Flashcards in 2 - The Endocrine System Deck (15)
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1
Define the endocrine system
An important communication system in the body, based on chemical signals that are transmitted in the form of hormones
2
Outline how the endocrine system works
- Glands in the body produce hormones
- Hormones are secreted into the bloodstream
- Hormones affect target organs (with receptor cells to match the hormone)
3
What regulates the endocrine system + triggers glands to make and secrete hormones?
Hypothalamus + pituitary gland
4
Define a gland
Organ in the body that synthesises substances such as hormones
5
Define a hormone
Biochemical substance that circulates in the blood + affects target organs
6
Give 2 examples of hormones (which glands produce them + their role)
1) Thyroxine
- Produced by: thyroid gland
- Role: increases heart rate, increases metabolic rate
2) Adrenaline
- Produced by: adrenal gland
- Role: multiple, including… increased heart rate/blood flow to muscles and brain, increased breathing/oxygen flow to muscles and brain
7
Where is the pituitary gland + what does it do?
- In the brain (controlled by the hypothalamus)
- The ‘master gland’ that controls the secretion of hormones from other glands
8
What is the fight or flight response?
Way an animal responds when its stressed. Body is physiologically aroused in readiness to fight an aggressor or flee.
9
What systems are involved in the fight or flight response?
- The Autonomic Nervous System (unconscious branch of PNS)
- The Endocrine System
10
What activates the fight or flight response?
The hypothalamus when danger is detected
11
Outline the fight or flight response
- Danger is presented + hypothalamus is stimulated
- Hypothalamus activates 2 forms of physiological arousal…
ANS: Shift from parasympathetic to sympathetic state. This prepares + excited the body for action.
ENDOCRINE SYSTEM: Pituitary gland produces ACTH to trigger adrenal glands to release adrenaline. Adrenaline arouses body.
- Once danger removed, parasympathetic nervous system activated to calm the body (return to rest + digest)
12
How do the effects of adrenaline help the fight or flight response?
- Increased heart rate: more blood flow provides brain + muscles with more glucose to run or fight
- Increased breathing rate: more oxygen for brain to make quick decisions
13
What is ACTH?
Short term stress hormone
- Triggers adrenal glands in the fight or flight response
14
Give one negative evaluation point for the fight or flight response
May only apply to men
- Taylor et al said it only applies to men + women have evolved a different response based on role as primary caregivers
- Women TEND (use nurturing behaviours to protect themselves + their offspring) + BEFRIEND (form protective alliance with other females against the danger)
- Experiments using females rats supported this (oxytocin hormone released - de-stressor, prohibiting fight or flight)
- So, evidence supports that women have a different response to danger
15
