Biopsych 1 Flashcards
What is the nervous system?
How is it split up?
Network of nerve cells carry messages to and from brain and spinal cord
Cns- brain, spinal cord
Pns- somatic, autonomic (sympathetic, parasympathetic)
What does the CNS do
Controls behaviour
Regulates body’s physiological processes
whatis the spinal cord/ what is its role?
relays info between brain and body
connects to diff parts of body via pairs of spinal nerves
contains nerve cells allowing us to do reflexes wo brain
what happens if spinal cord is damaged?
area below damage is cut off from brain and cant function
Cerebrum
largest part of brain
split down middle into cerebral hemispheres which communicate through corpus collosum
divided into 4 lobes
frontal lobe
speaking, planning, making judgements, abstract thinking, personality
parietal lobe
sense of touch, body position
occipital lobe
vision/ info related to sight
temporal lobe
comprehension, sound, speech
whatis the cerebellum?
what do abnormalities with it lead to?
controls motor skills, balance, coordination
abnormalities lead to speech problems, motor problems, epilepsy
Brain stem
regulates automatic functions like breathing
Diencephalon
beneath cerebrum and above brain stem
contains:
hypothalamus- regulates body temp, hunger, thirst, release of hormones from pituitary
thalamus- relay station for nerve impulses from senses
what is the PNS?
what does it do?
all nerves outside cns
relay impulses from cns to rest of body and back to cns
what is the somatic nervous system? what is it made up of?
connects senses to brain
controls voluntary movement
involved in reflex actions
made of 12 pairs of cranial nerves and 31 pairs of spinal nerves
what is the autonomic nervous system?
what is it split into?
carries out processes that arent under our conscious control like heart rate and digestion
sympathetic and parasympathetic
Autonomic- sympathetic
involved in responses helping us deal with emergencies (fight flight)
increases hr, bp, dilates blood vessels, stops salivation, digestion, lacrimation, urination, defecation
Autonomic- parasympathetic
relaxes body after emergency has passed
decreases hr, bp, processes start back up etc
Neurone
Structure function
specialised cells whose function is to move impulses to and from cns.
dendrites- receive signal
cell body and nucleus- impulse travels through cell body
axon
myelin sheath- insulates so travels faster
axon terminal
action potential(electrical signal)
what are sensory neurons?
carry impulses from sensory receptors to spinal cord and towards the brain
some terminate in spinal cord for reflexes
what is a relay neuron
found in brain and spinal cord and allow motor and sensory neurons to communicate
where are motor neurons found?
found in cns but project axons outside to control muscles
describe synaptic transmission
action potential reaches terminal of presynaptic neuron
causes vesicles to purge and release neurotransmitters which diffuse across the synapse
bind to specific receptor sites
excitatory- + charges post synaptic neuron so more likely to fire
inhibitory- opposite
summation- sees if fires or not
reuptake- neurotransmitters pop back into pre synaptic neuron to be used again
Endocrines system
network of glands that manufacture and release hormones into the blood stream. hormones go to target organs
Negative feedback
hypothalamus releases releasing hormone causing pituitary to release stimulating hormone to target gland. levels too high, hypothalamus stops secretion so does everything else
what is the pituitary gland? what is it made up of?
produces hormones which influence release of other hormones. controlled by hypothalamus
Anterior: front. ACTH-response to stress-stimulates glands to produce cortisol, LH and FSH
Posterior:back. oxytocin-stimulates uterus contractions, important for bonding
what are the adrenal glands made up of?
on top of kidneys
Adrenal cortex(inner)- hormones necessary for life. Cortisol-cardiovascular and antiinflam functions. aldosterone- maintains blood pressure and vol
Adrenal medulla- adrenaline- increase hr,bp etc. noradrenaline- constricts blood vessels so increases bp
Ovaries
production of eggs and oestrogen (males produce in adrenal glands) and progesterone
progesterone is important in post ovulation phase
Testes
produce testosterone- development of facial hair, deep voice, growth
controlled by hypothalamus and pituitary
plays role in sex drive,sperm production, maintaining strength
women have it but in smaller amounts
Fight/ flight response
- body responding to stressful situations for survival.
- amygdala mobilised- associates sensory signals with emotions associated with fight flight
- sends distress signal to hypothalamus which communicates w rest of body through sympathetic nervous system
- bodys response has 2 systems one for acute one for chronic
Acute stress response
SNS triggered sends signal to adrenal medulla which releases adrenaline
this increases heart rate (blood round bod), breathing (oxygen) and triggers release of sugar (energy)
parasympathetic when stress passed
AMYGDALA TO HYPOTHALAMUS TO SNS TO ADRENAL MEDULLA TO ADRENALINE
what is chronic stress?
what is the HPA axis?
starts when brain continues to perceive something as threatening
adrenaline decreases and hypothalamus activate HPA axis
H hypothalamus releases CRH
P this causes pituitary gland to release ACTH to target organ
A this stimulates adrenal cortex to release stress based hormones like cortisol
effects of cortisol
+
burst of energy,less sensitive to pain
-
decrease immune system, impaired cognitive function
Too much or little cortisol problems
Reduce it by
too much- high bp leads to stroke and heart attack, less able to fight infections, can lead to diabetes, fat build up especially round abdomen
too little-low bp, poor immune system, cant deal w stress
reduce levels- exercise
and meditation
Evaluation of fight/ flight
-different responses to stress (tend and befriend)
- stressors today dont need physical reaction, frequently activated causes high cortisol
- 1st stage is freeze which is useful as makes you vigilant and aware
-may cause positive not fight flight behavior eg cooperative behavior
-SRY gene in men causes aggression so fight flight but women dont have (Y chromosome)
