all biopscyh ao1

Nervous system

consists of the central nervous system and the peripheral nervous system. Communicates using electrical signals.

Central nervous system

consists of the brain and the spinal cord and is the origin of all complex commands and decisions

Peripheral nervous system

sends information to the CNS from the outside world, and transmits messages from the CNS to muscles and glands in the body

Somatic nervous system

transmits information from receptor cells in the sense organs to the CNS. It also receives information from the CNS that directs muscles to act.

Autonomic nervous system

transmits information to and from internal bodily organs. It is ‘autonomic’ as the system operates involuntarily (i.e. automatic). It has two main divisions

Endocrine system

one of the body's major information systems that instructs glands to release hormones directly into the bloodstream. These hormones are carried towards target organs in the body. Communicates via chemicals.

Gland

an organ in the body that synthesizes substances such as hormones.

Hormones

chemical substances that circulate throughout the bloodstream and only affect target organs. They are produced in large quantities but disappear quickly. Their effects are very powerful.

Fight or flight response

the way an animal responds when stressed. The body becomes physiologically aroused in readiness to fight an aggressor or, in some cases, flee.

Adrenaline

a hormone produced by the adrenal glands which is part of the human body’s immediate stress response system. Adrenaline has a strong effect on the cells of the cardiovascular system - stimulating heart rate, contracting blood vessels and dilating air passages.

Neuron

the basic building blocks of the nervous system, neurons are nerve cells that process and transmit messages through electrical and chemical signals.

Sensory neurons

these carry messages from the PNS to the CNS. thye have long dendrites and short axons.

Motor neurons

these connect the CNS to effectors such as muscles and glands. They have short dendrites and long axons.

Relay neuron

these connect the sensory neuron to the motor or other relay neurons. Tey have short dendrites and short axons.

Synaptic transmission

the process by which neighboring neurons communicate with each other by sending chemical messages across the gap that separates them.

Neurotransmitter

brain chemicals released from synaptic vesicles that relay signals across the synapse from one neuron to another. Neurotransmitters can be broadly divided into those that perform an excitatory function and those that perform an inhibitory function

Excitation

when a neurotransmitter, such as adrenaline, increases the positive charge of the postsynaptic neuron. This increases the likelihood that the postsynaptic neuron will pass on the electrical impulse.

Inhibition

when a neurotransmitter, such as serotonin, increases the negative charge of the postsynaptic neuron. This decreases the likelihood that the postsynaptic neuron will pass on the electrical impulse.

Lateralisation of function

the theory that different areas of the brain are responsible for specific behaviours, processes or activities

Motor area

a region of the frontal lobe involved in regulating movement

Somatosensory area

an area of the parietal lobe that processes sensory information such as touch

Visual area

a part of the occipital lobe that receives and processes visual information

Auditory area

located in the temporal lobe and concerned with the analysis of speech-based information

Broca’s area

an area of the frontal lobe in the left hemisphere (in most people), responsible for speech production

Wernicke’s area

an area of the temporal lobe (encircling the auditory cortex) in the left hemisphere (in most people), responsible for language comprehension

What is the nervous system

A specialised network of cells in the human body and is our primary internal communication system

What is the nervous system based on

Electrical and chemical signals

What is the endocrine system based on

Hormones

What are the two main functions of the nervous system

-to collect, process and respond to information in the environment -to coordinate the working of different organs and cells in the body

What two subsystems is the nervous system divided into

The central nervous system and the peripheral nervous system

What is the central nervous system made up of

The brain and the spinal cord

What is the brain

The centre of all conscious awareness

What is the brain's outer layer called

The cerebral cortex

How thick is the cerebral cortex

Only 3mm

What does the cerebral cortex do

Covers the brain like an orange peel covers an orange

In what animals is the cerebral cortex found

Mammals

What distinguishes humans' higher mental functions from those of animals

The human brain is highly developed

What is the brian divided into

Two hemispheres

What is the spinal cord

An extension of the brain

What does the spinal cord do

It passes messages to and from the brain and connects nerves to the PNS. It is also responsible for reflex actions such as pulling your hand away from a hot plate

What does the PNS do

Transmits messages, via millions of neurons (nerve cells), to and from the central nervous system

What is the PNS subdivided into

The autonomic nervous system and the somatic nervous system

What does the autonomic nervous system do

It governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses

What does the somatic nervous system do

It governs muscle movement and receives information from sensory receptors

What does the endocrine system work alongside

The nervous system

Why does the endocrine system work alongside the nervous system

To control vital functions in the body

Pros and cons of the endocrine system as opposed to the nervous system

it acts more slowly but has very widespread and powerful effects

What part of the body produces hormones

Various glands such as the thyroid gland

What do hormones do

They are secreted into the bloodstream and affect any cell in the body that has a receptor for that particular hormone

What do most hormones affect

Cells in more than one body organ, leading to many diverse and powerful responses

What does the thyroid gland produce

The hormone thyroxine

What does the hormone thyroxine do

Affects cells in the heart (increases heart rate). It also affects cells throughout the body increasing metabolic rates (the chemical processes taking place in the cells). This in turn affects growth rates.

What are the main glands of the endocrine system

Hypothalamus, pituitary, thyroid, parathyroid, adrenals, pancreas, ovaries, testes

What is the key endocrine gland

The pituitary gland

Where is the pituitary gland located

In the brain

What is the pituitary gland often called

The master gland

What is the role of the pituitary gland

It controls the release of hormones from all the other endocrine glands in the body

How do the endocrine system and the autonomic nervous system often work together

In parallel with one another, for instance during a stressful event

What is the first thing that happens in fight or flight when a stressor is perceived

A part of the brain called the hypothalamus activates the pituitary gland and this triggers activity in the sympathetic branch of the autonomic nervous system

How does the ANS change in the fight or flight response

From its normal resting state (the parasympathetic state) to the physiologically aroused sympathetic state

Where is the stress hormone adrenaline released from

From the adrenal medulla

What is the adrenal medulla

A part of the adrenal gland lying near your kidneys

Where is adrenaline released into

The bloodstream

What does adrenaline trigger

Physiological changes in the body (e.g. increased heart rate) which creates the physiological arousal necessary for the fight or flight response

How long does the fight or flight response occur over

It happens in an instant as soon as the threat is detected

What type of response is the fight or flight response

An acute response

What type of reaction is the fight or flight response

An automatic reaction in the body

What are the physiological changes associated with the sympathetic response

Increased heart rate, increased breathing rate, dilates pupils, inhibits digestion, inhibits saliva production, contracts rectum

What are the physiological changes associated with the parasympathetic response

Decreases heart rate, decreases breathing rate, constricts pupils, stimulates digestion, stimulates saliva production, relaxes rectum

What is the fight or flight response also called

The sympathetic response

What is the sympathetic response also called

The fight or flight response

What do the physiological changes associated with the sympathetic response explain

Why stress, panic, or even excitement, are often experienced as a ‘sick’ feeling

What happens once the threat has passed in the endocrine system

The parasympathetic nervous system returns the body to its resting state

What branch works in opposition to the sympathetic nervous system

The parasympathetic branch of the ANS

What are the parasympathetic branch’s actions like

Antagonistic to the sympathetic system

What does the parasympathetic system act as

A ‘brake’ reduces the activities of the body that were increased by the actions of the sympathetic branch.

What are the actions of the parasympathetic system sometimes referred to as

The rest and digest response

What is the average response time of the nervous system

0.25 seconds but may be as quick as 100 milliseconds

What is the average response time of the endocrine responses

About 2 or 3 seconds, which is slower than the nervous system, but the responses last longer

How many neurons (nerve cells) are there in the human nervous system

100 billion

How many of the neurons in the human nervous system are located in the brain

80%

How do neurons provide the nervous system with its primary means of communication

By transmitting signals electrically and chemically

How many types of neurons are there

3

What are the different types of neurons

Sensory, relay and motor neurons

What is the size of a neuron like

They vary in size from less than a millimetre to up to a metre long

What do all neurons have in common

The same basic structure

What does the cell body include

A nucleus

What does a nucleus contain

The genetic material of the cell

What are dendrites

Branchlike structures that protrude from the cell body

What do dendrites do

Carry nerve impulses from neighbouring neurons towards the cell body

What does the axon do

Carry the impulses away from the cell body down the length of the neuron

What is the axon covered in

A fatty layer of myelin sheath

What does the myelin sheath do

Protects the axon and speeds up electrical transmission of the impulse

What would happen if the myelin sheath was continuous

The role of the myelin sheath would have a reverse effect and slow down the electrical impulse

What are nodes of ranvier

Gaps that segment the myelin sheath

What do the nodes of ranvier do

Speed up the transmission of the impulse by forcing it to ‘jump’ across the gaps along the axon

Where are terminal buttons located

At the end of the axon

What do terminal buttons do

They communicate with the next neuron in the chain across a gap known as the synapse

Where are the cell bodies of motor neurons located

In the central nervous system