Chapter Two: Hormones of the Endocrine Glands

Question 1

Pineal gland

Answer 1

Melatonin

Gonadal function
Seasonal breeding
Skin pigmentation

Question 2

Thyroid

Answer 2

Thyroxin (T4) - Metabolic rate

Triiodothyronine (T3) - Brain development, bone growth

Calcitonin - Reduces blood clacium

Question 3

Parathyroid

Answer 3

Parathyroid hormone - Elevates blood Ca++

Question 4

Thymus (above the heart)

Answer 4

Thymosins - Regulate immune system, release cytokines

Question 5

Heart

Answer 5

Atrial Netiuretic peptide (ANP) - Reduces blood pressure

B-Type Natiuretic peptide - Marker for congestive heart failure

Question 6

Pancreas (Islets of Langerhans)

Answer 6

Insulin (beta cells)
Glucagon (alpha cells)
Somatostatin (delta cells)
Pancreatic polypeptide (F cells)

Regulation of glucose levels

Question 7

Adrenal cortex

Answer 7

Mineralocorticoid - Na+ retention

Glucocorticoid - Stress anti-inflammatory

Sex steroids - Puberty, 2nd sex characteristics, sex differences

Question 8

Adrenal medulla

Answer 8

Epinepherine - Stress reponse (heartrate, O2)

Norepinepherine - Blood pressure increase

Question 9

Kidney

Answer 9

Vitamin D - Maintains blood calcium levels, bone and immune system

Erythropoietin - Production of red blood cells (erythrocytes)

Question 10

Important GI hormones

Answer 10

Gastrin - Stimulation of hydrochloric acid, stimulates pancreatic enzyme, increasing intestinal motility, stomach

Ghrelin - Increases hunger, stimulates feeding, stimulates growth hormone release, stomach

Cholecystokinin - stimulates vagus nerve to signal ‘fullness’, duodenum

Secretin - Stimulates bile secretion, after digested food has passed through the duodenem

Question 11

Testes

Answer 11

Leydig cells - androgens (testosterone), male sex characteristics

Sertoli cells - Inhibin and activin, control FSH secretion

Question 12

Ovary - Granulosa cells

Answer 12

Estradiol - Female sexual characteristics; menstrual cycle

Question 13

Ovary - Luteal cells

Answer 13

Progesterone - Uterine function - pregnancy

Inhibin, Actin, Relaxin - Controls FSH during pregnancy

Question 14

Placenta

Answer 14

Human chorionic gonadotropin - secreted after implantation

Question 15

Adipose tissue

Answer 15

Adipokines, control of body weight

A. Leptin, reduce food intake

B. Insulin resistance

Question 16

Muscle

Answer 16

Myostatin, interleukins, irisin - control of fat mass and insulin secretion

Question 17

Bone

Answer 17

Osteocalcin - insulin secretion and testosterone levels

Question 18

Liver

Answer 18

Fetuin-A, insulin control

FGF-21

Betatrophin, B-cell proliferation

Question 19

Three main classes of hormones

Answer 19

Protein hormones (GH, ACTH, LH, FSH, GnRH)

Amine hormones (epinepherine, norepinepherine, melatonin)

Steroid hormones (cortisol, estrogen, progesterone, androgens)

Question 20

Protein hormone action

Answer 20

Hormones enter through receptor –>

secondary messenger inside the cell –>

Altered cell function, biological effects

Question 21

Steroid hormone action

Answer 21

Enter through lipid bilayer –>

Attach to steroid receptor which enters the nucleus –>

New protein production and biological effects