Unit Eleven - Human Body - Endocrine System Flashcards
(34 cards)
Definition of Endocrine System
Network of glands that produce and release hormones to regulate various bodily function
Definition of Glands (3)
- Organ/group of cells
- Produces/Secretes hormones
- Directly into the bloodstream
Definition of Hormones (2)
- Chemical messengers produced and released by glands
- Released by 1 cell and travel to affect a different cell
Definition of Target Cell (3)
- Recognizes/reacts to hormone
- Contains specific receptors (bind to correct hormone)
- Target cells ensure that hormones only affect correct tissues
What is the process of target cells and hormones? (3)
- Hormone is released & circulates into blood stream
- Target Cell w/ correct receptors recognizes hormone
- Hormone binds to the receptor, triggering a response inside the cell
Definition of Feedback Mechanism (3)
- Regulatory mechanisms
- Controls hormone levels
- To maintain homeostasis
(Level of one hormone in the body can inhibit/stimulate the production of another hormone)
Definition of Positive Feedback (3)
- Amplifies a process instead of stopping it
- Used when a strong, rapid response is needed
- Oxytocin and Childbirth
- When contraction occurs
- Pituitary gland releases oxytocin
- Stimulates stronger uterine contractions
- Once baby is delivered, stimulus (pressure on the cervix) is gone
- Decreases oxytocin concentration
Definition of Negative Feedback (5)
- Maintaining homeostasis
- When hormone levels get too high
- Body reduces production
- When levels drop too low,
- Body increases production
Definition of Stimulus
A trigger that initiates hormone release
ex: Low blood sugar triggers the pancreas to release insulin
Definition of Inhibit
Process of reducing/stopping hormone secretion
Ex:
- Blood sugar is too high
- Insulin is released
- Glucagon secretion is inhibited
- To prevent further increases in glucose
Definition of Signal
A chemical message sent by hormones to target cells
(Communication between hormones & target cells)
Ex: TSH signals thyroid gland to produce thyroid hormones
Definition of Response
The reaction of target cells to a hormone
Ex: When adrenaline binds to heart cells, the response is an increased heart rate
Definition of Glycogen
Stored form of glucose found in the liver and muscles
Definition of Glucagon (3)
- Hormone produced by pancreas
- Signals liver to convert glycogen into glucose
- Raising BS levels when they are too low
Definition of Insulin (3)
- Hormone produced by pancreas
- Helps cells absorb glucose from bloodstream
- Lowers BS levels when they are too high
How does negative feedback apply to control of blood sugar levels?
(7/Stimulus, Signal, Response, Inhibit)
- After eating, glucose/BS levels in blood ↑
- Pancreas detects hi BS & releases insulin
- Insulin signals cells to absorb glucose
- BS levels in blood decrease
- Pancreas detects lo BS & releases glucagon
- Glucagon signals liver to convert glycogen to glucose
- BS levels in blood rise again
Stimulus:
Increase in BS levels
Decrease in BS levels
Signal:
Insulin signals cells to absorb glucose
Glucagon signals liver to convert glycogen to glucose
Response:
Low BS levels increase
High BS levels decrease
Inhibit:
Blood Sugar levels are balanced
So insulin/glucagon production stopped
What are the different types of endocrine glands? (9)
- Pineal
- Pituitary
- Hypothalamus
- Thyroid
- Parathyroid
- Adrenal
- Pancreas
- Ovaries
- Testes
Definition of Pineal Gland (3)
- Pea-shaped, located deep in center of brain
- Regulates body’s circadian rhythm
- Produces/Releases Melatonin
Definition of Hypothalamus (3)
- Region of the brain
- Primary link between nervous & endocrine systems
- Controls the release of hormones from the pituitary glands
Definition of Pituitary Gland (5)
- Master Gland at base of brain
- Releases many hormones
- Controls activities of other glands
- Releases Growth Hormone (GH), TSH, ACTH, FHS, LSH
- Located underneath the hypothalamus
Definition of Thyroid Stimulating Hormone (TSH) (2)
- Hormone produced by the pituitary gland
- Stimulates thyroid to produce thyroxin
Definition of Follicle-Stimulating Hormone (FSH) (3)
- Hormone produced by the pituitary gland
- Stimulates ovaries to produce estrogen/develop egg
- Stimulates testes to produce sperm
Definition of Luteinizing hormone (LH) (3)
- Hormone produced by the pituitary gland
- Triggers ovulation in females
- Triggers testosterone production in males.
Definition of Adrenocorticotropic hormone (ACTH) (2)
- Hormone produced by the pituitary gland
- Signals the adrenal glands to produce cortisol
