11: Central Nervous System

Meninges structure

connective tissues surrounding the brain and spinal cord that are called of dura, arachnoid and pia maters

Dura Mater

tough outer covering - encloses entire CNS and major blood vessels

Dura Septa

the infoldings of the dura that line large crevices of the brain, helping to compartementalize the brain and hold the cerebrum and cerebellum in place

Arachnoid Mater

spiderweb, sac-like structure filled with CSF in the subarachnoid space

Pia Mater

inermost layer that’s in direct contact with the outer tissue layers of the brain and spinal cord

Meninges function

separate the brain from the skull, enclose and protect the blood vessels supplying the brain, and contain and circulates cerebrospinal fluid

type of brain ventricles

lateral, (1 and 2), third, fourth, and cerebral aqueduct

cerebrospinal fluid funcions

bouyant, protective, and helps environmental stability

Where is cerebrospinal fluid made and its properties

produced in the choroid plexus and its clear and colorless fluid

Where is cerebrospinal fluid located?

circulates through the ventricles and subarachnoid space surrounding the CNS

top arrow

choroid plexus - where CSF is produced - found in all four ventricles

arrow on right

right lateral ventricle - there are 2 - found in the cerebrum and connected by a interbentricular foramen

bottom arrow on left

third ventricle - thin space bounded by medial walls of hypothalamus and thalamus

top arrow

Cerebral aqueduct - opens just inferior to the epithalamus and passes through the midbrain. The aqueduct opens up to the fourth ventricle

bottom arrow

fourth ventricle.- the floor is the dorsal surface of the pons and upper medulla, then continues to the central canal of the spinal cord

Hydrocephalus and causes

an excess of CSF - caused by obstruction of flow, overproduction, or impaired drainage

Cerebrum

pink part - a two hemisphere structure, connected by the corpus callosum, location of conscious thought processes and completes intellectual functions

what helps increase the surface area of the cerebrum?

Gyri and sulci

2 parts of the cerebrum

gray and white matter

frontal lobe

responsible for decision making, personality, verbal communication, voluntary motor control of skeletal muscles

Parietal Lobe

sensory interpretation of textures, shapes, and understanding speech

Temporal Lobe

auditory and olfactory expierience

Occipital Lobe

Vision

Insula

Taste

Lateral sulcus

seperates the temporal lobe from all

Central sulcus

seperates the parietal and frontal lobe

Parietoccipital sulcus

seperate parietal and occipital lobes

Postcentral Gyrus

acts as primary somatosensory cortesx - skin and muscles

somatosensory homunculus

mapping of the location of somatosensory receptors in the body laid across a portion of the cerebral cortex

Where is the primary motor cortex located?

precentral gyrus - sends motor commands down the spinal cord to contract specific muscles

motor homunculus

topographical map of the body

tracts or fasciculi

Groups of axons in the central nervous system white matter

three major classifications of axons

association fibers, commissural fibers, and projection fibers

Association Fibers

connect the gyrus to gyrus and lobe to lobe within same hemisphere

Commissural Fibers

top arrow - cross over the middle, connecting one hemisphere to the other

Projection Fibers

bottom arrow - connect different brain structures and regions to each other

hippocampus and amygdala 

Bottom 2 arrows - (first am) medial temporal lobe structures that, along with the adjacent cortex, are involved in long-term memory formation and emotional responses.

Basal nuclei

group of nuclei deep in the cerebrum responsible for starting, stopping and monitoring movement.

major structures of the basal nuclei

Topish 3 lines in this order - caudate, putamen, and globus pallidus.

Diencephalon

one region of the adult brain that retains its name from embryonic development - connection between the cerebrum and the rest of the nervous system - send information to the cerebrum through

major regions of the diencephalon

thalamus, the hypothalamus, the epithalamus, and the subthalamus.

thalamus

lies on either side of the third ventricle and relays information for the sensory and motor neurons entering the cerebrum

Hypothalamus

B behavior, E endocrine, E motion, T temperature control, S sleep/ wake cycles, H hunger/thriist, Autonomic control, and M memory

Infundibulum and pituitary gland?

Cerebellum functions

fine-tunes, smooths, and coordinates muscle movements, and helps maintain balance

Brainstem

bidirectional passageway between cerebrum and spinal cord, contains many autonomic and reflex centers essential for survival, and point of attachment for cranial nerves

Parts of the brainstem

midbrain, pons and medulla

Limbic system

a connected set of structures that regulate emotion and behaviors related to fear and motivation, and memory

important parts of the limbic systems

amygdala - help sensation of fear and fearful faces

cingulate gyrus - regulates emotions and pain

Fornix

Parahippocampal gyrus

Hippocampus

Ascending pathway

found in the CNS white matter - sensory information from the spinal cord and brainstem to higher CNS processing

ascending tracts in the spinal cord

tracts of posterior funiculus, spinocerebeller tracts, and spinothalamic tracts

Descending pathways

Found in CNS white matter - conducts motor information from higher CNS processing centers to the spinal cord

Descending tracts in the spinal cord

lateral corticospinal tract and anterior corticospinal tract

responsibility of posterior horn

sensory processing

responsibility of anterior horn

sends out motor signals to skeletal muscles

responsibility of lateral horn

only in uper lumbar regions and is the central component of the sympatheric division of ANS