The nervous system

Question 1

What are the functions of the nervous system?

Answer 1

• Monitors the internal and external environments
• Integrates sensory info
• coordinates voluntary and involuntary response of organ systems

Question 2

Name the receptors and what they respond to

Answer 2

Thermoreceptors- change in temp
Mechanoreceptors- mechanical pressure or distortion
Chemoreceptors- chemical change
Photoreceptors- light

Question 3

What is the CNS?

Answer 3

Central nervous system consisting of the brain and the spinal cord
Its function is to integrate and coordinate sensory data and motor commands

Question 4

What is the PNS?

Answer 4

All neural tissue outside the CNS
Relays sensory info to the CNS and carries motor commands to the peripheral tissues

Question 5

What is the afferent division?

Answer 5

The sensory information

Question 6

What is the efferent division?

Answer 6

The responses
Split into somatic n.s - skeletal muscle contraction and the autonomic ns consisting of parasympathetic and sympathetic

Question 7

What is the main structure of a multipolar neuron?

Answer 7

Dendrites, cell body (organelles), axon hillock, axon, axon terminal

Question 7

What is the function of the dendrites?

Answer 7

They are sensitive to sensory stimuli

Question 8

What are the 4 types of neuron?

Answer 8

Anaxonic, bipolar, unipolar, multipolar

Question 9

What is an anaxonic neuron?

Answer 9

Mainly found in the brain
small
No anatomic features to distinguish between dendrites from axon

Question 10

What is a bipolar neuron?

Answer 10

Rare
Special sense organs
1 dendrite and 1 axon with cell body between them

Question 11

What is a unipolar neuron?

Answer 11

Dendrites and axon are continuous with the cell body off to the side - most sensory neurons in the PNS

Question 12

What is a multipolar neuron?

Answer 12

2 or more dendrites with 1 axon
Most common in the CNS and all motor neurons in skeletal muscle control

Question 13

What is the spinal cord and its function?

Answer 13

A major passageway of sensory and motor impulses to and from the brain
It integrates info on its own and control spinal reflexes and automatic responses

Question 14

What is the difference between a fissure and a sulcus?

Answer 14

They are both grooves but a fissure is deeper

Question 15

What is grey matter?

Answer 15

Contains cell bodies and neuroglia cells

Question 16

What is white matter?

Answer 16

Consists of myelinated and unmyelinated neurons

Question 17

How does the central shape of the spinal cord change as we go down the body?

Answer 17

It decreases

Question 18

How many segments are in the spinal cord?

Answer 18

31

Question 19

What is a dermatone?

Answer 19

Each pair of spinal nerves monitor a specific region of the the body surface

Question 20

What is a dorsal root ganglia?

Answer 20

A bundle of neurons that bring sensory info (afferent) into the spinal cord

Question 21

What is a ventral root?

Answer 21

Contains axon of motor neurons (efferent)
Does bind with the dorsal to form a spinal nerve

Question 22

What are horns?

Answer 22

Projections of grey matter

Question 23

What is the cauda equina?

Answer 23

The sack of nerve roots at the lower end of the lumbar spinal cord

Question 24

What is the process of the reflex arc?

Answer 24

Arrival of stimulus, receptor, sensory neuron (dorsal root), info processing by CNS, activation of motor neuron (ventral root), effector , response

Question 25

What do golgi tendon organs do?

Answer 25

Sense tension in the tendon when the muscle contracts Has an inhibitive afferent neuron So high forces lead to decrease in muscle activation for protection

Question 26

What do the muscle spindles do?

Answer 26

Detect rate of change of muscle length Efferent neuron causes the spindle to contract to maintain tension so if it is stretching rapidly then a vigorous contraction occurs to prevent overstretching

Question 27

What are the 3 sections of the brain?

Answer 27

Reptilian - stem Mammalian - limbic system Higher brain - neocortex - emotional, logic, creativity

Question 28

What does the brain stem consist of?

Answer 28

Diencephalon Midbrain Pons Medulla oblongata Cerebellum

Question 29

What is the dienchepalon?

Answer 29

Consists of the thalamus which relays and processes sensory info and the hypothalamus which centers controlling emotions

Question 30

What is the mid brain?

Answer 30

Processes visual and auditory data Maintains consciousness

Question 31

What is the pons?

Answer 31

Relays sensory info to the cerebellum and thalamus

Question 32

What is the medulla oblongata?

Answer 32

Relays sensory info to thalamus and autonomic centre for visceral function

Question 33

What is the cerebullum?

Answer 33

Coordinates complex somatic motor patterns

Question 34

What is a gyrus?

Answer 34

A ridge on the cerebral cortex

Question 35

What does the cerebrum consist of?

Answer 35

Frontal lobe- (primary motor cortex- motor response) Temporal lobe- auditory association area Occipital lobe- visual association area Parietal - Primary sensory cortex- receiving and processing sensory info

Question 36

What are the biochemical protection methods for the brain?

Answer 36

Blood brain barrier Isolation of CNS from general circulation through variation in permeability of CNS capillaries (astrocytes)

Question 37

What are the physical protection methods for the brain?

Answer 37

Bones of the cranium Cranial meninges Cerebrospinal fluid

Question 38

Describe the cranial meninges

Answer 38

Layers of connective tissue Dura mater (Periosteal) then the dural sinus and the dura mater (meningeal layer) Arachnoid mater Pia mater - connective tissues between brain and protective layers

Question 39

Describe the cerebrospinal fluid

Answer 39

Surrounds all exposed surfaces of CNS Function - cushion, support, transport of nutrients and chemical messengers and waste products

Question 40

What are the 12 cranial nerves?

Answer 40

olfactory, optic, occulomotor, trochlear, trigeminal, abducens, facial, vestibulocochlear, glossopharyngeal, vagus, accessory, hypoglossal

Question 41

What is the olfactory nerve?

Answer 41

Sensor Receptor- olfactory epithelium in nasal cavity

Question 42

What is the optic nerve?

Answer 42

Sensor Receptor in the retina Input from receptors in the eye through optic foramina of the orbits

Question 43

What is the occulomotor nerve?

Answer 43

Motor Control eye movement Innervates 4 of the 6 extrinsic muscles

Question 44

What is the trochlear nerve?

Answer 44

Motor Moves the eye down and laterally

Question 45

What is the trigeminal nerve?

Answer 45

Sensor and motor Sensation in eyes, nose, forehead, structures of the mouth. Motor control of the chewing muscles

Question 46

What is the abducens nerve?

Answer 46

Motor Motor control for the lateral movement of the eye

Question 47

What is the facial nerve?

Answer 47

Sensor and motor Sensation of taste, motor control of facial expressions, tear gland and salivary glands

Question 48

What is the vestibulocochlear (acoustic) nerve?

Answer 48

Sensor Balance and hearing

Question 49

What is the glossopharyngeal nerve?

Answer 49

Sensor and motor Sensation of taste, motor control of pharyngeal muscles for swallowing

Question 50

What is the vagus nerve?

Answer 50

Sensor and motor Wide roles in abdomen and thorax Key in cv system

Question 51

What is the accessory nerve?

Answer 51

Motor Motor control of the neck and upper back muscles

Question 52

What is the hypoglossal nerve?

Answer 52

Motor Motor control of muscles in the tongue