Physiology Growth and Metabolism

Question 1

Hypothalamic-Pituitary-Axis types and levels

Answer 1

Types: Adrenal
Gonadal
Thyroid

Levels: Hypothalamic: CNS
Pituitary: Hypothalamic trophic hormones
Endocrine gland: Pituitary trophic hormones

Question 2

Negative feedback controls (Growth and Metabolism)

Answer 2

1. Hypothalamus produces trophic hormone 1
2. Stimulate production of anterior pituitary hormone (trophic 2)
3. Act on peripheral endocrine gland for trophic hormone 3

Question 2

Pituitary Gland

Answer 2

Secretes six different hormones: Prolactin, GH, TSH, ACTH, LH, and FSH

Question 2

Adrenal Gland and what it secretes

Answer 2

Sits on top of the kidney, secretes aldosterone, glucocorticoids, sex hormones, and catecholamines

Question 3

Control of cortisol secretion

Answer 3

CRH –> ACTH –> Cortisol –> Immune system, liver, muscle, and adipose tissue

Question 4

Cortisol

Answer 4

Promotes gluconeogenesis

Breakdown of skeletal muscle proteins

Enhance lipolysis

Suppress immune system

Cause negative calcium balance

Influence brain function and mood change

Question 5

Effects of exercise intensity on cortisol levels

Answer 5

Plasma cortisol decreases at low intensity

Plasma cortisol increases at high intensity

Question 6

Cortisol as a therapeutic drug

Answer 6

Suppresses the immune system and histamine

Helps in recovery of inflammation

Used for allergic reactions, joint injuries, and organ transplant

Question 7

Exogenous cortisol effect

Answer 7

Decrease in CRH, ACTH, and Cortisol

Question 8

Hypercortisolism

Answer 8

Most commonly caused by exogenous corticosteroids, adrenal tumor that secretes cortisol, and pituitary tumors that secrete ACTH

Symptoms: Trunk and face fat deposition, thin skin, capillary fragility, muscle wasting and weakness, hyperglycemia, and insulin resistance

Question 9

Hypocortisolism

Answer 9

Addison’s disease: Hyposecretion of all adrenal steroid hormones, autoimmune destruction of adrenal cortex, and ACTH level increases

Question 10

Thyroid gland and hormones

Answer 10

One of the largest endocrine glands

Around anterior and lateral surfaces of trachea, below the larynx

Release thyroid hormone and calcitonin

Question 11

Thyroid gland: Follicles

Answer 11

Sacs containing colloid and lined with follicular cells

Colloid: Sticky glycoprotein with enzymes, thyroglobulin, and hormone

Follicle cells actively concentrate dietary iodine

Enzymes free T3 and T4 from thyroglobulin to enter circulation

Question 12

Hyperthyroidism

Answer 12

Increased oxygen consumption and metabolic heat production

Increased protein catabolism and may cause weakness

Hyperexcitable reflexes

Influences B-adrenergic receptors in the heart (High heart rate and contraction force overall)

Question 12

TSH and Thyroid hormones

Answer 12

Release TRH from hypothalamus

TSH released after from anterior pituitary

T3 and T4 released from thyroid gland and it shuts off release of TRH and TSH