Nervous system functioning

Question 1

Define the Central Nervous System and its role.

Answer 1

(CNS) A major division of the nervous system consisting of all the nerves in the brain and spinal cord. It transmits sensory messages from the PNS to the brain and spinal cord and sends motor messages to the PNS.

Question 2

Define the Peripheral Nervous System and its role.

Answer 2

(PNS) A major divison of the nervous system consisting of all the nerves outside of the CNS. It transmits sensory information inwards to the CNS and carries motor messages from the brain outwards to the rest of the body.

Question 3

What is the role of the Spinal Cord?

Answer 3

A part of the CNS stretching from the base of the brain to the lower back. Transmits sensory information from the PNS to the brain and motor messages from the brain to the PNS.

Question 4

Define the Somatic Nervous System and its role.

Answer 4

(SNS) A division of the PNS that transmits sensory information received from receptor cells towards the CNS and motor messages from the CNS to skeletal nervous system.

Question 5

Define the Automatic Nervous System and its role.

Answer 5

(ANS) A division of the PNS that transmits motor messages from the brain to the body internal organs and glands and transmits messages back to the brain about the activity level of these organs and glands (involuntary).

Question 6

Define the Sympathetic Nervous System and its role.

Answer 6

(SYNS) A division of the ANS that alters the activity level of internal muscles, organs and glands to prepare our body for increased activity (high emotional or physical arousal).

Question 7

Define the Parasympathetic Nervous System and its role.

Answer 7

(PANS) A division of the ANS that maintains energy levels appropriate for for normal functioning. Calms us after physical periods of high arousal through changes in bodily functioning (PANS dominates over the SYNS).

Question 8

What is a conscious response?

Answer 8

A voluntary response that occurs as a result of communication between the brain and SNS.

Question 9

What is an unconscious response?

Answer 9

Responses that occur automatically by the ANS and the Spinal Cord before communication with the brain (involuntary responses to stimuli).

Question 10

Define a reflex action.

Answer 10

A simple automatic response that is hardwired into our nervous system. Allow us to rapidly respond to a potential danger without having to think about it.

Question 11

Define a spinal reflex and its role.

Answer 11

The simplest stimulus response that occurs in the Spinal Cord. A behaviour response pattern that occurs independently of the brain that allows us to, upon detecting intense sensations, quickly respond

Question 12

What are the 7 parts of the neuron?

Answer 12

Dendrites. Which receive incoming messages.
Soma. The main cell body that contains the nucleus.
Nucleus. The control centre of the neuron that contains the DNA.
Axon. The fibre that carries information to the Axon terminals.
Myelin Sheath. Fatty layer protecting axon which assists with delivery of the information quickly.
Nodes of Ranvier. Small gaps in the Myelin Sheath that increase the speed of transmission.
Axon Terminals. Fibres that link the dendrites of the pre and post synaptic neuron.

Question 13

Define synapse.

Answer 13

The gap between two neurons which messages are passed over.

Question 14

Define neurotransmitters.

Answer 14

A chemical messenger transmitted across the synapse (eg GABA or serotonin).

Question 15

Define synaptogenesis.

Answer 15

The process by which synapses are formed between neurons.

Question 16

Define synaptic pruning.

Answer 16

A process of removing weak, extra or unused synaptic connections so that neural transmission can be as efficient as possible.

Question 17

What are the 3 different types of neurons?

Answer 17

Sensory (afferent), Motor (efferent) and Inter neuron.

Question 18

Explain Motor Neurons.

Answer 18

Located mostly in the PNS, they carry commands from the brain to the body’s muscles, organs and glands to enable movement.

Question 19

Explain Sensory Neurons.

Answer 19

Located mostly in the PNS, they detect energy from the external environment and internal environment and carry information about it to the CNS.

Question 20

Explain Inter neurons.

Answer 20

Located mostly in the Spinal Cord, they carry information directly between sensory and motor neurons and are involved in reflex actions.

Question 21

Explain the Lock and Key analogy of neurotransmitters.

Answer 21

The neurotransmitters particular molecular shape fits in a particularly shaped molecular site (like how one specific key opens a lock).

Question 22

Define excitatory messages and inhibitory messages.

Answer 22

Excitatory messages are transmitted by neurotransmitters and stimulate the next neuron to fire.
Inhibitory messages are transmitted by neurotransmitters and make the next neuron less likely to fire.

Question 23

What is the role of the neurotransmitter GABA?

Answer 23

It is the primary inhibitory neurotransmitter. Overall effects are to calm or slow neural transmission and the body’s response.

Question 24

What is the role of the neurotransmitter Dopamine?

Answer 24

It is invloved in smooth and coordinated voluntary movements, learning, arousal and emotional experience. A lack of dopamine is associated with Parkinson’s disease.

Question 25

Explain Parkinson’s disease.

Answer 25

(PD) It is a chronic neruodegenerative disease which changes the brain through malfunction and deterioration of neurons which leads to impairment in movement.