Endocrine system Flashcards
What is the endocrine system mostly comprised of?
Glands
What are secreted by the glands in the endocrine system?
Hormones are secreted in the blood stream where a target cell has a receptor for
How does the endocrine system compare to the nervous system?
The nervous system is fast but results fade quickly while the endocrine system is slower but has more prolonged responses
What are the major parts of the Endocrine system? (11ish)
The Hypothalamus
The Pituitary Gland (posterior and anterior)
The Pineal gland
The Thyroid
The Parathyroids
The Thymus
The Adrenal gland & cortex
The Pancreas
The Gonads (Testes & Ovaries)
The Kidney and Heart
What are the three classes of hormones?
Peptide/protein hormones
Steroid hormones
Amino acid derivatives
What are examples of Peptide/protein hormones?
Insulin, glucagon, leptin
What are steroid hormones derived from?
Cholesterol
What are steroid hormones? Example?
They are lipids that enter a cell’s nucleus and affect gene activity (thus protein systhesis) Ex. Testosterone
Where do amino acid derivatives derive from?
Tyrosine
What does the posterior pituitary gland do?
It stores (doesn’t produce) ADH (Antidiuretic) and Oxytocin made by the hypothalamus
What does ADH do?
It regulates water balance by reabsorbing water into the bloodstream
What does Oxytocin do?
It causes uterine contractions during childbirth and allows milk to be released during nursing (It’s also a positive feedback loop)
What does the Anterior pituitary gland do?
It controls other hormones and is controlled by the hypothalamus
What hormones are produced by the anterior pituitary gland?
- TSH (Thyroid-Stimulating hormone) which stimulates the thyroid to produce thyroid hormones
- ACTH (Adrenocorticotropic hormone) which stimulates the Adreanal cortex to produce cortisol
- Gonadotropic hormones which stimulate gonads to produce sex cells and hormones
- PRL (Prolactin) which stimulates mammary glands to develop and produce milk only after childbirth
- Melanocyte-stimulanting hormone (MSH) which causes skin color changes
- GH (Growth hormone) which promotes skeletal and muscular growth
What are affects of too much or too little growth hormone?
Pituitary dwarfism - too little GH is produced during childhood
Gigantism - too much GH is produced during childhood (often times results in poor health)
Acromegaly - overproduction of GH as an adult which results in larger than normal feet, hands, and face
What is needed to allow the thyroid gland to produce its hormones?
Iodine
What does the Thyroid gland do?
It produces TH (thyroid hormone) which regulates metabolism
What is is called when there are low blood levels of thyroid hormones?
Hypothyroidism