most superficial

thick and strong brain protection

avascular network of collagen and elastic fibers

thin, vascular

close contact with brain and spinal cord

about 80-150 ml

forms a liquid cushion & holds CNS structure

minor exchange of nutrients and waste

secreted from choroid plexuses in walls of ventricles

consists of brain capillary endothelial cells joined by tight junctions

processes of astrocytes

continuous basement membrane

more stringent permeability to restrict passage of many toxins & pathogens

100 million neurons

extends from foramen magnum to L1

protected by CSF and meninges

axons of sensory neurons that enter the spinal cord

sending information UPWARDS

cell bodies of sensory neurons

motor axons leaving the spinal column

coming DOWN to muscle and glands

functions of spinal cord within nervous system

"H shaped"

contains cell bodies, dendrites

thinking/processing

Mostly unmyelinated

divide into columns

beneath grey matter (connects different brain regions)

role in wires/communication

contains myelinated tracts

"makes you aware of it"

carries impulses from thalamus to the primary sensory area of cerebral cortex

Conveys signal to conscious perception

"relays it"

From spinal cord or brainstem to thalamus

Usually decussates (crosses to the opposite side)

Relays sensory information upward to the brain

"feels it"

From receptor to spinal cord or brainstem

cell body in dorsal root ganglion

extend from primary motor cortex to ventral horn of spinal cord

CNS neurons with cell bodies in brain

terminates in LMNs

extend from primary motor cortex to ventral horn of spinal cord

CNS neurons with cell bodies in brain

terminates in LMNs

pyramidal tracts

precise, voluntary movement

contralateral action

peripheral neurons

cell bodies in ventral horns of spinal cord

terminates in effectors

extrapyramidal tracts

posture, course movement

much is involuntary reflexive

automatic movements

neurons travel in bundle

100s to 1000s neurons per nerve

thin layer or connective tissue surrounding each neuron

group of fibers wrapped around to form fascicles

surrounding the group of fascicles bundled to form a nerve

which are true about spinal nerves?

protective: minimize unwanted exposure

maintain balance, posture, coordination

move skeletal muscle

e.g. touching something hot

involves smooth muscle and glands

e.g. secretion of saliva while eating

may indicate neural pathology

85 Billion Neurons

main parts include:

Cerebrum

Diencephalon

Brain Stem

Cerebellum

divides into TWO hemisphere (left and right)

and LOBES: Frontal, Parietal, Temporal, Occipital

separated by the falx cerebri (dura)

includes Thalamus, Hypothalamus, and Epithalamus

includes

Midbrain,

Pons,

Medulla Oblongata, and

Reticular Formation

coordinates voluntary limb movement (related to intended action)

cerebral hemisphere has:

folds

mound of tissue

cerebral hemisphere has:

shallow groove

cerebral hemisphere has:

deeper groove

Cortical Distribution of Motor Functions:

amount of cortex devoted to body parts is proportional to precision of motor control

e.g. larger amount devoted to hands and face

• Location: Just anterior to the central sulcus

• Function: Controls voluntary movements of skeletal muscles

• Motor homunculus represents body regions controlled

anterior to primary motor area

Plans and coordinates complex movements before sending to primary motor cortex

role in: learning, repetition, and motor skills

Location: Most anterior part of frontal lobe

Function: abstract ideas, conscience, judgement, motivation, intelligence, personality

modified by experience

predominantly in left frontal lobe

motor speech area: planning and production of speech

responsible for voluntary control of movement

"higher" mental processes

influences motivation, foresight, planning, and social judgement

receives and interprets sensory information

e.g. touch, temperature, pressure, pain

somatosensory association area

somatosensory association area can store memories from past somatic sensory experiences

receives and interprets PRIMARY information about

HEARING and SMELL

receives and interprets information about VISION

-primary visual and association areas

receives & interprets information about taste

visceral sensorimotor processing

(e.g. abdominal discomfort)

left hemisphere

comprehension of written and spoken language

translating words into though

i.e. speech but incoherent

refers to the structures located beneath the cerebral cortex, within the central part of the cerebrum

these deep structures coordinate movement, process emotions, and relay information

bundle of white matter that connects the hemispheres

largest of three commissural tracts that connect L & R Hemispheres

It allows the two hemispheres to communicate and share information

masses of cerebral grey matter deep within the cerebral white matter

Regulates voluntary movement, posture, and coordination

receive input from entire cerebral cortex

involved in subconscious contractions of skeletal muscles

e.g. arms while walking

regulate initiation and termination of movements

"emotional brain"

plays primary role in range of emotions

e.g. pleasure, pain, anger, affection

role in memory storage and recall

forms lateral walls of 3rd ventricle

relay center for auditory, visual, taste, somatic impulses

role in conscience, emotions, memory, & cognition

RECEIVES: impulses from spinal cord, brainstem, cerebellum, basal nuclei

SENDS: information to the primary sensory areas & motor area

control ANS

part of endocrine system

major regulator of homeostasis

superior & posterior to hypothalamus

consist of pineal gland (melatonin) & habenular nuclei (olfaction/emotions)

lower part of the brain that connects the cerebrum to the spinal cord.
It acts as a relay center for sensory and motor pathways and controls many basic life functions (breathing, heart rate, consciousness).

reflex center for control of:

eye movement, visual and auditory reflexes

"startle reflex"

release DOPAMINE to help control subconscious muscle activities

(e.g. Parkinson's Disease)

bridge between medulla & higher brain centers

some coordination of voluntary motor output and patterns of breathing

contains several nuclei:

1: Cardiovascular Center - rate and force of heart beat

2: Respiratory Center - rate and depth or breathing

diffuse network of neurons in medulla, pons, midbrain

helps with regulatory muscle tone (involuntary contraction)

regulates level of consciousness, arousal, and attention

alerts cerebrum to sensory signals

afferent pathways run though ____ then Thalamus

controls smooth, cardiac muscle & glands

under involuntary control

fight or flight

emerge from spinal cord

increase heart rate, blood pressure, blood glucose and dilates RS

decrease blood to uneccessary organs

resting & digesting

emerge from brainstem & sacral

ganglia close to effectors

increases digestive & urinary functions

blood pressure & respiratory rate decrease

releases norepinephrine

releases acetylcholine

cell body is in CNS

axon extends to ganglion

cell body is in ganglion

axon extends to effector

cell body is in ganglion

axon extends to effector