Week 9 Anatomy - Endocrine System Flashcards
What are the Endocrine organs?
- Hypothalums
- Pituitary gland
- Parathyroid gland
- Thyroid gland
- Adrenal gland
- Pancreas
What do hormones regulate?
- Metabolsim and energy balance
- Smooth andn cardiac muscle contraction
- Growth and Development
- Reproductive processes
- Circadian rhythms
Outline the Pituitary gland (Hypophysis)
- Bean-shaped, 1cm wide
- Located in pituitary fossa
- Inferior to hypothalamus
- Connecting stalk -> infundibulum
- Anterioir and posterior lobe
Describe the actions of the endocrine organs
- Secrete hormones -> mediator molecule
- Enters bloodstream
- Effects target cells
- Slower response than nervous system but broader effects throughout body
Compare the anterior and posterior lobe of pituitary
Anterior lobe (adenohypophysis)
- Hypothalamic neurons release hormones into blood vessels (hypophyseal portal system), activiating the release of anterioir pituitary hormones
Posterior lobe (neurohypophysis)
- Nerve impulses travel down the axons of hypothalamic neurons through the hypothalamo-hypopyseal tract, causing hormone relase from the axon terminarls in the posterior pituitary
Outline the target and function of hormones of the anterior lobe of pituitary
Growth hormone (GH)
Target: all cells
Function: stimulates body cell growth, protein synthesis and tissue repair
Thyroid-stimulating hormone (TSH)
Target: thyroid gland
Function: controls thyroid hormone secretion
Adrenocorticotropic hormone (ACTH)
Target: adrenal cortex
Function: control adrenal cortex hormone secretion
Prolactin
Target: mammary glands (breast)
Function: produces milk secretion
Follicle-stimulating gland
Target: ovaries or testes
Function: develops egg-containing follicales and stimulates estrogen porduction (F) sperm cell production (M)
Luteinising hormone
Target: ovaties or testes
Function: stimulates sex hormone (estrogen and progesterone or testosterone) production
Outline the target and function of hormones of the posterior lobe of pituitary
- Produced in hypothalamus and stored in posterior lobe
Oxytocin
Target: Uterus and mammary glands
Function: Stimulates uterine contractions (child labour) and milk secretion
Antidiuretic hormone (ADH)
Target: Kidneys
Function: stimulates kidney to reabsorb water and controls blood pressure
Outline the Thyroid Gland
- Located in the neck
- Inferior to larynx
- Anterior to trachea
- Close relation to vagus nerves and common corocoid arteries
Outline the Parathyroid Gland
- 4 glands (round masses of tissue)
- On posterioir surface of thyroid lobes
- Sits posterior to thyroid gland
Outline the cells and hormones of the thyroid gland
- Inside has a round structure (thyroid follicle) filled by colloid which stores hormones and is surrounded by follicular cells
- Follicular cells produces thyroid hormones (T3 and T4) -> stimulates metabolism, protein synthesis, growth and development
- Surrounding cells (parafollicular cell) produces calcitonin -> decreases blood Ca2+ by inhibiting bone resporption by osteoclasts
Outline the cells and hormones of the parathyroid gland
- Made up of chief cells which produce parathyroid hormones (PTH) -> regulates calcium homestasis with calcitonin -> increases blood Ca2+ by increasing bone resorption by osteoclasts, stimulates formation of calcitrol, increases absorption of Ca2+ from food
Outline the Adrenal glands (Suprarenal)
- Located in the posterior abdomen
- Immediately superior to kidney
- Enclosed within and separated from kidneys by renal fascia
- Outer cortex
- Inner medulla
