nervous system PNB

gray matter

group of neuronal cell bodies in the CNS

white matter

bundles of myelinated axons of the CNS

ganglia

groups of neuronal cell bodies in the PNS

nerves

bundles of axons in the PNS

ganglia and nerves belong to which system

PNS

grey and white matter belong to which system

CNS

cells of CNS

neurons

astrocytes

microglia

oligodendrocytes

ependymal cells

astrocytes

support, BBB, ion homeostasis, synaptic formation

glial cells

microglia

macrophages of the brain

glial cells

oligodendrocytes

myelination

ependymal cells

lining ventricles, production of cerebrospinal fluid

protection components of brain

skin

cranial bones

cranial meninges (fibrous CT)

CSF

meninges of bone

dura mater: thick

arachnoid: thick and filamentous mesh

pia mater: thin fibrous

what layers of the meninges contains most blood vessels

pia and arachnoid

symptoms of bacterial meningitis

stroke, hearing loss, permanent brain damage

viral meningitis

caused by enteroviruses, less serious than bacterial

fungal infections can cause…

meningitis

treatment of bacterial meningitis

antibodies that can cross BBB

subarachnoid space

between pia and arachnoid mater

where CSF circulates, which is then drained into the superior sagittal sinus

role of cerebrospinal fluid

produced by ependymal cells in choroid plexus

support, homeostatic regulation of ions and nutrients, immune functions

flows through subarachnoid space and spinal cord

where is CSF produced

20% produced by interstitial fluid

80% produced by choroid plexus within ventricles

where does excess CSF flow

arachnoid villi, then drains into dural venous sinuses

how does CSF help detect meningitis, multiple sclerosis, neurosyphilis, and encephalitis?

its tested for cell count, glucose, protein, and oligoclonal band

lumbar puncture spinal tap from subarachnoid space

astrocytes foot processes

attached to capillaries that have epithelial cells

functions of epithelial cells

tight junctions

control molecular traffic and keep out toxins

ion homeostasis

maintain low protein environment to limit proliferation

pericytes

make up neuromuscular unit

has tight junctions, only certain molecules can pass through BBB

how is BBB maintained

pericytes and astrocytes

metabolic needs of brain

oxygen: freely passes through BBB

glucose: membrane transporters move glucose from plasma to brains interstitial fluid

blood supply to brain

internal carotid arteries (anterior)

vertebral arteries (posterior)

circle of willis

blood return to brain

jugular vein: exits through jugular foramen to return blood

cerebrum

higher brain function

diencephalon

homeostatic controls

epithalamus, thalamus, hypothalamus

brainstem

autonomic reflex center

midbrain, pons, medulla

cerebellum

coordination of movement

longitudinal fissures

divide left and right hemisphere

transverse fissure

divide cerebrum and cerebellum

lateral fissure

divides frontal, parietal, and temporal

central sulcus

divides parietal and temporal

lobes of cerebrum

frontal, occipital, parental, temporal, insula

insula

blood pressure, heart rate, digestion, smell and taste

consciousness, emotions

organization of cortex

horizontal layers

parietal, occipital, temporal, frontal are part of the neocortex - 6 layers

medial and inferior surface of the temporal lobe is part of the pyriform cortex - 3 layers

coronal section of brain

shows gray matter in cerebral cortex and deep gray matter in basal ganglia

shows orientation of white matter commissural fibers (crosses midline), projection fibers (up and down), association fibers (front and back)

commissural fibers

myelinated bundles of axons that connect 2 hemispheres

projection fibers

bundles of white matter axons that connect the cerebral cortex with lower structures
carries afferent (ascending) and efferent (descending) signals

association fibers

myelinated nerve tracts that connect different cortical regions within the same cerebral hemisphere

cerebral features

gyrus- ridges

sulcus- grooves

deep gray matter: basal ganglia

functions in modulating motor movements

works with precentral gyrus and cerebellum

epithalamus

pineal glands secretes melatonin

thalamus

central relay station for sensory and motor signals

all senses except smell

hypothalamus

regulates homeostatic mechanisms

master control of Ans, endocrine system

regulates temp

controls emotional behavior

controls food and water intake

regulation of circadian rhythm

bidirectional passageways

brainstem relays all ascending (sensory) and descending (motor) nerve tracts between the brain and the spinal cord, and also houses vital autonomic centers

midbrain

movement, eye tracking, auditory reflexes, looking reflexes, sleep and alertness

cerebral penducles, superior colliculi, inferior colliculi

medulla

cardiovascular and respiratory regulation

cranial nerve nuclei majority

pyramidal system

pyramidal system of medulla

contains axonal fibers which contain motor info for motor control

pons

respiratory center

cranial nerve nuclei

cerebellum functions

adjust postural muscles

correcting movement

complex motor learning

automating and optimizing behavior

enabling synchronicity and timing of movements

limbic system

emotional brain

amygdala

hypothalamus

cingulate gyrus

basal ganglia

olfactory bulbs

mammillary body and hippocampus

cingulate gyrus

emotional responses, behavior reactions, pain perception

basal ganglia

reward processes, habits, movements

spinal cord

gray matter

31 pairs of spinal nerves

white matter- ascending and descending pathways

semiautomatic control and subconscious control of basal ganglia:

subthalamic nucleus, substantia nigra, global pallidus, caudate nucleus, putamen

cerebral penducles

contains fibers coming from motor cortex to spine

superior colliculi

visual reflexes

inferior colliculi

auditory reflexes

where is the primary motor cortex and what does it do

in the frontal lobe, it is stimulated so your body will move

where is Broca’s area

left hemisphere in frontal lobe, responsible for speech

where is the primary somatosensory association cortex?

parietal lobe

where is wernicke’s area

in temporal lobe, responsible for language comprehension

four major regions of brain

cerebrum, diencephalon, brainstem, cerebellum

location of meninges

directly between the skull/vertebrae and soft neural tissue of brain and spinal cord

purpose of meninges

protect CNS, anchor brain inside skull, support blood vessels, contains fluid to cushion

purpose of CSF

liquid shock absorber, makes brain float, transports nutrients and clears out waste

composition of CSF

water, glucose, salts, oxygen, very little proteins or cells

CSF vs plasma

CSF is a cleaner version of plasma. plasma is high in protein and cell count

components of BBB

tight junctions between capillary cells, thick basement membrane, astrocytes wrapped tightly around capillaries

motor regions

controlled by precentral gyrus in frontal lobe

sensory regions

received by post central gyrus in parietal lobe

homunculi

distorted map of human body drawn across the motor and sensory strips. body parts that are sensitive are drawn bigger

5 major regions of spinal cord

cervical, thoracic, lumbar, sacral, coccygeal

damage of cerebral cortex

loss of conscious thinking, reasoning, or voluntary movement control

basal nuclei damage

tremors, stiffness, trouble starting/stopping movements (Parkinson’s)

diencephalon damage

severe disruption to body temp regulation, sleep cycles, and hormonal balance

cerebellum damage

ataxia- clumsiness, slurred speech, tremors, and total loss of coordination and balance