Chapter 5: endocrine and hormones

Question 1

GnRH releases

Answer 1

Gonadotropin-releasing hormone (GnRH)

LH (luteinizing hormone), and FSH (follicle-stimulating hormone)

Question 2

GHRH releases

Answer 2

GHRH (growth hormone releasing hormone)

GH (growth hormone)

Question 3

TRH releases

Answer 3

TRH (Thyroid Releasing Hormone)

Thyrotropin-stimulating hormone (TSH)

Question 4

CRF

Answer 4

CRF Corticotropin-releasing factor(or hormone)

ACTH (Adrenocortico tropic Hormone)

Question 5

PIF causes what?

Answer 5

It’s a catecholamine.

stands for:PIF (Prolactin Inhibiting Factor)

Decrease in Prolactin

Will increase levels of dopamine.

Question 6

Pancreas:

Answer 6

A large gland behind the stomach. It secretes digestive enzymes into the duodenum. Embedded in the pancreas are the islets of Langerhans which secrete insulin and glucagon into the blood.

Insulin:
Beta islets, Decrease Glucose
*Peptide hormone secreted by b-islet cells. Its function is to help glucose enter the cell. Increasing ­Glucose triggers insulin secretion. Inhibited by norepinephrine.

Glucagon:
ALPHA-islets, Increase Glucose
*Peptide hormone secreted by alpha-islet cells. Its function is to help glucose enter the blood stream. Decrease glucose triggers glucagon secretion.

Somatostatin (GHIH):
Growth Hormone-Inhibiting Hormone. A peptide hormone secreted by d-islet (delta) cells. Inhibits GH and also leads to decrease insulin and decrease glucagon.

Question 7

ADH and Oxytocin is produced where and released where?

Answer 7

produced in the hypothalamus and released from the posterior pituitary

Question 8

Gonads?

Answer 8

A gland that produces gametes (sex cells) and sex hormones. In males, the gonads are testicles, in females they are ovaries.

Testosterone: Produced by the testes in men and ovaries in women with a small amount produced by the Adrenal Cortex. In males, it is the
primary sex hormone and an anabolic steroid.

Estrogen:
Produced by the ovaries. It is the primary female sex hormone and leads to the development of secondary sexual characteristics. Estrogen also regulates the menstrual cycle.
Decrease milk production.

Progesterone: Produced by the ovaries. Prepares the endometrium for potential pregnancy following ovulation.
Decrease milk production

Question 9

Pineal Gland

Answer 9

Located in the epithalamus, tucked into a groove between the two thalamus halves.

Melatonin:
Regulates sleep/ wakefulness and controls the circadian rhythm

Question 10

Adrenal Cortex

Answer 10

Sits along the perimeter of the adrenal gland (top of kidney). Mediates stress response.

Glucocorticoids:
Cortisol is released during stress.
-inc Glucose in blood through gluconeogenesis.
-dec Immune system
-dec Protein synthesis
-Cortisone is similar to Cortisol
-dec Immune response so decreases inflammation and decreaes allergic response.

Mineralcorticoids:
Aldosterone causes increase Na+ in blood which increase­ BP. It is regulated by K+ and angiotensin II which is derived from angiotensin I.

Androgens:
Converted to Testosterone and Estrogen in the gonads.

Question 11

Anterior Pituitary

Answer 11

Anterior lobe of the pituitary gland. It regulates several physiological processes including stress, growth, reproduction, and lactation.

FSH:
Follicle-Stimulating Hormone. A gonadotropin. In males it promotes spermatogenesis. In females it stimulates growth of ovarian follicles.

LH:
Luteinizing Hormone. A gonadotropin that induces ovulation.

ACTH:
Adrenocorticotropic Hormone. Stimulates the production and release of cortisol.

TSH:
Thyroid-Stimulating Hormone. Stimulates the Thyroid to produce Thyroxine (T4) and Triiodothyronine (T3), which stimulates metabolism.

GH Growth Hormone:
Also known as somatotropin. Stimulates growth and cell reproduction.

PROLACTIN:
Stimulates milk production.

ENDORPHINS:
Decreases pain

Question 12

Posterior Pituitary

Answer 12

Posterior lobe of the pituitary gland.

ADH (AKA:Vasopressin):
Antidiuretic Hormone. A peptide hormone synthesized in the hypothalamus and released by the posterior pituitary. It regulates the tonicity of body fluids. ADH is released in response to hypertonicity and causes the kidneys to reabsorb H2O. Results in concentrated urine and reduced urine volume. Can also increase ­BP.

OXYTOCIN:
A peptide hormone synthesized in the hypothalamus and released by the posterior pituitary. During childbirth, it increases uterine contractions and is released in response to cervix stretching. Also increases milk production and certain bonding behaviors.

Question 13

Thyroid Gland

Answer 13

In the neck and below the Adam’s Apple. Secretes thyroid hormones that regulate metabolism. Also helps regulate calcium homeostasis.

T4 & T3:
Thyroxine (T4) and Triiodothyronine (T3).
T4 is a precursor to T3. Regulates metabolism. Created from Iodine and Tyrosine.

Calcitonin: 
Builds bones
-inc Ca in bone
-inc Ca excretion from kidneys
-dec Ca in blood
-dec Ca absorption in gut

Question 14

Parathyroid Glands

Answer 14

A collection of 4 parathyroid glands located on the back of the thyroid. Primary function is to maintain the body’s Ca2+ and K+ levels so that the nervous and muscular systems can function properly.

PTH:
Parathyroid Hormone. Bone Breakdown. 
-inc Ca in blood
-inc Ca absorption in gut
-dec Ca in bone
-dec Ca excretion from kidney 

Activated Vitamin D (Calcitriol)

Question 15

Adrenal Medulla

Answer 15

Sits on top of the kidney. Adrenal Medulla is located at the center of the adrenal gland, surrounded by the adrenal cortex. It converts tyrosine into catecholamines.

Epinephrine:

• Increase HR and BP.
• Primarily a hormone. Also an anti-histamine.

Norepinephrine:
-increase HR and BP.
*A hormone and a neurotransmitter; inhibits
insulin.

Dopamine:
The adrenal medulla secretes a small amount of dopamine.