physiology Flashcards
Hormones released by the hypothalamus
ADH, oxytocin, inhibiting and increasing hormones
Anterior pituitary hormones
ACTH, TSH, GH, PRL, FSH, LH, MSH
Posterior hormones
Releases oxytocin and ADH made in hypothalamus.
Pinal gland hormones
melatonin
parathyroid gland Hormones
Parathyroid hormones
Thyroid gland hormones
thyroxine (T4), triiodonthyronin (T3), calcitonin
Adrenal medulla
Epinephrine and norepinephrine
Adrenal cortex
cortisol, corticosterone, aldosterone, androgens
Adipose tissue hormone secretion
Leptin
Kidney hormone secretion
Erythropoetin (EPO) and calcitriol
Heart hormone secretion
Natriuretic peptides: atrial natriuretic and brain natriuretic peptides.
Amino acid derivatives hormones
Small molecules structurally related to individual amino acids
Hormone derivative to tryptophan
Melatoni, seratonin
Hormone derivative of tyrosine
thyroxine (T4) and catecholamines (epinephrine/norepinephrine/dopamine).
Peptide hormones
Chains of amino acids. Most are synthesized as pro-hormones. Are composed of short polypeptides and small proteins
Glycoproteins
Proteins of more than 200 amino acids that have carbohydrate side chain
Lipid derived hormones
Carbon rings and side chains, built from fatty acid and cholesterol
Eicosanoids hormones
Lipid derivative of arachidonic acid. Paracrine factors. Included leukotrienes, prostaglandins, thromboxanes, and prostacyclins.
Steroid hormones
Similar to cholesterol, lipid derived hormone. Derived from cholesterol. Released by gonads, adrenal cortex, and the kidney. Remain in circulation longer than secreted peptide hormones because steroids are transported by specific transport proteins.
Free hormone stability
Remain functional less than 1 hour. Bind receptors, are broken down by liver/kidney, or broken down by enzymes in plasma or interstitial fluids.
Catecholamines and peptide receptors
Found on outside of cells since not lipid soluble. Extracellular receptors
Eicosanoids and steroid cell receptors
Intracellular receptors. Hormone is lipid soluble. Pass through membrane to receptor on inside of plasma membrane.
Hormone first messenger
Hormone and primary extracellular receptor. Leads to secondary messenger. Results in change in rates of metabolic reactions
Hormone secondary messenger
cAMP, cGTP, calcium ions. Secondary messengers lead to amplification of small number of hormones.
Hormone down regulation
Abundant hormone triggers decrease in hormone receptors. Cells become less sensitive to hormone.
Hormone up regulation
Absence of hormone triggers increase in number of receptors. Cells become more sensitive to hormone.
G protein
Enzyme complex coupled to membrane receptor that links first receptor to second messenger. The G protein activation increases cellular cAMP in cell.
When is cAMP increased inside of a cell
cAMP increased when hormones bind receptors on cell surface. This leads to an increase of cAMP and accelerates metabolic activity. G protein activation increases cAMP inside cell.
What opens calcium ion channels in extracellular membrane and intracellular reserves?
Activated G protein. Calcium ions activate calmodulin.
What hormones alter rate of DNA transcriptions?
Steroids and thyroid hormones.
Humoral stimuli
Changes the composition of extracellular fluid
Hormonal stimuli
Arrival or removal of specific hormone
Neural stimuli
Arrival of neurotransmitters at neuroglandular junctions.
Simple endocrine reflexes
Involves only one hormone. Controls secretion of heart, pancrease, parathyroid gland and GI.
Complex endocrine reflexes
One or more intermediary steps requiring two or more hormones.
Antagonistic interaction
Actions oppose each other
Synergistic interaction
Action enhance effects of each other
Permissive interaction
One hormone requires the effects of the other to function.
Integrative interaction
One hormone has different effects on other organs.
Neuroendocrine reflexes
Both hormonal and neural components.
Complex hormone control
Changed by amount of hormone released or pattern or hormone release (sudden burst).
How is hormone regulated in the blood?
Negative feedback. Low levels of hormone trigger the release of more hormone.
Location, size, and name of pituitary gland
Lies in sella turcica surrounded by sellar diaphragm. Size of a pea and also called hypophysis. Connected to hypothalamus via the infundibulum.
What type of hormones does the anterior pituitary release?
Peptide hormones that use cAMP as secondary messenger.
Anterior pituitary lobe anatomical parts
Pars tuberalis, pars distalis, pars intermedia.
Adenohypophysis
Another name for anterior pituitary
What is the hypophyseal portal system
Median eminence near infundibulum. Hypothalamic neurons release regulatory factors to control anterior pituitary.
Blood vessel portal system
Allows hypothalamus to release inhibiting/releasing hormones then allow anterior pituitary to release their hormones into circularity system.
Neurohypophysis
The posterior pituitary
Antidiuretic hormone (ADH)
Vasopressin, water re absorption during dehydration, increase blood pressure via vasoconstriction. Targes kidneys.
Diabetes insipidus
Hyposecretion of ADH. Large amounts of dilute urine.
Oxytocin
Hypothalamus via posterior pituitary. Uterine contractions. Male/female contraction during orgasm and milk let down.
Pineal gland
Produce melatonin, made from seratonin.
Melatonin
Regulates circadian rhythm, protects from free radical, and inhibit reproductive function
Thyroid gland
Butterfly shaped, inferior to larynx, largest pure endocrine gland with two lobes.
Endemic Goiter
Lack of diet iodine cause thyroid swelling
Thyroid hormone function
Affects most cells, essential to development of skeletal, muscular, and nervous system. Calorigenic effect produce heat.
Hyperthyroidism
Thyrotoxicosis, Graves disease (exophthalmos).
Calcitonin
Produced by C cells (parafollicular). Decrease calcium levels and osteoclast activity. Stimulates calcium excretion by the kidneys.
Parathyroid gland
Secretes parathyroid hormone that increases osteoclast activity and blood calcium levels. Calcium reabsorption in kidneys.
Parathyroid gland
Four glands on posterior surface of thyroid gland.
