Endocrine System

Question 1

Direct communications

Answer 1

Exchange of ions or materials between adjacent cells of the same type. via gap junctions

Question 2

Paracrine communications

Answer 2

uses chemical signals to transfer information from cell to cell within same tissue

Question 3

Endocrine communications

Answer 3

Endocrine cells release hormones into blood stream altering tissues and organs simultaneously

Question 4

Hormone

Answer 4

A substance that stimulate synthesis of enzymes or structure proteins; can increase or decrease the rate of synthesis

Question 5

Target cell

Answer 5

Specific cells that possess receptors needed to bind and read hormonal messages

Question 6

Classes of hormones

Answer 6

1. amino acid derivatives
2. lipid derivatives
3. protein hormones

Question 7

Hormones: amino acid derivatives

Answer 7

amino acid structure

synthesized from tyrosine (TH, E, NE) and tryptophan (melatonin)

Question 8

Hormones:

peptide hormones

Answer 8

1. glycoproteins
2. short polypeptides, small proteins
   (ADH, oxytocin)

Question 9

Hormones:

lipid derivatives

Answer 9

1. eicosanoids (paracrine - prostaglandins)

2. steroids (reproductive organs, adrenal cortex, kidneys)

Question 10

Components of the endocrine system

Answer 10

Hypothalamus
Pituitary gland
Thyroid gland
Adrenal glands
Pancreatic islets
Pineal gland
Parathyroid glands
Heart
Thymus
Adipose tissues
Digestive tract
Kidneys
Gonads

Question 11

Hypothalamic control in endocrine function

Answer 11

1. Endocrine organ - synthesizes AVP and oxytocin (posterior pituitary)
2. Regulatory hormones (anterior pituitary)
3. Neural control (adrenal medulla)

Question 12

Pituitary gland hormones and feedback effect

Answer 12

Anterior:

1. Prolactin (milk production)
2. / 3. FSH/LH (egg/sperm maturation and estrogen/testosterone)
3. ACTH (cortisol; diurnal pattern)
4. GH (growth, protein synthesis, catabolism, opposes insulin)
5. TSH (metabolism via T3/T4)

Posterior:

1. AVP (ADH) (reaborption of whater, increase blood volume/pressure)
2. oxytocin (stimulate mammary glands and labor contractions)

*MSH - melanocytes for melanin synthesis

Question 13

Thyroid gland

Answer 13

Stimulated by TRH (hypothalamus) and TSH (pituitary)
Produces T4 that is converted into T3 (active form) in tissues
Functions in growth and metabolism.

Question 14

Parathyroid gland

Answer 14

Stimulated by decreased Ca2+.
PTH increase osteoclast activity, conversion of cholesterol to vitamin-D for increase absorption of Ca2+ in the intestines, and increase Ca2+ reabsorption in kidneys

Question 15

Adrenal glands

Answer 15

Adrenal cortex:

1. zona glomerulosa (aldosterone - Na+ reaborption)
2. zona fasciculata (cortisol - glucose production and sparing)
3. zona reticularis (androgen)

Adrenal medulla:
- epinephrine and norepinephrine (sympathetic stimulation; glucose usage)

Question 16

Hormones of adrenal glands

Answer 16

Aldosterone, cortisol, epinephrine, norepinephrine

Question 17

Hormones of pancreas

Answer 17

Insulin, glucagon, secretin, somatostatin, gastrin

Question 18

Clinical tissues:

1. Pituitary tumors
2. Hypo/hyperthyroidsim
3. Pheochromocytoma

Answer 18

1. Enlargement of the pituitary due to tumor grows outside the sella turcica interrupting optic chiams and resulting in visual field deficit
2. Low/High thyroid hormones; low energy v. irritability
3. Overactive sympathetic due to increased NE (and E)