Ch. 12: Central Nervous System

astrocyte

• Anchor neurons and blood vessels

• Transport nutrients between blood vessels and neurons

• Form the blood-brain barrier

• Repair damaged tissue

• CNS

oligodendrocytes

• Myelinate certain axons in the CNS

microglial

• Act as phagocytes (engulf and destroy pathogens, debris); assists with immune response

• CNS

ependymal

• Line ventricles of brain and central canal of spinal cord

• Produce and circulate cerebrospinal fluid (CSF)

• CNS

schwann cell

Myelinate certain axons in the PNS

satellite cell

Wraps/surrounds neuron cell bodies (somas) in the PNS for support and protection

Brain tumors are usually gliomas because

glial cells divide. Neurons do NOT.

Sympathetic division of autonomic nervous system

• mobilizes body systems during activity

• “Fight-or-flight" (stress, danger) – speeds things up

Paraympathetic division of autonomic nervous system

• promotes housekeeping functions during rest

• "Rest-and-digest" (relaxation) – slows things down, conserves energy

white matter

made out of groups of myelinated axons

grey matter

made out of groups of cell bodies (somas)

nuclei

grey matter (cell bodies/somas) in the CNS

ganglion

grey matter (cell bodies/somas) in the PNS

tract

white matter (myelinated axons) in the CNS

nerve

white matter (myelinated axons) in the PNS

forebrain secondary brain vesicles

telencephalon and diencephalon

midbrain secondary brain vesicles

mesencephalon

hindbrain secondary brain vesicles

metencephalon and myelencephalon

telencephalon adult brain structures

cerebrum (outer shell of brain): cerebral cortex (grey matter), fibers (white matter), and basal nuclei

diencephalon adult brain structures

thalamus, hypothalamus, epithalamus (and retina)

mesencephalon adult brain structures

midbrain portion of the brainstem

metencephalon adult brain structures

pons portion of the brainstem and the cerebellum

myelencephalon adult brain structures

medulla oblongata portion of the brainstem

j

find the Lateral Sulcus/Fissure

-

find the Longitudinal Fissure

b

find the central sulcus

yellow and blue gyri between central sulcus

find the precentral gyrus and the postcentral gyrus

corpus callosum

The cerebral hemispheres are the two halves (left and right) of the cerebrum, connected by the

decussation

The crossing of nerve fibers or tracts from one hemisphere of the central nervous system to the other, resulting in contralateral control of the body

cerebral cortex

superficial grey matter that has specialized sensory, motor, and association areas separated by different lobes

precentral gyrus

this is the primary motor cortex; damage to this structure may cause loss or impairment of voluntary movement on the contralateral side of the body

postcentral gyrus

this is the primary somatosensory cortex; damage to this may cause loss or impairment of somatic sensation (touch, pain, temperature, proprioception) on the contralateral side of the body.

Broca’s Area

Motor speech area responsible for speech production; damage makes it hard to form words and sentences, though comprehension often remains intact

Wernicke’s Area

Language/speech comprehension area; damage may lead to fluent but meaningless speech and difficulty comprehending others

occipital lobe

the primary visual cortex is located in the..

temporal lobe

the primary auditory cortex is located in the..

insula lobe

the vestibular (equilibrium/balance) and gustatory (taste) complex are located in the…

temporal lobe

the olfactory (smell) cortex is located in the inferior…

somas

integrate and process information

axons

transmit information to other neurons or target cells; communication

Commissural fibers

axons that connect corresponding regions of the left and right hemispheres; corpus callosum is the largest bundle of this fiber

Association fibers

Axons that connect different regions within the same cerebral hemisphere, allowing communication between cortical areas on the same side of the brain

Projection fibers

Axons that connect the cerebral cortex with lower brain regions and the spinal cord, carrying information to and from the cortex; these fibers go up and down

Basal Nuclei

group of somas in the CNS deep to the cerebral cortex that influences skeletal muscle movements (it filters movement patterns); people with Tourette’s Syndrome have something wrong with this part of the brain; this also plays a role in cognition and emotion

thalamus

sensory relay station (except smell/olfaction); the gateway to the cerebral cortex; made of nuclei

hypothalamus

controls the autonomic (visceral) nervous system (ex. heart rate, body temperature, hunger and satiety, water balance and thirst); contains nuclei; controls the endocrine system specifically the pituitary gland (anterior)

epithalamus

the pineal gland (posterior) is located here; melatonin is secreted from here and this structure controls circadian rhythm

midbrain, pons, medulla oblongata

the regions of the brainstem

midbrain

contains the superior and inferior colliculi

superior colliculi

midbrain structures that act as visual reflex centers, coordinating automatic eye, head, and neck movements in response to visual stimuli; hint: these little balls kinda look like eyes

inferior colliculi

midbrain structures that serve as auditory reflex centers, processing sound information and coordinating reflexive responses to auditory stimuli such as turning the head or eyes toward a sound; hint: this structure looks like a hearing aid

pons

the part of the brainstem below the midbrain; a lot of cranial nerves originate here; it relays impulses between the motor cortex (precentral gyrus of the frontal lobe) and the cerebellum

medulla oblongata

cardiovascular center (controls HR) and respiratory center (controls breathing); this is and area of decussation (crossing over of nerve fibers—specifically corticospinal tracts); hint: “______ = Makes you live (HR, breathing)”

cerebellum

associated with movement patterns; allows smooth, coordinated movements

arbor vitae

white matter in the middle of the cerebellum used for communication; looks like the veins of a leaf

the limbic system

controls emotional response and memory; houses the hippocampus and amygdala

hippocampus

part of the limbic system associated with long-term memory

amygdala

part of the limbic system that processes emotion

Reticular Activating System (RAS)

Maintains cerebral cortical alertness AKA consciousness

reticular formation

filters sensory information

EEG (Electroencephalogram)

Measures electrical activity of the brain

Alpha Waves represent

calm and relaxed; eyes probably closed

Beta Waves represent

awake and alert; eyes open and mentally stimulated

Theta Waves represent

children, more irregular wave pattern

Delta Waves represent

Deep sleep or in awake adults is representative of brain damage

meninges

dura mater, arachnoid mater, and pia mater (superficial to deep); these protective layers are deep to the cranium and wrap around the brain

dura mater

most superficial meninges layer; very tough

arachnoid mater

thin, web-like middle meninges layer

pia mater

soft, innermost layer of the meninges

Subdural space

space between the dura mater and arachnoid mater

Subarachnoid space

space between the arachnoid mater and pia mater that contains cerebrospinal fluid (CSF)

Cerebrospinal Fluid