nervous System and endo ao1 Flashcards
Difference between nervous and endocrine
Nervous - transmits electrical impulse, short lasting, quicker, temporary and localised
Endocrine - transmits hormones (chemical messengers) in the blood stream, longer lasting, slower, more localised and wide
A Hormone is …
Chemical substances circulate in bloodstream only affecting target organs produced in large quantities and disappear quickly
Affect cells w receptors specific to hormone on it
What is HPA axis
a system that directly influences the endocrine system to active the stress response
Describe HPA axis
- When the brain interprets a stressor, the hypothalamus produces a hormone CRF
- stimulates the pituitary gland to secrete ACTH - stimulates the adrenal cortex, part of the adrenal glands. The adrenal cortex then secretes corticosteroids, which help to increase energy levels.
Role of pituarty gland
Regulate endocrine system
Adrenal glands
Flight or fight
Adrenaline or cortisol
Adrenaline medulla
Adrenal cortex
Testes
Sexual and reproductive dev
Testosterone
Ovaries
Oestrogen
Progesterone
Oestrogen
Male and female sex hormone
More in females
Puberty menstrual cycle pregnancy and bone strength
Maintaing cholesterol and brain heart and skin
Progesterone
Prepares endometrium for potential for pregnancy after ovulation
Thickens endometrium for egg
Prohibits muscle contraction which would cause rejection of egg
Pineal gland
Melatonin
Pituitary gland sepeated into 2 lobes
Anterior lobe (front)
Prosterior (rear)
Anterior lobe
Created adrenal tropic hormone
Posterior lobe - what hormone and what does the hormone do
Oxytocin
Rise during physical contact w another human
And maternal horome large amounts rel during childbirth and rel of milk during breast feeding
Parts of adrenal gland and what do they produce
Adrenal medulla ~ adrenaline and noradrenaline
Adrenal cortex - cortisol
Cortisol
Stim release of glucose to provide body with energy and suppressing immune system
More cortisol when stressed
Testes release
Androgens and testosterone
Testosterone
Dev of male sex characteristics during puberty and promoting muscle growth
ACTH hormone
Released by pituitary gland
Tiggers adrenal gland to release adrenaline and cortisol
Noradrenaline
Supports the nervous system to engage the Brain for a fight or flight
Sympathetic NS
Prepared the body for rapid action associated with fight of flight
Feedback loop
Cortisol levels are monitored so that CRH and ACTH production is inhibited if cortisol is too high
Human nervous system is separated into the…
Peripheral nervous system
Central nervous system
The central nervous system is split into the…
Brain and the spinal cord
The peripheral nervous system is split into the..
Autonomic nervous system
Somatic nervous system
Autonomic nervous system is split into …
Sympathetic nervous system
Parasympathetic nervous system
Struc and function of brain
Centre of awareness
Divided into right and left hemisphere
Struc and function of spinal cord
Transports message to and from the brain to the pns
Responsible for reflexes
Function of somatic ns
Receives info from senses and transmits it to the CNS
Also transmits info from the cns to direct movement of muscles
Function of autonomic ns
Responsible for vital functions eg heart and breathing rate
Sexual arousal
Digestion
Parasympathetic and sympathetic ns needed for what response
Fight or flight
What is endocrine system
Works alongside ns to control vital functions
System of glands which releases hormones into the blood
Describe how systems work together during fight or flight
The endocrine and ANS often work in parallel with one another eg during a stressful event
When a stressor is perceived the hypothalamus triggers the sympathetic nervous system and the autonomic NS changes from the parasympathetic state (resting state) to the sympathetic state
Adrenaline rel from adrenal medulla into bloodstream = physical arousal needed for fight or flight
Once threat has passed parasympathetic NS returns body to natural resting state
When body in sympathetic state…
- increased heart rate
- increased breathing rate
- pupils dilate
- less blood flow to less needed mechanisms like digestion and salivation
Parasympathetic state leads to
- decreased heart rate
- decreased breathing rate
- dilates pupils
- blood flow returns to less needed mechanisms returns to normal (digestion/salivation)
Outline role of adrenaline in fight or flight
Ms :
Adrenaline is released from the adrenal medulla in response to activation of the sympathomedullary pathway.
Adrenaline has a range of effects on the body
Direct effects of adrenaline
- increase heart rate
- constricts blood vessels, increasing rate of blood flow and raising blood pressure
- diverts blood away from the skin, kidneys and digestive system
- increases blood to brain and skeletal muscle
- increases respiration and sweating
The general effects of adrenaline
- prepare the body for action, fight or flight,
- increase blood supply/oxygen, to skeletal muscle for physical action
- increase oxygen to brain for rapid response planning
