Physio- Ch 11 Endocrine Glands

Describe the endocrine system

the major physiological that controls the glands and cells that secrete hormones.

define gland

a group of epithelial cells or an organ that synthesize and secretes chemical substances

what are the two types of glands

endocrine and exocrine

describe endocrine glands

- ductless -secrete hormones into blood stream in order to travel to their target cell

describe exocrine glands

have ducts

Define hormones

a biologically active molecule that serves as a chemical messenger in the blood (this causes a response to organs/cells)

what does the pancreases secrete?

insulin and glucagon

Describe the pathway hormones take

-released from the endocrine gland or cell into the interstitial fluid -diffuse from isf into blood to travel to target cell.

Where is the pituitary gland found?

in the brain

where is the hypothalamus found?

in the brain

where is the thyroid gland found?

in the neck

where is the adrenal gland found?

above the kidneys

what does the adrenal cortex secrete?

Glucocorticoids and mineralocorticoids

what are the adrenal cortex's primary target organs

liver, muscle and kidneys

What is the effect of glucocorticoids to their target cells? (adrenal cortex)

influence glucose metabolism

What is the effect of mineralocorticoids to their target cells? (adrenal cortex)

promote Na+ retention and K+ excretion

What does the adrenal medulla secrete?

epinephrine

what is the target organ for the epinephrine?

Heart, bronchioles and blood vessels

what effect does epinephrine have?

causes adrenergic stimulation

what does the hypothalamus secrete?

releasing and inhibiting hormones

what is the target organs for hypothalamus secreted hormones?

anterior pituitary

what is the effects of the hormones in the hypothalamus?

Regulates secretion of anterior pituitary hormones

What is does the anterior lobe of the pituitary gland secrete?

Trophic hormones

what are the trophic hormones target organs?

Endocrine glands and other organs

What effects do tropic hormones have?

stimulate growth and development of target organs and stimulate secretion of other hormones

what does the posterior lobe of the pituitary gland secrete?

Antidiuretic hormone and oxytocin

what are the target organs of the antidiuretic hormone and oxytocin?

antidiuretic = kidney and blood vessels oxytocin = uterus and mammary glands

what are the effects of antidiuretic hormones?

promotes water retention and vasoconstriction

what are the effects of oxytocin hormones

stimulates contraction of uterus and mammary secretion units (milk ejection)

what does the thyroid glad secrete?

T4, T3 and calcitonin

what does the thyroid gland target?

most organs

what are the effects of thyroid glands hormones?

growth and development of the basal rate of cell respiration and regulation of Ca2+ levels in blood

What are the four structures of hormones?

amines, polypeptides (and proteins), glycoproteins, and steroids

Describe amines

-are amino acids derived from tyrosine and tryptophan

what type of hormones are classified as amines?

-Thyroid hormones -E and NE (adrenal glands) -Dopamine ( hypothalamus) -Melatonin (pineal glad)

What hormones are classified polypeptides and proteins?

most hormones (ex. insulin and antidiuretic) [think... poly= most]

describe glycoproteins

proteins that are bound to carbohydrate groups (ex. thyroid-stimulating hormone)

describe steroids.

they are lipids based on cholesterol

what hormones are classified as steroids?

-sex steroids (gonads) -Corticosteroids and sex steroids (adrenal cortex)

What are three things that control the rate of hormone secretion?

-Concentration of ions and/or nutrients -Nervous System -Hormones

Hormones regulate ____ concentration of an ion or nutrient via _____ feedback

plasma // negative

The autonomic nervous system controls secretion of hormones what two structures?

adrenal medulla and other endocrine glands

How are hypothalamus and posterior pituitary regulated

they are directly regulated by neurons of the brain

t/f hormones can regulate secretion of other hormones

True

what gland stores and releases hormones that ate synthesized in the hypothalamus?

the posterior pituitary gland

explain the hypothalamo-hypopyseal tract

Hormones are transported to capillaries in the posterior pituitary by axons in the hypothalamo-hypopyseal tract