ENDOCRINE SYSTEM Flashcards
What are Endocrine Glands?
Organs that secrete substances into blood in response to stimuli
Another term for ‘Chemical Messengers/Hormones’ is?
Mediator Molecules
Explain the function of Hormones.
They are released into one part of body to regulate activity in another.
Explain the process of hormones accessing the body cell.
- Released into interstitial fluid
- Into bloodstream
- To body cells
Explain how hormones deliver their ‘message’.
- Hormones bind to receptors on cell membrane to target cells/organs
- Changes shape of receptors
- Activates pathways modifying cellular function (messaged delivered)
What does ‘Upregulation’ mean?
Increase in target cell receptors from lack of hormone circulation - Increases hormone sensitivity
What does ‘Down Regulation’ mean?
Decrease in target cell receptors from an excess of hormone circulation - Decreases hormone sensitivity
Explain how Hormone Levels fluctuate.
Will depend on demand and normal body rhythm
Explain how Normal Hormone Levels function.
Altered by environment/stress/inflammation/pathologies - absent in disease states
What are hormone levels managed through?
Negative Feedback Loops
List the Primary Glands of the Endocrine Glands.
Pituitary Thyroid Parathyroid Adrenal Pineal
What is the function of the Hypothalamus and Pituitary together?
Regulate growth/development/metabolism/homeostasis
Explain the function of the Hypothalamus.
Receives information from structures - controls ANS, regulate body temperature, thirst/hunger, emotions
What is the function of the Hypothalamus hormonally?
- Release of Anterior pituitary glands
- Regulate synthesis
What is the function of the Hypothalamus neurologically?
- Release Posterior pituitary glands
- Regulate synthesis
Describe the structure of the Pituitary/Hypophysis.
Small gland with 2 lobes in the sella turcica of the sphenoid bone
AKA for ‘Adenohypophysis’?
Anterior pituitary Lobe
AKA for ‘Neurohypophysis’?
Posterior pituitary Lobe
The hormone release from the Anterior Pituitary Gland is controlled…?
Hormonally by hypothalamus
List the functions of Human Growth Hormone.
- Stimulates growth tissue/repair
- Use lipids for energy
- Elevates blood glucose levels
- functions every few hours
Explain the Thyroid Stimulating Hormone.
Released by thyroid gland depending on thyroid levels in blood
Explain the Adrenocorticotropic Hormone.
Cortisol release from adrenal glands in stress-related stimuli
Explain the Luteinizing Hormone in females.
Triggers ovulation
Explain the Luteinizing Hormone in males.
Stimulates testes releasing testosterone
Explain the Follicle Stimulating Hormone in females.
Ovarian follicle development
Explain the Follicle Stimulating Hormone in males.
Sperm production in testes
Explain Prolactin.
initiates and maintains milk production in mammary glands
The hormone release from the Posterior Pituitary Gland is controlled…?
Neurologically by Hypothalamus
What are the two hormones from the Posterior Pituitary Gland?
- Oxytocin
- Antidiuretic Hormone (ADH)
Explain Oxytocin.
Enhances smooth muscle contraction of uterus and stimulates milk ejection
Explain Antidiuretic Hormone (ADH)/Vasopressin.
- Decrease urine production
- Causes arteriolar vasoconstriction
Describe the function of the Parathyroid Gland.
Increase blood calcium/magnesium/phosphate by increasing osteoclasts - works with kidneys to promote calcitriol
Describe the function of the Thyroid Gland.
Produces thyroid hormones and Calcitonin - controlled by hypothalamus-pituitary
What is the function of Calcitonin?
- Active form of VItD
- Decrease blood calcium levels by inhibiting osteoclast activity
