endocrine system 1 Flashcards

1
Q

nervous system vs endocrine system

A

nervous

  • communicates via AP and release of NT
  • extremely rapid (less than a sec)
  • frequency
  • neurons going to a specific site

endocrine system
-communicates via hormones into the blood stream
-slow ( minutes hours days)
-amplitude modulation
-receptor specificity (hormone will only bind to that spot)
tissues and cells capable of secreting and responding to hormones

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2
Q

endocrine system overview

A

includes endocrine glands that secret hormones and hormone secreting cells located in various organs

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3
Q

endocrine vs exocrine

A

endocrine glands are DUCTLESS and release hormones into the blood (this class)

exocrine glands secrete their products into a duct, then either exit body or enter lumen/another organ (can be duct or ductless) (more 132)

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4
Q

hormones

A

chemical messengers that are formed in one organ or part of the body and carried in the blood to another organ or part

  • target cells
  • can alter the functional activity of just one organ or of various numbers of them
  • heavily depends on target receptors and target cells
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5
Q

3 classes of hormones

A

peptide/protein

steroid

amine

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6
Q

hypothalamus

A

considered part of endocrine system

-portal system or blood system that connects hypothalamus to anterior pituitary gland

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7
Q

anterior pituitary gland

A

produces hormones with diverse actions related to metabolism, reproduction, growth and others

-ACTH, FSH, LH, GH, PRL, TSH

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8
Q

HPA axis

A

interaction between hypothalamus-pituitary gland and adrenal gland

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9
Q

a single gland can secrete

a single cell type can secrete

A

single gland can secrete multiple hormones

single cell types can secret only one hormone**

hormones can be secreted by certain endocrine glands but also other cell type and serve in these other locations as NT’s, paracrine or autocrine substances

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10
Q

paracrine activation hormone vs autocrine

A

paracrine hormone is released to cell adjacent to the cell that is releasing

autocrine is releasing itself

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11
Q

amine hormones derivatives of what

A

amino acid tyrosine

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12
Q

amine hormones water soluble?

A

are water soluble

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13
Q

examples of amine hormones

A
  • thyroid hormones (produced by thyroid gland)
  • epinephrine and norepinephrine (produced by adrenal medulla)
  • dopamine (produced by hypothalamus)
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14
Q

thyroid hormones produced by what? where

A

produced by thyroid gland on trachea

-just above the sternum

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15
Q

epinephrine and norepinephrine produced by ? where? which hormone is secreted more?

A

adrenal medulla

sits on top of kidney, medulla middle

  • epinephrine is secreted 4x more than norepinephrine
  • it is secreted more because it eventually gets converted to norepi by PMMT?
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16
Q

dopamine produced by?

A

synthesized by neurons in hypothalamus (catecholamine hormone = produced in brain/nerve tissue/adrenal gland)

17
Q

posterior pituitary vs anterior pituitary

A

posterior still neural tissue

anterior is seperate

can develop cancer in this region

18
Q

peptide and protein hormones made of?

A

polypeptides

  • can be short polypeptides (peptides)
  • can be long polypeptides with tertiary structure (proteins)

→these range from small peptides to large proteins which contain carbohydrates which makes them glycoproteins = peptide hormones

  • are water soluble
  • doesn’t require secondary transporter, diffuse right into blood
19
Q

peptide hormones sequence of events

A

Synthesized on ribosome of endocrine cells as larger molecules known as pre-prohormones which are then cleaved to pro hormones by protealytic envymes in the rough endoplasmic reticulum.

Then pro hormone is packaged into secretory vesicles by the Golgi apparatus. When cell is stimulated to release contents of the secretory vesicles by exocytosis, there are other peptides that are secreted along with the hormone. Eg. Insulin and c-peptide

20
Q

steroid hormones produced by

A

adrenal cortex (outside) and the gonads (testes/ovaries)

-are lipid soluble, NOT water soluble

→require a fat bubble to transport them through blood, still through blood but need help

21
Q

steroid hormones formation

A

Steroid hormones are based on cholesterol** is a very distinct structure

DHEA- precursors to steroid hormone

Hormone producing cells are stimulated by the binding of an anterior pituitary gland hormone to its plasma membrane protein. The receptors are linked to G proteins which activated adenylyl cyclase and cAMP production. Protein kinase A then gets activated by cAMP and results in phosphorylation of numerous intracellular proteins. This leads cholesterol to energy several enzymatic conversions and become the final steroid hormone which is diffused into blood

22
Q

hormones of the adrenal cortex - Aldosterone

A

known as mineralocorticoid

  • production is under control of angiotensin 2 (orginally from liver)
  • many effects on maintaining salt balance in blood.
  • were able to retain or lose water as we need, water follows salt, able to regulate salt in urine
  • if we retain water we increase blood volume and in turn increase BP

-renin is activator of the entire pathway which gets release of the condition of low blood pressure

23
Q

hormones of AC - cortisol and corticosterone and glucocorticoids functions?

A
  • metabolism of glucose and other organic nutrients
  • facilitation of the body’s responses to stress and regulation of the immune system

glucocorticoids” bc they have an important effect on metabolism of glucose

-also release sugar into bloodstream when you are stressed

high stress= high cortisol=high chance of diabetes

  • glucocorticoids suppress release of pro inflammatory cytokines
  • regulates immune cell maturation, regulate hydration, regulate apoptosis (cell death)
24
Q

AC hormones -DHEA and Androstenedione

A
  • DHEA and androstenedione belong to class of steroid hormones called androgens
  • functions in adult female and female and male in the fetus and at puberty
25
Q

gonads hormones -testes and ovaries

A

testes- secrete testosterone

ovaries - secrete estrogens (estradiol and estrone)

-secretes progesterone (maintaining corpus luteum)

estradiol expressed in large amounts

26
Q

breakdown of peptide/protein/ steroid/ amine characteristics

check last slide

A
27
Q

examples of peptide/ protein, steroid and amine hormones

A

peptide/protein : pituitary hormones

steroid : testosterone, estrogen and cortisol

amine : catecholamines and thyroid hormone

28
Q

precursors for peptide/ protein, steroid and amine

A

peptide/protein : amino acids

steroid : cholesterol

amine: tyrosine

29
Q

solubility of protein/peptide, steroids and amines

A

peptide/protein: dissolves

steroid : bound to blood proteins

amine : depends

30
Q

time before onset of action for each

A

peptide/protein : quick

steroid : slow

amine : depends