The Brain and Nervous System

Question 1

Human Nervous System

Answer 1

network of nerve cells + fibers which transmits nerve impulses (messages) btwn parts of the body. Hierarchal structure reacts to changes both outside + inside the body.
Receives + processes sensory info. from the environment, + transmits motor info. around the body, that, in turn, determine our reaction to environmental stimuli.

Question 2

Division of Nervous System

Answer 2

Divided into a number of branches and divisions. NS also interacts w + influences other branches.

1. The Central Nervous System
2. The Peripheral Nervous System

Question 3

Central Nervous system

Answer 3

composed of brain + spinal cord. Processes sensory info. to activate appropriate actions.

• Brain receives + processes info. + co - ordinates a response.
• Spinal cord connects brain to rest of the body.
  1. Sends info. from sensory neurons in various parts of body to brain.
  2. Relays motor commands back to muscles + organs via motor neurons.

Question 4

Peripheral Nervous System

Answer 4

Connected to the spinal cord + consists of all nerves outside the Central NS. Carries sensory info. from body to central NS + motor info. from the central NS to the body. Consists of Somatic NS + Autonomic NS. Central NS + Peripheral NS work together.

Question 5

Somatic Nervous System

Answer 5

transmits sensory info. to central NS + carries out its motor commands. somatic NS = involved in voluntary muscle movements, so it is often called the ‘voluntary nervous system’.

Question 6

Autonomous system

Answer 6

response for automatic responses. Carries info. btwn the central NS+ carries info. btwn the central NS + internal bodily structures (e.g. heart, lungs, glands) that carry out basic life processes =. Divide into 2 main systems: sympathetic and parasympathetic.

Question 7

Sympathetic Nervous System

Answer 7

readies the body for the ‘fight or flight’ response when its exposed to threats. (e.g. predator).
e.g. stops digestion, increases heart rate, dilates pupils, diverts blood away from the stomach to muscles (which may need it more).

Question 8

Parasympathetic Nervous System

Answer 8

Supports more mundane, or routine activities, that maintain the body’s store of energy (e.g. regulating blood sugar levels, secreting saliva).
When a threat has passed, the parasympathetic NS resumes control from the sympathetic NS.

Question 9

Key Stages of Neural Communication

Answer 9

(Read The Dingo’s Research).

1. Resting potential
2. Threshold
3. Depolarization (Action Potential)
4. Repolarization

Question 10

Resting Potential

Answer 10

Neuron is not sending electrical signals.
Inside of neuron is negative (relative to the outside) = polarized.
Voltage inside cell = -70mV
(SOAPI PONI)
Sodium Outside And Potassium Inside.
Positive Outside, Negative Inside.

Question 11

Threshold

Answer 11

Increases charge of cell because neurotransmitters binding at dendrite receptors. (-70 –> -65 –> -60…).
Once -55mV threshold is reached, neuron will fire ‘all or nothing’ event, which causes sodium channels to open.

Question 12

Depolarization

Answer 12

After threshold is reached, depolarization occurs. Action potential/electrical impulse is being sent. Positively charged Na+ channels open, and Na+ rushes in. –> the cell becomes positive. +30mV –> 40mV. Cell which was polarized (i.e. positive on outside, negative on inside) now reverses that polarization. The process only occurs in one section of the cell at a time before triggering the adjacent section.

Question 13

Repolarization

Answer 13

(reset). K+ channels open. K+ rushes out of the cell. Na+ pumps remove Na+. Charge returns to -70mV to be at resting potential again.

Question 14

Corpus Callosum

Answer 14

Bridge of nerve tissue that connects two hemispheres.

Allows communication between both hemispheres.

Question 15

Frontal Lobe (inc. Primary Motor Cortex)

Answer 15

Other Functions: planning, judgements, behaving, impulse controls, personality, feeling.

Primary motor cortex:

• controls voluntary bodily movements of dskeletal muscles.
• organised contra-laterally
• parts higher on body are controlled by lower parts of the primary motor cortex and vice versa.
• areas of the body that require greater dexterity and complexity of movement have more area of cerebral cortex devoted to them.

Question 16

Broca’s Area (inc. Broca’s aphasia)

Answer 16

Region in the frontal lobe of the left hemisphere of human brain with functions linked to speech production. linked to: producing articular speech.

Broca’s Aphasia (production of speech): an impairment in language production or comprehension brought about by neurological damage. Characterized by non fluent speech. Speech perception is not affected and language comprehension is normal.

Question 17

Temporal Lobe (inc. Primary Auditory Cortex)

Answer 17

Association Areas: Memory (linked to hippocampus and associated with linking emotions to memory and determining appropriate emotional response to memory). Involved in face and object recognition.

Primary Auditory Cortex:

• The auditory cortex is situated in the temporal lobe.
• Critical role in ability to perceive sound.
• Also thought to be involved in higher-level auditory processing, such as recognising aspects of sounds that are specific to speech.
• Verbal sounds are mainly processed in the left hemisphere.
• Non-verbal (e.g. music) is mainly processed in the left hemisphere.

Question 18

Wernicke’s Area (inc. Wercnicke’s Aphasia)

Question 19

Auditory Cortex

Question 20

Occipital Lobe (inc. Primary visual cortex)

Question 21

Parietal Lobe (inc. Primary somatosensory cortex and Spatial Neglect)