ANPH 209: Unit 8 (Endocrine system)

Physical memorization not added to this set: Endocrine gland locations (pituitary, thyroid, adrenal, pancreas, gonads). Pituitary hormone chart: Anterior vs Posterior hormones, targets, and effects. Feedback loops: Cortisol negative feedback Thyroid hormone regulation Calcium homeostasis (Calcitonin vs PTH) Glucose homeostasis (Insulin vs Glucagon) Thyroid gland anatomy (lobes, position relative to trachea). Adrenal gland structure (cortex vs medulla). Summary tables: Thyroid hormones (T3, T4, Calcitonin) Parathyroid hormone actions Adrenal cortex & medulla hormones Pancreatic hormones Flowcharts for: Hormone secretion control Calcium regulation Blood glucose regulation

Exocrine glands

Secrete products into ducts (e.g., sweat, sebaceous glands

Endocrine glands

Ductless, secrete hormones directly into bloodstream (e.g., pituitary, thyroid, adrenal

Hormones

• Chemical messenger maintaining homeostasis

• Secreted in short bursts

• Target cell response

Target cell response depends on…

• Hormone concentration

• Receptor availability

• Interaction with other hormones

Regulation by hormones

Mostly negative feedback

Hypothalamus

Controls pituitary via releasing/inhibiting hormones.

Anterior pituitary gland hormones produced 

• GH: Growth & metabolism

• TSH: Stimulates thyroid

• FSH & LH: Gamete production & sex hormones

• ACTH: Stimulates adrenal cortex

• PRL: Milk production

• Endorphins 

Posterior pituitary gland hormones stored and secreted 

• ADH: Water retention

• Oxytocin: Uterine contractions & milk ejection

Pineal gland

Produces melatonin (sleep-wake cycle, circadian rhythm).

Thyroid gland

Requires iodine.

• T3 & T4: Increase BMR, protein synthesis, growth.

• Calcitonin: Lowers blood calcium (inhibits osteoclasts, promotes bone deposition-new bone forming).

Parathyroid glands

PTH: Raises blood calcium (stimulates bone resorption, kidney reabsorption, activates vitamin D).

Adrenal glands

Cortex:

• Aldosterone: Na⁺ retention, K⁺ excretion

• Cortisol: Stress response, metabolism

• Sex hormones

Medulla:

• Epinephrine & norepinephrine: Fight-or-flight response

Pancreas

• Insulin (β cells): Lowers blood glucose (glycogenesis, lipogenesis).

• Glucagon (α cells): Raises blood glucose (glycogenolysis, gluconeogenesis).

Gonads

• Testes: Testosterone (male traits, sperm production).

• Ovaries: Estrogen & progesterone (female traits, pregnancy prep).

Key Homeostatic Mechanisms

• Calcium regulation: Calcitonin ↓ blood Ca²⁺; PTH ↑ blood Ca²⁺.

• Glucose regulation: Insulin ↓ blood glucose; Glucagon ↑ blood glucose.