Chapter 11 Endocrine System

Front 1

What does the endocrine system do?

Back 1

Acts as a means of internal communications, coordinating the activities of the organ systems.

Front 2

What do endocrine glands do?

Back 2

Synthesize and secrete chemicals called hormones directly into the circulatory system.

Front 3

What do hormones do?

Back 3

Regulate the function of target organs or tissues. Some regulate single type of cell/organ; some have more widespread actions.

Front 4

Which glands/organs synthesize or secrete hormones?

Back 4

pituitary, pineal. hypothalamus, thyroid, parathyroids, thymus, adrenals, pancreas, testes, ovaries, kidneys, gastrointestinal glands, heart.

Front 5

Where is the pituitary and what does it look like?

Back 5

At Sella Turcica of Sphenoid bone - small tri-lobed gland (lanterior, posterior, intermediate)

Front 6

What does the anterior pituitary do?

Back 6

It synthesizes both direct hormones and tropic hormones.

Front 7

What regulates the hormonal secretions of the anterior pituitary?

Back 7

Hypothalamic secretions called releasing/inhibiting hormones or factors

Front 8

Which direct hormones are synthesized by the anterior pituitary and what do they do?

Back 8

~ Growth Hormone (aka GH or somatotropin)
~ Prolactin

GH promotes bone and muscle growth, inhibits uptake of glucose by certain cells, and stimulates the breakdown of fatty acid, conserving glucose. GH secretion stimulated by GHRH, inhibited by somatostatin.
GH deficiency - dwarfism,
" overproduction - gigantism/acromegaly.

Prolactin - milk production/secretion in mammary glands.

Front 9

Which tropic hormones are synthesized by the anterior pituitary and what do they do?

Back 9

~Adrenocorticotropic hormone (ACTH),
~Thyroid-stimulating hormone (TSH),
~Luteinizing hormone (LH)
ACTH stimulates adrenal cortex to synthesize and secrete glucocorticoids - regulated by releasing hormone corticotropin releasing factor (CRF)

TSH stimulates thyroid gland to absorb iodine and synthesize and release thyroid hormone. - Regulated by releasing hormone TRH.

LH stimulates ovulation and formation of corpus luteum. In males LH stimulates interstitial cells of testes to synthesize testosterone. Regulated by estrogen, progesterone, GnRH).

FSH in females causes maturation of ovarian follicles; in males FSH stimulates maturation of the seminiferous tubules and sperm production. Regulated by estrogen and GnRH.
Follicle stimulating hormone (FSH)

Front 10

What does the posterior pituitary store and release? What do they do? What regulates the secretion of these hormones?

Back 10

Stores and releases oxytocin and ADH. Stimulated by action potentials descending from hypothalamus.

Oxytocin increases strength and frequency of uterine muscle contractions; stimulates milk secretion in mammary glands.

ADH (antidiuretic hormone, vasopressin) increases permeabilty of nephron's collecting duct to water, promoting water reabsorption and increasing blood volume. Secreted when plasma osmotic concentration increases, as sense by osmoreceptors in hypothalamus, or when blood volume decreases, as sense by baroreceptors in circ. system.

Front 11

What regulates the hormonal secretions of the anterior pituitary?

Back 11

Hypothalamic secretions called releasing/inhibiting hormones or factors

Front 12

Where is hypothalamus located? What triggers it? What does it do?

Back 12

It is part of the forebrain and is located directly above the pituitary gland. Receives neural transmissions from other parts of the brain and from peripheral nerves that trigger specific responses from its neurosecretory cells. The cells regulate pituitary gland secretions via negative feedback mechanisms and through the actions of inhibiting/releasing hormones.

Front 13

Which direct hormones are synthesized by the anterior pituitary and what do they do?

Back 13

Growth hormone (aka GH or somatotropin) & prolactin

GH promotes bone and muscle growth, inhibites uptake of glucose by certain cells, and stimulates the breakdown of fatty acid, conserving glucose. GH secretion stimulated by GHRH, inhibited by somatostatin. GH deficiency can lead to dwarfism, overproduction result in gigantism/acromegaly.

Prolactin stimualates milk production and secretion in female mammary glands.

Front 14

How does the hypothalamus interact with the anterior pituitary?

Back 14

Hypothalamic releasing hormones are hormones that stimulate or inhibit the secretions of the anterior pituitary. GnRH stimulates the anterior pituitary to secrete FSH and LH. Releasing hormones are secreted into the hypothalamic-hypophyseal portal system. In this circulatory pathway, blood from teh capillary bed in the hypothalamus flows through a portal vein into the anterior pituitary, where it diverges into a 2nd capillary network. In this way, releasing hormones can immediately reach the anterior pituitary.

Front 15

Which tropic hormones are synthesized by the anterior pituitary and what do they do?

Back 15

adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), luteinizing hormone (LH), follicle stimulating hormone (FSH)

ACTH stimulates adrenal cortex to synthesize and secrete glucocorticoids and is regulated by releasing hormone corticotropin releasing factor (CRF)

TSH stimulates thyroid gland to absorb iodine and synthesize and release thyroid hormone. Regulated by releasing hormone TRH.

LH stimulates ovulation and formation of corpus luteum. In males LH stimulates interstitial cells of testes to synthesize testosterone. Regulated by estrogen, progesterone, GnRH).

FSH in females causes maturation of ovarian follicles; in males FSH stimulates maturation of the seminiferous tubules and sperm production. Regulated by estrogen and GnRH.

Front 16

THYROID
~T3/T4 Target tissue / Function?

~Calcitonin: Target tissue/Function?

Back 16

Whole Body / Increase metabolism

Bone / Decreases blood calcium levels (by inhibiting osteoclast activity)

Front 17

PARATHYROID
~Parathyroid Hormone (PTH): Target tissue / Function?

Back 17

Bone / PTH promotes resorption of bone matrix, which releases calcium ions into the blood

Front 18

ADRENAL CORTEX
~Aldosterone: Target tissue/Function?

~Cortisol: ditto

~Androgens: ditto

Back 18

Blood/Helps adjust BP /blood volume /pH control

Blood/Anti-inflammatory, reduced immune system

Secondary sex characteristics

Front 19

ADRENAL MEDULLA
~Norepinephrine:

Back 19

Blood / Quick stress response

Front 20

PANCREAS
~Alpha cells (glucagon)

~Beta Cells (Insulin)

~Delta Cells (Somatostatin)

~F Cells (Pancreatic polypeptide)

Back 20

Blood / Raises blood glucose level

Blood /Decreases blood glucose level

Blood / Inhibits release of glucagon and insulin

Inhibits Somatostatin

Front 21

PINEAL GLAND

~Melatonin

Back 21

Sleep

Front 22

ORGAN / HORMONE

~Stomach

Back 22

ACTION

~Promotes secretion of gastric juices and increases motility of the astomach

Front 23

SMALL INTESTINE

~ gastric inhibitory polypeptide (GIP)

~ cholecystokinin (CCK)


~ Secretin

Back 23

ACTION

~Stimulates release of insulin by pancreatic Beta Cells

~Stimulates secretion of pancreatic juice, regulates release of bile from gall bladder

~Stimulates secretion of pancreatic juice and bile from liver

Front 24

PLACENTA

~ human Chorionic Gonadotropin (hCG)



~ estrogens and progesterone


~human chorionic somato-mamma-tropin ( hCS)

Back 24

ACTION

~Stimulates the corpus luteum in the ovary to continue the production of estrogens and progesterone to maintain pregnancy

~Maintain pregnancy and help prepare mammary glands for lactation

~Stimulates development of mammary glands for lactation

Front 25

KIDNEYS

~Erythropoietin (EPO)

~Calcitriol


~Renin

Back 25

ACTION

~increases the rate of red blood cell formation

~aids in the absorption of dietary calcium and phosphorous

~converts angiotensinogen to angiotensinogen 1

Front 26

LUNGS

~Angiotensin Converting Enzyme

Back 26

ACTION

~Converts angiotensin I to angiotensin II

Front 27

HEART

~Atrial Natriuretic Peptide

Back 27

ACTION

~Decreases BP

Front 28

ADIPOSE TISSUE

~Leptin

Back 28

ACTION

~Suppresses appetite

Front 29

LIVER

~Thrombopoetin

~Angiotensinogen

Back 29

ACTION

~Stimulates production of platelets

~Becomes angiotensin II, a vasoconstrictor and stimulates release of aldosterone from adrenal cortex

Front 30

VITAMIN D

Back 30

1. Skin - precursor to Vitamin D (inactive)
2. Liver - Calcidiol (inactive)
3. Kidney - Calcitriol (active Vitamin D3)

Front 31

SERATONIN

Back 31

~ derived from tryptophan - regulates mood, appetite and sleep.