Endocrine System Flashcards
Endocrine Gland
Secretes hormones into the bloodstream
Hormone
Chemical messenger that regulates activity of other body cells
Slow messenger
REquires blood supply to carry the hormone
Why is it better to send information through hormones?
System is slower, but it also has longer lasting effects
Hormone levels…
are constantly adjusted by feedback loops
Negative Feedback Loop
a stimulus causes an endocrine organ to release hormones
the hormone helps bring the body back to homeostasis
* once homestasis is achieved, the hormone release stops
Endocrine System
all endocrine glands in the body
Endocrine system overseen by…
hypothalamus
the hypothalamus exerts its control over the endocrine system in 3 ways
Hypothalamus and Endocrine system (1)
Produces “releasing” hormones that regulate the anterior pituitary (middle management) (Sends the stuff out to other organs of the body)
Hypothalamus and Endocrine system (2)
Produces hormones that are stored in posterior pituitary gland
Hypothalamus and Endocrine system (3)
Oversees Autonomic Nervous System
Pituitary Gland
connected to hypothalamus via theinfundibulum
Posterior Pituitary
- axons from hypothalamus cells
* stores two hormones produced by hypothalamus:
Posterior Pituitary - Oxytocin
• Target: Reproductive Organs
• Function: Stimulate smooth muscle contraction in repro (especially in the uterus)
• Function: Stimulates breastmilk RELEASE
Posterior Pituitary - Antidiuretic Hormone
This makes you not pee as much
• Target: kidneys (and blood vessels)
• Function: Inhibits urine formation/production
Anterior Pituitary - Thyroid Stimulating Hormone
• Target: Thyroid Gland
• Function: stimulates thyroid to produce/release its own hormones
Anterior Pituitary - Prolactin (PRL)
- Target: Mammary glands
* Function: Stimulates breastmilk production
Anterior Pituitary - Adrenocorticotropic Hormone (ACTH)
- Target: Adrenal Cortex
* Function: stimulates adrenal cortex to release its hormones
Anterior Pituitary - Growth Hormone (GH)
- Target: most body cells, but especially bone & skeletal muscle
- Function: Stimulates Growth (Especially of bone and muscle)
Anterior Pituitary - Follicle Stimulating Hormone (FSH)
• Target: Ovaries/Testes
Anterior Pituitary - Luteinizing Hormone (LH)
• Target: Ovaries/Testes
ADH is produced by the __ and stored in the __.
Hypothalamus, Posterior Pituitary
Name the hormone that if secreted in large quantities by the pituitary in a child will produce rapid growth including bones. If left untreated, person may become abnormally tall.
Growth Hormone
Thyroid Gland Location
anterior to trachea and inferior to larynx
Thyroid Hormone (TH)
stimulated by TSH (Thyroid Stimulated Hormone)
- produced by follicle cells
- Target: virtually all cells of the body
- Function: Increase metabolism (& thus, heat production) (Which will then cause someone to normally burn through calories)
In a healthy person, as thyroid hormone levels increase, TSH secretion will ____
Decrease
Thyroid Gland - Calcitonin
stimulated by high calcium levels in blood
* produced by parafollicular cells (Produce Calcitonin)
Thyroid Gland - Calcitonin Target
bone – encourages deposition of calcium from bloodstream into bone tissue
* so it lowers blood calcium levels (By encouraging osteoblasts; which are things that build bone)
Parathyroid Gland
4 tiny oval masses on posterior thyroid
Parathyroid Hormone (PTH)
stimulated by low levels of calcium in blood
Parathyroid Hormone (PTH) Target
bone – encourages uptake of calcium into bloodstream from bone
* so it raises blood calcium levels
Adrenal Cortex
releasescorticosteroids in response to ACTH
Adrenal Cortex (1)
one group of these steroids: controls balance of sodium (Na+) and potassium
(K+) ions in body fluids
Adrenal Cortex (2)
another (2nd) group of steroids stimulates metabolism of glucose
Adrenal Cortex (3)
another (3rd) group of these steroids: secretes small amounts of androgens (male sexhormones)
* in females, some androgens are converted to estrogen
Adrenal Medulla
- stimulated by sympathetic nervous system (In charge of Fight or Flight)
secretesepinephrine(adrenaline) andnorepinephrine(noradrenalin)
Pancreas
has bothexocrine andendocrine functions
* exocrine functions were discussed w/digestive system
Pancreatic islets
produce hormones
Pancreas - Insulin
lowers blood sugar (glucose) levels
* enhances cells to pick up glucose
* helps convert some glucose into glycogen (a carbohydrate)
Pancreas - glucagon
raises blood sugar levels
* breaks down glycogen into glucose
Gonads (Ovaries and Testes)
ovaries produceestrogenandprogesteroe
– testes produce androgens (especiallytestosterone)
– will discuss in reproductive system lectures
