Biopsychology

Question 1

WHAT IS OUR NERVOUS SYSTEM?

Answer 1

The nervous system is a specialised network of cells in our body.

It is our primary internal communication system and sends information around our body using electrical and chemical signals.

Question 2

WHAT ARE THE NERVOUS SYSTEMS FUNCTIONS?

Answer 2

Its two main functions are to:
Collect, process and respond to information in the environment
Co-ordinate the working of different organs and cells in the body

Question 3

WHATS THE NERVOUS SYSTEM DIVIDED INTO?

Answer 3

The nervous system is divided into two subsystems:
The central nervous system (CNS)
The peripheral nervous system (PNS)

Question 4

WHATS THE CNS MADE UP OF?

ITS THE ORIGIN OF?

Answer 4

The CNS is made up of the brain and the spinal cord.

It is the origin of all complex commands and decisions.

Question 5

THE CNS BRAIN

Answer 5

Comprised of billions of interconnected neurons.

It is highly developed in humans and is what distinguishes our higher mental functions from other animals.

It is divided into two hemispheres and also has distinct lobes. A

ll of the areas of the brain interact with one another to provide the foundation for our thoughts and behaviours.

Question 6

CNS SPINAL CORD

Answer 6

The spinal cord is like a relay station.

It not only passes messages to and from the brain, but it also has its own system of automatic processes, called reflexes.

The top of the spinal cord merges with the brain stem, where the basic processes of life are controlled, such as breathing and digestion and ends just below the ribs.

Question 7

THE PERIPHERAL NERVOUS SYSTEM (PNS)

Answer 7

The PNS transmits messages via nerves, carrying messages back and forth between the CNS and the muscles, organs and glands in the periphery of the body (i.e. everything outside the CNS).

Question 8

WHAT IS THE PNS SUBDIVIDED INTO?

Answer 8

Somatic nervous system (SNS)

Autonomic nervous system (ANS)

Question 9

WHAT IS THE SOMATIC NERVOUS SYSTEM?

Answer 9

The SNS is associated with activities traditionally thought of as conscious or voluntary.

It is involved in the relay of sensory and motor information to and from the CNS; therefore, it consists of sensory neurons and motor neurons.

Sensory neurons carry sensory information to the CNS. These are known as afferent neurons, they carry information to the CNS.

Motor neurons carry instructions from the CNS to the muscles. These are known as efferent neurons, they carry information from the CNS.

Question 10

WHAT IS THE AUTONOMIC NERVOUS SYSTEM?

Answer 10

The ANS controls our internal organs and glands and is generally considered to be outside the realm of voluntary control.

Question 11

WHATS THE ANS SUBDIVIDED INTO?

Answer 11

It can be further subdivided into the sympathetic and parasympathetic divisions.

Question 12

WHAT IS THE SYMPATHETIC NERVOUS SYSTEM?

Answer 12

The sympathetic nervous system is involved in preparing the body for stress-related activities (‘fight-and-flight’).

Question 13

WHAT IS THE PARASYMPATHETIC NERVOUS SYSTEM?

Answer 13

The parasympathetic nervous system is associated with returning the body to routine, day-to-day operations (‘rest-and-digest’).

Question 14

WHAT ARE THE TWO SYSTEMS COMPLEMENTARY FUNCTIONS?

Answer 14

Operating in tandem to maintain the body’s homeostasis. Homeostasis is a state of equilibrium, in which biological conditions (such as body temperature) are maintained at optimal levels.

Question 15

ENDOCRINE SYSTEM
WHAT DOES IT WORK ALONGSIDE WITH?
WHAT DOES IT DO?

Answer 15

The endocrine system works alongside the nervous system to control vital functions in the body.

It acts more slowly than the nervous system, but is equally as important. It regulates all biological processes in the body from conception through adulthood and into old age, including the development of the brain and nervous system, the growth and function of the reproductive system, as well as the metabolism and blood sugar levels.

Question 16

WHAT IS THE ENDOCRINE SYSTEM MADE UP OF?

Answer 16

The endocrine system is made up of glands that produce hormones.

Question 17

WHAT ARE HORMONES?

Answer 17

Hormones are chemical substances that are secreted into the bloodstream and affect any cell in the body that has a receptor (like a lock and key) for that particular hormone. When a hormone binds to a receptor, the receptor carries out the hormone’s instructions.

Hormones affect cells in more than one organ.

Question 18

FIGHT OR FLIGHT RESPONSE

1ST STEP

Answer 18

Stressor perceived (for example, a bat flies into your bedroom)

Question 19

FIGHT OR FLIGHT

2ND STEP

Answer 19

The hypothalamus (a part of the brain) activates the pituitary gland
This activates the sympathetic branch of the ANS

Question 20

FIGHT OR FLIGHT

3RD STEP

Answer 20

The sympathetic branch sends a signal to the adrenal medulla (part of the adrenal glands)

Question 21

FIGHT OR FLIGHT

4TH STEP

Answer 21

The adrenal medulla then releases the hormone adrenaline

Question 22

FIGHT OR FLIGHT

5TH STEP

Answer 22

Adrenaline circulates through the body targeting key organs such as the heart and muscles, causing the heart to beat faster, blood pressure to rise, an increase in breathing rate, dilation of pupils and the inhibition of digestion and saliva production

Question 23

FIGHT OR FLIGHT

6TH STEP

Answer 23

When the threat has passed, the stress response is dampened by the parasympathetic branch of the ANS and the body is returned to its resting state (‘rest and digest’). The parasympathetic and sympathetic branches work in opposition to each others – their actions are antagonistic to each other.

Question 24

WHAT ARE NEURONS?

Answer 24

Neurons are nerve cells that process and transmit messages through electrical and chemical signals.
There are 100 billion neurons in the human nervous system.
80 billion of these are located in the brain.

Question 25

STRUCTURE OF NEURONS (SIZE)

Answer 25

There are different types of neurons, as we shall shortly see, and they vary in size from less than a millimetre long up to a metre long, but they all share the same basic structure.

Question 26

WHAT ARE THE TYPES OF NEURONS?

Answer 26

SENSORY MOTOR RELAY

Question 27

``` SENSORY NEURONS LOCATION? WHERE DO THEY CARY MESSAGES? WHAT ARE THEY? DENDRITES? AXONS? ```

Answer 27

Sensory neurons are located in clusters (known as ganglia) in the PNS. They carry messages from the PNS to the CNS. They are the nerve cells that are activated by sensory input from the environment. For example, when you touch a hot surface with your fingertips, the sensory neurons will be the ones firing and sending off signals to the rest of the nervous system about the information they have received. They have long dendrites and short axons.

Question 28

``` MOTOR NEURONS LOCATION? WHERE DO THEY CARY MESSAGES? WHAT ARE THEY? DENDRITES? AXONS? ```

Answer 28

Motor neurons are part of the CNS. These neurons transmit impulses from the CNS to muscles, glands and organs (collectively known as effectors) throughout the body, and so directly control all of our muscle movements. For example, when you touch a hot surface with your fingertips, the motor neurons will be the ones that move our hand away from the hot surface. They have short dendrites and long axons. Their axons are so long they actually do form part of the PNS, even though the cell bodies of the motor neurons are found in the CNS.

Question 29

``` RELAY NEURONS LOCATION? WHERE DO THEY CONNECT? HOW MANY ARE THERE? DENDRITES? AXONS? ```

Answer 29

Relay neurons connect the sensory neurons to the motor neurons. They are found in the brain, visual system and spinal cord. They have short dendrites and long axons. Relay neurons make up 97% of all neurons.

Question 30

SYNAPTIC TRANSMITION | WHAT IS EACH NEURON SEPARATED BY?

Answer 30

Each neuron is separated from the next by an extremely tiny gap. When the electrical impulse reaches the end of the neuron, the message needs to ‘get across’ the synapse to allow the neurons to communicate the message with each other.

Question 31

WHAT IS SYNAPTIC TRANSMITTION?

Answer 31

Synaptic transmission refers to the process by which neighbouring neurons communicate with each other. This is done by sending chemical messages across the synapse. So while signals within neurons are transmitted electrically, signals between neurons are transmitted chemically.

Question 32

WHATS EXCITATION AND INHIBITION?

Answer 32

Neurotransmitters have either an excitatory or an inhibitory effect on the neighbouring neuron. For example, adrenaline causes excitation of the postsynaptic neuron by increasing its positive charge and making it more likely to fire. Whereas serotonin causes inhibition in the receiving neuron, resulting in the neuron becoming more negatively charged and therefore less likely to fire.

Question 33

SUMMATION | SO WHETHER A POSTSYNAPTIC NEURON FIRES OR NOT IS DECIDED BY?

Answer 33

The process of summation.

Question 34

SUMMATION | WHAT INFLUENCES ARE ADDED TOGETHER?

Answer 34

The excitatory and inhibitory influences are ‘added together’.

Question 35

SUMMATION | WHEN IS IT MORE OR LESS LIKELY TO FIRE?

Answer 35

If the overall effect is excitatory then the postsynaptic neuron is more likely to fire. And if the overall effect is inhibitory, then it is less likely to fire.

Question 36

SUMMATION | WHEN IS THE ACTION POTENTIAL OF THE POSTSYNAPTIC NEURON TRIGGERED?

Answer 36

The action potential of the postsynaptic neuron is only triggered if the sum of the excitatory and inhibitory influences reaches the ‘firing threshold’.