Chapter 11 - Nervous System

Question 1

Meninges and Layers of Meninges

Answer 1

membranes that protect brain and spinal cord due to lying between bone and soft tissues of the nervous system

Layers of Meninges:
○ Epidural space
- Dura mater: tough dense connective tissue
○ subdural
- Arachnoid: middle web like layer
○ Subarachnoid space containing cerebrospinal fluid
- Pia mater: attached to the surface of brain, spinal cord and contains blood vessels and nerves to nourish the CNS

Question 2

Cerebrospinal Fluid(CSF) and Ventricles

Answer 2

• CSF is produced in the 4 ventricles circulated through the brain and spinal cord
  
  • It is constantly being made and drained
  • Helps protect and brings nutrients to the CNS neurons
  • Maintains stable ionic concentrations
  • 2 lateral, 3rd ventricle and 4th ventricle

Question 3

CSF pressure:

Answer 3

interference with continuous secretion and circulation of CSF can increase intracranial pressure which can lead to collapse of cerebral blood vessels or injury of the brain tissue
- Pressure can be relieved by insertions of a drain into the subarachnoid space

Question 4

Traumatic Brain Injury(TBI) and the 3 types

Answer 4

a result of mechanical force(fall, attack, incident
- Concussion: mild TBI resulting from a onetime injury with no lasting symptoms
- Chronic Traumatic Encephalopathy: sports related, mild repetitive TBI from small injuries over time which lead to symptoms beginning years later
- Blast related brain injury: sever TBI resulting from explosions in combat situations leading to cognitive decline years after injury

Question 5

4 Portions of Brain

Answer 5

○ Cerebrum(2 hemispheres connected by corpus callosum)
○ Cerebellum
○ Diencephalon (thalamus and hypothalamus)
○ Brainstem (midbrain, pons, medulla oblongata)

Question 6

Features of Cerebrum

Answer 6

§ Gyri: ridges
§ Sulci: grooves
§ Fissures: longitudinal and transverse
§ Grey matter contains neuron cell bodies which are unmyelinated
§ White matter is composed of myelinated axons connecting to the cell bodies in the grey matter

Question 7

Sensory Areas of Cortex and their location

Answer 7

Speech:
- Wernicke’s area(posterior superior temporal lobe)
Cutaneous sensory area: interpretation of skin sensations
- Parietal lobe
Visual area:
- Occipital lobe
Auditory area:
- Temporal lobe
Taste:
- Base of insula

Question 8

Association Areas of the Cortex

Answer 8

regions not primarily motor or sensory but connect to each other and other structures in the brain

- Frontal lobe: concentrating, planning, problem solving
- Parietal Lobe: understanding speech and choosing words
- Temporal Lobe: interpreting sensory experiences(speech, reading) storing memories
- Occipital Lobe: analyzing and combining visual images Insula: translating sensory information into emotional responses

Question 9

Motor Areas of the Cortex(3)

Answer 9

Primary Motor Cortex: Frontal lobes controls voluntary muscles
- Crossing over of axons occur

Broca’s area: in the inferior frontal lobe and controls muscles needed for speech

Frontal Eye Field: superior frontal lobe controls voluntary movement of eyes and eyelids

Question 10

Hemisphere Dominance

Answer 10

we all have one hemisphere which is dominant and often it’s the left hemisphere for people(right handed)
- Dominant controls language skills in speech, writing, reading, verbal, analytical skills
- Non dominant controls nonverbal tasks, motor orientation in space, interpreting musical and visual patterns, emotional responses

Question 11

Long Term Potentiation

Answer 11

increase in neurotransmitter release and effectiveness on post synaptic transmission upon repeated stimulation

Question 12

Basal Nuclei

Answer 12

the basal ganglia which is a cluster of neuron bodies in the PNS that produce dopamine and control voluntary movement

Question 13

Parkinsons Disease

Answer 13

degeneration of neurons in the substantia nigra, resulting in less production of dopamine
- Creates symptoms such as tremors, rigidity, small handwriting, speech difficulties
- No treatments only meds to treat the symptoms

Question 14

Diancephalon

Answer 14

between the cerebral hemisphere and above the brainstem

- Thalamus: gateway for sensory impulses and channels impulses to appriopriate part of cerebral cortex for interpretation
- Hypothalamus: maintains homeostasis by linking nervous and endocrine systems

Question 15

Limbic System

Answer 15

several structures in the brain which controls emotional responses, feelings, behavior oriented toward survival

Question 16

4 F’s in Limbic System

Answer 16

• Fighting
  
  • Feeding
  • Feeling
  • Reproduction

Question 17

Brainstem

Answer 17

lowest part of the brain functionally and location wise which connects brain to the spinal cord

• Midbrain
• pons
• reticular formation

Question 18

Midbrain

Answer 18

contains bundles of fibers that join lower parts of brainstem
- Cerebral aqueduct: connects 3&4th ventricle
- Cerebral peduncles: main motor pathway
- Corpora quadrigemina: centers for visual and auditory reflexes
Red nucleus: role in postural reflexes

Question 19

Pons

Answer 19

relays nerve impulses between medulla oblongata and cerebrum and helps regulate rhythm of breathing

Question 20

Medulla Oblongata

Answer 20

conducts impulses between brain and spinal cord and controls cardiac vasomotor and respirator centers
- Injuries to this area is often fatal

Question 21

Reticular Formation

Answer 21

a complex network of nerve fibers throughout the brainstem which filters incoming sensory information and discarding the unimportant ones
- Decreased activity causes sleep

Question 22

Sleep

Answer 22

normal, recurring and reversible state of unconsciousness characterized by limited sensory input and inhibited skeletal muscle activity

Types of Sleep:
REM:
- Paradoxical: some areas are highly active
- Dreaming occurs

NREM:
- Person is tired
- No dreams
- Decreased activity of reticular formation
- 3 stages

Question 23

Cerebellum

Answer 23

integrates sensory information concerning position of body parts, coordinates skeletal muscle activity and maintains posture
- Abror vitae(white matter)
- Cerebella cortex(gray matter)

Question 24

Brain Waves

Answer 24

recordings of fluctuating electrical changes in the brain
Types of waves:
- Alpha: awake, resting
- Beta: active mental activity, under tension
- Theta: mostly in children, in adults during stress/sleep
- Delta: when your asleep

Question 25

Amyotrophic Lateral Sclerosis

Answer 25

involves degeneration of motor neurons in spinal cord, brainstem and cerebral cortex leading to speaking difficulties, dragging foot, clumsiness, fatigue, coordination issues and muscle twitches
- Cognitive function remains normal

Question 26

Spinal Cord Injuries

Answer 26

compression or distortion of the spinal cord resulting in damage or death of neurons
- Injury to ascending leads to loss of sensation
- Injury to descending leads to loss of movement
- Paralysis is from injury to both

Question 27

Peripheral Nervous System

Answer 27

nerves that connect the CNS to the rest of the body
- 12 pairs of cranial nerves
- 31 pairs of Spinal nerves

Question 28

Peripheral Nerve Structure

Answer 28

• Endoneurium: surrounds axons
  
  • Perineurium: surrounds bundles of axons in fascicles
    
    • Epineurium: surrounds

Question 29

Cranial Nerves, # and Basic Function

Answer 29

I - Olfactory: sense of smell
II - optic: sense of sight
III - oculomotor: movement and blinking of eyes
IV - trochlear: moving eyes up and down
V - trigemial: nerves to facial muscle and mastication muscles
VI - abducens: nerves to muscles in the eye
VII - facial: nerves to facial muscles
VIII vestibulocochlear: nerves for hearing and equilibrium
IX - Glossopharyngeal: nerves for muscles in swallowing and taste
X - Vagus: nerves for heart, larynth and gastro tract
XI - Accessory: nerves for neck muscles
XII - Hypoglossal: nerves for movement of tongue

Question 30

Optic Chiasma

Answer 30

the area where optic nerves from the eyes cross over to allow full sight even if one area of the brain is damaged

Question 31

Functions of the Spinal Cord

Answer 31

• Center for spinal reflexes(withdrawal reflexes, crossed extensor reflex, contraction reflex)
  - Conduit for impulses to and from the brain

Question 32

Spinal Cord

Answer 32

• Begins at the foramen magnum and terminates at the first and second lumbar vertebrae
  
  • Enlargements are areas where nerves go out to the limbs(cervical and lumbar regions)
  • Gray matter is on the inside arranged in horns
  • White matter is on the outside arranged in funiculus
  • Posterior roots contain sensory neurons
  • Anterior roots contain motor neurons

Question 33

Nerve Plexus

Answer 33

complex networks formed by anterior rami of spinal nerves. Various nerves are recombined so they all head to the same peripheral body part

Question 34

3 Main Plexus

Answer 34

Cervical Plexus: formed from C1-C4 spinal nerves which supply muscles and skin of the neck

Brachial Plexus: branches of C5-T1 which lie deep within the shoulders and supply muscles of arms and forearm

Lumbosacral Plexus: suppies motor impulses and blood to the thighs and legs

Question 35

Spinal Nerve Injuries

Answer 35

• Whiplash: sudden bending of the neck
  
  • Broken/dislocation of vertebra: results in damaged axons which can paralyze the diaphragm
  • Sciatica: compression of intervertebral disc in lumbar region resulting in pain in lower back, gluteal region
    
    • Carpal tunnel syndrome: repeated movements of hand inflame tendons that pass through the carpal tunnel.

Question 36

Autonomic Nervous System

Answer 36

• Controlled by hypothalamus

Divided into sympathetic and parasympathetic