BIOLOGICAL - INTRO TO BIOLOGICAL

Question 1

central nervous system (CNS)

Answer 1

WHAT IS THE NERVOUS SYSTEM:
->the CNS is made up of the brain and the spinal cord; this system is responsible for sending, receiving, and interpreting information from all parts of the body
->the nervous system consists of the brain, spinal cord, and a complex network of neurones
–>it coordinates the voluntary and involuntary actions of the brain to the other body parts
–>the nervous system is made up of 2 subsystems: the central nervous system (CNS) and the peripheral nervous system (PNS)
–>the PNS includes motor neurones (mediating voluntary movement), the autonomic nervous system (ANS) comprising of the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS), which regulate involuntary functions

OUTLINE THE ROLE OF THE CNS:
->the CNS, made up of the brain and spinal cord, is the major controller of the body’s functions, charged with interpreting sensory information and responding to it with its own directives
->the CNS interprets information coming in from the senses, formulates an appropriate reaction, and sends responses to the appropriate system to respond accordingly
->everything that we see, hear, smell, touch, taste is conveyed to us from our sensory organs as neural impulses, and each of the commands that the brain sends to the body, both consciously and unconsciously travels through this system as well

Question 2

synaptic transmission

Answer 2

HOW DOES SYNAPTIC TRANSMISSION WORK?
1) the action potential triggers the release of neurotransmitters into the synaptic gap. The vesicles release neurotransmitters
2) the NTs diffuse across the synaptic gap and then they bond to the receptor sites of the post synaptic gap
3) ions cross the membrane through the open channels. This produces a synaptic potential in the posy synaptic neuron, so it carries the information forward depending on what type of neuron it is
4) once the signal has been passed on, the NT gets reuptaken by the presynaptic neuron and recycled to be used again

->the NTs that cross the synapses are an important way in which psychologists can study the function of the nervous system
->by passing messages on from one neuron to the next, NTs are directly responsible for our behaviour
->they are crucial to both the functioning of the brain and the transmission of instructions from the brain to the body
->they therefore have a direct effect on our behaviour

Question 3

the brain

Answer 3

FRONTAL LOBE:
->thinking, problem solving, planning, emotions, behavioural control, decision making

TEMPORAL LOBE:
->memory, understanding, language, facial recognition, hearing, vision, speech, emotion

PARIETAL LOBE:
->perception, object classification, spelling, knowledge of numbers, visuospatial processing

OCCIPITAL LOBE:
->vision, visual processing, colour identification

CEREBELLUM:
->gross and fine motor skills, hand-eye coordination, balance

BRAIN STEM:
->regulates body temperature, heart rate, swallowing, breathing

Question 4

neurones

Answer 4

->neurones are made up of 3 major parts:
–>a cell body (or soma) - contains the nucleus of the cell and that keeps the cell alive
–>a branching, tree-like fibre known as the dendrite, that collects information from other cells and sends the information to the soma
–>the axon - transmits information away from the cell body towards other neurons, muscles, or glands

3 main types of neurons are:
->motor: transmits information to muscles and glands
->inter: responsible for communicating among the neurons
->sensory: carries information from the sensory receptors

HOW DOES A NEURON FUNCTION?
->neurones send messages electrochemically
->when a neuron is not sending a signal it is “at rest”. When a neuron is “at rest”, the inside of the neuron is negative and the outside is positive, the resting potential is about -70mV
->an action potential occurs when a neuron sends information down the axon, away from the cell body. Action potential is an explosion of electrical activity that is created by a depolarising current (this means that a stimulus causing the resting potential to move toward becoming a positive charge. At around -55mV a neuron will open the ion channels to make a neuron more positive) If a neuron does not reach this critical level, the message will not continue
->because the inside of a neuron is negative, positive ions rush inside, which causes a more positive and depolarised neuron, causing the electrical impulse to fire along a neuron to the axon terminal
->it takes longer for some channels to open. When they do, potassium rushes out of the cell, therefore reversing the depolarisation. This causes the action potential to go back towards -70mV (repolarisation)
->hyperpolarisation occurs when the action potential goes past -70mV because the channels stay open for too long
->gradually, the ion concentrations go back to resting levels and the cell returns to -70mV

CELL BODY (SOMA):
->houses the genetic material for that neuron
->the cell body also contains other materials that allows cells to function, such as mitochondria, which provide the neuron with energy
DENDRITES:
->receives messages from other neurons in order to trigger an action potential (electrical impulse) within the cell
MYELIN SHEATH:
->layers of fatty deposit that provides an insulating layer to the axon and helps to speed up the rate of message transmission
NODES OF RANVIER:
->breaks in the axon, the electric impulse jumps to each section of the axon
THE AXON:
->made up of the myelin sheath and nodes of ranvier
->is an extension of the cell body that passes electrical impulses away from the cell body to the axon terminals
AXON TERMINALS:
-»form terminals with other passing nerve impulses from the cell body to parts of the body they control or activate - this could be another neuron or a muscle or a gland