A&P II Exam 1 Pt. 1

Endocrine system

A system of ductless glands that releases hormones into the blood.

Endocrine vs nervous system

Endocrine hormones travel through blood and generally have slower, longer-lasting effects.

Steroid hormones

Lipid-soluble hormones synthesized from cholesterol.

Protein hormones

Water-soluble chains of amino acids; most hormones are proteins

Thyroid hormone

An exception among biogenic amines because it is lipid-soluble

Carrier protein

A blood protein that transports lipid-soluble hormones.

Lipid-soluble hormone mechanism

Hormone enters cell → binds receptor → binds DNA → transcription → mRNA → protein.

Insulin vs glucagon

Insulin lowers blood glucose; glucagon raises blood glucose.

Biogenic amines

Modified amino acids that include catecholamines, thyroid hormone, and melatonin.

Water-soluble hormone mechanism

Hormone binds membrane receptor → G-protein → enzyme → second messenger → cellular response.

Hypothalamus

Controls the pituitary and produces hormones released by the posterior pituitary.

Pituitary gland

A pea-sized gland below the hypothalamus that controls several other endocrine glands.

Anterior pituitary

The portion of the pituitary that produces and releases its own hormones.

Posterior pituitary

The portion of the pituitary that stores and releases hormones made by the hypothalamus.

Infundibulum

The stalk connecting the hypothalamus to the pituitary gland.

ADH

Decreases urine production, stimulates thirst, and constricts blood vessels.

Oxytocin

Stimulates uterine contractions, milk ejection, and emotional bonding.

TRH

Stimulates the anterior pituitary to release TSH.

Gonadotropin-releasing hormone

Stimulates the anterior pituitary to release FSH and LH.

CRH

Stimulates the anterior pituitary to release ACTH.

GHRH

Stimulates the anterior pituitary to release GH.

PIH

Decreases prolactin secretion.

TSH

Stimulates the thyroid gland to release thyroid hormone.

Prolactin

Stimulates milk production and mammary gland growth.

ACTH

Stimulates the adrenal cortex to release corticosteroids.

FSH In females, ; and in males

promotes ovarian development and estrogen/progesterone secretion ; promotes sperm development.

LH In females, ; and in males

causes ovulation ; stimulates testosterone secretion

GH

Stimulates growth and causes the liver to release IGFs.

IGFs

Stimulate cell growth and division.

Growth hormone deficiency

Too little GH; causes short stature and hypoglycemia.

Pituitary gigantism

Excess GH during childhood; causes excessive growth and enlarged organs.

Acromegaly Excess GH in adults;

causes enlargement of facial bones, hands, feet, and internal organs.

Thyroid gland

An endocrine gland located inferior to the larynx.

Thyroid hormone

Increases metabolic rate and protein synthesis.

Parafollicular cells

Thyroid cells that produce calcitonin.

Calcitonin

Decreases blood calcium levels.

Adrenal medulla

The inner part of the adrenal gland that releases epinephrine and norepinephrine.

Adrenal cortex

The outer part of the adrenal gland that produces corticosteroids.

Aldosterone

A mineralocorticoid that promotes sodium retention and potassium secretion.

Cortisol

A glucocorticoid that increases sugar and nutrients in the blood.

Cushing syndrome

A condition caused by chronic excessive glucocorticoids.

Addison disease

Adrenal insufficiency causing a chronic shortage of glucocorticoids and sometimes mineralocorticoids.

Alpha cells

Produce glucagon.

Beta cells

Produce insulin.

Insulin and liver

Causes the liver to take up glucose and store it as glycogen.

Glucagon and liver

Causes the liver to release glucose into the blood.

Pineal gland

A gland in the diencephalon that secretes melatonin

Parathyroid glands

Usually four glands on the posterior surface of the thyroid

Thymus A gland where T lymphocytes mature;

it grows during childhood and shrinks during adulthood.

PTH

Increases blood calcium by releasing calcium from bone, decreasing urinary calcium loss, and activating calcitriol.

Erythropoietin

A kidney hormone released when blood oxygen is low that increases red blood cell production.

ANP

A heart hormone that lowers blood pressure by increasing urine output and dilating blood vessels.

Angiotensin II

Raises blood pressure, constricts blood vessels, decreases urine output, and stimulates thirst.

Gastrin

A stomach hormone that increases secretion and motility for digestion.

Secretin

A small intestine hormone that stimulates bile and pancreatic juice secretion.

CCK

A small intestine hormone that stimulates the gallbladder to release bile.

Calcitriol

The active form of vitamin D that raises blood calcium by increasing intestinal calcium absorption.

Leptin

A hormone from adipose tissue that helps regulate appetite.