Chapter 7 - Endocrine System

Question 1

Major classes of hormones

Answer 1

1) Amines: derivations of tyrosine
- thyroid: triiodothyronine (T3) and thyroxine (T4)
- catecholamines: Epi, NorEpi, dopamine
2) Peptides: small peptides and amino acid chains
3) Steroids
- Adrenal: mineralcoricoids and glucocorticoids
- Gonadal: testosterone, progesterone, estradiol

Question 2

Hormonal transport

Answer 2

-water soluble: catecholamines and peptides
• transport easily in blood
• easily degraded by enzymes (short half life)
-lipid soluble: thyroid and steroids
• small amounts in free plasma, mostly carried by transport proteins
• not readily degraded by enzymes

Question 3

Hormonal action

Answer 3

-peptides and catecholamines
• must act on an extracellular receptor, activating a second
messenger protein
-thyroid and steroids
• diffuse directly through the membrane
• usually alter gene expression

Question 4

Factors that control hormone secretion

Answer 4

1) change in plasma ion concentration
• aldosterone secreted by adrenal cortex stimulates increased Na
resorption
2) change in plasma nutrient concentration
3) neural input: neural input causes secretion from a gland
4) (neuro)hormonal input: (neuro)hormone stimulates the secretion of another
hormone

Question 5

Tropic hormone (def)

Answer 5

A hormone that stimulates the secretion of another hormone

Question 6

Major hypophysiotropic hormones

Answer 6

• gonadotropin releasing hormone (GNRH)
• corticotropin releasing hormone (CRH)
• thyrotropin releasing hormone (TRH)
• growth hormone releasing hormone (GHRH)
• somatostatin
• dopamine/prolactin-release inhibiting hormone

Question 7

Major hormones of the Anterior Pituitary

Answer 7

• follicle-stimulating hormone (FSH)
• luteinizing hormone (LH)
• thyroid stimulating hormone (TSH)
• adrenocorticotropic hormone (ACTH)
• growth hormone (GH)
• prolactin

Question 8

Hormones of the posterior pituitary

Answer 8

• vasopressin (ADH)
- kidney tubules
• oxytocin
- mammary glands or uterus

Question 9

Endocrine disorders

Answer 9

1) hypersecretion
2) hyposecretion
3) hyporesponsiveness
4) hyperresponsiveness

Question 10

Hypersecretion (def and types)

Answer 10

• too much hormone secretion for prevailing conditions (Grave’s disease,
Cushing’s syndrome)
- primary hypersecretion: secreting organ produces too much hormone
- secondary hypersecretion: tropic hormones are produced at too high of
level (hypothalamus or ant. pituitary)

Question 11

Hyposecretion (def and types)

Answer 11

• too little hormone secreted for the prevailing conditions (Addison’s
disease, Type I diabetes, hypothyroidism)
-primary hyposecretion: secreting organ fails
-secondary hyposecretion: tropic hormones are too low

Question 12

Hyporesponsiveness (def and types)

Answer 12

• cellular receptors do not respond to appropriate levels of hormone

    - receptors defective
    - lack of receptors

Question 13

Hyperresponsiveness (def)

Answer 13

• gland overresponds to appropriate levels of hormone