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Flashcards in endocrine 3 Deck (17)
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1
Q

Adrenal gland is composed of what 2 parts?

How do they function and what are they made from?

A
    1. Adrenal cortex: made up of cortex zones
    1. Adrenal Medulla:
  • Each function separately
  • Adrenal Cortex-Develops from epithelial tissue
  • Adrenal Medulla- Develops from nervous tissue
2
Q

Adrenal Cortex stimulated by____from____.
What does it release, and what are the functions
Are these polar or non polar

A

ACTH, Ant. Pituitary

a. mineralcorticoids (na absorption/proximal 2/3)
b. Glucocorticoids (cortisol-increases glucose, other functions)aka corticosteroid, “one” ending made from cholesterol
c. sex steroids (androgen/DHEA) secondary sex characteristics DHEA->testosterone, in women testosterone->estrogen

Non polar

3
Q

What is the action of these hormones

  1. aldosterone:
  2. cortisol:
  3. Adrenal androgens:
A

aldosterone: regulate the concentration of extracellular electrolytes by conserving sodium ions and excreting potassium ions. Factors: electrolyte concentrations in body fluids and renin-angiotensis mehcanism.
Cortisol: decreases protein synthesis, increases fatty acid release, and stimulates glucose synthesis from noncarbohydrates. factors: CRH from hypothalamus and ACTH from anterior pituitary gland
Adrenal androgens: supplement sex hormoens from the gonads; may be converted into estrogens

4
Q

Adrenal medulla located?
Secretes what?
Released when?

A

: on top of kidney
: secretes epinephrine ( it takes longer but lasts longer in bloodstream) and Norepinephrine (4:1)
: released when stimulated by sympathetic division of the autonomic nervous system- tissue of medulla acts like neurons. Under fight or flight conditions (medulla post synaptic tissue)

5
Q

Thyroid gland secretes what 2 hormones?

A
  1. Thyroid hormone

2. calcitonin

6
Q

Thyroid gland is made up of what?

What is it stimulated by?

A

spherical structure with fluid filled follicle

: TSH

7
Q

Thyroid hormone is stimulated by what, and where does it come from?
What is thyroid hormones function?

A

: stim by TSH from anterior pituitary->thyroid gland
: takes iodide out of blood converts to iodine, forms thyroid hormone T4 and T3(active form) both are non polar. These regulate cellular metabolism, causes transcription of DNA for protein synthesis
: secretion controlled by negative feedback

8
Q

What is an example of negative feedback involving Thyroid hormone

A

-elevated T3 and T4 cause TSH secretion to decrease
1. decreases TRH from hypothalamus, which decreases TSH secretion from Ant. Pituitary
2. Also has direct effect of decreasing TSH from Ant. Pituitary
-When blood levels of thyroid hormone are low
stimulates TSH release via hypothalmic, ant pituitary

9
Q

Characteristics of Iodine deficiency

A
  • production of thyroid hormone is low, no negative feedback working
  • TSH increases->causes thyroid gland to grow and try and compensate has growth stimulating effect
  • hypertrophy and hyperplasia
10
Q

Calcitonin direct or indirect
where is it produced, what is its function, what does it secret?
How does it decrease certain hormone?

A

Direct
: produced by parafollicular cells in thyroid
: functions to regulate calcium levels in blood
: secreted in response to high levels of blood calcium (NOT stimulated by another hormone)
:decreases ca from being liberated form bone, and increase ca exretion in urine

11
Q

Parathyroid glands located where?
what do they secrete?
Parathyroid hormone stimulates what?

A
  • Embedded in the posterior surfaces of the lateral lobes of the Thyroid gland, usually 4 lobes.
  • secretes: parathyroid hormone(most important hormone in control of blod calcium levels)
  • Released in response to low blood calcium (DIRECT- not in response to another hormone)
  • stimulates: osteoclasts to reabsorb bone and liberate calcium to blood
  • stimulates kidneys to reabsorb calium form filtered blood
  • stimulates renal enzyme that activates vitamin d3 which stimulates intestines to absorb calcium from food fluids
12
Q

What is the functioning unit in the pancreas and what types of cells make it up?

A
  • Pancreatic Islets (endocrine portion of gland) also exocrine (digestive portion)
  • Alpha-25%
  • Beta-60%
  • Delta-15%
13
Q

B cells secrete what (direct or indirect), in response to what?
Through what mechanism?
What does it promote?

A
  • Secrete insulin in response to high blood glucose >120 (direct)
  • binds to RTK cell membrane receptor, activates carrier protein within cell, carrier protein(GLUT 4) moves glucose into the cell by FACILITATED DIFFUSION
  • promotes: conversion of glucose into Glycogen and Lipids if not used to make ATP
  • promotes: entry of Amino acids into cells
14
Q

A cells secrete what, in response to what?

This promotes?

A
  • secretes glucagon in response to low blood glucose levels.
  • Glucagon promotes glycogenolysis(splitting of glycogen to liberate glucose into the blood)
  • gluconeogenesis- formation o glucose form non-carbohydrate sources (fatty acids, amino acids)
15
Q

Where is the pineal gland located?
What does it secrete?
Release of hormone is in response to what?
What is the action of the hormone?

A

:below diencephelaon located between the cerebral hemispheres, adjacent to the thalamus.
:secretes melatonin (from seratonin-neurotransmitter)
:released in response to changes in sunlight; secreted at night, inhibited by light.
: Action aides in the regulation of circadian rythm (associated with somatostatin, main funciton regulates other hormones based on sun)

16
Q

What do the ovaries secrete?
What are they secreted from AND in response to?
What do the ovaries stimulate?
1st half or 2nd half?

A

:Secrete estrogen in 1st half of cycle, secreted from developing follicle in response to FSH.
:estrogen stimulates growth of uterine lining, maturation of undeveloped egg.
:ovary secretes progesterone in 2nd half of cycle, secreted from corpeus luteum in responseto LH(keeps all structures stable until fertilization)-helps uterine lining to mature for implantation.

17
Q

What do the testes secrete, what is the hormone secreted from?
What is the hormone secreted in response to?
What does it stimulate?

A

:testosterone from Leydig cells in response to LH hormone.

: stimulates growth of male characteristics and spermatogenesis.