biological bases

Question 1

central nervous system

Answer 1

made of brain and spinal cord including neurons:
motor neurons: descending tract, send messages/impulse down to muscles
sensory neurons: ascending tract, send messages up to brain
interneurons: are within the spinal cord and connect/pass on messages to sensory/motor neurons and vice versa

Question 2

spinal reflex

Answer 2

is an adaptive response means that brain avoids potential harm/injury/death, it is quick and occurs as the sensory message from PNS is still being sent to the brain for processing (reaches spinal cord and is sent back to site of injury/issue

Question 3

peripheral nervous system

Answer 3

Made up of nerves that branch out from spinal cord to muscles and organs and branch out from sensory receptors to spinal cord

Question 4

Structure of PNS

Answer 4

PNS -> somatic nervous system (controls voluntary actions) and autonomic nervous system (automatically controls actions of internal organs, smooth muscle/glands) -> sympathetic nervous system (activates fight/flight/freeze response during threat) and parasympathetic nervous system (restores body to state of calm)

Question 5

frontal lobe

Answer 5

performs executive functions, control of socially unacceptable responses, control of movement, problem solving, symbolic thinking, risk analysis, contains primary motor cortex which controls contralateral organisation

Question 6

parietal lobe

Answer 6

bodily sensations, pain, temp, touch, spatial awareness (proprioception), contains the primary somatosensory cortex

Question 7

occipital lobe

Answer 7

vision,contains primary visual cortex which is responsible for visual perception, colour recognition, visuospatial processing, distance, depth perception

Question 8

temporal lobe

Answer 8

responsible for hearing, auditory processing, language recognition, memory, long term memory associated with emotion visual memory, facial recognition, auditory memory

Question 9

Broca’s area

Answer 9

Responsible for speech production, in left frontal lobe

Question 10

structure and function of neuron

Answer 10

dendrite detect and recieve information from presynaptic neuron, has receptors so messages can be received from different chemical messengers
soma: collects and integrates information from thousands of of other neurons then transmits along axon
axon: single, tube like extension that transmit neural info to other neurons, nerves are cable like bundles of multiple axons
myelin: fatty white substance that surrounds and insulates axon, allows for rapid movement of message along axon
nodes of ranvier: separates segments of myelin causing messages to jump from node and speed up transmission
axon terminals: small knob like swelling at end of each branch, stores and secretes neurotransmitters manufactured by neuron and carries chemical messages to other neurons

Question 11

sensory neurons

Answer 11

recieve and carry sensory information from both internal and external environments

Question 12

Motor neurons

Answer 12

Carries message from CNS to cells in skeletal muscles, organs, glands to stimulate activity

Question 13

interneuron

Answer 13

Sends message between sensory and motor neurons within CNS relaying information from one to the other

Question 14

action potential

Answer 14

• occurs when a neurons sends info down an axon away from cell body, electrical signal that passes through neuron depends on infra and extra cellular fluids being electrically different meaning there is more sodium ions on the outside of the neuron compared to potassium ions on the inside of the neuron which gives it an overall negative charge. - the membrane is semipermeable
• Resting potential: when a neuron is not sending a signal as it is at rest, inside of neuron is negatively charged (-70mV)
• A stimulus causes depolarising current and resting potential moves towards 0mV,when depolarisation reaches -55 mV a neuron will fire an action potential (if it doesn’t reach -55 then its a failed initiative: all or nothing phenomena), continues to depolarise (sodium ions rush in) until it reaches peace action potential (+40 mV),
• repolarisation potassium channels open to let out potassium ions (AP starts to go down
• hyperpolarisationm AP goes lower than -70mV but then gradually returns to resting potential (-70mV)

Question 15

role of synapse

Answer 15

synaptic transmission relies on chemical imbalances in cells and electrical transmission of impulses through neuron

Question 16

neurotransmitter

Answer 16

chemical substance produced by a neuron that carries a message to other neurons or cells

Question 17

transport of neurotransmitters

Answer 17

works by binding to receptor on site of post synaptic neurons that are specialised to recieve specific neurotransmitters,

• neurotransmitters that do not bind to receptors in postsynaptic neurons go through reuptake: where they are reabsorbed into terminal buttons of presynaptic neuron
• lock and key processm each type of neurotransmitters has a chemically distinct shape and searches for correctly shaped receptor site on dendrites of post synaptic neuron, binding unlocks post synaptic neurons response to neutron transmitter, causes change to neuron, resulting in inhibiting or excitatory effect

Question 18

excitatory neurotransmitter

Answer 18

stimulate or activate postsynaptic neurons to perform their functions (encourage action potential to be fired down to next neuron)

Question 19

inhibitory

Answer 19

block or prevent postsynaptic neurons from firing

Question 20

serotonin

Answer 20

inhibitory neurotransmitter

• regulates mood, anxiety, sleepy cycle, body temp,
• adequate amounts of serotonin are necessary for stable mood and to balance any excessive excitatory neurotransmitters firing in the brain
• deficit of serotonin has been linked to depression
• drug SSRI (selective serotonin reuptake inhibitor) increase availability of serotonin in some brain regions

Question 21

Dopamine

Answer 21

can be either excitatory or inhibitory depending on receptors present

• creates feelings of motivation/drive
• involved in liking, attention, pleasurable sensations, learning, movement
• degeneration of neurons that produce dopamine in one area of the brain cause Parkinson’s disease

Question 22

Endorphins

Answer 22

regulates feelings and perceptions of pain, body’s natural pain killing drugs and manufactured and released when body is stressed or when you experience a positive mood e.g runners high

Question 23

Hormones

Answer 23

Chemical messengers produced by endocrine glands, travel through blood stream and affect other parts of the body, slower than neurotransmitter

Question 24

Hormones vs neurotransmitter

Answer 24

Origin: glands of endocrine system / neurons of NS
Transport medium: blood / neurons
Target: organs/glands / local receptors on nerve cells
Action: slow (few days) / fast (almost instant)
Duration of effect: short and long lived / short
Response: involuntary / voluntary & involuntary

Question 25

Adrenaline

Answer 25

Makes individual more fearful/agitated heightened in exercise, can enhance physical strength

Question 26

Noradrenaline

Answer 26

Vigilance function keep us alert increase arousal, affects attention and focus promotes stress avoiding behaviour, both work in conjunction with sympathetic nervous system

Question 27

Sympathetic nervous system

Answer 27

controls muscle contraction, increase breathing rate, heart rate, pupil dialation, even after emergency has passed feeling may continue as a result of hormones still in bloodstream

Question 28

Role of genetics

Answer 28

Plays large role in areas of physical growth, intelligence and development

Question 29

Mitosis

Answer 29

When when cells die need repair or when cells split part, only one division occurs which results in w genetically identical daughter cells with 46 chromosomes each (diploid)

Question 30

Meiosis

Answer 30

for sexual reproduction of sperm/ova , occurs in gonads, one mother cell divides twice ms crossing over occurs after first division and results in 4 genetically different daughter cells that have 23 chromosomes each (haploid)