

briefly describe some common disorders of pituitary, thyroid, parathyroid, and adrenal function

Pituitary: -gigantism- hypersecretion of growth hormone during childhood. Epiphyseal growth plates are targeted. Abnormally tall (7-8 ft), but normal body proportions. -pituitary dwarfism- childhood hyposecretion. -Acromegaly- In adulthood, hypo secretion causes this. thickening of the bones and soft tissues, with especially noticeable effects on the hands, feet, and face. Thyroid: -congenital hypothyroidism- thyroid hyposecretion present from birth -Myxedema- caused by severe or prolonged adult hypothyroidism. -Endemic goiter- When there is an iodine deficiency, your body cannot make T3 and T4. Since TSH operates on a negative feedback loop, there is nothing to shut off its production. The thyroid gland becomes enlarged due to the increased production of TSH. parathyroid: -hypoparathyroidism- parathyroids are sometimes accidentally removed in thyroid surgery or degenerate when neck surgeries cut off their blood supply. W/o hormone replacement therapy, hypoparathyroidism causes a rapid decline in blood calcium level. this can lead to a fatal, suffocating spasm of the muscles of the larynx. -hyperparathyroidism- excess PTH secretion, usually caused by a parathyroid tumor. causes bones to become soft, deformed, and fragile. it raises the blood levels of calcium and phosphate ions. promotes the formation of kidney stones. Adrenal: -cushing syndrome- excess cortisol secretion owing to any of several causes; ACTH hyper secretion by the pituitary, ACTH-secreting tumors, or hyperactivity of the adrenal cortex independently of ACTH. cushing syndrome disrupts carbohydrate and protein metabolism, leading to hyperglycemia, hypertension, muscular weakness, and edema. -Adrenogenital syndrome- the hypersecretion of adrenal androgens, commonly accompanies cushing syndrome. In children, AGS often causes enlargement of the penis or clitoris and the premature onset of puberty.

state and define some clinical measurements of RBC and hemoglobin quantities

RBC count and hemoglobin concentration are important clinical data because they determine the amount of oxygen the blood can carry. 3 most common measurements: hematocrit, hemoglobin concentration, and RBC count. -Hematocrit (packed cell volume, PVC) is the percentage of whole blood volume composed of RBCs. In men it normally ranges between 42% and 52%; women, between 37% and 48%. -Hemoglobin concentration of the whole blood is normally 13 to 18 g/dL in men and 12 to 16 g/dL. -RBC count is normally 4.6 to 6.2 million RBCs/uL in men and 4.2 to 5.4 million RBCs/uL in women. Often expressed as cells per cubic millimeter.

name and describe the types, causes, and effects of RBC excesses and deficiencies

RBC excess- polycythemia RBC or hemoglobin deficiency- anemia 1. Primary Polycythemia -cause: due to cancer of the erythropoietic line of the red bone marrow. -effect: it can result in a RBC count as high as 11 million RBCs/uL and a hematocrit as high as 80%. Blood volume can double and cause the circulatory system to become tremendously engorged. Blood viscosity may rise to 3 times normal. circulation is poor, the capillaries are congested with viscous blood, and the heart is dangerously strained. chronic polycythemia can lead to embolism, stroke, or heart failure. The deadly consequences of emphysema and some other lung diseases are due in part to polycythemia. 2. Secondary polycythemia (Polycythemia from all other causes) causes: dehydration (because water is lost from the bloodstream white erythrocytes remain and become abnormally concentrated), more often it is caused by smoking, are pollution, emphysema, high altitude, excessive aerobic exercise, or other factors that create a state of hypoxemia and stimulate erythropoietin secretion. effect: characterized by RBC counts as high as 6 to 8 million RBCs/uL . Principle dangers/effects of polycythemia are increased blood volume, pressure, and viscosity. 3. Anemia Causes (3 categories): -inadequate erythropoiesis or hemoglobin synthesis -hemorrhagic anemia from bleeding (blood loss) -hemolytic anemia from RBC destruction. -often results from kidney failure, b/c RBC production depends on erythropoietin (produced mainly by the kidneys) -erythropoiesis declines with age b/c kidneys atrophy and produce less and less EPO. -nutritional anemia results form a dietary deficiency, most commonly an iron deficiency caused by blood loss w/o getting enough dietary iron to compensate for it. also from a deficiency of vitamin B12 (occurs when not eating enough meat or stomach gland issue) powerpoint: Blood's oxygen-carrying capacity is too low to support metabolism Sign of a disorder, not a disease itself Anemic individuals are fatigued, short of breath, chilled, may be pale Causes: hemorrhage, not enough RBCs Iron-deficiency anemia Pernicious anemia - autoimmune disorder that attacks stomach cells that produce intrinsic factor necessary for hemopoiesis Renal anemia - lack of EPO Aplastic anemia - destruction or inhibition of red bone marrow (blood transfusions necessary until bone marrow transplant can occur) Hemorragic anemia - due to uncontrolled bleeding Effects/3 potential consequences: -tissues suffer hypoxia (oxygen deprivation). fatigued, short of breath, chilled, may be pale. can cause life-threatening necrosis of brain, heart, and kidney tissues. -blood osmolarity is reduced. more fluid thus transfers from the bloodstream to the intercellular spaces, resulting in edema. -blood viscosity is reduced. b/c blood puts up so little resistance to flow, the heart beats faster than normal and cardiac failure may ensue. Blood pressure also drops and because of the reduced volume and viscosity. AKA -Tissues suffer hypoxia Pallid skin Short of breath Lethargic -Reduced blood osmolarity Edema -Reduced blood viscosity Faster heartbeat Lower blood pressure 4. Sickle-cell anemia Abnormal Hb causes sickling of RBC RBCs rupture easily and block small blood vessels Occurs primarily in malaria belt of Africa Heterozygous individuals are better protected against malaria

describe the effects of a blood type incompatibility between mother and fetus

Rh blood group -People whose RBCs have the Rh antigen are Rh+ -People who lack the Rh antigen are Rh- -Normally, blood plasma does not contain anti-RH antibodies Hemolytic disease of the newborn (HDN) can occur when a woman has a baby with a mismatched blood type mostly when mother is Rh- and carries an Rh+ fetus. If blood from Rh+ fetus contacts Rh- mother during birth (placental leakage or miscarriage), mother produces anti-Rh antibodies. If she becomes pregnant again with another RH+ fetus, her Anti-Rh antibodies may pass through the placenta and agglutinate the fetal erythrocytes. Agglutinated RBCs hemolyze and the baby is born with hemolytic anemia. ***Effect is only on second Rh+ baby

discuss the hormones produced by organs and tissues other than the classical endocrine glands

Skin- Keratinocytes of the epidermis convert a cholesterol like steroid into cholecalciferol using energy from solar UV radiation. The liver and kidneys further convert it to a calcium-regulating hormone, calcitriol. Liver- involved in the production of at least 5 hormones: calcitriol (from the skin), angiotensin II, a regulator of blood pressure (converted from the protein angiotensinogen by the kidneys, lungs and other organs), erythropoietin (a hormone that stimulates the red bone marrow to produce RBCs), IGF (a hormone that mediates the action of hGH), and hepcidin (the principal hormonal mechanism of iron homeostasis). Kidneys- play role in production of 3 hormones: calcitrol (skin/liver), renin (converts angiotensinogen to angiotensin), and about 85% of the body erythropoietin. Heart- Rising blood pressure stimulates cardiac muscle in the atria to secrete two similar natriuretic peptides. they increase sodium excretion and urine output to lower blood pressure. Stomach and intestines- These have various endocrine cells which secrete at least 10 different enteric hormones. -peptide YY signals fullness and terminates eating. -cholecystokinin stimulates the gallbladder to release bile, has appetite suppressing effect. -Ghrelin, stimulates appetite. -Gastrin- stimulates cells of the stomach to secrete hydrochloric acid. Adipose tissue- Fat cells secrete leptin, has long term effects on appetite regulating centers of the hypothalamus. Osseous tissue- Osteoblasts secrete osteocalcin, effects insulin secretion and inhibits weight gain. Placenta- Secretes estrogen, progesterone, and other hormones that regulate pregnancy and stimulate fetal development and mammary gland development.

give a physiological definition of stress

Stress is defined as any situation that upsets homeostasis and threatens ones physical or emotional well-being. Stressors may include: heat/cold, poisons, bleeding from surgery, strong emotions Your body's homeostatic mechanisms attempt to counteract stress Stress response mainly controlled by hypothalamus (HPA axis), resulting in cortisol release physiological causes- injury, surgery, hemorrhage, infection, intense exercise, temperature extremes, pain, and malnutrition. emotional causes- anger, grief, depression, anxiety, and guilt.

explain how target cells regulate their sensitivity to circulating hormones

Target cells can adjust their sensitivity to a hormone by changing the number of receptors for it. In up-regulation, a cell increases the number of hormone receptors and becomes more sensitive to the hormone. Down regulation is the process in which a cell reduces its receptor population and this becomes less sensitive to a hormone. Up-regulation makes a cell more sensitive to its receptor Down-regulation makes a cell less sensitive

describe the functions and major components of the circulatory system

The circulatory system consists of the heart, blood vessels, and blood. Functions: Transport: -Blood carries oxygen from the lungs to all of the body's tissues, while it picks up carbon dioxide from those tissues and carries it to the lungs to be removed from the body. -It picks up nutrients from the digestive tract and delivers them to all of the body's tissues. -It carries metabolic wastes to the kidneys for removal. -It carries hormones from endocrine cells to their target organs. -It transports a variety of stem cells from the bone marrow and other origins to the tissues where they lodge and mature. Protection: -Blood plays several roles in inflammation, a mechanism for limiting the spread of infection. -White blood cells destroy microorganisms and cancer cells and remove debris from the tissues. -Antibodies and other blood proteins neutralize toxins and help to destroy pathogens. -Platelets secrete factors that initiate blood clotting and other processes for minimizing blood loss, and contribute to tissue growth and blood vessel maintenance. Regulation: -By absorbing or giving off fluid under different conditions, the blood capillaries help to stabilize fluid distribution in the body. -By buffering acids and bases, blood proteins help to stabilize the pH of the extracellular fluids. -Cutaneous blood flow is extremely important in dissipating metabolic heat from the body. Shifts in blood flow help to regulate body temperature by routing blood to the skin for heat loss or retaining it deeper in the body to conserve heat.

Define Endocrine System

The glands, tissues, and cells that secrete hormones.

explain how the pituitary is controlled by the hypothalamus and its target organs

The timing and amount of pituitary secretion are regulated by the hypothalamus, other brain centers, and feedback from the target organs. Hypothalamic control enables the brain to monitor conditions within and outside the body and to stimulate or inhibit the release of anterior lobe hormones in response. The posterior pituitary is controlled by neuroendocrine reflexes- the release of hormones in response to nerve signals. Negative feedback inhibition- the pituitary stimulates another endocrine gland to secrete its hormone, and that hormone feeds back to the pituitary or hypothalamus and inhibits further secretion of the pituitary hormone. Feedback from a target organ is not always inhibitory. can be a positive feedback cycle as well.

identify the chemical classes to which various hormones belong

Three chemical classes: steroids, monoamines, and peptides. Steroids - synthesized from cholesterol Peptide- chains of 3-200 or more amino acids. most hormones Monoamines: -Catecholamines: dopamine, epinephrine, norepinephrine -melatonin, thyroid hormone -made from amino acids and retain an amino group Eicosanoids -Paracrine messengers -2 families of eicosanoids synthesized by arachidonic acid: -Prostaglandins affect smooth muscle contraction, blood flow, reproductive processes, platelet function, intensifying pain, etc. -Leukotrienes - stimulate chemotaxis of white blood cells, mediate inflammation hormone classification: -Lipid-soluble - use transport proteins Steroid hormones Thyroid hormones (T3 and T4) Nitric oxide (NO) Eicosanoids -Water-soluble - are "free" Amine hormones Peptide/protein hormones

describe the effects of growth hormone

Unlike the other pituitary hormones, GH is not targeted to just one or a few organs but has widespread effects on the body. -stimulates diverse tissues such as muscle and bone. -it induces the liver and other tissues to secrete growth stimulants called insulin-like growth factors which stimulate other target cells. important in fetal growth. Function: promote synthesis & secretion of IGFs IGFs: insulinlike growth factors -Cause cells to grow and multiply by increasing protein synthesis -Lipid metabolism: Enhances lipolysis for more ATP. protein sparing effect-makes it unnecessary for cells to consume their own proteins. -Protein synthesis for tissue growth -Carbohydrate metabolism: Glucose-sparing effect; reduces the dependence of most cells on glucose so they will not compete with the brain. -Electrolyte balance: promotes Na+, K+, and Cl- retention by the kidneys, enhances Ca2+ absorption by the small intestine, and makes these electrolytes available to the growing tissues.

explain what determines a person's ABO and Rh blood types and how this relates to transfusion compatibility

background info: Blood group - based on presence or absence of antigens -At least 24 blood groups and more than 100 antigens -ABO and Rh are examples of blood groups Antigens- complex molecules such as proteins, glycoproteins, and glycolipids that are genetically unique to each individual (except identical twins). They occur on the surfaces of all cells and enable the body to distinguish its own cells form foreign matter. When the body detects an antigen of a foreign origin, it activates an immune response. Antibodies bind to antigens and mark them, or the cells bearing them, for destruction. Agglutinogens - surface of RBCs contain genetically determined assortment of antigens Agglutinins - antibodies in the blood plasma Agglutination - clumping from antigens and antibodies mixing ABO Blood Groups: determined by the hereditary presence or absence of antigens A and B on the RBCs. -Type AB blood has antigens A and B -Universal recipients - neither anti-A or anti-B antibodies Type O blood has neither antigen -Universal donor Reason for antibodies not clear type A: A antigen on RBCs and Anti-B antibody in plasma. compatible with A and O donor. type B: B antigen on RBCs and Anti-A antibody in plasma. Compatible with B and O donor. Type AB: Both A and B antigens on RBCs, neither antibody in plasma. universal receiver Type O: No antigens, both anti-A and anti-B antibodies. universal donor. only receive from O donor. RH Blood Group: Rh antigen (D antigen) found in blood of some -Rh positive -Rh negative (lack the Rh/D antigen) Anti-Rh antibodies not normally present in the blood. form only in Rh- individuals who are exposed to Rh+ blood: If an Rh- person receives an Rh+ blood transfusion, the immune system will make anti-Rh antibodies > agglutination > hemolysis

explain some general causes and examples of hormone hyposecretion and hypersecretion

hyposecretion: inadequate hormone release. cause: can result from tumors or lesions that destroy an endocrine gland or interfere with its ability to receive signals from another cell. ex: a fractured sphenoid bone can sever the hypothalamo-hypophyseal tract and prevent the transport of oxytocin and antidiuretic hormone to the posterior pituitary. The resulting ADH hypo secretion disables the water-conserving capability of the kidneys and leads to diabetes insidious, an output of abundant but glucose-free urine. cause: autoimmune disease can lead to hypo secretion ex: when endocrine cells are attacked by autoantibodies- antibodies that fail to distinguish foreign matter from ones own tissues. Hypersecretion: Excessive hormone release cause: some tumors result in the overgrowth of functional endocrine tissue. Ex: A pheochromocytoma is a tumor of the adrenal medulla that secretes excessive amounts of epinephrine and norepinephrine. cause: some tumors in nonendocrine organs produce hormones ex: some lung tumors secrete ACTH and overstimulate cortisol secretion by the adrenal gland. Ex: toxic goiter- autoantibodies mimic the effect of TSH on the thyroid, activating the TSH receptor and causing thyroid hyper secretion.

describe several physiological roles of prostaglandins

inflammatory- promote fever and pain, two cardinal signs of inflammation endocrine- mimic effects of TSH, ACTH, and other hormones nervous- function as neuromodulators, altering the release or effects of neurotransmitters in the brain. reproductive- promote ovulation and formation of corpus luteum; induce labor contractions gastrointestinal- inhibit gastric secretion vascular- act as vasodilators and vasoconstrictors respiratory- constrict or dilate bronchioles Renal- promote blood circulation through the kidney, increase water and electrolyte excretion.

describe the structure and function of hemoglobin

powerpoint: 1 Hemoglobin molecule carries 4 molecules O2 Globin - 4 polypeptide chains Heme pigment in each of 4 chains Fe2+ in each heme that binds oxygen reversibly -Each RBC contains 280 million hemoglobin -Also transports 23% of total carbon dioxide Combines with amino acids of globin -Nitric oxide (NO) binds to hemoglobin Releases NO causing vasodilation to improve blood flow and oxygen delivery -Also binds carbon monoxide... more strongly than it binds oxygen forms of hemoglobin: -Oxyhemoglobin - Hb saturated with oxygen -Deoxyhemoglobin - "reduced" Hb -Carbaminohemoglobin - Carbon dioxide bound to amino acids of Hb function: carry oxygen

discuss the structure and function of erythrocytes (RBCs)

powerpoint: Aka red blood cells Biconcave discs No nucleus or organelles (remarkably devoid of internal structure) Some glycolipids on the plasma membrane are antigens (ABO groups) Contain hemoglobin -Pigment that gives blood its red color -Carries oxygen function: Main function: transport oxygen (& some CO2) -No nucleus = more space for oxygen -Anaerobic respiration = no oxygen used -Biconcave shape = more surface area for diffusion -Lots of hemoglobin = lots of gas transport Book: functions- pick up oxygen and transport it to tissues elsewhere & to pick up carbon dioxide from the tissues and unload it in the lungs.

identify some classes and functions of eicosanoids

prostacyclin- is produced by the walls of the blood vessels, where it inhibits blood clotting and vasoconstriction. Thromboxanes- are produces by blood platelets. In the event of injury, they override prostacyclin and stimulate vasoconstriction and clotting. Prostaglandins- The most diverse eicosanoids. They have a five-sided carbon ring in their backbone. thought to be produced in most organs of the body. The PGE family relaxes smooth muscle in the bladder, intestines, bronchioles, and uterus and stimulates contraction of the smooth muscles of blood vessels. PGF has the opposite effect.

Describe similarities and differences between the nervous and endocrine systems

similarities: -both serve for internal communication -both communicate chemically; several chemicals function as both neurotransmitters and hormones. -some hormones and neurotransmitters produce identical effects on the same organ. differences (image)

describe how hormones affect each other when two or more of them stimulate the same target cells

synergistic effects: two or more hormones act together to produce an effect that is greater than the sum of their separate effects. Permissive effects: one hormone enhances the target organs response to a second hormone to come later. Antagonistic effects: One hormone opposes the action of another.

explain the significance of blood viscosity and osmolarity

viscosity- The resistance of a fluid to flow, resulting from the cohesion of its particles. It is the thickness or stickiness of a fluid. viscosity is important in circulatory function because it partially governs the flow of blood through the vessels. An RBC or protein deficiency reduces viscosity an causes blood to flow too easily, whereas an excess causes blood to flow too sluggishly. Either of these conditions puts a stain on the heart that may lead to serious cardiovascular problems if not corrected. Osmolarity- is the total molarity of dissolved particles that cannot pass through the blood vessel wall. ** from powerpoint: Colloid osmotic pressure - the osmotic pressure exerted by plasma proteins Helps to maintain blood volume and blood pressure. Draws fluid into blood and prevents the loss of fluid in the capillaries If plasma protein levels decrease, colloid osmotic pressure decreases,resulting in fluid loss from the blood and edema In order to nourish surrounding cells and remove their wastes, substances must pass between the bloodstream and tissue fluid through the capillary walls. This transfer of fluids depends on a balance between the filtration of fluid from the capillary and its reabsorption by osmosis. The rate of reabsorption is governed by the relative osmolarity of the blood versus the tissue fluid. If the blood osmolarity is too high, the bloodstream absorbs too much water. This raises the blood volume, resulting in high blood pressure and a potentially dangerous strain on the heart and arteries. If the osmolarity drops too low, too much water remains in the tissues. They become edematous (swollen) and the blood pressure may drop to dangerously low levels because of the water lost from the bloodstream. It is important that blood maintain an optimal osmolarity.