Chapter 10 questions Flashcards
(9 cards)
What are glands that make up this system and where in the anatomy can they be found?
1) Pineal2) Pituitary3) Thyroid4) Parathyroid
5) Suprarenal Picture for anatomical location on slide 4.
What are the three types of hormones and examples of each? What are the different ways in which they exert their effect on the target organs?
The Hormones
1) Proteins and polypeptides: insulin, glucagon, FSH
2) Amino acid derivatives: thyroxine, epinephrine
3) Steroid and fatty acid derivatives: progesterone, estradiol, testosterone
- bind to receptors or directly enter the cell
- feedback mechanism
- many in the blood are oversupplied and inactive
What are two divisions of the pituitary gland? What hormones do they secrete, what organ do they target and what affect do they have on the target? How are each of the divisions subdivided?
-adenohypophysis - derived from the oral ectoderm - neurohypophysis - derived from neural ectoderm
Pars anterior
Acidophils- Most abundant- Somatotrophs - secrete somatotropin (growth hormone; ↑ metabolic rates, stimulates liver cells to make somatomedins such as IGF)- Mammotrophs - produce prolactin
Basophils- Corticotrophs - secrete ACTH and LPH- Thyrotrophs - secrete thyrotropin
Gonadotrophs - FSH and LH
Pars nervosa
-neurosecretory cells synthesize vasopressin (ADH), oxytocin (OT) and a carrier protein, neurophysin, that carries the hormones in the axons down to pars nervosa
How is the anterior pituitary prompted to secrete its hormones?
superior hypophyseal arteries supply the pars tuberalis, infundibulum, and primary capillary plexus of the median eminence
What cell types demarcate the pars distalis and what hormones do they produce?
Acidophils- Most abundant- Somatotrophs - secrete somatotropin (growth hormone; ↑ metabolic rates, stimulates liver cells to make somatomedins such as IGF)- Mammotrophs - produce prolactin
Basophils- Corticotrophs - secrete ACTH and LPH- Thyrotrophs - secrete thyrotropin
Gonadotrophs - FSH and LH
Pars nervosa
-neurosecretory cells synthesize vasopressin (ADH), oxytocin (OT) and a carrier protein, neurophysin, that carries the hormones in the axons down to pars.nervosa
What cell types do you find in the thyroid, how are they organized? What is colloid composed of and how is it synthesized and released?
- Follicular cells synthesize thyroxine (T4), triiodothyronine (T3) and thyroglobulin
- Parafollicular cells produce calcitonin (inhibits bone resorption by osteoclasts)
T4 and T3 hormones are stored in the colloid, and bound to glycoprotein thyroglobulin
-Slide 14
What do the parathyroid glands do that is vital to life? What are the cell types found in this organ and what do they produce?
PTH acts on bone, kidneys, and the intestines in maintaining the optimal calcium concentrations in blood and interstitial tissue fluid by ↑ blood calcium levels.
What are the divisions of the adrenal glands? What are the layers of each? What is so unusual about the chromaffin cells?
1.) Zona glomerulosa - synthesizes and releases aldosterone and deoxycorticosterone (target – kidney)
2.) Zona fasciculata (cells are referred to as spongiocytes) - synthesizes and releases cortisol and corticosterone (fat and protein catabolism, gluconeogenesis)
3.) Zona reticularis - synthesizes and releases androgens and some glucocorticoids (testosterone and estrogen)
Chromaffin cells are actually postganglionic neurons lacking dendrites and axons
What is the function of the pineal gland and what is distinct about the histology?
Pinealocytes synthesize melatonin; secretions governed by the light and darkness of the day (plays a role in the circadian rhythm); SAD- Contains “brain sand” - calcified elements that increases in number with age
