Endocrine System Flashcards
What does the endocrine system consist of?
A number of organs and major glands located in different areas of the body.
What compound do glands produce?
Hormones.
What do hormones target?
Particular organs or systems.
Why are the glands called endocrine glands?
They do not have an opening to discharge their secretions, but discharge them directly into the bloodstream.
Do all hormones function alone?
No, some work synergistically.
What is the pituitary gland?
A pea-sized gland located at the base of the brain.
What is the pituitary gland colloquially referred to as and why?
- The master gland.
- It releases many hormones that target similar glands and cause them to release hormones.
What are the two parts of the pituitary gland?
- Anterior pituitary gland.
- Posterior pituitary gland.
What 6 hormones are released from the anterior pituitary?
- TSH.
- ACTH.
- LH.
- FSH.
- Melanin Stimulating Hormone.
- Growth Hormone.
What does the quantity of hormones produced by the pituitary gland influence?
The level of activity of the target organ or response.
*The more produced, the greater the response.
What does the posterior pituitary gland PRODUCE?
Arginine vasotocin.
What two hormones does the posterior pituitary gland STORE?
- OT.
- ADH.
What gland produces OT and ADH?
Hypothalamus.
What is the role of OT?
The release of the yolk into the oviduct and oviposition.
What is the role of ADH?
The resorption of water in the kidney collecting ducts.
Where is the hypothalamus located?
The base of the brain.
What two things does the hypothalamus release?
- Releasing factors for the anterior pituitary gland.
- OT.
What influences the amount of OT and releasing factor released?
Day length.
When does the amount of things released from the hypothalamus begin to become maximized?
If the day is longer than 18 hours.
Where are the adrenal glands located?
Anterior to the kidneys.
What are the two parts of the adrenal gland?
- Adrenal cortex.
- Adrenal medulla.
What 3 compounds does the adrenal cortex produce?
- Corticosterone.
- 8-hydroxycorticosterone.
- Aldosterone.
What are the three functions of corticosterone?
- Facilitates carbohydrate and fat metabolism.
- Protein breakdown.
- Stress.
What is the function of aldosterone?
Increased resorption and retention of sodium.
What are the two functions of 8-hydroxycorticosterone?
- Stress response.
- Overall physiological regulation.
What two compounds does the adrenal medulla produce?
- Epinephrine.
- Norepinephrine.
What is the function of epinephrine?
Blood pressure control.
What is the function of norepinephrine?
Fat metabolism.
Where is the thyroid gland located?
On either side of the base of the next.
What two hormones are produced by the thyroid?
- Thyroxine.
- T3.
What are the 4 functions of thyroxine?
- Promote growth.
- Carbohydrate metabolism.
- Regulate heat production.
- Promotes high blood sugar levels.
What is the function of T3?
Development of skin and feathers.
Where are parathyroid glands located?
Located at the base of the thyroid glands.
What hormone do the parathyroid gland produce?
Parathyroid hormone/parathormone.
What is the function of parathormone?
Increases blood calcium.
What are the ultimobrachial bodies?
Structures located posterior to the parathyroid gland that produce calcitonin.
What hormone is calcitonin antagonistic to?
Parathormone.
What are the islets of Langerhans?
Small clumps of specialized cells located in the pancreas that produce glucagon and insulin.
What are the two functions of glucagon?
- Affects fatty acid levels.
- Increases blood sugar.
What is the function of insulin?
Lowers blood sugar.
What is the function of estrogen?
Regulates the female reproductive system and secondary sex characteristics.
What is the function of testosterone?
Plays an important role in the development of male reproductive tissues and promotes male secondary sex characteristics.
What processes is progesterone involved in?
- Menstrual cycle.
- Pregnancy.
- Embryogenesis.
- Intermediate in the production of other endogenous steroids.
What happens when the hormones are not in balance/at the appropriate levels?
The animal may take on characteristics of the other sex.
*Ex: A capon will eventually do this given time.
