Flashcards in 2 - The Endocrine System Deck (15)
Define the endocrine system
An important communication system in the body, based on chemical signals that are transmitted in the form of hormones
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)
What regulates the endocrine system + triggers glands to make and secrete hormones?
Hypothalamus + pituitary gland
Define a gland
Organ in the body that synthesises substances such as hormones
Define a hormone
Biochemical substance that circulates in the blood + affects target organs
Give 2 examples of hormones (which glands produce them + their role)
- Produced by: thyroid gland
- Role: increases heart rate, increases metabolic rate
- Produced by: adrenal gland
- Role: multiple, including… increased heart rate/blood flow to muscles and brain, increased breathing/oxygen flow to muscles and brain
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
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.
What systems are involved in the fight or flight response?
- The Autonomic Nervous System (unconscious branch of PNS)
- The Endocrine System
What activates the fight or flight response?
The hypothalamus when danger is detected
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)
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
What is ACTH?
Short term stress hormone
- Triggers adrenal glands in the fight or flight response
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