Exam 4: Endocrine System

Question 1

Endocrine gland

Answer 1

-secretes hormones into bloodstream.

Question 2

Hormone

Answer 2

• chemical messenger that regulates activity of other body cells.
• hormone levles constantly adjusted by feedback loops.

Question 3

Negative Feedback Loop

Answer 3

• a stimulus causes an endocrine organ to release hormones
• the hormone helps bring the body back to homeostasis
• once homestasis is achieved, the hormone release stops

Question 4

Endocrine System

Answer 4

• all endocrine glands in body

- overseen by hypothamus

Question 5

Hypothalamus’ Control (3 Ways)

Answer 5

• produces regulatory hormones that stimulate or inhibit anterior pituitary hormone secretion
• produces ADH and oxytocin and are stored in posterior pituitary
• oversees ANS, stimulates hormone secretion of adrenal medulla via sympathetic innervation

Question 6

Pituitary Gland

Answer 6

• connected to hypothalums via infundibulum

- split into anterior and posterior

Question 7

Posterior Pituitary

Answer 7

• axons from hypothalamus cells

- stores two hormones produced by hypothalamus: oxytocin and ADH

Question 8

Oxytocin

Answer 8

• cuddling/trust hormone
• stimulates uterine contractions/ induces labor (menstrual cramps)
• stimulates breast milk release in response to suckling infant
• males: stimulates smooth muscle contraction in reproductive tract

Question 9

ADH

Answer 9

• diuresis = urine production
• inhibits urine formation/production
• concentrates urine
• ADH targets the kidneys and blood vessels
• secreted when dehydrated
• tells kidneys to concentrate urine by reabsorbing more water
• blood vessels constrict to increase blood pressure

Question 10

Anterior Pituitary

Answer 10

• VP of endocrine system, controlled by hypothalamus
• controls growth hormone (GH), thyroid stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), follicle stimulating hormone (FSH), luteinizing hormone (LH), and prolactin (PRL)

Question 11

Growth Hormone (GH)

Answer 11

• stimulates cell growth and mitosis in most cells
• especially affects skeletal and muscular systems, and adipose tissue
• anterior pituitary–>secretes GH–>targets muscle, bone, fat

Question 12

Thyroid Stimulating Hormone (TSH)

Answer 12

• targets thyroid gland
• stimulates thyroid to produce/release its own hormones
• anterior pituitary–>secretes TSH–>targets thyroid gland–>secretes TH

Question 13

Adrenocorticotropic Hormone (ACTH)

Answer 13

• target organ: adrenal cortex
• stimulates adrenal cortex to release its hormones
• anterior pituitary–>secretes ACT–>adrenal cortex–>secretes hormones

Question 14

Follicle Stimulation Hormone (FSH)

Answer 14

• target organs: ovaries and testes

- anterior pituitary–>secretes FSH–>targets onads

Question 15

Luteinizing Hormone (LH)

Answer 15

• target organs: ovaries and testes

- anterior pituitary–>secretes LH–>targets gonads

Question 16

Prolactin (PRL)

Answer 16

• target organs: mammary glands
• stimulates breast milk production
• anterior pituitary–>secretes PRL–>targets mammary glands

Question 17

Thyroid Gland

Answer 17

• anterior to trachea and inferior to larynx

- secretes thyroid hormone (TH) anad calcitonin

Question 18

Thyroid Hormone (TH)

Answer 18

• increases cellular activity (metabolic rate) in most cells of body
• hypothalamus–>anterior pituitary–>secretes TSH–>targets thyroid gland–>secretes TH

Question 19

Calcitonin

Answer 19

• encourages deposition of calcium from bloodstream into bone tissue
• secreted when blood calcium levels are high
• lowers blood calcium levels
• increases bone deposition

Question 20

Parathyroid Glands

Answer 20

• 4 tiny oval masses behind thyroid
• secrete parathyroid hormone (PTH) when blood calcium levels are low
• increases blood calcium levels
• stimulates osteoclasts to resorb bone, release calcium into blood

Question 21

Adrenal Glands

Answer 21

• superior to kidneys

- have outer cortex and inner medulla

Question 22

Adrenal Cortex

Answer 22

• releases corticosteroids in response to ACTH
• one group of these steroids: controls balance of sodium (Na+) and potassium (K+) ions in body fluids (regulates salt)
• another (2nd) group of steroids stimulates metabolism of glucose from fats and proteins (regulates blood sugar levels)
• another (3rd) group of these steroids: secretes small amounts of androgens (male sex hormones)
• in females, some androgens are converted to estrogen (regulates sex)

Question 23

Adrenal Medulla

Answer 23

• stimulated by sympathetic division of ANS
• secretes epinephrine and norepinephrine
• prolongs “fight or fligh” response by sympathetic innervation
• hypothalamus–>sympathetic innervation–>adrenal medulla–>epinephrine and norepinephrine

Question 24

Pancreas

Answer 24

• has both exocrine and endocrine functions

- exocrine functions were discussed w/digestive system

Question 25

Pancreatic Islets

Answer 25

• produces hormones
• Insulin and glucagon
• helps convert some glucose into glycogen (a carbohydrate)

Question 26

Insulin

Answer 26

• lowers blood sugar (glucose) levels, enhances cells ability to pick up glucose
• secreted when you eat a meal

Question 27

Glucagon

Answer 27

• raises blood sugar levels
• breaks down glycogen into glucose
• secreted when you haven’t eaten in a while

Question 28

Gonads

Answer 28

• ovaries produce estrogen and progesterone

- testes produce androgens (especially testosterone)