anatomy lab final exam

nervous system functions

receive, process, and respond to information. Transmit electrical signals throughout the body

sensory input

monitor external and internal changes

integration

processes sensory input and determines response

motor output

dictates response by activating effector organs

neurons

nerve cells

soma

cell body, contains nucleus, cytoplasm, organelles

dendrites

receive signal, transmit to cell body. receptor site for incoming signals from other neurons or receptors

axon

transmits signal to end, conduct signal away form the cell body of the neuron to target tissues

myelin

insulates neuron, helps to propagate signal. made from glial cells

central nervous system

spinal cord/brain, includes neural tissue, blood vessels, and connective tissues.

Responsibilities of CNS

integrating, processing, and coordinating sensory data and motor commands. Higher functioning occurs here

CNS Structures

gray matter and white matter

Gray matter

dense clusters of neuron cell bodies, also dendrites and glia. Synapses happen here

white matter

myelinated regions of CNS, includes axon and glia, bundles of axons are nerve tracts

glial cells

provide supportive functions to neurons

types of glial cells in cns

microglia, oligodendrocytes, astrocytes, and ependymal cells

microglia

small immune cells

oligodendrocytes

processes wrap around neurons, myelin for multiple nodes or neurons

astrocytes

maintain blood

ependymal cells

line the ventricles, connect to capillaries and constantly produce cerebrospinal fluid (CSF)

Peripheral Nervous System (PNS)

all nerves outside the spinal cord and brain, carriers motor and sensory information to and from the peripheral tissues (innervates)

purpose of sensory vs motor nerves

sensory innervate areas of skin while motor innervate skeletal or smooth muscles

ganglia

clusters of cell bodies of neurons located in peripheral nervous system

nerve

a discrete collection of neuronal axons located in the PNS

special somatic sensations

vision, hearing, balance

afferent information

travels toward the cns. receptors for touch, pain, pressure, vibration, temp, proprioception in skin, body wall and limbs

efferent information

travels from cns to body. signal exists from brain or spinal cored. voluntary nervous system

glial cells of the pns

satellite cells and schwann cells

satellite cells

surround cell bodies in ganglia, modulate neurotransmitter levels

Schwann cell

wraps around axons, creates myelin sheath for pns neurons

functions of the brain

control center for the entire body; integrates, processes, and coordinates sensory and motor commands; regulates homeostasis through the autonomic nervous system, controls body temp, hunger, thirst; produces language, forms memories, modulates emotion

gyrus

ridges (hills) of brain tissue

sulcus

a groove (valley) between adjacent gyri

what the cerebrum does

intelligence, complex thinking, sensory and motor processing and perception

Major functional areas of cerebrum

sensory (conscious awareness of sensation), association areas (integrate information), motor areas (voluntary motion)

location of primary somatosensory cortex

postcentral gyrus of parietal lobe

location of primary auditory cortex

the temporal lobe

location of the primary visual cortex

occipital lobe (calcarine sulcus)

location of primary motor cortex

the precentral gyrus of the frontal lobe

broca's area

in left frontal lobe, involved with the physical production of language, damage to this area causes trouble speaking

wernicke's area

the left hemisphere (parietal and temporal), recognizing and understanding speech happens here, damage here experience aphasia

corpus callosum

large bank of axons that connect the right and left hemispheres of the cerebrum

diencephalon

deep to the cerebral hemispheres, includes thalamus, epithalamus, hypothalamus, and third ventricle

thalamus

gray matter deep to the cerebrum, forms the lateral walls of the midline third ventricle, gateway to the cerebral cortex, processes all sensory information (except smell) coming into the cerebrum from pns

hypothalamus

main visceral control center of the body, maintains homeostasis, controls autonomic ns, endocrine system, emotional response, and motivational behavior, controls sleep cycles, involved in formation of memory

brain stem

midbrain, pons, and medulla

midbrain

large bundles of white matter (cerebral peduncles), contains cerebral aqueduct and nuclei for cranial nerves associated with the eye, involved with visual and auditory processing

pons

located between midbrain and medulla, separated from the cerebellum by the fourth ventricle

where does the root of cranial nerve five attach

to the pons laterally

medulla oblongata

continuous with the spinal cord, contains the pyramids and olive

pyramids

carry descending voluntary motor fibers to skeletal muscle

olive

a small prominence posterior to the pyramids that contains a nucleus

cerebellum0

11% of brain mass, 50% of the neurons, coordiantes body movements, helps maintiain posture, balance, language, motor learning

cerebellar structures

posterior to the fourth ventricle, contains aperatures that transmit csf from the ventricles to the subarachnoid space

vermis

connects teh two hemispheres of the cerebellar structures

folia

leaf like fold that increase surface area of the fcortex, made up of gray matter

spinal cord functions

transmit sensory and motor innervation to and from the brain, major center for reflexes that do not require communication with the brain

location of spinal cord

extends from the foramen magnum to level of L1/L2

pairs of spinal nerves

31 pairs that exit the spinal cord laterally

cervical/lumbar enlargements

additional nerves controlling the upper and lower limbs

conus medullaris

inferior cone shaped end of spinal cord

cauda equina

nerve roots at inferior end of vertebral canal

filum terminale

long filament of pia mater that comes directly off the tip of the conus and attaches to the coccyx to secure the spinal cord

gray matter in the spinal cord

forms an H or butterfly shape deep to white matter

posterior horns in spinal cord

transmit information

ventral horns in spinal cord

transmit motor information

cervical spinal cord

most white matter of all axons transiting the cns. large ventral horns for many neurons of the upper limbs

thoracic spinal cord

significant but less white matter. small horns only communicates with the intercostal muscles and skin

lumbar spinal cord

large horns relative to white matter, round cross

sacral spinal cord

least white matter, bulbous horns and overall, very small, near the end

arbor vitae

made up of white matter

dura matter

outer most layer, thick and durable. close to or attached to bone

arachnoid matter

middle layer, attached to dura, has fluid layer deep to it. spider like

pia mater

this delicate layer directly attached to brain and spinal cord

epidural space

superficial to the dura and filled with fat and veins in spine

cerebrospinoius fluid

made of ependymal cells of the choroid plexus in all four of the venticles

falx cerebri

separates right from left hemisphere, ends superior to corpus colosseumt

tentorium cerebelli

separates cerebellum from the cerebrum

dural venous sinuses

collect blood from veins in the brain and csf from the subarachnoid space via arachnoid granulations

found between two layers of dura and in the base of the dural folds

drains though the jugular foramen into the internal jugular vein

external carotid artery

supplies the structures of the face and neck

facial artery

supplies superficial face after arching over mandible

maxillary artery

supplies deep face passing behind the mandible

superficial temporal artery

supplies lateral aspect of the head and passes just anterior to the external auditory meatus

where in the brain does the anterior cerebral artey supply

anterior medial parts of the cerebrum

where in the brain does the middle cerebral artery supply

lateral aspects of the cerebrum

hydrocephalus

excess accumulation of csf inside the cranium in the brain’s ventricles

cerebral vascular accident (cva)

aka stroke, disruption of blood supply to the brian form a bloackage in a vessel that supplies the brain or an aneurysm causing blood to leak out of the vessels

spinal cord injury

disruption of communication between brain and body

axons inferior to the damage cannot get to/from their target tissues and so experience loss of function

intracranial hemorrhage

bleeding from artery or vein inside the cranium can cause blood to accumulate between the meningeal layers

potential spaces become actual spaces filled with blood

multiple sclerosis

chronic autoimmune disease where the immune system attaches and destroys the myelin sheath of nerves, disrupting signal transmission

number of pairs of spinal nerves

31 pairs

how spiinal nerves exit vertebral canal

intervertebral foramina

what part of the nervous system is the spinal nerves

peripheral nervous system (pns)

cervical spinal nerves

c1-c8

note: there is no c8 vertebra, but there is a spinal nerve c8

type of sensory information dorsal horns carry

sensory (afferent) information

type of sensory information ventral horns carry

motor (efferent) information

rami spinal nerves

contain both sensory and motor nerves

plexus

a network of nerves, usually formed by several adjacent ventral rami

cervical plexus

c1-c4 spinal nerves

innervates muscles of the hyoid to aid in moving the larynx via ansa cervicalis