Presentation 17: Endocrine System Flashcards

1
Q

What are the Functions of the endocrine system

A
  • integrates body functions
  • slower than the nervous system, but more sustained
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What types of arrangements can endocrine glands be?

A

GENERAL:
Ductless glands (no opening to outside), usually small and highly vascular that secrete hormones into the circulatory system

Split into Cordal vs Follicular arrangements
- cordal = usually associated w/ blood vessels, include parotid and salivar
- follicular = has cavity (colloid) surrounded by circulatory cells and epithelium made up of parafollicular and follicle cells, ex. thyroid gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Cordal arrangement

A

usually associated w/ blood vessels, include parotid and salivar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Follicular arrangement

A

has inner cavity (colloid) surrounded by circulatory cells and epithelium made up of parafollicular and follicle cells
- ex. thyroid gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Neurosecretory tissues

A

Specialized neurons that synthesize and secrete hormones
- extend from hypothalamus to postierior pituitary
- secrete neurohormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Neurohormones

A

released by axons of specialized neurosecretory cells into surrounding blood capillaries (i.e. sinusoids)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How do we categorize the Endocrine System?

A

Embryonic origin!
1. ectodermal origin (i.e. pituitary gland, pineal body, adrenal medulla) = secretes peptides/proteins = amino acid derivatives
2. mesodermal origin (i.e. gonads and adrenal cortex) = secretes steroids = modified lipids
3. Endodermal origin - from pharyngeal pouches (i.e. thyroid, endocrine pancreas, parathyroid, and ultimobranchial bodies)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Ectodermal origin

A

Secretes peptides or proteins (amino acid derivatives)
- Pituitary gland (hypophysis)
- Pineal body (melatonin)
- Adrenal medulla (stress responses)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Pituitary gland/hypohysis

A

Divided into Neurohypophysis (post. pituitary) which is an evagination of the infundibulum in the diencephalon, and the Adenohypophysis which is from Rathke’s pouch which is an outgrowth of the mouth cavity
- suspended from diencephalon via the sella turcica (turcic chair) of skull

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Neurohypophysis

A

Posterior pituitary: evagination of infundibulum
- Made up of median eminence (top) and Pars nervosa (post. lobe)
- median eminence absent in lungfish

Secretes:
- arginine-vasotocin (found in all craniates, helps reabsorb water in kidney)
- Vasotocin and vasopresin (thermoregulation)
- oxytocin (milk production and contraction of uterus in mammals)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

arginine-vasotocin

A

(found in all craniates, helps reabsorb water in kidney)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
  • Vasotocin and vasopresin
A

(thermoregulation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

oxytocin

A

(milk production and contraction of uterus in mammals)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Adenohypohysis

A

From Rathke’s pouch (an outgrowth of the mouth cavity)
- Split into pars intermedia, pars tuberalis, and pars distalis
- pars distalis is most secretory part and controlled by hypothalamus

Secretes:
- Thyrotropin (regulates thyroid gland)
- Adrenocorticotropin (regulates function of adrenal cortex (part of adrenal gland in assoc. w/ kidneys)
- FSH (follical-stimulationg hormone, stimulates growth of ovarian follicle)
- Leutinizing hormone (LH = ovulation and formation of corpus luteum, ICSH = androgen synthesis in testes)
- Somatotropin (growth hormone and imp. for breakdown of fats)
- Prolactin (lactation in mammals)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the diversity of the pituitary gland from protochordates to mammals/birds

A

Protochordates = no homology w/ pituitary gland

Agnathans
- adenohypohysis = not compact but scattered tissue around diff. organs
- neurohypohysis = relatively flat (pars nervosa = absent)

Fishes
- neurohypo = flat + pars nervosa = absent
- adreno + neurohypo = indistinguishable

Lungfishes
- much larger development
- pars nervosa becomes more distinguished

Reptiles
- largest pars intermedia

Mammals
- very small pars intermedia

Birds
- Pars intermedia = absent (func. taken over by pars distalis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Pineal body

A

Synchronized endocrine and non-endocrine activity patterns (ex. birds building nest)
- secretes melatonin
- both stimulate sympathetic responses in the body

17
Q

Adrenal medulla

A

adrenal gland (central tissue of mammals)
- differes in structure and function from adrenal cortex
- developed from neural crest cells
- consists of chromaffin cells
- secretes epinephrine (stress response) and norepinephrine (relax)
- both stimulate sympathetic responses in the body

18
Q

Mesodermal origin

A

Secrete steroids (modified lipids)
- Adrenals (i.e. adrenal cortex, secrete adrenocorticosteroids)
- Gonads (i.e. ovaries - secrete estrogens, and testes (secrete androgens)

19
Q

Adrenal Cortex

A

Interrenal tissue in fishes
- Secretes adrenocorticosteroids

  • Cortisone, cortisol, and corticosterone (affects metabolism of carbohydrates breakdown to glucose)
  • Deoxycorticosterone (affects metabolism of salt and water)
  • Aldosterone (affects metabolism of sodium and potassium)
  • Adrenosterone (affects stress response)
20
Q

Cortisone, cortisol, and corticosterone

A

(affects metabolism of carbohydrates breakdown to glucose)

21
Q

Deoxycorticosterone

A

(affects metabolism of salt and water)

22
Q

Aldosterone

A

(affects metabolism of sodium and potassium)

23
Q

Adrenosterone

A

(affects stress response)

24
Q

Ovaries

A

Secrete estrogens from ovarian follicles

  • estradiol and estrone (imp for growth/dev of female genital system and secondary sex characteristics)

Ovulation: ovarian follicle: corpus luteum
- progesterone (maintaining pregnancy and preparing uterine wall)
- relaxin (mammary glands and prepares the pubic area for birth)

25
Q

Testes

A

Secrete androgens
- testosterone : produced in interstitial cells (important for growth/dev. of male genital system and secondary sex characteristics)

26
Q

Endodermal origin

A

Comes from lining of pharyngeal pouches

  • Endocrine pancreas (lowers blood sugar)
  • Thyroid gland (from 2nd pharyngeal pouch)
  • Parathyroid (3rd/4th pharyngeal pouches)
  • Ultimobranchial bodies (post. pair of pharyngeal pouches)
27
Q

estradiol and estrone

A

imp for growth/dev of female genital system and secondary sex characteristics

28
Q

progesterone

A

maintaining pregnancy and preparing uterine wall

29
Q

relaxin

A

mammary glands and prepares the pubic area for birth

30
Q

Endocrine pancreas

A

Islands of langerhans in pancreus secrete insulin and glucagon

insulin (converts glucose to glycogen in liver/skeletal muscle to lower blood sugar)

glucagon (converts glycogen to glucose to raise blood sugar)

31
Q

insulin

A

(converts glucose to glycogen in liver/skeletal muscle to lower blood sugar)

32
Q

glucagon

A

(converts glycogen to glucose to raise blood sugar)

33
Q

Thyroid Gland

A

Develops from evagination of 2nd pharyngeal pouch
- highly vascular
- located close to larynx/trachea
- follicular structure (extracellular storage of secretion)
- imp during cell differentiation, metamorphosis, sex. development, molting, feather dev. and shape, and thermoreg.

Coroid has thyroglobulin (iodine rich protein) = precursor of hormones
- hydrolysis = thyroxine (T4) and triodotryonine

34
Q

Thyroid Gland Diversity

A
  • Homologoys to endostyle of protochordates
  • thyroids are paired in amphibians, lizards, and birds
  • thyroid is single in lungfish/mammals, but bilobed
  • thyroid is single in chondricythys and most reptiles
35
Q

Parathyroid

A

From the epithelium of 3rd and 4th pharyngeal pouches
- produces parathormone/parathyroid hormone (imp. in regulating Ca and phosphorous levels in bloodstream aka for muscle function)

36
Q

Parathyroid diversity

A

Present only in tetrapods (i.e. fishes and agnathans don’t have it)
Paure, either 2 or 4

37
Q

Ultimobranchial bodies

A

Single or paired, develop from post. part of pharyngeal pouches

  • Produces calcitonin (regulates calcium levels, blocks removal of calcium from bones)
38
Q

Ultimobranchial bodies diversity

A
  • Absent in agnathan, primitively present in gnathostomes
  • Mammals lacking: cells of last pharyngeal pouch captured into thyroid and in mammals calcitonin produced by parafollicular cells within the thyroid
39
Q

Transitory hormones

A

When mammals (placenta / Eutherian mammals)
- estrogen, progesterone, and prolactin are produced