The endocrine system Flashcards
glands and hormones
endocrine system works alongside the nervous system to control vital functions in the body
acts more slowly than the nervous system but has widespread effects
various glands in the body produce hormones
hormones are secreted into the blood stream and affect any cell in the body that has a receptor for that particular hormone
hormones
affect cells in more than one body organ
leading to many diverse powerful responses
example - thyroid gland produces the hormone thyroxine
this hormone affects cells in the heart (increases heart rate)
also affects cells throughout the body increasing metabolic rates(chemical process taking place in the cells)
affects growth rate
glands
main glands in the endocrine system are
hypothalamus
pituitary
thyroid
parathyroid
adrenals
pancreas
ovaries - female
testes-male
the key endocrine gland is the pituarity gland located in the brain
often called the master gland because it controls the release of hormones from all the other endocrine glands in the body
endocrine and ANS working together - fight or flight
endocrine system and the autonomic nervous system work in parallel - such as in a stressful event
when a stressor is perceived the first thing that happens is a part of the brain called the hypothalamus activatsthe pituitary gland and this triggers activity in the sympathetic branch of the autonomous nervous system
The ANS changes from its normal resting state (parasympathetic state) tot he physiologically aroused sympathetic state.
endocrine and ANS working together - fight or flight
adrenaline
the stress hormone adrenaline is released from the adrenal medulla into the bloodstream
adrenaline triggers physiological changes in the body such as increased heart rate
creates the physiological arousal necessary for flight to fight response
endocrine and ANS working together - fight or flight
immediate and automatic
all of this happens in an instant as soon as the threat is detected
this is an acute response and an automatic reaction in the body
endocrine and ANS working together - flight or flight
parasympathetic action
once the threat has passed the parasympathetic nervous system returns the body to its resting state
parasympathetic branch of ANS works in opposition to the sympathetic nervous system
it’s actions are antagonistic tot he sympathetic system
the parasympathetic system acts as a brake and reduced the activities of the body that were increased by the actions of the sympathetic branch
this is often referred to as the rest and digest response
biological changes associated with the sympathetic state
increases heart rate
increases breathing rate
dilates pupils
inhibits digestion
inhibits saliva production
contracts rectum
biological changes associated with the parasympathetic state
decreases heart rate
decreases breathing rate
constricts pupils
stimulates digestion
stimulates saliva production
relaxes rectum
