Chapter 9- Central Nervous System

gray matter

gray matter

◦ Nerve cell bodies, dendrites, axon terminals
◦ Without myelin
◦ Nuclei
◦ Ganglia

white matter

◦ Myelinated axons
◦ Tracts
◦ Nerves

lipids from myelin

what makes white matter appear white

gray matter on iside with white on outside

where are gray and white matter found in the spinal cord?

skull, vertebral column

bones that support the CNS

meninges

3 layered membrane that supports the CNS

dura mater

◦ Tough mother
◦ Forms sinuses for draining venous blood from brain

pia mater

◦ Thin, delicate membrane
◦ Clings to neural tissue

dura mater, arachnoid, pia mater

3 layers of the meninges from outside to inside

arachnoid

spidery tissue that separates subarachnoid space from next layer

blood, cerebrospinal fluid, interstitial fluid

fluids that support the CNS

cerebrospinal fluid

◦ Fills space between arachnoid and pia mater
◦ Ventricles

buyancy and reduces weight

how does cerebrospinal fluid protect the brain?

blood brain barrier

Barrier between interstitial fluid and the blood

astrocytes, basal lamina, capillaries in the brain

components of the formation of blood brain barrier

ascending tracts

move towards higher level in the CNS (to brain)

descending tracts

move towards lower level in the CNS (away from brain)

cervical, thoracic, lumbar, sacral

regions of spinal cord from anterior to posterior

spinal cord

which is shorter, the spinal cord or the vertebral column?

cauda equina

“horse’s tail” structure formed by spinal nerves at the end that must travel to get to their vertebral exit point

into 2 roots

how does a pair of spinal nerves split?

dorsal root

Carries incoming sensory information to spinal cord

ventral root

carries motor information out of spinal cord

spinal interneurons

what is the integrating center in spinal reflex

no

does spinal reflex require brain input?

coordinates movement

function of spinal reflex

mid brain

Eye movement and relay center

pons

Connection of cerebellum

medulla oblongata

Involuntary functions
◦ Corticospinal tracts, crossing over

reticular formation

Collection of nuclei (cell bodies)
◦ Sleep and arousal
◦ Muscle tone
◦ Pain modulation
◦ Breathing

medulla, pons, mid brain

3 main regions of the brain stem

brain stem

oldest part of the brain

cranial nerves

Peripheral nerves off the brain stem

sensory, efferent, mixed

types of cranial nerves

cerebellum

portion of the brain that coordinates muscle activity/balance

no

does the cerebellum initiate muscle ontraction?

body, cortex

the cerebellum receives sensory input from ________ and receives motor input from __________

diancephalon

developmental term for the structure that makes connections to higher centers

-hypothalamus, thalamus, pituitary/pineal glands

hypothalamus

homeostatic control center of the body

temperature, osmolarity, reproduction, food intake, emotions

some variables controlled by the hypothalamus

cerebrum

Controls higher brain functions and higher perception

frontal, parietal, occipital, temporal

4 lobes of the cerebrum

corpus callosum

white matter connector between 2 hemispheres of the brain

sulci

furrows/grooves surface structure of the brain

gyri

ridges surface structure of the brain

cerebral cortex

◦ “Neocortex”
◦ Outer covering
◦ Distinct layers and columns

basal ganglia

cerebrum gray matter that controls motor movements

limbic system

important cerebrum gray matter in regulating emotion

cingulate gyrus

limbic system component - fold along median of brain that plays a role in emotion

hippocampus

limbic system component -involved in memory formation and learning

Amygdala

limbic system component - involved in emotion, particularly fear

cognitive and intrinsic

2 possible types of integration in brain coordination of sensory information

physiological, behavioral

2 possible types of response in brain coordination of sensory information

sensory area

cortex area that translate into conscious awareness

motor areas

cortex area that initiates voluntary movement

association areas

cortex area that integrate information for voluntary behaviors

primary somatosensory cortex

section of the parietal lobe that registers sensations of touch on the body

primary motor cortex, premotor cortex

in the frontal lobe, the __________ initiates voluntary movement and contains pyramidal cells while the __________ is a motor association area

occipital lobe

Contains visual Cortex and visual association area

temporal lobe

auditory and olfactory sensation and interpretation

lateralization

occurs when some functions are specialized to one hemisphere

corpus callosum

Carries axons across the midline of brain

yes

does sensory information cross over from one sid eof the brain to the other side of the body?

PET scan

radioactive glucose scan for metabolic mapping of active areas of the brain

Wernicke’s area

◦ Temporal lobe
◦ Understanding language
◦ Damage causes receptive aphasia

Broca’s area

◦ Frontal lobe
◦ Producing language
◦ Damage causes expressive aphasia

aphasia

inability to communicate

diffuse modulatory systems

Originate in reticular formation

- Governs state of arousal
-Influence behavior states