Ch 11 Flashcards
Consists of brain and spinal cord:
CNS
What 4 things does the brain consist of?
2 cerebral hemispheres, diencephalon, brainstem, cerebellum
Connects the brain to the spinal cord:
brainstem
Membranes that protect brain and spinal cord; lie between bone and soft tissues of nervous system:
meninges
- Outer layer
- Tough, dense connective tissue
- Dural sinuses
- Epidural space
dura mater
- Middle layer; weblike
- Subarachnoid space contains cerebrospinal fluid (CSF)
arachnoid mater
- Inner layer; attached to surface of brain, spinal cord
- Blood vessels & nerves
- Nourishes CNS
pia mater
CSF is produced in 4 what?
ventricles
Interconnected cavities within cerebral hemispheres and brain stem:
ventricles
What are the 4 ventricles?
2 lateral ventricles (first and second), third, fourth
Cerebralspinal fluid is secreted by what?
choroid plexuses
Cerebralspinal fluid is ________ and _______.
nutritive and protective
What does cerebralspinal fluid help maintain?
stable ionic concentrations
Result of mechanical force such as fall, attack, accident, sports injury:
TBI
A mild TBI; typically results from a one-time injury and has no lasting symptoms:
concussion
Sports-related, mild repetitive TBI; results from many small injuries over time; symptoms begin years later and have long-lasting effects on memory and behavior:
CTE
Severe TBI, resulting from explosions in combat situations; often leads to cognitive decline years after injury:
blast-related brain injury
- Stroke
- Sudden interruption in blood flow
- Brain tissue die
- Transient ischemic attack is a brief interruption of blood flow to brain
cerebrovascular accident
- Motor impairment at birth
- Caused by blocked cerebral blood vessels during development
- Seizures
- Learning disabilities
cerebral palsy
What are the 4 main portions of the brain?
- cerebrum
- diencephalon
- cerebellum
- brainstem
What is the largest part of the brain?
cerebrum
What is the cerebral hemisphere separated by?
fall cerebri
What connects the cerebral hemisphere?
corpus callosum
Ridges or convolutions:
gyri
Shallow grooves in surface; central sulcus:
sulci
Deep grooves in surface:
fissure
Separates the cerebral hemisphere:
longitudinal fissure
Separates cerebrum from cerebellum:
transverse fissure
Thin layer of gray mater, which makes up outermost layer of the cerebrum:
cerebral cortex
What contains almost 75% of neuron cell bodies in nervous system?
cerebral cortex
What lies under the cerebral cortex and makes up most the cerebrum?
white mater of cerebrum
Contains bundles of myelinated axons that connect neuron cell bodies in cerebral cortex to other portions of nervous system:
white mater of cerebrum
Cerebral cortex is responsible for:
higher mental functions
The cerebral cortex can be divided into:
sensory, association, and motor areas
(sensory areas of the cortex)
- Parietal lob
- Interprets sensations on skin
cutaneous sensory area
(sensory areas of the cortex)
- Temporal/parietal lob
- Usually left hemisphere
- Understanding and formulating language
sensory speech area
(sensory areas of the cortex)
- Occipital lobe
- Interprets vision
visual area
(sensory areas of the cortex)
- Temporal lobe
- Interprets hearing
auditory area
(sensory areas of the cortex)
- Near base of the central sulcus
- Includes part of insula
taste
(sensory areas of the cortex)
-Arises from centers deep within temporal lobes
smell
- Regions that are not primarily motor or sensory
- Connect to each other and to other structures in brain
- Widespread throughout the cerebral cortex
- Analyze and interpret sensory experiences
- Provide memory, judgement, emotions
association areas of the cortex
(association areas)
- Concentrating
- Planning
- Complex problem solving
- Emotional behavior, judging consequences of behavior
frontal lobe
(association areas)
- Understanding speech
- Choosing words to express thoughts and feelings
parietal lobe
(association areas)
-Interpret complex sensory experiences (understanding speech, reading)
temporal lobe
(association areas)
-Analyze and combine visual images with other sensory experiences
occipital lobe
(association areas)
-Translating sensory information into proper emotional responses
insula
(motor areas of the cortex)
- Frontal lobe
- Controls voluntary muscles
- Most nerve fibers cross over brainstem
primary motor area
(motor areas of the cortex)
- Anterior to primary motor
- Usually in left hemisphere
- Controls muscles needed for speech
Broca’s area
(motor areas of the cortex)
- Above Broca’s area
- Controls voluntary movements of eyes and eyelids
Frontal eye field
What is the dominant hemisphere in most people?
left
(hemisphere dominance)
- Language skills of speech, writing reading
- Verbal, analytical, computational skills
dominant hemisphere
(hemisphere dominance) -Nonverbal taks
- Motor tasks
- Understanding and interpreting musical and visual patterns
- Provides emotional and intuitive thought processes
nondominant hemisphere
(memory)
- Neurons connected in a circuit
- Circuit is stimulated over and over
- When impulse flow ceases, memory does also unless it enters long-term memory via memory consolidation
short-term (working) memory
(memory)
- Holds more memory than short-term, lass a lifetime
- Changes structure or function of neurons
- Enhances synaptic transmission
long-term memory
- Masses of gray mater deep within cerebral hemisphere
- Consist of caudate nucleus, putamen, and globes pallidus
- Produce dopamine
- Help control voluntary movement
basla nuclei
This is when less dopamine reaches basal nuclei, which leads to motor problems, tremors, speech difficulties, etc.:
parkinson disease
- Between cerebral hemispheres and above brainstem
- Surrounds third ventricle
diencephalon
(diencephalon)
- Gateway for sensory impulses ascending to cerebral cortex
- Receives all sensory impulses (except smell)
- Channels impulses to appropriate part of cerebral cortex for interpretation
thalamus
(diencephalon)
- Maintains homeostasis by regulating visceral activities, such as heart rate, blood pressure, body temp, etc.
- Links nervous and endocrine system
hypothalamus
(diencephalon)
- Consists of several structures in various parts of the brain, including diencephalon
- Controls emotional responses
- Reacts to potentially life-threatening upsets
limbic system
- Between diencephalon and pons
- Contains bundles of fibers
midbrain
- Rounded bulge
- Between midbrain and medulla oblongata
- Relays neve impulses between medulla oblongata and cerebrum
- Relays impulses from cerebrum to cerebellum
- Helps regulate rhythm of breathing
pons
- Enlarged continuation of spinal cord
- Conducts ascending and descending impulses between brain and spinal cord
- Contains cardiac, vasomotor, and respiratory control centers
- Contains various nonmetal reflex control centers like sneezing, coughing, etc.
- Injuries are often fatal
medulla oblongata
- Complex network of nerve fibers scattered throughout brain stem
- Extends in the diencephalon
- Connects to centers of hypothalamus, basal nuclei, cerebellum, and cerebrum with ascending and descending tracts
- Filters incoming sensory info
- Arouses cerebral cortex into state of wakefulness
- Decreased activity causes sleep
reticular formation
(types of sleep)
- Slow wave sleep
- Person is tired
- Decreasing activity of reticular formation
- Restful and dreamless
- Reduced blood pressure and respiratory rate
- 3 stages, ranging from light to heavy
- Alternates with REM sleep
non-rapid eye movement sleep
(types of sleep)
- Paradoxical sleep (some areas of brain are active for breathing)
- Heart and respiratory rates irregular
- Dreaming occurs
rapid eye movement sleep
- Two hemispheres separated by fall cerebelli
- Integrates sensory info concerning positions of body parts
- Coordinates skeletal muscle activity
- Maintains posture
Cerebellum
What connects the hemispheres of the cerebellum?
vermis
(brain waves)
Awake, resting, eyes closed:
alpha
(brain waves)
Active mental activity, under tension:
beta
(brain waves)
Mostly in children:
theta
(brain waves)
Mainly during sleep:
delta
- Slender column of nervous tissue continuous with brain and brainstem
- Extends downward through vertebral canal
- Begins at the foramen magnum and terminates at the first and second lumbar vertebrae (L1-L2) space
- Consists of 31 segments; each gives rise to a pair of spinal nerves
spinal cord
- Center for spinal reflexes
- Conduit (pathway) for impulses to and from the brain
2 main functions of spinal cord
Autonomic subconscious response to stimuli within or outside the body:
reflex
Neural pathway, consisting of a sensory receptor, 2 or more neurons, and an effector:
reflex arc
- Consists of 2 neurons: sensory and motor; 1 synapse in spinal cord
- Example of a stretch reflex: the knee-jerk reflex
- Helps maintain an upright posture
monosynaptic reflex
-Occurs when person touches or steps on something painful
withdrawal reflex
- During withdrawal reflex, flexors on affected side contract, and extensors are inhibited
- Shifts body weight, so person remains upright
crossed extensor reflex
Conducts sensory impulses to brain:
ascending tracts
Conducts motor impulses from the brain to motor neurons reaching muscles and glands:
descending tracts
Injury to ascending tracts can result in:
loss of sensation
Injury to descending tracts can result in:
loss of motor function, paralysis
Consists of nerves that connect CNS to other body parts:
PNS
(PNS)
Arising from the brain:
cranial nerves
(PNS)
Arising from spinal cord:
spinal nerves
(PNS)
Cranial and spinal nerves that connect CNS to the skin and skeletal muscles (conscious activity):
somatic nervous system
(PNS)
Cranial and spinal nerves that connect CNS to viscera (subconscious activities):
autonomic nervous system
Bundles of axons:
nerves
Cover neurons:
endoneurium
Covers fascicles:
perineurium
Covers nerve:
epineurium
-Conduct impulses into brain or spinal cord
sensory nerves
-Conduct impulses to muscles or glands
motor nerves
- Contains both sensory and motor nerve fibers
- Most are this kind of nerve
- All spinal nerves are this nerve
mixed nerves
- Most of these are mixed nerves
- Some are sensory, associated with special senses
- Some are primarily motor, innervate muscles or glands
- Most are attached to the brainstem
cranial nerves
Formed by descending roots of lumbar, sacral, and coccygeal nerves:
cauda equina
Sensory root:
dorsal root
Contains cell bodies of sensory neurons:
dorsal root ganglion
- Motor root
- Axons of motor neurons whose cell bodies are in the spinal cord
ventral root
-Union of ventral root and dorsal roots
spinal nerve
(nerve plexuses)
- Complex network formed by ventral rami of spinal nerves
- Not in T2 through T12
- Fibers of various spinal nerves are sorted and recombined, so all fibers heading to same peripheral body part reach it in the same nerve
nerve plexus
(nerve plexuses)
- Formed by ventral rami of C1-C4 spinal nerves
- Lies deep in the neck
- Supply muscles and skin of the neck
- C3-C4-C5 nerve roots contribute to phrenic nerves, which transmit motor impulses to the diaphragm
cervical plexus
(nerve plexuses)
- Formed by ventral branches C5-T1
- Lies deep within shoulders
brachial plexus
(nerve plexuses)
- Formed by anterior branches L1-S4
- Extends from lumbar region into pelvic cavity
lumbosacral plexus
(brachial plexus)
-Supply muscles of anterior arms and skin of forearms
musculocutaneous nerve
(brachial plexus)
-Supply muscles of forearms and hands, skin of hands
ulnar and median nerves
(brachial plexus)
-Supply posterior muscles of arms and skin of forearms and hands
radial nerve
(brachial plexus)
-Supply muscles and skin of anterior, lateral, and posterior arm
axillary nerve
(lumbosacral plexus)
-Supply motor impulses to adductors of thighs
obturator nerve
(lumbosacral plexus)
-Supply motor impulses to muscles of anterior thigh and sensory impulses from skin of thighs and legs
femoral nerve
(lumbosacral plexus)
-Supply muscles and skin of thighs, legs and feet; largest and longest nerve in body
sciatic nerve
The autonomic nervous system is part of which nervous system?
PNS
- Functions without conscious effort
- Helps maintain homeostasis
- Prepares body for exercise
autonomic nervous system
- Prepares body for ‘fight or flight’; speeds body up
- Most active under energy-requiring, stressful, emergency situations
sympathetic division
- Prepares body for ‘resting and digesting’ activities; slows body down
- Most active under resting, non-stressful conditions
parasympathetic division