week 8

Question 1

3 parts of pituitary

Answer 1

Pars nervosa, pars distalis, pars intermedia

Question 2

function of pars nervosa

Answer 2

(post pituitary) site for the secretion ofneurohypophysial hormones(oxytocinandvasopressin) directly into the blood

Question 3

function of pars distalis

Answer 3

(ant. pituitary) responsible for secreting hormones into blood

Question 4

hypothalamic-hypophyseal portal system

Answer 4

system of blood vessels in the microcirculation at the base of the brain, connecting thehypothalamuswith the anterior pituitary. Its main function is to quicklytransportand exchange hormones between the hypothalamusarcuate nucleus and anterior pituitary gland.

Question 5

hypothalamic-hypophyseal tract

Answer 5

neurons that deliver vesicles with neurohormones to and from thehypothalamusto the posterior lobe of thepituitary gland

Question 6

Pars Ditalis epithelium cells

Answer 6

• chromophobes: do not stain; cells where hormones are stored
• acidophils: stain pink; secrete growth hormone (somatotrophs) or prolactin (lactotrophs)
• basophils: stain purple; are corticotrophs (ACTH), gonadotrophs (LH/FSH), and thyrotrophs (TSH)

Question 7

Pars Nervosa: pituicytes and herring bodies

Answer 7

• pituicytes: gleal cells that ensheath unmyelinated axons from hypothalamus to posterior pituitary
• herring bodies: swellings in axons of posterior pituitary neurons that release oxytocin or vasporessin

Question 8

Layers of adrenal gland and function

Answer 8

• Adrenal glands are each covered by a dense connective tissue CAPSULE that sends thin trabeculae into the gland’s parenchyma.

• Cortex secretes steroid hormones; has fenestrated capillaries
○ Zona glomerulosa: mineralocorticoids and the principle product is aldosterone (the major regulator of salt balance)
○ Zona fasciculata: glucocorticoids, especially cortisol
○ Zona reticularis: Cells produce cortisol but primarily secrete the weak androgens, including DHEA that is converted to testosterone in both men and women

• Adrenal medulla: secrete catecholamines (epinephrine or norepinephrine); has sinusoidal capillaries

Question 9

Thyroid gland

• location
• function of colloid
• parafollicular cell

Answer 9

• Thyroid gland is located anterior and inferior to the larynx
• Thyroid colloid contains the large glycoprotein thyroglobulin, the precursor for the active thyroid hormones.

-Parafollicular cells secrete calcitonin, a polypeptide involved with calcium metabolism.