CHAPTER 13 TEST REVIEW

Question 1

four main brain regions

Answer 1

Cerebrum
Diencephalon
Brainstem
Cerebellum

Question 2

Clinical View: Traumatic Brain Injuries

Answer 2

Traumatic brain injury (TBI)
* Acute brain damage occurring as a result of trauma

Concussion
* Most common type of TBI
* Temporary loss of consciousness, headache, drowsiness,
confusion, and amnesia possible
* May have cumulative effect on intellect, personality, mood

Contusion
* Bruising of brain due to trauma

Second impact syndrome (2nd injury before 1st resolves)
* Develop severe brain swelling
Progesterone is possibly therapeutic for TBI

Question 3

Clinical View: Neural Tube Defects

Answer 3

Serious developmental deformities of brain, spinal cord, meninges
Risk lowered by taking Vitamin B12 and folate in pregnancy

Anencephaly
* Substantial or complete absence of a brain
* Infant dies soon after birth

Spina bifida
* Failure to close caudal portion of neural tube
* Spina bifida cystica
* Almost no formation of vertebral arch; large cyst in back
* Often causes paralysis of lower limbs
* Spina bifida occulta
* Partial defect of bony arch
* Less serious, more common

Question 4

Clinical View: Epidural and Subdural Hematomas

Answer 4

Epidural hematoma
* Pool of blood in epidural space of brain
* Usually due to severe blow to the head
* Adjacent brain tissue distorted and compressed
* Can lead to severe neurological injury or death unless
bleeding stopped and blood removed

Subdural hematoma
* Hemorrhage in subdural space
* Typically from ruptured veins from fast rotational head
movement
* Compression of brain tissue, occurs more slowly than
epidural hematoma

Question 5

Clinical View: Meningitis and Encephalitis

Answer 5

Meningitis
* Inflammation of the meninges, typically caused by viral or
bacterial infections
* Symptoms—fever, headache, vomiting, stiff neck
* Pain from meninges sometimes referred to posterior neck
* May result in brain damage and death if untreated
* Bacterial meningitis with more severe symptoms

Encephalitis
* Inflammation of the brain, most often from viral infections
* Symptoms – drowsiness, fever, headache, neck pain, and
may result in death

Question 6

Clinical View: Hydrocephalus

Answer 6

Pathologic condition of excessive CSF
Often leads to brain distortion
May result from obstruction in CSF restricting reabsorption
May result from intrinsic problem with arachnoid villi
In a young child, head enlarged with possible neurological
damage
May be treated surgically
* Implant shunts that drain CSF to other body regions

Question 7

Clinical View: Autism Spectrum Disorder

Answer 7

Autism affects 1 in 88 U.S. children
Characterized by social and communication difficulties
Severity varies across autism spectrum
* Best predictors of independent adulthood are intelligence
and communication ability
Specific causes unknown
* Genetic, environmental, and biochemical factors have
been explored
* Males have four times higher incidence than females
* Vaccines found not to be a factor

Question 8

Clinical View: Epilepsy and Cerebral Lateralization

Answer 8

Epilepsy
* Neurological disorder
* Neurons transmitting action potentials too frequently and
rapidly
* Usually controlled by medications, but may require
surgical removal of part of brain
* In most severe cases, may require hemispherectomy: removal of
side of brain responsible for seizure activity
* Remaining hemisphere able to take over some functions of missing
hemisphere

Question 9

Clinical View: Cerebrovascular Accident

Answer 9

• Reduced blood supply to part of brain
• Due to blocked arterial blood vessel or hemorrhage
• May cause brain tissue death if prolonged for several
  minutes
• Symptoms of blurred vision, weakness, headache,
  dizziness, walking difficulty
• Affects opposite side of body
• Brief episode is a transient ischemic attack (TIA)

Question 10

Clinical View: Brain Disorders

Answer 10

Headache
* Due to dilated blood vessels in skull or muscle contraction
* Migraine headaches: severe, recurring, often unilateral
* Not true brain disorder, but may accompany them

Cerebral palsy
* Group of neuromuscular disorders
* Result from damage to infant brain before, during, or right
after birth
* Impairment of skeletal muscle, sometimes mental
retardation

Huntington disease
* Hereditary disease affecting cerebral nuclei
* Rapid, jerky, involuntary movements
* Intellectual deterioration
* Fatal within 10 to 20 years after onset

Parkinson disease
* Affects muscle movement and balance
* Stiff posture, slow voluntary movements, resting tremor
* Caused by decreased dopamine production in substantia
nigra

Question 11

Clinical View: Effects of Alcohol and Drugs on the
Cerebellum

Answer 11

Variety of drugs can impair cerebellar function
* Includes alcohol
* Symptoms
* Disturbance of gait
* Loss of balance and posture
* Inability to detect proprioceptive information

Question 12

Clinical View: Pathologic States of Unconsciousness

Answer 12

Fainting: brief loss of consciousness
* Often signals inadequate cerebral blood flow due to low
blood pressure

Stupor: arousable only to extreme stimuli
* Accompanies some metabolic disorders, liver or kidney
disease, brain trauma, or drug use

Coma: deep and profound unconsciousness; nonresponsive
* Causes include severe head injury, metabolic failure, CVA,
very low blood sugar, or drugs

Persistent vegetative state: Lack of thought and awareness
but noncognitive brain functions continue
* Some spontaneous movements possible

Question 13

Clinical View Alzheimer Disease: The “Long Goodbye”

Answer 13

Leading cause of dementia in developed world
Slow, progressive loss of higher intellectual function
Usually starts after age 65
Changes in mood and behavior
Eventual loss of memory and personality
Underlying cause unknown
* Significance of beta amyloid plaques and tau tangles is
debated
No cure, some medications to help slow course
Seems identifiable with positron emission tomography (PET)
Loss of sense of smell may be an early sign of the disease

Question 14

Clinical View: Amnesia

Answer 14

Partial or complete loss of memory
Usually temporary and affecting only a portion of experiences
Causes
* Psychological trauma
* Direct brain injury
Type and degree of recovery
* Depends on part of the brain damaged
Damage to thalamus and limbic structures, especially
hippocampus, disrupts or prevents formation of new
memories

Question 15

Clinical View: Dyslexia

Answer 15

Inherited learning disability
Problems with single-word decoding
Individuals with trouble reading, writing, and spelling
Level of reading competence below expected intelligence
Improvement in some individuals with time
May be form of disconnect syndrome
* Impaired transfer of information through corpus callosum

Question 16

embryology of the brain

Answer 16

Primary brain vesicles
form by late 4th week from
cranial neural tube
* Forebrain =
prosencephalon
* Midbrain
=mesencephalon
* Hindbrain =
rhombencephalon

secdoary brain vesicles form
by 5th week
* Telencephalon
* Diencephalon
* Mesencephalon
* Metencephalon
* Myelencephalon

Question 17

gray/white matter

Answer 17

Gray matter made of neuron cell bodies, dendrites, and
unmyelinated axons

White matter consists of myelinated axons

Question 18

meninges

Answer 18

Three connective tissue layers
Separate and support soft tissue of brain
Enclose and protect blood vessels supplying the brain
Help contain and circulate cerebrospinal fluid
From deep to superficial
* Pia mater
* Arachnoid mater
* Dura mater

Question 19

ventricles

Answer 19

Cavities within the brain
Lined with ependymal cells
Contain cerebrospinal fluid
Connect with each other and with spinal cord’s central
canal

Four ventricles within brain
Two lateral ventricles
Third ventricle
Fourth ventricle

Question 20

CSF-characteristics/formation

Answer 20

Clear, colorless liquid surrounding CNS
Circulates in ventricles and subarachnoid space

Functions:
* Buoyancy – reduces brain’s apparent weight by 95%
* Protection – provides a liquid cushion
* Environmental stability – transport of nutrients / wastes and
protects against fluctuations

Question 21

CSF-formation

Answer 21

Formed by choroid plexus in each ventricle
* Layer of ependymal cells and blood capillaries (within pia)
* Blood plasma is filtered through capillary and modified by
ependymal cells
* Compared to plasma, CSF has more Na+, Cl–; less K+, Ca2+,
glucose
* In addition, ependymal cell secretions and interstitial fluid
from subarachnoid space help make up CSF

CSF is continually formed and reabsorbed
* Excess CSF flows into arachnoid villi and drains into
dural venous sinuses
* An arachnoid granulation is a collection of these villi

Question 22

BBB

Answer 22

Functions of blood-brain barrier (BBB)
* Regulates which substances enter brain’s interstitial fluid
* Helps prevent neuron exposure to harmful substances
* Drugs, wastes, abnormal solute concentrations
* Note: some drugs can pass and affect the brain (for example,
alcohol

BBB composed of specialized capillaries
* Endothelial cells are connected by many tight junctions
* Walls have a thick basement membrane
* Wrapped by perivascular feet of astrocytes

BBB reduced in certain locations for functional reasons
* Choroid plexus needs to produce CSF
* Hypothalamus and pineal gland need to secrete hormones

Question 23

Motor areas

Answer 23

• Housed within frontal lobes
• Primary motor cortex located in precentral gyrus
• Also called somatic motor area
• Controls skeletal muscle activity on opposite side of body
• Project contralaterally (opposite side) within brainstem or spinal cord
• The controlled body regions map as a motor homunculus
• Distorted proportions of the body reflect amount of cortex dedicated to
  each part
• For example, hands are large on homunculus because large area of
  brain controls their precise movements

Motor speech area (Broca area)
* Located in inferolateral portion of left frontal lobe (in most people)
* Controls movements for vocalization
* Frontal eye field
* On superior surface of middle frontal gyrus
* Regulates eye movements needed for reading and binocular vision
* Premotor cortex (somatic motor association area)
* Located anterior to premotor cortex
* Coordinates learned, skilled activities

Question 24

sensory areas

Answer 24

Primary somatosensory cortex
* Located in postcentral gyrus of parietal lobes
* Receives somatic sensory information from
* Proprioceptors, touch, pressure, pain, temperature receptors
* Areas of the body sending input can be mapped as a sensory
homunculus
* Distorted proportions reflect the amount of sensory information collected
from that region
* Large regions for lips, fingers, genital regions

Somatosensory association area
* Immediately posterior to postcentral gyrus (in parietal lobe)
* Integrates touch information allowing us to identify objects by fee

Primary visual cortex
* Located within occipital lobe; receives, processes, stores visual
information

Visual association area
* Surrounds primary visual cortex; integrates and interprets color,
form, to allow identification/recognition of things (for example,
faces)

Primary auditory cortex
* Located within temporal lobe; receives, processes, stores auditory
information

Auditory association area
* Located in temporal lobe; integrates and interprets sounds

Primary olfactory cortex
* Located within temporal lobe
* Receives, processes, stores odor information

Primary gustatory cortex
* Located within insula
* Receives, processes, stores taste information

Question 25

hypothalamus—functions

Answer 25

Functions of the hypothalamus
* Control of autonomic nervous system
* Control of endocrine system
* Regulation of body temperature
* Food intake
* Water intake
* Sleep-wake rhythms
* Emotional behavior

Question 26

parts of the brainstem—-functions

Answer 26

Connects cerebrum, diencephalon, and cerebellum to
spinal cord
* Contains ascending and descending tracts
* Contains autonomic nuclei, nuclei of cranial nerves, and
reflex centers
* Consists of the midbrain, pons, and medulla oblongata

Question 27

functions of the cerebellum

Answer 27

Cerebellum coordinates and “fine-tunes” movements
* Ensures muscle activity follows correct pattern

• Stores memories of previously learned movements
• Regulates activity along voluntary and involuntary motor
  paths
• Adjusts movements initiated by cerebrum, ensuring
  smoothness
• Helps maintain equilibrium and posture
• Receives proprioceptive information from muscles and joints
• Continuously receives motor plans and sensory feedback
• May generate error-correcting signals to be sent to premotor and
  primary motor cortex
• Regulate behavioral expression and cognitive skills
• Language processing and retrieval

Question 28

limbic system

Answer 28

Limbic system: the emotional brain
* Composed of multiple cerebral and diencephalic structures
that process and experience emotions

Question 29

EEG

Answer 29

Electroencephalogram (EEG): electrodes attached to head
to record brain activity

• Used in studies of sleep, brain lesions, coma, vegetative
  state
• Used to evaluate epilepsy: repeated seizures
• Seizures may involve blackouts, muscle spasms, shaking
• Activity occurs with different frequencies designated by
  Greek letters
• Alpha and beta waves common in wakefulness
• Delta and theta waves common in sleep
• Electrodes are placed over many spots on the head to
  examine the location of different types of brain activity

Question 30

sleep

Answer 30

Sleep: natural, temporary absence of consciousness
* Less cortical activity, vital brainstem functions maintained
* Sleep stages characterized by EEG frequency and eye
movements

• Non-REM sleep: slower frequency brain waves
• Takes up about 75% of total sleep time
• Important for growth, rest, energy conservation, and strength renewal

REM (rapid eye movement) sleep: brain is active, eyes move
* Takes up about 25% of total sleep time

Sleep requirements change through lifespan
* Infants need 17 to 18 hours; teens: 8.5 to 9.5 hours;
adults: 7 to 8 hours

Lack of sleep is unhealthy
* Associated with depression, poor memory, poor immune
function

Insomnia: difficulty in falling asleep or staying asleep
* More common as we age

Sleep apnea: breathing interruptions during sleep
* Frequent awakenings = lack of sleep
* Treated with CPAP (continuous positive airway
pressure) mask

Question 31

types of memory

Answer 31

Sensory memory
* Associations based on sensory input (for example, smell of café)
that last for seconds

Short-term memory (STM)
* Limited capacity (about seven bits of information)
* Brief duration (seconds to hours)

Long-term memory (LTM)
* Can be encoded from short-term memory if information repeated
* May exist indefinitely, but can be lost if not retrieved occasionally

Question 32

language

Answer 32

Language involves reading,
understanding, speaking, and
writing words
* Wernicke area interprets
language
* Motor speech (Broca)
area initiates speech motor
program
* Primary motor cortex
signals motor neurons to
produce speech

Question 33

cranial nerves/innervations

Answer 33

CN I Olfactory Nerve
Sensory nerve for olfaction (smell)

CN II Optic Nerve
Sensory nerve for vision

CN III Oculomotor Nerve
Motor nerve that controls muscles that move eye, lift
eyelid, change pupil diameter, change lens shape

CN IV Trochlear Nerve
Motor nerve that controls superior oblique eye muscle

CN V Trigeminal Nerve
Mixed nerve that receives somatic sensation from face;
controls muscles involved in chewing

CN VI Abducens Nerve
Motor nerve that controls lateral rectus muscle that abducts
eye

CN VII Facial Nerve
Mixed nerve that controls muscles of facial expression and
conducts taste sensations from tongue

CN VIII Vestibulocochlear Nerve
Sensory nerve involved in hearing and equilibrium

CN IX Glossopharyngeal Nerve
Mixed nerve that receives taste and touch from tongue;
motor control of a pharynx muscle

CN X Vagus Nerve
Mixed nerve that
controls muscles
in pharynx and
larynx

CN XI Accessory Nerve
Motor nerve that controls muscles of neck, pharynx

CN XII Hypoglossal Nerve
Motor nerve that controls tongue muscles