Endocrine System

Question 1

endocrine system characteristics

Answer 1

• has ductless glands and composed of endocrine tissues

- secretes hormones into blood

Question 2

target cells

Answer 2

any cell w/ receptor for specific hormone

Question 3

hormone classes

Answer 3

steroid hormone, hormones derived from amino acids & peptide+protein hormones

Question 4

steroid hormones

Answer 4

• derived from cholesterol

- has lipids: hydrophobic, lipid soluble

Question 5

hormones derived from amino acids

Answer 5

• tyrosine: amino acids used to make thyroid hormones (T4)

- tryptophan: amino acid makes serotonin + melatonin

Question 6

peptide & protein hormones

Answer 6

• from chains of amino acids
• hydrophilic, water soluble
• ex: oxytocin + growth hormone

Question 7

pituitary glands characteristics

Answer 7

• suspended by hypothalamus
• located at sella turcica o sphenoid bone
• highly vascular (allows secretions of hormones)
• composed of the anterior + posterior pituitary

Question 8

what secretes from the hypothalamus?

Answer 8

regulating hormones are secreted

Question 9

what do the regulating hormones do?

Answer 9

regulate the secretion of hormones from the pituitary gland

Question 10

anterior pituitary gland function

Answer 10

secretes hormones that affect growth, metabolism + reproduction

Question 11

hormones anterior pituitary gland secrets:

Answer 11

• follicle stimulating hormone (FSH): reproduction
• leutinizing hormone (LH): reproduction
• adrenocorticotropic hormone (ACTH): stimulates secretion of steroids from adrenal glandss
• thyroid stimulating hormone (TSH): stimulates secretion of thyroid
• prolactin (PRL): milk formation
• growth hormone (GH): growth + metabolism

Question 12

posterior pituitary gland

Answer 12

• ext. of hypothalamus formed from nervous tissue

- secretes hormones produced in hypothalamus

Question 13

hormones posterior pituitary gland secretes:

Answer 13

• oxytocin: stimulates uterine contractions

- antidieuretic hormone (ADH): vasopressin–stimulates water reabsorption in kidney

Question 14

thyroid gland characteristics

Answer 14

• located on superior surface of trachea below larynx
• shaped like butterfly
• composed of 2 diff cells (follicles + parafollicular)

Question 15

thyroid gland cell types follicles:

Answer 15

• follicular epithelial cells
• produce thyroxine (T4) hormone
• controls metabolism, growth + development
• produced in lumen of gland + secreted from follicular cells

Question 16

thyroid gland cell types parafollicular cells:

Answer 16

• surround follicle

- secrete calcitonin

Question 17

what does calcitonin do?

Answer 17

• stimulates calcium uptake by bone, decreasing plasma calcium
• builds bone matrix (osteoblasts)

Question 18

parathyroid gland

Answer 18

• consists of 4 glands on posterior surface of thyroid gland

- produces parathyroid hormone (PTH)

Question 19

functions of PTH

Answer 19

• acts to increase calcium levels

- stimulates breakdown of bone matrix (osteoclasts)

Question 20

how can PTH increase calcium levels?

Answer 20

• decreasing calcium excretion from kidney

- increasing vitamin D activation in kidney

Question 21

function of vitamin D

Answer 21

increase calcium reabsorption in intestine

Question 22

adrenal gland basic characteristics

Answer 22

• located on superior surface of kidney

- 2 glands (adrenal cortex + adrenal medulla)

Question 23

adrenal cortex

Answer 23

• secretes steroid hormones

- 3 layers (zona glomerulosa, fasciculata, reticularis)

Question 24

zona glomerulosa

Answer 24

• secretes mineralocorticoids: predominantly aldosterone (regulates salt balance)

Question 25

zona fasciculata

Answer 25

- secrets glucocorticoids: predominantly cortisol (regulates stress response)

Question 26

zona reticularis

Answer 26

- secretes androgens: small amounts of testosterone

Question 27

testosterone functions

Answer 27

- female sex drive converted to estrogen in both male and female

Question 28

adrenal medulla

Answer 28

- produce epinephrine (80%) & norepinephrine (20%) | - help body combat short term stress (fight or flight response)

Question 29

endocrine tissues

Answer 29

- found in organs that have additional functions (diff primary function) - pancreas, hypothalamus, gonads

Question 30

endocrine tissues: pancreas

Answer 30

- endocrine part called Islets of Langerhans - ALPHA CELLS: secrete glucagon - BETA CELLS: secrete insulin

Question 31

glucagon

Answer 31

- increase blood glucose during hypoglycemic state | - secreted by alpha cells

Question 32

insulin

Answer 32

- decrease blood glucose during hyperglycemic state | - secreted by beta cells

Question 33

endocrine tissues: hypothalamus

Answer 33

- 3 endocrine functions 1) PRODUCE REGULATORY HORMONES [stimulate/inhibit release of hormones] 2) SYNTHESIZE HORMONES from P pituitary 3) NERVOUS FUNCTION: controls body temp, thirst, urine output, hunger, daily rhythms + behavioural patterns

Question 34

endocrine tissues: gonads

Answer 34

- OVARIES: primary + secondary follicles secrete estrogen & corpus luteum secrete estrogen + progesterone - TESTES: Leydig cells secrete testosterone

Question 35

endocrine tissues: other

Answer 35

- digestive tract: secretin - heart: atrial natriuretic peptide - kidney: renin - placenta: estrogen, progesterone, human chorionic gonadotropin