biopsychology 1

no evaluation

what is the nervous system?

network of nerve cells that carry messages to and from the brain and spinal cord

helps the body communicate

provides conciousness

label this

what are the main functions of the central nervous system?

1. control behaviour

2. regulate body’s physical proceses
   

   brain needs to be able to recieve information from sensory receptors and send messages to muscles and glands
   

   the spinal cord attaches to the brain and nerve cells run the length of the spinal cord

explain the spinal cord in relation to the central nervous system

it relays information between the brain and body, allowing the brain to monitor and regulate bodily processes

spinal cord is connected to different parts of the body by pairs of spinal nerves which connect to specific glands or muscles

allows us to perform simple reflexes without direct involvement of the brain through circuits of nerve cells- e.g. pulling hand away from something hot

if it is damaged, areas below the damaged site will stop working

give a simple summary of functions of the spinal cord

1. relays info from brain and body

2. spinal cord connects to different parts of the body, specific glands and muscles

3. perform simple and quick reflexes

label this

what is SPATVOMF

Somatosensory cortex

Parietal lobe

Auditory cortex

Temporal lobe

Visual cortex

Occipital lobe

Motor cortex

Frontal lobe

what is the outerlayer of the brain called? how thick is it?

cerebral cortex- 3 mm thick

where is the centre of concious awareness?

brain

what are the two parts of the central nervous system called?

brain and spinal cord

what are the two parts of the peripheral nervous system called?

somatic and autonomic nervous system

what is the somatic nervous system?

voluntary actions

made up of 12 pairs of cranial nerves and 31 pairs of spinal nerves

cranial nerves- come from under the brain

sensory neurons pick up from environment and the motor does the action for that

also involved in reflex actions

what is the autonomic nervous system?

involuntary actions

unconscious ones like breathing or digestion

this is needed so the body can work more efficiently

has 2 parts- sympathetic and parasympathetic

what is the sympathetic nervous system?

fight or flight

help us deal with emergencies- increase blood pressure and heart rate

neurons from SNS travel to almost every organ and gland

causes body to release stored energy

slows the less important bodily processes (e.g. digestion or urination) in emergencies so the energy can be used elsewhere like running

what is the parasympathetic nervous system?

rest and digest

slows heartbeat down and reduces blood pressure

bodily processes will start again, e.g. digestion

compare sympathetic and parasympathetic nervous system for these:

pupils

heartbeat

digestion

pupils:

S- dilate / P- constricts

heartbeat:

S- increases / P- slows

digestive system:

S- decreases activity / P- increases activity

somatic nervous system: how many pairs of cranial nerves?

how many pairs of spinal nerves?

12 pairs of cranial nerves

31 pairs of spinal nerves

where are cranial nerves found?

from under the brain

what are neurons?

specialised cells which transmit impulses to and from the CNS

what is the axon terminal?

communicate with the next neuron in the chain

what is the mylon sheath?

layer that protects axon and speeds up electrical transmission

what is the axon?

carries action potential away from the cell body and down the length of the neuron

what is the cell body?

controls centre of the neuron

what is the nucleus?

contains genetic info of the cell

what are dendrites?

carry nerve impulses from neighbouring neurons/receptors to the cell body

what are nodes of ranvier?

gaps in the mylein sheath- speeds up action potential by forcing impulse to jump over the gaps in the axon

explain using neurons how someone can move hand to catch a ball

stimulus

sensory receptor

sensory neuron

relay neuron

motor neuron

muscle

response

what type of neuron is this?

sensory

label this sensory neuron

explain what the sensory neuron does

converts information from sensory receptor into neural responses

impulses are translated into sensations (e.g. pain or visual input) so we can respond appropriately

not all sensory info travels to the brain and stops at the spinal cord to allow reflex actions

what type of neuron is this

relay

label this relay neuron

explain what relay neurons do

allow sensory and motor neurons to communicate with each other

lie between the brain and spinal cord

most neurons are relay neurons

what type of neuron is this?

motor neuron

label this motor neuron

explain what motor neurons do

controls muscles and releases neurotransmitters that bind to receptors on muscles to trigger a response

axon fires = muscle contracts

muscle relaxation is caused by neuron not sending it signals

explain synaptic transmission stages

1. Axon: Action potential travels down the neuron and reaches the axon terminal

2. Tosses: This triggers the release of neurotransmitters from vesicles

3. Neurotransmitters: Neurotransmitters diffuse across the synapse

4. Between: Bind to receptor sites or are taken back to vesicles

5. Synapses: Summation. NTs are excitatory (positive charge- message more likely to fire) or inhibitory (negative charge- stops firing). Sum of Ex and In = whichever there is more of that’s what will happen (e.g. message will fire or message will stop) (only use if 6 marks)

explain summation in synaptic transmission

NTs are excitatory (positive charge- message more likely to fire) or inhibitory (negative charge- stops firing). Sum of Ex and In = whichever there is more of that’s what will happen (e.g. message will fire or message will stop) (only use if 6 marks)

what do excitatory neurotransmitters have and do?

positive charge- message more likely to fire

what do inhibitory neurotransmitters have and do?

negative charge

stops firing of message

what is this?

synaptic transmission

label synaptic transmission

what is the endocrine system?

network of glands throughout the body that create and secrete hormones

instructs the glands to release hormones directly into the blood stream and be carried towards target organs

label the endocrine system

what does there have to be for cells for a hormone to influence it?

particular receptors for particular hormones

if cell doesn’t have that receptor, the hormone can’t influence it

why is timing of hormone release for the endocrine system critical?

there could be dysfunctions of the systems otherwise if levels are wrong or if timing is off

where is the pituitary gland and what does it do?

controlled by hypothalamus

known as the master gland- produces hormones that travel in the bloodstream to their target

the hormones either directly cause changes in body processes or stimulate glands to produce other hormones

high levels of hormones in other glands can stop the hypothalamus and the pituitary gland from release hormones to stop levels rising too high

explain the hormones released by the pituitary glands

PG has 2 parts- anterior (front) and posterior (back)

they release different hormones that target different parts of the body

anterior produces ACTH as a response to stress as well as LH and FSH to produce oestrogen, progesterone and testosterone

posterior produces oxytocin- this stimulates contractions during birth and helps mother infant relationships

what hormones does the anterior of the PG create?

1. ACTH- help with stress

2. LH and FSH (both help producing progesterone, oestrogen and testosterone)

what hormone does the posterior of the PG create?

oxytocin- stimulates contractions during birth and helps mother/infant bonding

explain the adrenal glands

2 glands that sit on top of the kidney

each has 2 parts- adrenal cortex and adrenal medulla

adrenal cortex:

on the outer part

produces cortisol (a stress hormone)

releases hormones that are necessary for life

has cardiovascular and anti-inflamatory functions

if cortisol levels are low, person has low blood pressure, poor immune system and can’t deal with stress

adrenal medulla:

on the inner part

releases adrenaline and noradrenaline

releases hormones that aren’t necessary for life

prepares fight or flight which helps body respond to stressful situations (adrenaline)

noradrenaline constricts blood vessels to increase blood pressure

what hormone does the adrenal cortex release? what does it do?

cortisol

if levels of cortisol are low the person has:

low blood pressure, poor immune function and inability to deal with stress

what hormones does the adrenal cortex release? what does it do?

adrenaline- prepares fight or flight which helps the body respond in stressful situations

noradrenaline- constricts blood vessels to increase blood pressure

what do the ovaries do?

2 ovaries- responsible for the production of eggs

produces oestrogen and progesterone

progesterone is more important post-ovulation

what do the testes do?

produce testosterone

causes facial hair growth, deepening of voice and growth spurts

plays a role in sex drive and strength

women also have this but in small volumes

explain the process of getting a hormone to the target area

hypothalamus → sends signal → pituitary gland → secretes hormones → blood stream → target gland

how does the endorcrine system balance concentration of hormones?

as levels of hormones rise, hypothalamus and PG shut down the secretion which allows stable concentration

what is fight or flight?

when a person experiences stressful/threatening situations their body has adapted to react quickly

link to sympathetic and parasympathetic nervous system

for acute stress (immediate like murder)

also activated when its unhelpful- e.g. before an exam

how does fight or flight happen biologically? (stages)

1. A- Amygdala- amygdala associates sensory signals with emotions like fear and sends the distress signal to the hypothalamus

2. H- Hypothalamus- hypothalamus releases CRH into the bloodstream

3. P- Pituitary gland- releases ACTH into the blood stream and then it goes to the target site

4. A- Adrenal medulla- releases adrenaline into the blood stream causing rapid changes

what hormone does the hypothalamus release in fight or flight?

CRH

what hormone does the pituitary gland release in fight or flight?

ACTH

what hormone does the adrenal medulla release in fight or flight?

adrenaline