Endocrine System

Question 1

Hormones

Answer 1

Always travel through blood

Derived from steroids, proteins, or modified a.a.

Chemical signals

Question 2

Hypothalamus

Answer 2

Monitors condition of external and internal environment

Stimulates hormone production

Question 3

Neurosecretory cells

Answer 3

Link hypothalamus to pituitary gland

Built like neurons but secrete hormones instead of NT

Question 4

Anterior Pituitary

Answer 4

Release tropic hormones (directly affect other endocrine glands)

Releasing hormones made in hypothalamus and release into the blood to go to anterior pituitary

Question 5

Posterior Pituitary

Answer 5

ADH and Oxytocin produced in hypothalamus by neurosecretory cells, but are stored in posterior pituitary

Do not affect other glands like the ant. pit. but directly affect tissues

Question 6

Islets and Langerhans

Answer 6

Bundles of cells in the pancreas

Combination of alpha cells and beta cells

Question 7

Beta Cells

Answer 7

Secrete Insulin

Insulin released when blood glucose is high

Stimulates liver and other body cells to take up glucose

Liver and muscles convert glucose to glycogen

adipose cells convert glucose into fat

Question 8

Alpha Cells

Answer 8

Secrete glucagon

Stimulates liver to release glucose into bloodstream

Liver also produces and releases glucose by converting a.a./FA into glucose when needed

Question 9

Steroid Hormones

Answer 9

Diffuses through PM of cell and goes directly into the nucleus

Binds to receptor in nucleus which activates gene transcription

Question 10

Peptide Hormones

Answer 10

Can’t diffuse through PM

Binds to receptor on membrane (receptor mediated endocytosis)

Second messenger like cAMP or IP3 continue the message

Question 11

Amino Acid Derived Hormone

Answer 11

Small molecules derived from Tyr and Trp

i.e. EPi, NE, thyroxine, melatonin

Question 12

Tropic Hormones

Answer 12

Thyroid Stimulating Hormone

Adrenocorticotropic Hormone

Follicle Stimulating Hormone

Luteinizing Hormone

Question 13

Thyroid Stimulating Hormone (TSH)

Answer 13

Peptide

Target thyroid gland

Thyroid secretes T3 and T4

Question 14

Adrenocorticotropic Hormone (ACTH)

Answer 14

Peptide

Targets adrenal cortex

Adrenal cortex secretes glucocorticoids (steroid hormones)

Question 15

Follicle Stimulating Hormone (FSH)

Answer 15

Peptide

Targets follicles (ovaries and testis)

Regulates oogenesis and spermatogenesis

In females, FSH stimulates the maturation of ovarian follicles to secrete estrogen

in males, stimulates maturation of seminiferous tubules and sperm production

Question 16

Luteinizing Hormone (LH)

Answer 16

Peptide

Targets ovaries and testis

Also regulate oogenesis and spermatogenesis

During follicular phase of ovarian cycle, estrogen levels spike upward, stimulates hypothalamus to produce surge of LH

Surge trigger ovulation

In females, LH stimulates formation of corpus luteum

In males, stimulates interstitial cells of testes to produce testosterone

Question 17

Prolactin (PRL)

Answer 17

Peptide

Targets tissues in mammary glands

Stimulates milk production

Question 18

Growth Hormone (GH)

Answer 18

Peptide

Targets bone and muscle

Stimulates growth

Question 19

Medulla

Answer 19

Amino acid

Releases EPI/NE

Targets blood vessels, heart, liver

Increases blood glucose

Constricts blood vessels (fight or flight)

Question 20

Cortisol

Answer 20

Steroid

Secreted by Adrenal cortex

Glucocorticoid

Increases blood glucose

Increases absorption of Na

Increases excretion of K

Question 21

Aldosterone

Answer 21

Steroid

Secreted by adrenal cortex

Mineralocorticoid

Increases blood glucose

Increases absorption of Na

Increases excretion of K

Question 22

Triiodothyronine (T3), Thyroxin (T4)

Answer 22

Amino acid

Increases cell metabolism

Question 23

Calcitonin

Answer 23

Peptide

Released when blood P and Ca are high
Thyroid hormone

Targets bone

Decreases blood Ca, increases bone Ca

Question 24

Parathyroid Hormone (PTH)

Answer 24

Peptide

Thyroid Hormone

Targets bones and increases blood Ca and P, decreases bone Ca and P

Question 25

Testosterone

Answer 25

Steroid hormone

Targets testis and other general areas

Spermatogenesis

Secondary sex characteristics

Question 26

Estrogen

Answer 26

Steroid Hormone
Targets uterus and other general areas

Secondary sex characteristics

Rising levels of estrogen stimulate hypothalamus to produce LH surge (triggering ovulation), but not directly responsible for ovulation

Question 27

Progesterone

Answer 27

Steroid hormone

Targets uterus

Role in menstrual cycle and pregnancy

Question 28

Melantonin

Answer 28

Pineal gland

amino acid

Regulates circadian rhythm

Targets body in general

Question 29

Minerals in Bones

Answer 29

Ca and P

Question 30

Bone Resorption

Answer 30

Done by osteoclasts

Question 31

Osteoblasts

Answer 31

Build up bone

Connective tissue cell

Secrete osteoid (collagen and mucopolysaccharide)

Question 32

Osteocyte

Answer 32

Maintains bone tissue

Question 33

Osteogenic cell

Answer 33

Stem cell

Question 34

Epiphysis

Answer 34

Wider section at end of bone

Filled with spongy bone

Spaces in spongy bone filled with red marrow

Increased length of bones originates at epiphyseal plate

Question 35

Medullary Cavity

Answer 35

In diaphysis

Hollow region

Filled with yellow marrow

Has endosteum lining - where bone growth, repair, and remodeling occur

Question 36

Periosteum

Answer 36

Covers outer surface of bone

Fibrous membrane

Contains blood vessels, nerves, lymphatic vessels

Question 37

Diaphysis

Answer 37

Tubular shaft of one (middle part)

Walls made of compact bone

Question 38

C Cells

Answer 38

In the thyroid

Also called parafollicular cells

Produce calcitonin (decreases blood Ca, increases bone)