CHAPTER 2

Question 1

Central Nervous System (CNS)

Answer 1

a major division of the nervous system comprising the brain and spinal cord, which receives sensory neural messages from and transmits motor neural messages to the PNS

Question 2

Brain

Answer 2

a complex organ contained within the skull that coordinates mental processes and behaviour, and regulates bodily activity

Question 3

Spinal cord

Answer 3

a cable of nerve tissue that extends from the brain, connecting it to the PNS and is composed of afferent and efferent tracts (SAME)

Question 4

Afferent tracts

Answer 4

transmit sensory messages from the PNS to the brain (sensory = afferent)

Question 5

Efferent tracts

Answer 5

transmit motor messages from the brain to the PNS (motor = efferent)

Question 6

Peripheral Nervous System (PNS)

Answer 6

a major division of the nervous system comprising every neuron in the body outside the CNS, and transmits neural messages between the CNS and the body

Question 7

Two subdivisions of the PNS

Answer 7

somatic and autonomic nervous systems

Question 8

Somatic nervous system

Answer 8

a division of the PNS that transmits neural messages related to voluntary motor movement

Question 9

What is the somatic nervous system comprised of?

Answer 9

sensory neural pathways and motor neural pathways

Question 10

Skeletal muscles

Answer 10

muscles connected to the skeleton that carry out voluntary motor movements

Question 11

Sensory receptors

Answer 11

nerve endings that detect sensations

Question 12

Motor neural messages

Answer 12

travel from the CNS to skeletal muscles via efferent pathways

Question 13

Sensory neural messages

Answer 13

travel from sensory receptors to the CNS via afferent pathways

Question 14

Autonomic nervous system

Answer 14

a division of the PNS that regulates visceral muscles, organs, and glands, and transmits neural messages to the CNS about their activity

Question 15

Visceral muscles, organs, and glands

Answer 15

muscles, organs, and glands not connected to the skeleton that are predominantly self-regulating and do not require conscious control

Question 16

Two subdivisions of the autonomic nervous system

Answer 16

Sympathetic and parasympathetic nervous systems

Question 17

Sympathetic nervous system

Answer 17

a division of the autonomic nervous system that activates visceral muscles, organs, and glands, preparing the body to respond to a threat or stressor

Question 18

Parasympathetic nervous system

Answer 18

a division of the autonomic nervous system that maintains the optimal and balanced functioning of visceral muscles, organs, and glands

Question 19

3 types of neurons

Answer 19

motor neurons, sensory neurons, interneurons

Question 20

Motor neurons (efferent)

Answer 20

transmit neural messages about motor movement from the CNS to the PNS

Question 21

Sensory neurons (afferent)

Answer 21

transmit neural messages about bodily sensations from the PNS to the CNS

Question 22

Interneurons

Answer 22

transfer neural messages between sensory neurons and motor neurons and make up the entirety of the CNS

Question 23

Dendrites

Answer 23

branched extensions of a neuron on which receptor sites are located

Question 24

Receptor sites

Answer 24

protein molecules on the dendrites of a neuron that receive neurotransmitters

Question 25

Soma

Answer 25

the cell body of a neuron, which contains the nucleus

Question 26

Myelin sheath

Answer 26

insulates the neuron and prevents disturbance from other neurons

Question 27

Axon

Answer 27

transmits electrical impulses from the cell body to the dendrites of other neurons

Question 28

Axon terminal

Answer 28

the ends of a neuron that release neurotransmitters into the neural synapse

Question 29

Conscious response

Answer 29

a deliberate and voluntary action that is initiated by the brain and performed intentionally by the body

Question 30

5 steps to how the somatic nervous system and the central nervous system interact to enable conscious responses

Answer 30

1. The sensory stimulus comes into contact with sensory receptors 2. This sensory neural message is transmitted to the brain 3. The brain processes this sensory information, coordinating and initiating a conscious motor response 4. This motor neural message is transmitted via efferent pathways to skeletal muscles 5. The skeletal muscles carry out the conscious motor response to the sensory stimulus

Question 31

Sensory receptors

Answer 31

nerve endings that detect internal sensations in the body and external sensations from the environment

Question 32

Unconscious response

Answer 32

an automatic and involuntary action that is performed by the body independently of the brain

Question 33

8 unconscious physiological sympathetic responses

Answer 33

1. Heart rate increases to increase blood flow 2. Breathing rate increases and lung airways expand to increase oxygenation 3. Pupils dilate to allow more light to enter the eyes 4. Adrenal glands secrete stress hormones, such as adrenaline 5. Sweat glands are activated 6. Digestion is inhibited 7. The bladder relaxes 8. The body releases more glucose

Question 34

8 unconscious physiological parasympathetic responses

Answer 34

1. The heart beats at a regular rate 2. Lung airways constrict to enable regular breathing rate 3. Pupils constrict according to external light levels 4. Adrenal glands do not secrete stress hormones 5. Sweat glands are regulated 6. Digestion occurs normally 7. Urination is controlled 8. The body releases less glucose

Question 35

Spinal reflex

Answer 35

an unconscious response to sensory stimuli that is initiated by interneurons in the spinal cord independently of the brain

Question 36

Why is the spinal reflex important?

Answer 36

it is a survival tool as it requires less processing than conscious responses because it is immediately initiated by the spinal cord in response to sensory stimuli, rather than consciously processed by the brain

Question 37

4 steps of the spinal reflex

Answer 37

1. A dangerous or harmful sensory stimulus is detected by sensory receptors, which transmit this sensory message via sensory neurons in the somatic nervous system to the spinal cord 2. An interneuron in the spinal cord immediately relays this sensory neural signal from a sensory neuron to a motor neuron as a motor neural signal, initiating an automatic and unconscious motor response 3. The motor message is transmitted via motor neurons in the somatic nervous system to skeletal muscles, which carry out this unconscious motor response to the dangerous or harmful sensory stimulus 4. The sensory message continues to travel via afferent tracts in the spinal cord to the brain, which then independently registers the sensation that triggered the spinal reflex