CH. 17 Test Review

Explain negative and positive feedback control of hormone release. Give examples of each.

- Negative Feedback = most hormones, including HPT axis and HPA axis - Positive Feedback = Oxytocin

Ovary Gland Horomones

1) Exocrine Function of Ovaries: Production and periodical release of egg cells 2) Hormones - 2a)Estrogen: Pituitary gland secretes FSH, FSH stimulates Granulosa cells which stimulate Ovarian Follicles to produces Estrogen; Function: female sex horomone, promotes puberty, regulates menstral cycle. 2b)Progesterone: Pituitary gland secretes LH, LH stimulates corpus luteum of ovary to produce Progesterone; Function: Prepares uterus for ovulation; 2c) Relaxin - Produced by corpus luteum; Funtion: Relaxes uterus by inhibiting contraction of myometrium At end of pregnancy, increases flexibility of pubis symphysis and dilates uterine cervix; 2d) Inhibin - Secreted by granulose cells of growing follicles and by corpus luteum; Function: Inhibits secretion of FSH and LH;

Adrenal Gland Hormones & Disorders

1) Hormones - 1a) Adrenal Medulla: - Catecholamines: Produces epinephrine (adrenaline) and norepinephrine (noradrenaline) that work with sympathetic nervous system in "fight-or-flight" responses 1b) Adrenal Cortex: All stimulated by ACTH (3 Classes of Corticoids: - Zonula glomerulosa: produces mineralocorticoids (e.g., aldosterone) that regulate sodium/potassium ratio in blood and body fluids; - Zonula fasciculata: produces glucocorticoids (e.g., cortisol) that stimulate lipid and protein metabolism, and regulate blood glucose levels; - Zonula reticularis: produces steroid sex hormones called gonadocorticoids (e.g., dehydroepiandrosterone or DHEA) aid in development of sex characteristics during puberty include androgens eventually convert into estrogen and testosterone; 2) Disorders - 2a) Cushing's disease: results from the chronic exposure of the body's tissues to excessive levels of glucocorticoid hormones; 2b) Addison's disease: form of adrenal insufficiency that develops when the adrenal glands fail, resulting in a chronic shortage of glucocorticoids and sometimes mineralocorticoids; 2c) Aldosteronism: excess production of the hormone aldosterone by the adrenal glands. Often it produces high blood pressure which may cause poor vision or headaches; 2d) Adrenogenital syndrome: characterized by the inability to synthesize corticosteroids this produces hyperplasia (increased size) of the adrenal cortex; 2e) Pheochromocytoma: a small vascular tumor of the adrenal medulla, causing irregular secretion of epinephrine and norepinephrine, leading to attacks of raised blood pressure, palpitations, and headache.

Pancreas Gland Hormones & Disorders

1) Hormones - 1a) Insulin: hormone secreted by the isles of Langerhans in the pancreas; produced by beta cells to lowers blood sugar levels. 1b) Glucagon: hormone secreted by the isles of Langerhans in the pancreas; alpha cells increase blood sugar levels. 2) Disorders - 2a) Hyperglycemia: Caused by prolonged elevated blood glucose. Sugar in the urine. 2b) Diabetes Mellitus Type 1: disorder in which the body cannot produce enough insulin. 2c) Diabetes Mellitus Type 2: progressive disorder in which body cells become less responsive to insulin. 2d) Hypoglycemia: Caused by low levels of blood glucose. 2e) Gestational Diabetes: A form of high blood sugar affecting pregnant women. 2f) Hyperinsulinism: Above normal level of insulin in the blood. 3) Pancreas Exocrine Function: secretes pancreatic fluid that contains digestive enzymes that pass to the small intestine.

Parathyroid Gland Hormones & Disorders

1) Hormones - 1a) Parathyroid Hormone (PTH) - Located in the parathyroid gland, increase blood calcium levels by tells osteoclasts to break down bones, intestines absorb calcium, kidneys save calcium which decreases secretion. 2) Disorders - 2a) Hyperparathyroidism: abnormally high concentration of parathyroid hormone in the blood, resulting in weakening of the bones through loss of calcium; 2b) Hypoparathyroidism: diminished concentration of parathyroid hormone in the blood, which causes deficiencies of calcium and phosphorus compounds in the blood and results in muscular spasms;

Testes Gland Hormones

1) Hormones - 1a) Testosterone: Hypothalmus produces GnRH, GnRH stimulates Pituitary Gland which secretes LH, LH stimulates Testes which produce testosterone; Function: Male sex hormones, promotes puberty and spermatogenesis.

Thyroid Gland Hormones & Disorders

1) Thyroxine (T4) & Triiodothyronine (T3) - Hypothalamus secretes TRH, TRH stimulates Pituitary Gland which secretes TSH, TSH stimulates Thyroid gland which secrete T3&T4; Function: Thyroid hormone that stimulated cellular metabolism; The body needs iodine to make thyroid hormones. *Disorders - Hyperthyroidism: Overproduction of T3&T4 (Graves' disease is a common cause); Hypothyroidism: Underproduction of T3 & T4; Myxedema: Swelling of the skin and underlying tissues giving a waxy consistency; Cretinism - untreated congenital deficiency of thyroid hormones (congenital hypothyroidism); Goiter - Abnormal enlargement of your thyroid gland usually due to lack of iodine.

Anterior Pituitary Hormones & Disorders

1) follicle stimulating hormone (FSH) - from: anterior pituitary gland; target: ovaries & testes; females - growth of ovarian follicles and secretion of estrogen; males - sperm productin 2) Luteinizing hormone (LH) - from: anterior pituitary gland; target: ovaries & testes; females: ovulation, maintenance of corpus luteum, males: testosterone secretion (testosterone, estrogen, & progesterone). 3) thyroid stimulating hormone (TSH) (thyrotropin) - from: anterior pituitary gland; target: thyroid gland; stim growth of thyroid gland and the secretion of thyroid hormone. 4) Growth Hormone (GH) - from: anterior pituitary gland; target: liver, bone, cartilage, muscel, fat; stimulates cell division in most cells ( major targets are bones and skeletal muscles). *Disorders - Gigantism is growth hormone excess prior to puberty and Acromegaly is GH excess once one is a fully grown adult. Inadequate growth hormone production is known as Pituitary Dwarfism. 5) Prolactin (PRL) - from: anterior pituitary gland; target: mammary glands, testes; stimulates milk production by mammary glands of breasts males: increases LH sensitivity *Disorders - abnormally high levels of prolactin in the blood = Hyperprolactinaemia 6) adrenocorticotropic hormone (ACTH) - from: anterior pituitary gland; target: adrenal gland; stim the adrenal cortex to secrete hormones called glucocorticoids (especially cortisol) which regulates glucose, protein, and fat metabolism.

Know the hormones produced by the hypothalamus that are stored in the posterior pituitary. Know the route of these hormones from the hypothalamus to the posterior pituitary.

Antidiuretic Hormone (ADH) - from: posterior pituitary gland; target: kidneys; produced by supraoptic nucleus of hypothalamus; stimulates kidney tubules to retain water, reduces urine volume, and helps prevent dehydration. *Disorder - Deficiency (under production) of ADH secretion leads to Diabetes Insipidus (excessive urine production) Oxytocin (OT) - from: posterior pituitary gland; target: uterus & mammary glands; labor contractions, milk release, possible involved in ejacu sperm, sexual affection, and mother-infant bonding *Both of these are transported to the posterior pituitary by the hypothalamo-hypophysial tract.

Explain the three types of stimuli that cause hormones to be produced. Give examples of each.

Hormonal - gland to gland stimulation; EX - Thyroid stimulating hormone (TSH) released to stimulate thyroid from the pituitary gland. Humoral - release of a hormone in response to change in level of nutrient or ion in the blood; EX - pancreas releasing insulin or glucagon depending on the blood glucose. Neural - release of a hormone in response to stimulation by the nervous system; EX - nerve impulses to the adrenal medulla trigger the release of epinephrine.

Pineal Gland Hormones & Disorders

Melatonin: Secreted by the Pineal Gland; Function: Regulate sleep cycle; Seasonal affective disorder: Underproduction of Melatonin

Define permissiveness, synergistic effect and antagonistic effect of hormones interacting at a target cell. Give examples of each.

Synergistic - two hormones work together to produce an effect; Estrogen and progesterone = work together to have a synergistic effect. Permissive - a hormone requires another hormone in order to be effective; Prolactin and oxytocin = target mammary glands to work properly (need each other) Antagonistic - opposite effects of two hormones; Insulin and glucagon = one decreases and one increases blood glucose level

Thymus Gland Hormones & Disorders

Thymopoietins & Thymosins: Secreted by the Thymus; Function: Help with T Cell maturation.

Know the hormones produced by the hypothalamus that target the anterior pituitary. Know the route of these hormones from the hypothalamus to the anterior pituitary.

Thyrotropin-releasing hormone (TRH) - stimulate anterior pituitary to secrete thyroid-stimulating hormone (TSH) & prolactin (PRL) Gonadotropin-releasing hormone (GnRH) - stimulate anterior pituitary to secrete follicle stimulating hormone (FSH) & luteinizing hormone (LH) Growth hormone-releasing hormone (GHRH) - stimulate anterior pituitary to secrete growth hormone (GH). Corticotropin-releasing hormone (CRH) - stimulate anterior pituitary to secrete adrenocorticotropic hormone (ACTH) Somatostatin - inhibit the release of growth hormone (GH) & thyroid-stimulating hormone (TSH) Dopamine - inhibiting the release of prolactin (PRL) *These are transported from the hypothalmus to anterior pituitary via the hypothalamo-hypophysial portal system where they release or inhibit the secretion of hormones.