Endocrinology- Exam 1- Anterior Pituitary (copy)

What is another name for the anterior pituitary?

adenohypophysis

how is the communication from the hypothalamus differ when going to the anterior pituitary vs the posterior pituitary?

- to get to ant. pituitary hormones must travel through infundibulum using the hypophyseal portal system (veins)

-to get to the post. pituitary hormones travel directly down neurons

what are the three parts that make up the anterior pituitary?

Which part is largest?

1. Pars distalis (largest 90%)

2. Pars tuberalis

3. pars intermedia

Hypothalamic hormones are stimulated by ____________ but enter the ant. pituitary through ______________ ____________.

neurons; blood vessels

What is the pathway called with the infundibulum connecting (with blood vessels) the hypothalamus to the anterior pituitary.

Hypothalamic-hypophyseal portal system

What system allows hypothalamic hormones to be transported to the anterior pituitary.

Does this require the hormones to enter circulation?

-hypothalamic hypophyseal portal system

- does this WITHOUT hormones entering circulation

Where does the hypothalamic hypophyseal portal system originate?

superior hypophyseal artery

Hypothalamic hormones travel through the ____________ ______________ ___________ to the __________ ___________, which carry them to the anterior pituitary gland.

from the ant. pituitary, hormones released from here travel through a ____________ ____________ __________ and then drain into _______________.

primary capillary plexus; portal veins

secondary portal plexus; circulation

How does a hypothalamic hormone get to the anterior pituitary and into circulation? (pathway)

Hypothalamus-> primary capillary plexus-> portal veins-> anterior pituitary-> secondary capillary plexus-> circulation

T/F: topic hormones control secretion of other glands.

TRUE

What are the hypothalamic releasing hormones? (5)

What are the inhibiting hormones? (2)

LONG CARD

releasing:

1. Growth Hormone Releasing hormone (GHRH)

2. Corticotrophin releasing hormone (CRH)

3. Thyrotrophin releasing hormone (TRH)

4. Prolactin releasing hormone (PRH)

5. Gonadotrophin releasing hormone (GnRH)

inhibiting:

1. Somatostatin

2.Dopamine

The anterior pituitary secretes hormones known as ________ hormones.

tropic

What are the 5 tropic cells and the hormones they secrete?

1. Somatotrophs- hGH

2. Corticotrophs- ACTH

3. Thyrotrophs- TSH

4. Lactotrophs-PRL

5. Gonadotrophs-FSH and LH

what are the 6 tropic hormones?

(also put their category)

1. Human growth hormone (hGH)- somatotroph

2. Prolactin (PRL)- lactotroph

3. Thyroid stimulating hormone (TSH)- thyrotroph

4. Adrenocorticotrophic hormone (ACTH)- corticotroph

5. Follicle-stimulating hormone (FSH)- gonadotroph

6. Luteinizing hormone (LH) gonadotroph

What are the acidophils?

somatotrophs and lactotrophs/mammotrophs

what are the basophils?

-Corticotrophs

-Thyrotrophs

-Gonadotrophs

Prolactin and dopamine have an ________________ relationship.

inverse

somatotrophs are stimulated by what?

Which mechanism does this use?

- Growth hormone releasing hormone (GHRH)

-adenylyl cyclase AND phospholipase C mechanism

What is secreted from somatotrophs once stimulated by GHRH?

What mechanism does this use?

-human growth hormone (hGH)

-tyrosine kinase mechanism

What is the role of human growth hormone? (2)

1. provide enough nutrition for ATP and protein synthesis

2. Cell proliferation and differentiation (growth)

Corticotrophs are stimulated by which hormone?

Which mechanism does this use?

- Corticotrophin releasing hormone (CRH)

- adenylyl cyclase mechanism

When corticotrophs are stimulated by CRH, what do they secrete?

Which mechanism does this use?

-Adrenocorticotrophic hormone (ACTH)

- adenylyl cyclase mechanism

What is the target for Adrenocorticotrophic hormone (ACTH)

cortex of adrenal gland

What is secreted by the cortex of the adrenal gland once stimulated by ACTH? (3)

what is the role of these hormones?

-aldosterone, cortisol and androgens (steroid hormones)

what is the role of aldosterone, cortisol and androgens (all from adrenal cortex)?

-regulate salt and water for BP, metabolism of glucose/proteins/fats, produce adrenal androgens

What are the three layers of the adrenal cortex from outside to inside?

-Glomerulosa (salt)

-Fasciculata (sugar)

-Reticularis (sex)

Thyrotrophs are stimulated by what?

What mechanism do these use?

-Thyrotropin releasing hormone (TRH)

- phospholipase C mechanism

Once thyrotrophs are stimulated by TRH, what is secreted?

What mechanism does this use?

-Thyroid stimulating hormone (TSH)/Thyrotropin

- adenylyl cyclase mechanism

What is the target tissue of thyroid stimulating hormone? (BE SPECIFIC, two sites)

- Thyroid gland->Thyroxine (T4)

-Thyroid gland -> Triiodothyronine (T3)

both areas control metabolism

What are lacrotrophs/mammotrophs stimulated by?

Which mechanism does this use?

-Prolactin Releasing Hormone- PRH/PRH

-phospholipase C mechanism

What are lactotrophs/mammotrophs inhibited by?

what mechanism is used?

-Dopamine (Prolactin inhibiting hormone)

-adenylyl cyclase mechanism

When lactotrophs are stimulated by PRH, what is secreted?

What is the target organ of this secretion?

-prolactin (PRL)

-mammary glands (milk production)

What are gonadotrophs stimulated by?

What mechanism does this use?

-Gonadotrophin releasing hormone (GnRH)

- phospholipase C mechanism

When gonadotrophs are stimulated by GnRH, what is secreted?

What mechanism does this use?

-Luteinizing hormone (LH) and follicle stimulating hormone (FSH)

-adenylyl cyclase mechanism

What are the target organs of LH and FSL?

What is then released from these organs?

Ovaries and testes

ovaries-> progesterone and estrogen

testes->testosterone

Progesterone and estrogen are vital for _____________________.

oogenesis

Testosterone is vital for ________________.

spermatogenesis