Question | Answer |
Pacracrine communication | use of chemical messengers to transfer infromation from cell to cell within a single tissue |
Hormones | chemical messengers that are released in one tissue and transported in the bloodstream to reach specific cells in other tissues. |
endocrine communication | use of hormones to coordinate cellular activities in tissues in distant protions of the body |
endocrine system | includes all the endocrine cells and tissues of the body which produce hormones or pacrine factors rthat have effects beyond their tissue of origin |
Amino Acid Derivatives | are relatively small molecules that are structurally similiar to amino acids, sometimes known as biogenic amines |
Biogenic amines include | epinephrine, nrepinephrine, dopamine, the thyroid hormones and melatonin |
Melatonin | manufactured from molecules of the amino acid Tryptophan |
Peptide Hormones | are chains of amino acids, also produced as prohormones |
prohormones | inactive molecules that are converted to active hormones either before or after they are secreted |
Lipid derivatives, two classes | steroid hormones derived from cholesterol, and eicosanoids, derived form arachidonic acid |
Steriod Hormones | released by male and female reproductive organs, and the adrenal glands and the kidneys |
Eicosanoids | small molecules with a 5-carbon ring at one end. also important pacrine factors that coordinate cellular activities and affect enzymatic processes that occur in extracellular fluind |
Leukatrienes | released by activate white blood cells, are important in coordinating tissue responses to injury or disease |
Prostaglandins | produced in most tisues of the body, involved in coordinating local cellular acitvies |
G Protein | an enzyme complex coupled to a membrane receptor. Refers to the fact the this protein binds to GTP |
Kinase | an enzyme that performs phosphorylation, the attachment of a phospahte group to another molecule |
Endocrine reflexes | can be triggered by 1. humoral stimuli 2. hormonal stimuli 3. nerual stimuli |
the adrenal medullae secret E and NE in response to | action potential rather than circulatinf hormones |
Pulses | several hormones of the hypothalamus and pituitary gland are released in sudden bursts |
When hormones arrive in pulses | target cells may vary their response with frequency |
Diaphragma sellae | the pituitary gland is cradled by the sella turcia and held in position by the .... |
adenohypophysis | anterior lobe of pituitary gland |
3 regions of the adenohypophysis | pars distalis, pars tuberalis, pars intermedia |
par distalis | the largest and most anterior portion of the pituitary gland |
pars tuberalis | wraps arond the adjeacent portion of the infundibulum |
pars intermedia | forms a narrow band bordering the posterior lobe |
Fenestrated capillaries | allow relatively large molecules to enter or leave the circulatory system |
Superior hypohyseal artery | supplies the capillary networks in the median eminence |
Portal vessels | blood vessels that link two capillary networks |
2 classes of hypothalamic regulatory hormones | 1) releasing hormones 2) inhibitiing hormones |
Releasing hormone (RH) | stimulates the synthesis and secretion of one or more hormones at the anterior lobe |
inhibiting hormones (IH) | prevent the synthesis and secretion of hormones at the anterior lobe |
Thyroid-stimulating hormones (TSH) | or Thyrotropin, target the thyroid gland and triggers the release of thyroid hormones |
Adrenocorticotropic hormone (ACTH) | or Corticotropin, stimulates the release of steroid hormones by the adrenal cortex |
Gonadotropins | follicle-stimulating hormone and luteinizing hormone are called... because they regulate the activities of the gonads |
Follicle-stimulating Hormone (FSH) | or follitropin, promotes follicle development in females and stimulates sustentacular cells in males |
sustentacular cells | specialixed cells in the tubules where sperm differentiate |
Luteinizing hormones (LH) | or lutropin, induces ovulation in females, |
Growth Hormone (GH) | or somatotroping, stimulates cell growth and replication by accelerating the rate of protein synthesis |
Liver cells respond to the presence of GH by | synthesizing and releasing somatomedians, or insuinlike growth factors (IGFs) |
GH stimulates stem cell division and the differentiation of daughter cells in | epithelia and connective tissue |
GH stimulates the breakdown fo stored trglycoerides by adipocytes , which then release fatty acids int the blood stream | in adipose tissue |
thyroid follicles | spheres lined by a simple cuboidal epithelium |
Follicle cells synthesize | a globular protein called thyroglobulin and secretes it into the colloid of the thryoid follicles |
major factor controlling the rate of thyroid hormone release | concentration of TSH in the circulating blood |
If intracellular levels of thyroid hormones decline | the bound thyroid hormones are released into the cytoplasm |
Thyroid hormones binding to mitochondria | increase the rates of mitchondrial ATP production |
Tetraiodothyronine represents | T4, or thyroxine which contains 4 iodide ions |
Triidothyronine represents | T3, contains 3 iodide ions |
Thyroid-binding globulins (TBGs) | a transport molecule, 75%of T4 and 70% T3 enter the blood stream attached to transport proteins called |
Cheif Cells | monitor the circulating concentration of calcium ions in the parathyroid glands |
Adrenal Gland | yellow, pyramid-shaped, sits on the superior border of each kidney |
Adrenal Cortex | yellowish color is due to the presence of stored lipids, especially cholesterol and various fatty acids |
Corticosteriods | more than two dozen steriod hormones that are produced in the adrenal cortex are called..... |
Zona Glomerulosa | outer most region of the adrenal cortex, produces mineralocorticoids |
mineralocorticoids | steroid hormones that affect the electrolye composition of body fluids |
Aldosterone | the principal minerocorticoid produced by the adrenal cortex |
Zona Fasciculata | produces steroid hormones collectively known as glucocorticoids |
Zona Reticularis | forms a narrow band bordering each adrenal medulla , the endocrine cells form a folded, branching network, and fenestrated blood vessels wind between cells |
This combination increases both muscular strength and endurance. | E and NE Trigger a mobilization of glycogen reserves in skeletal muscle and accelerate the breakdown of glucose to provide ATP |
Pineal Gland | part of epithalamus, lies in the posterior protion of the roof of the third ventricle |
the Pineal Glad contains | neors, neuroglia, and special secretory cells called pinealocytes |
Pinealocytes | synthesize hormone melatonin form molecules of the nerotransmitter serotonin |
Pancreas | lies within the abdominopelvic cavity in the J-shaped loop between the stomach and the small intestine |
Exocrine pancreas | consists of clusters of gland cells, called pancreatic acini, and their attached ducts |
Endocrine pancreas | consist of small groups of cells scattered among the exocrine cells |
Pancreatic islets | or ISLETS OF LANGERHANS, endocrine clusters |
Alpha cells | produce the horm. glucagon. |
Glucagon | raises blood glucose levels by incrasing the rates of glycogen breakdown and glucose release by the liver |
Beta cells | produce the Horm. insulin |
Insulin | lower blood glucose levers by increasing the rate of glucose uptake and utilization by most body cells |