Biopsych Flashcards
function of cerebellum
-controls motor skills, balance, coordination of muscles to allow precise movement
function of cerebrum
-enables speech, judgement, thinking, problem solving, emotions
function of diencephalon
-contains thalamus (relay for nerve impulses between senses and brain) and hypothalamus (temp reg, hunger, thirst, acts as link between endocrine system and nervous system)
function of brain stem
-regulates automatic functions eg. breathing, heart rate, swallowing
-motor and sensory neurons travel through brain stem, allowing impulses to pass between brain and spinal cord
what does the spinal cord do
-connects brain w peripheral nervous system to relay info between brain + body to allow regulation of breathing, digestion etc
-contains circuits of nerve cells to allow reflex actions
2 parts of peripheral nervous system (brief)
-somatic nervous system
-autonomic nervous system
function of somatic nervous system
-responsible for relay of sensory and motor info to and from CNS
function of autonomic nervous system
-responsible for involuntary actions eg. heartrate, digestion
2 parts of autonomic nervous system
-sympathetic nervous system (SNS)
-parasympathetic nervous system (PNS)
function of sympathetic nervous system (SNS)
-involved in emergency responses (fight or flight)
-increase heartrate, dilate pupils, slows digestion, dilate blood vessels in muscles. increase BP
function of parasympathetic nervous system (PNS)
-involved in calming down after emergencies
-decreases heartrate, decreases BP, restarts digestion
structure and function (of parts) of neurons
-dendrites - receive signals from other neurons
-axon - carries action potential towards axon terminal, surrounded by myelin sheath
-axon terminal - has vesicles that contain neurotransmitters, connects neuron to others by synaptic transmission
function of sensory neurons
-found in sensory receptors (eyes, ears, nose etc)
-carry impulses to spinal cord and brain
-impulses translated into sensations (vision, hearing)
-not all reach brain - some stop at spinal cord for reflex actions
function of relay neurons
-found in brain and spinal cord
-allow sensory and motor neurons to communicate
function of motor neurons
-found in CNS
-control muscle movements
-when stimulated, they release neurotransmitters that bind to receptors on muscles and trigger a response which leads to movement
process of synaptic transmission
- action potential travels down axon and arrives at axon terminal
- AP stimulates synaptic vesicles to release neurotransmitters
- neurotransmitters diffuse across synapse and bind to receptor sites on dendrites of post-synaptic neuron
- chemical message is converted to an electrical impulse to begin transmission again (if summation allows)
- neurotransmitters ‘re-uptaken’ by pre-synaptic neuron
what are excitatory neurotransmitters
-make post-synaptic neuron MORE likely to fire as they increase the pos charge
-this results in an excitatory post-synaptic potential (EPSP)
what are inhibitory neurotransmitters
-make post-synaptic neuron LESS likely to fire as they cause a more neg charge
-this results in an inhibitory post-synaptic potential (IPSP)
what is summation
-the net sum of adding up the excitatory and inhibitory synaptic input
-this determines whether the neuron will fire or not
what is the endocrine system
-network of glands that produce and secrete hormones via circulatory system to target organs
-system is regulated by feedback to ensure stable conc of hormones
location and function of the pituitary gland
-‘master gland’
-located in brain
-stimulates all other glands to release hormones
location and function of adrenal glands
-located above kidneys
-release adrenaline/cortisol
function of testes
-produce testosterone which deepens voice, stimulates growth and sperm production
function of ovaries
-produces progesterone which maintains uterine lining and oestrogen which stimulates egg production and release
function of thyroid gland
-releases thyroxine which is responsible for regulating metabolism
5 glands (brief)
-pituitary
-adrenal
-thyroid
-testes
-ovaries
structure and function (of parts) of pituitary gland
- anterior pituitary (front) - produces ACTH as response to stress - ACTH stimulates adrenal glands to produce cortisol. Also produces LH and FSH
- posterior pituitary (back) - releases oxytocin which stimulates uterus contraction in childbirth and is important for bonding
structure and function (of parts) of adrenal glands
- adrenal cortex (outer) - produces cortisol
- adrenal medulla (inner) - produces adrenaline and noradrenaline - prepare body for fight or flight
what do low cortisol levels lead to
-low BP
-poor immune functioning
-inability to deal w stress
what is the fight or flight response (brief)
-evolutionary survival mechanism that allows animals and humans to respond quickly to life-threatening situations
acute stress response
- Sympathetic NS (SNS) triggered by hypothalamus (after amygdala sends distress signal)
- SNS sends signal to adrenal medulla to release adrenaline
3.adrenaline causes increased heartrate/BP, vasoconstriction etc
4.when threat has passed, parasympathetic NS (PNS) calms the body down again
chronic stress response
-HPA axis
1.Hypothalamus activates HPA axis by releasing CRH
2. CRH causes pituitary gland to release ACTH
3. ACTH stimulates adrenal cortex to release cortisol, which causes glucose to be continually released from liver to provide energy
what does continual release of cortisol lead to
-increased risk of heart attack
-weakened immune system
-increased blood sugar
limitations of fight or flight response
-gender differences - women have less ‘flight’ response due to being primary caregiver, not wanting to leave children
-not generally needed in modern society and can cause health risks - high BP can cause damage to blood vessels, weakened immune system
-also a ‘freeze’ reaction - Gray - 1st phase of reaction is to avoid confrontation and freeze. allows us to become aware of surroundings and prepare