A&P - The Endocrine System - S10

What is the endocrine system?

System of glands that secrte hormones into the blood to target cellular receptors

What are the 7 major glands of the endocrine system?

1. Pineal

2. Pituitary

3. Thyroid

4. Parathyroid

5. Thymus

6. Adrenals

7. Pancreas

What hormone does the pineal gland secrete and its primary function?

Melatonin - Regulates sleep-wake cycle

What hormone does the anterior pituitary gland secrete and its primary function?

Growth Hormone - Promotes growth of bone, muscle, adipose tissue

Prolactin - Stimulates lactation

TSH, FSH, LH, ACTH

What hormone does the posterior pituitary gland secrete and its primary function?

Oxytocin - Uterus contraction, expression of milk

Vasopressin AKA antidiuretic hormone - promotes kidney resorption of water and vasoconstriction

What hormone does the thyroid gland secrete and its primary function?

Thryoxine (T4), Triiodothyronine (T3), Calcitonin - regulates metabolism, growth and calcium balance

What hormone does the Parathyroid gland secrete and its primary function?

Parathyroid hormone (PTH) - Increase blood calcium levels when there is an imbalance

What hormone does the thymus gland secrete and its primary function?

Thymosin, Thymopoietin, Thymulin - Maturation of T-cells, helps establish immune competence in early life

What hormone does the adrenal glands secrete and its primary function?

Cortisol, Aldosterone, Adrenaline, Noradrenaline

What hormone does the pancreas gland secrete and its primary function?

Insulin, Glucagon - regulates blood glucose levels

Which system works with endocrine system to maintain homeostasis?

Nervous system

Where do peptide/lipophobic hormones bind to receptors?

Bind to cell surface receptors

Where do lipophilic/lipid soluble hormones bind to receptors?

Bind to intracellular receptors

What is the role of the hypothalamus?

Controls pituitary gland by releasing hormones

What is the role of Insulin?

Redues blood glucose concentration when blood suagr rises and is secreted by beta cells

What is the role of glucagon?

Increases blood glucose concentration when blood sugar falls and is secreted by alpha cells

What is glucose stored as?

Glycogen

What is it called when insulin stimulates the liver to store glucose?

Glycogenesis

What is it called when glucagon stimulates glycogen breakdown?

Glycogenolysis

Does insulin promote fat storage or stimulate fat breakdown?

Fat storage

What does insulin do to glucagon?

Inhibits its secretion

What happens to the thymus after puberty?

gradually shrinks and activity decreases

Which hormones are secreted by the adrenal medulla?

Epinephrine, Norepinephrine, adrenalin

Which hormones are secreted by the adrenal cortex?

Cortisol, Aldosterone, Steroid hormones

Steroid hormones are derived from?

Cholesterol

Which hormone type binds to receptors inside the cell?

Steroid hormones

Where does the adrenal glands sit?

on top of the kidneys

What section of the cortex is aldosterone secreted and its role?

Zone glomerulosa - fluid and electrolyte balance and BP regulation

What section of the cortex is cortisone secreted and its role?

Zone fasciculate - involved in stress response

What section of the cortex is androgens secreted and its role?

Zone reticularis - maintenance of sex hormones

What is the 3 stages of the stress response?

1. Alarm reaction

2. resistance or adaption

3. exhaustion

What is the role of cortisol in the stress response?

maintains long term alert with continued triggers of stress

What does the renin-angiotensin system (RAS) regulate?

Blood volume, electrolyte balance, systemic vascular resistance

How does the RAS regulate blood volume, electrolyte balance, systemic vascular resistance?

Vasoconstriction, sodium ion resorption and water retention, sympathetic activation