A&P 2 Exam 3 Study Guide PDF

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Chapter 18 Know the types of hormones, what constitutes a target cell, the effects of hormones, the mechanisms for causing those effects, and the kinds of stimuli for hormone release. Any related terms (e.g., up-regulation, receptor, G protein, cAMP) are fair game.

Types of Hormones: 1. Peptide Hormones= amino acid/amino acid sequences a. protein= ADH b. polypeptide= insulin c. Individual amino acid= thyroxine (“thyroid hormone”) 2. Steroid Hormone a. Aldosterone, cortisone, estrogen b. Made by GONADS and the ADRENAL CORTEX 3. Eicosanoids a. Made from plasma membrane phospholipids b. Released in paracrine (release to nearby cells) and/or autocrine fashion (release to itself) c. Figure prominently in inflammation and other immune activities i. 2 types: 1. Leukotrienes= generate responses in WBCs (chemotaxis, leukocytosis) 2. Prostaglandins= generate hyperemia, pain, swelling Target Cell= a cell bearing receptors for a specific hormone Effects of Hormones on target cells: ● Change target cells membrane potential ● Cause target cell to reproduce via mitosis/meiosis ● Cause target cell to secrete ● Cause target cell to make a specific protein (including enzymes) ● Cause target cell to increase/decrease current levels of proteins

2 Mechanisms hormones use to influence target cells: 1. Second Messenger Systems a. Used by hormones that are TOO POLAR to cross plasma membrane

b. Make a chemical called a second messenger inside target cell that does as hormone wishes i. 1. cAMP (cyclic AMP) second messenger system - First, hormone binds to a membrane receptor - Second, receptor activates G (relay) protein - Third, G Protein uses molecule of GTP to activate an effector protein - Fourth, Effector Protein (Adenylyl Cyclase) makes second messenger cyclic AMP (cAMP) out of a molecule of ATP - Lastly, cAMP causes desired responses by activating kinases 2. Direct Gene Activation a. Used by NONPOLAR hormones which easily cross the plasma membrane i. 1. Hormone enters cells and binds with a receptor ii. 2. Receptor-hormone complex enters nucleus and activates the genes that will produce desired chemicals Kinds of Stimuli for Hormone Release: 1. Humoral Stimuli a. Changes in levels of chemicals within blood i. Ex: hypocalcemia causes parathyroid glands to release parathormone (PTH) 2. Neural a. Direct input from the nervous system (neurotransmitters act like acetylcholine or norepinephrine i. Ex: sympathetic nervous system causes the adrenal medulla to release the hormone epinephrine 3. Hormone a. Tropic hormone (a hormone that influences the release of some other hormone) i. Ex: thyroid stimulating hormone (TSH) causes the thyroid gland to release thyroxine (“thyroid hormone”)

Know the specific anatomy of the pituitary, thyroid, parathyroids, adrenal glands (cortices and medullae), thymus, pancreas, pineal gland, gonads; the names and functions of all hormones made by each of these structures, the cells/areas that secrete given hormones (e.g., somatotrope, chromaffin cell, zona reticularis), and the specific stimuli used to elicit the release of each hormone, particularly the hypothalamic hormones. Pituitary Gland = consists of a posterior lobe and anterior lobe 1. Posterior Lobe= contains the endings of a hypothalamic neuroendocrine cells which release the following 2 hypothalamic hormones a. 1. ADH= released when hypothalamic osmoreceptors detect that plasma osmolarity is TOO HIGH i. Increases water reabsorption in DCT ii. Causes urine concentration b. 2. Oxytocin i. Causes smooth muscle contraction in reproductive ducts (ex: labor contraction of uterus in female and peristalsis in epididymes during ejactulation) ii. Causes smooth muscle contraction in mammary glands (release milk= “milk letdown”) iii. Promotes nurturing behavior iv. Promotes sexual satisfaction 2. Anterior Lobe=releases 6 hormones a. 1. Growth Hormone (GH) i. Affects most cell types, but to major targets HYALINE CARTILAGE (causes longitudinal bone growth) AND SKELETAL MUSCLE ii. Effects: promotes uptake of a.a from bloodstream, promote protein synthesis, promote lipolysis, promote glycogenolysis iii. 2 hypothalamic hormones that control GH release 1. GHRH (growth hormone releasing hormone)= released by hypothalamus in response to HYPOglycemia 2. GHIH (growth hormone inhibiting hormone)= released by hypothalamus in response to HYPERglycemia b. 2. Prolactin (PRL)= promotes lactation

i.

Regulated by 2 hypothalamic hormones 1. PRH (prolactin releasing hormone)= kept closely linked to estrogen levels 2. PIH (prolactin inhibiting hormone) c. 3. Thyroid Stimulating Hormone (TSH) i. Hypothalamus releases TRH (thyrotropin releasing hormone) ii. Anterior Pituitary releases TSH iii. Thyroid Gland releases thyroxine d. 4. Adrenocorticotropic Hormone (ACTH) i. Hypothalamus releases CRH (corticotropin releasing hormone) ii. Anterior Pituitary releases ACTH iii. Adrenal Glands release corticosteroid e. 5 & 6 (Follicle Stimulating Hormone FSH and Luteinizing Hormone LH) i. Hypothalamus releases GnRH (gonadotropin releasing hormone) ii. Anterior Pituitary releases FSH, LH (gonadotropins) iii. Gonads release gonadal hormones (testosterone & progesterone/estrogen) Thyroid Gland Follicular Cells= make use of the iodine in colloid to transform the amino acid TYROSINE into “thyroid hormone”

Colloi d

2 chemicals that act as “thyroid hormone” 1. T3 (triiodothyronine) 2. T4 (thryoxine) - Both T3 + T4 cause a slight but extremely prolonged (9-12 mo.) increase in target cell metabolic rate Parathyroid Glands

Chief cells release parathormone (PTH) in response to HYPOcalcemia Effects: 1. Activates osteoclasts to perform bone resorption, which releases calcium from bone into blood 2. Promotes transformation of cholesterol into VIT D in the kidneys (vit d promotes calcium reabsorption from GI tract) 3. Increases calcium reabsorption in kidneys Adrenal Glands = consists of an adrenal medulla and adrenal cortex 1. Medulla a. Releases the hormones epinephrine and norepinephrine in response to direct input from sympathetic nervous system i. Effects of EPI & NE 1. Increases HR and force of HB 2. Increase breathing rate/ more frequent inspiration 3. Dilate Airways 4. Increase Blood Flow to skeletal muscles, brain, heart, lungs 2. Cortex a. 3 secretory zones or layers from superficial to deep; each zone makes a specific kind of corticosteroid i. 1. Zona Glomerulosa = releases corticosteroids MINERALOCORTICOIDS which regulate mineral levels in blood (ex: aldosterone, which is normally released in response to hyponatremia) 1. Detected by hypothalamus and releases CRH > anterior pituitary release ACTH > zona glomerulus release aldosterone > increase Na+ and H2O reabsorption in DCT 2. Hypothalamus releases CRH in response to stress a. ACTM released > aldosterone released (long term stress) > water retention (elevated BV/BP)

Know relevant disorders involving having abnormal levels of these hormones (e.g., hyperthyroidism, diabetes mellitus, etc).

Chapter 28 Male repro Know the anatomy (including the histology, where relevant) and functioning of the testes, epididymis, ductus deferens, ejaculatory duct, urethra, penis, accessory glands Know the physiology of erection and ejaculation Know the accessory glands, their locations, and specific functions Know the process of spermatogenesis (including spermiogenesis), the cells involved, and the hormonal controls Female repro Know the anatomy (including the histology, where relevant) of the ovary, Fallopian tubes, uterus, cervix, vaginal canal, and vulva Know the physiology of arousal and climax Know the events of oogenesis as they occur within the follicular and luteal phases of the ovarian cycle Know the events of follicular development as they occur in the follicular phase of the ovarian cycle Know the events of the luteal phase of the ovarian cycle Know the hormonal controls of the ovarian cycle Know the phases and events of the menstrual cycle and the hormonal stimuli responsible forthese events (this will of course require prior knowledge of the ovarian cycle and its hormonal controls)...