APHY 102 Midterm Exam - Ivy Tech with complete solutions

What is a hormone and how does it act? Hormones are chemical messengers that are responsible for regulation. They are secreted into body fluids, mainly blood. It has specific actions on target tissues, which are any tissue that has specific receptors for that particular hormone. What is a paracrine gland? a secretion that enters interstitial fluid but affects only neighboring cells What is an autocrine gland? A secretion that only affects the secreting cell. What is an endocrine gland? A gland that secretes a substance (a hormone) into the bloodstream and act on target cells What is an exocrine gland? A ducted gland that produces a secretion onto a body surface. Where is the thymus located? mediastinum; behind the sternum Where is the pineal gland located? center of brain Where are the reproductive organs located? abdomen; pelvic Where is the pituitary gland located? sella turcica of the sphenoid bone; base of the brain Where are the adrenal glands located? on top of each kidney Where is the pancreas located? posterior to the stomach What are the two steroid hormones? Sex hormones and adrenal cortex hormones; estrogen and testosterone Describe steroid hormones -diffuse through cell membranes into cytoplasm or nucleus -combine with a receptor molecule binding to DNA -promote transcription of mRNA -mRNA enters cytoplasm directing protein synthesis Describe non-steroid hormones. Amines, proteins, peptides, and glycoproteins. The endocrine gland secretes nonsteroid hormones, which body fluid carries hormone to its target cell. Hormone combines with receptor site on membrane of its target cell, activating G protein. Cellular changes produce the hormone's effects. How is the anterior pituitary gland different than the posterior pituitary gland? The anterior pituitary becomes an endocrine gland producing and secreting hormones for the body and connects to the posterior pituitary when fully formed. Meanwhile, the posterior pituitary remains connected to the hypothalamus, functioning as a repository for hormones produced by the hypothalamus and receiving messages from it that regulate when hormones are to be released to and through the anterior pituitary What regulates pituitary gland secretion? Hypothalamus Describe tropic hormones stimulate other endocrine glands to release hormones anterior pituitary hormones ACTH - controls manufacture and secretion of certain hormones from the outer layer of the adrenal gland. FSH - controls growth and development of follicles that house egg cells in ovaries and stimulate production of sperm cells in the testes. GH - stimulates cells to enlarge and more rapidly divide LH - promotes secretion of sex hormones and allows release of egg cells from ovaries PRL - promotes milk production TSH - controls secretion of certain hormones from the thyroid posterior pituitary hormones ADH - reduces volume of water that kidneys secrete Oxytocin - smooth muscle contraction and allows contraction of the uterus during childbirth and may stimulate the movement of certain fluids in the male reproductive tract during sexual activity Thyroid hormones Calcitonin - controls blood calcium and phosphate ion concentration Thyroxine(T4) - more prevalent in circulation Triiodothyronine(T3) - more potent than T4 Parathyroid hormones PTH - increases blood calcium ion concentration and decreases blood phosphate ion concentration through actions in the bones, kidneys, and intestines adrenal medulla hormones epinephrine and norepinephrine - increase heart rate, BP, breathing, decrease digestion adrenal cortex hormones Aldosterone - helps regulate concentration of sodium and potassium ions Cortisol - affects glucose metabolism and influences proteins and fat metabolism Pancreas hormones Glucagon - stimulates liver to break down glycogen into glucose Insulin - stimulates the liver to form glycogen from glucose Somatostatin - helps regulate glucose metabolism by inhibiting secretion of glucagon and insulin pineal gland hormone Melatonin - made from serotonin and regulates circadian rhythms Thymus Gland Hormones Thymosins - affect production and differentiation of T lymphocytes How are glucagon and insulin alike? Both work to keep blood glucose concentration constant How are glucagon and insulin different? Glucagon stimulates the liver to break down glycogen into glucose and insulin promotes the formation of glycogen from glucose How is diabetes insipitus different from diabetes mellitus? Diabetes insipitus - a person is insatiably thirsty and has large amounts of urine output Diabetes mellitus - two types (type 1 and type 2). Type 1 occurs when body makes no insulin. Type 2 occurs when the body reaches insulin resistance How are pheromones different than hormones? Pheromones are a type of hormone that are released in small quantities and play a big role in physical attraction between people. How does aging affect the endocrine system? As people get older, their endocrine glands decrease in size, muscular strength decreases as GH levels decrease, ADH levels increase due to slower breakdown in liver & kidneys. Calcitonin levels decrease, and insulin resistance may develop. Describe normal blood: number of each cell type, pH. Blood is about 8% of body weight. Adult blood volume is about 5 L. RBC count is usually 4,600,000-6,200,000 in males, 4,200,000-5,400,000 in females. WBC are usually 5,000-10,000 per cubic mm of blood. Platelets are usually 130,000-360,000 per cubic mm of blood. Normal blood pH is around 7.4. Describe the different formed elements and their origins RBCs originate in red bone marrow from hemocytoblasts (stem cells) which then differentiate in a process called hematopoiesis. WBCs are called leukocytes and are split into granulocytes and agranulocytes. Platelets are cell fragments of megakaryocytes; they lack a nucleus and are half the size of a RBC. Compare the formed elements of the blood. RBCs, WBCs, and platelets all act together to maintain life. RBCs transport oxygen to the body's tissues, WBCs fight infections in the body, and platelets clot wounds that occur. What are normal levels and percentages of RBC 4,600,000-6,200,000 in males. 4,200,000-5,400,000 in females. 4,500,000-5,100,000 in children. RBCs are 45% of the blood. How is the shape of a red blood cell important to its function? It allows them to squeeze through vessel walls and transport oxygen to tissues Why might blood volume differ from one person to the next? It might differ depending on a person's health and age, and women tend to have lower blood volume due to their menstrual cycle. What is hematocrit? the ratio of the volume of red blood cells to the total volume of blood Neutrophils Most abundant WBC; 54-62%. Phagocytic and tend to self-destruct as they destroy foreign invaders, limiting their life span to a few days. Eosinophils Deep red granules in acid stain, bi-lobed nucleus, 1-3% of WBC Basophils release histamine and heparin, <1% of WBC Monocytes Largest of all blood cells, kidney or oval shaped nuclei, become macrophages, 3-9% of WBC Lymphocytes Slightly larger than RBC, 25-33% WBC Compare serum versus plasma Plasma is the liquid part of blood, in which blood cells, nutrients and hormones float. Serum is the fluid part of blood, without the clotting factors or blood cells. Describe the steps in clot formation Hemostasis - the stoppage of bleeding. 1. Blood vessel spasm - smooth muscle in blood vessel contracts 2. Platelet plug formation: a. break in vessel wall b. blood escapes through break c. platelets adhere to each other, to end of broken vessel, and to exposed collagen d. platelet plug helps control blood loss 3. Blood coagulation - clot forms (occurs extrinsically or intrinsically). What happens if clots form within blood vessels? A thrombus is made. If it breaks loose of the vessel wall and begins circulating through the body, it is then called an embolus, which can travel into tighter vessels and get trapped, causing death. What is edema? Abnormal accumulation of fluid in the interstitial spaces, causing swelling of the tissues What antigens can be found on RBC? Antigens A, B, AB, or none. What antibodies can be found in the plasma? Antibodies A, B, AB, or none. Type A Contains A antigens on cell surface and anti-B antibodies in plasma Type B Contains B antigens on cell surface and anti-A antibodies in plasma Type AB Contains both A and B antigens on cell surface and no antibodies in plasma Type O Contains no antigens on cell surface and has both anti-A and anti-B antibodies in plasma (universal donor) Type A can give to Either Type A or Type AB Type A can receive from Either Type A or Type O Type B can give to Either Type B or Type AB Type B can receive from Either Type B or Type O Type AB can give to only AB Type AB can receive from A, B, AB, O Type O can give to A, B, AB, O Type O can receive from only O How does the Rh factor affect a developing fetus and its mother? Rh positive - presence of antigen D or other Rh antigens on the RBC membranes. Rh negative - lack of these antigens If a mother is Rh negative and her baby is Rh positive, her antibodies form to fight Rh-positive blood cells. If a mother is Rh positive and her baby is Rh positive, her antibodies attack the baby's RBC. Complications can lead the baby to develop erythroblastosis fetalis or hemolytic disease.