Chapter 2 - Biological Bases of Behaviour

Question 1

What is an axon?

Answer 1

Part of a neutron that transmits information from the cell body to other neurons, or cells in glands or muscles.

Question 2

What is a soma/cell body?

Answer 2

Part of the neuron that contains the nucleus. The soma integrates neural information from dendrites and sends it to the axon.

Question 3

What is a dendrite?

Answer 3

A fine branch that stretches from the soma, which receives incoming information from other neurons and transmits it to the soma.

Question 4

What is myelin sheath?

Answer 4

A layer that protects the axon and assists with a fast transmission of nerve impulses.

Question 5

What are the nodes of Raviner?

Answer 5

Gaps between myelin sheath that speed the transmission of electrical signals.

Question 6

Define synapse.

Answer 6

Point of connection between two neurons where electrical or chemical signals are passed to other neurons.

Question 7

Define axon terminal.

Answer 7

Part of the nerve cell that makes synaptic connections with other neurons.

Question 8

What are neurotransmitters?

Answer 8

Chemical agents released by neurons to stimulate other nerve, muscle or gland cells.

Question 9

Describe the major functions of the Frontal Lobe.

Answer 9

Primary Motor Cortex controls voluntary movement, abstract thoughts, personality traits and regulates emotions.

Question 10

Describe the major functions of the Parietal Lobe.

Answer 10

Primary Somasensory Cortex integrates sensory information regarding touch, temperature and enables one to position their body in space (spatial reasoning)

Question 11

Describe the major functions of the Temporal Lobe.

Answer 11

Primary Auditory Cortex receives and processes verbal and non-verbal auditory information.

Question 12

Describe the major functions of the Occipital Lobe.

Answer 12

Primary Visual Cortex receives and processes visual information (e.g.. colour and shape)

Question 13

Describe the Hindbrain, mentioning its functions and the parts of the brain that comprise it.

Answer 13

Parts: Pons, Medulla Oblongata and Cerebellum
Function: Controls autonomic body systems, such as heart rate, breathing, sleep patterns and bladder function.

Question 14

Describe the Midbrain, mentioning its functions and the parts of the brain that comprise it.

Answer 14

Parts: Tectum and Tegmentum
Functions: Controls vision, hearing, motor control, sleep/wake (alertness) and temperature regulation. The midbrain receives sensory information from neutrons and sends them to higher brain regions to illicit a response.

Question 15

Describe the Forebrain, mentioning its functions and the parts of the brain that comprise it.

Answer 15

Parts: Amygdala, Hippocampus, Thalamus, Hypothalamus and Cerebral Cortex (4 lobes)
Functions: Regulates the release of hormones (which control body temperature, biological clock etc.) and filters sensory information and passes it to the appropriate part of the brain for processing (lobes in forebrain).

Question 16

Explain the functions of the left and right hemispheres of the brain.

Answer 16

Left: manages verbal functions (reading, writing ,recognition of words, speaking ) and analytical/step-by-step tasks (logical reasoning, maths problems, baking a cake). Lobes on the left hemisphere control functions on the right side of the body (contralateral).

Right: manages non-verbal functions that do not depend on language (spatial/visual reasoning eg. jigsaw puzzles, creative thinking, facial recognition) .Lobes on the right hemisphere control functions on the left side of the body (contralateral).

While hemispheres do have specialities, they do not function separately as they are joined by the Corpus Callosum.

Question 17

What is the Corpus Callosum’s function?

Answer 17

Combines, motor, cognitive and sensory functions with axons that connect the two hemispheres in the forebrain.

Question 18

Describe an external recording method for investigating brain function, identifying strengths and limitations.

Answer 18

Electroenphalography (EEG)
- uses electrodes attached to the scalp to detect and amplify electrical brain activity
Strengths:
- observes activity in the whole brain
- studies different states of consciousness eg. awake,sleeping,dreaming
- different patterns show epilepsy or tumours
Limitations:
- does not produce images
-cannot detect the area of the brain responsible for brain activity

Question 19

Describe two still picture methods for investigating brain function, identifying strengths and limitations.

Answer 19

1. Computed Tomography (CT)
   - x-ray scans brain at different angles
   information is computerised, showing cross-sectional pictures of the brain
   Strengths:
   - detects tumours and strokes
   - looks at abnormalities in the brain’s structure that may be linked with mental illness
   Limitations:
   - does not show brain activity and functions
2. Magnetic Resonance Imaging (MRI)
   - uses strong magnetic fields to produce 3D images form which 2D slices can be seen
   Strengths:
   - images have a higher spatial resolution than CT
   - shows cancerous and non-cancerous tissue
   Limitations:
   - cannot be used if metal is in the body (eg. pacemaker)
   - uncomfortable and time-concsuming-patients lay still in machine for 20-30 mins

Question 20

Describe two dynamic picture methods for investigating brain function, identifying strengths and limitations.

Answer 20

1. Functional Magnetic Resonance Imaging (fMRI)
   - measures changes in oxygen levels inthe brain using contrasts (indicates blood flow) with the assumption that increased brain activity in an area depends on the delivery of more blood
   Strengths:
   - non-invasive
   - high spatial resolution
   Limitations:
   - hard to tell what part of the brain is active as it measures blood flow, which is slower than neural activity
2. Position Emission Tomography (PET)
   - provides images of high, medium and low brain activation different parts of the brain - injected with a radioactive glucose solution
   Strengths:
   - shows parts of the brain that are active during different tasks
   - more sensitive than MRI or CT
   Limitations:
   - risks caused by radioactive injection
   - expensive procedure which requires highly-trained staff

Question 21

Define and give examples of depressants, stimulants and hallucinogens.

Answer 21

Depressant (eg. alcohol): A drug that slows the activity of the Nervous System and bodily functions.
Stimulant (eg. amphetamines): A drug that excites the Nervous System and arouses bodily functions.
Hallucinogen (eg. marijuana): A drug that changes perceptions and gives sensory images without input from the senses.

Question 22

What are the physical and psychological effects of cannabis?

Answer 22

Pyhsical: Bronchitis, Lung Cancer, stroke
Psychological: hallucinations, feeling of euphoria, relaxation, louder noises, vivid colours, paranoia

Question 23

What are the physical and psychological effects of alcohol?

Answer 23

Physical: liver Cirrhosis, weakened immune system, high blood pressure.
Psychological: loss of coordination and balance, slurred speech, loss of inhibitions and impaired memory

Question 24

What are the physical and psychological effects of amphetamines?

Answer 24

Physical: increased body temperature, irregular heartbeat, dry mouth/dehydration and increased blood pressure
Psychological: paranoia, aggression, increased feelings of power and talkativeness.

Question 25

What is a recreational drug?

Answer 25

A drug used without medical justification for its psychoactive effects.

Question 26

Define physical activity.

Answer 26

Bodily motion generated by the contracting of muscles which uses energy above the Basal Level.

Question 27

How can physical activity affect our wellbeing?

Answer 27

• exercise increases blood flow and lowers blood pressure, which increases during stress and decreases during relaxation.
• exercise increases the production of mood-boosting neurotransmitters eg. serotonin and endorphins

Question 28

What is an action-potential?

Answer 28

An action-potential occurs when a neuron sends information down an axon, away from the soma.