neuron exam

Neuron

specialized nerve cells, receive/transmit electrical and chemical signals throughout the body

Cell body

(soma) contains the nucleus and organelles, integrates info received from dendrites

Dendrites

receives signals, sends them towards the cell body

Axon hillock

where action potential is initiated if threshold is reached

Axon

carries impulses away from dendrites

Myelin

insulates and speeds up impulses

Neurilemma

outermost layer of schwann cells, helps with axon regeneration in PNS

Nodes of Ranvier

gaps between myelin sheath

Synaptic terminals (synaptic end bulbs)

release neurotransmitters

PNS neuroglial cell types

schwann cells (forms myelin sheath around PNS, forms neurolemma), satellite cells (supports and cushions cell bodies in PNS ganglia

CNS neuroglical cell types

oligodendrocytes (form myelin sheaths around multiple CNS axons to speed up electrical signals), microglia (phagocytes), astrocytes (blood brain barrier), ependymal cells (produces/circulates cerebral spinal fluid)

Gray Matter

H-shaped, dyes easily, unmyelinated, collects messages and coordinates reflexes

White Matter

around gray matter, myelinated axons, carries messages; ascending tracts carry sensory info toward the brain, descending tracts carry motor commands from the brain

Posterior median sulcus

Anterior median fissure

Central Canal

contains spinal fluid

Posterior gray horn

sensory processing, sensory goes in

Lateral gray horn

controls involuntary actions

Anterior gray horn

sends motor signals out to skeletal muscles

Gray commissure

Posterior white column

contains ascending sensory tracts, carries info about proprioception toward the brain

Anterior white column

contains both ascending and descending tracts, carries sensory info towards the brain and motor commands away from the brain

Lateral white column

contains both ascending and descending tracts, carries sensory info towards the brain and motor commands away from the brain

Posterior/dorsal root of spinal nerve

carries sensory info into the spinal cord

Posterior/dorsal root ganglion

houses the cell bodies of neurons that carry sensory info to the spinal cord

Anterior/ventral root of spinal nerve

carries motor commands out of spinal cord to muscles

Dorsal ramus

supplies deep back muscles and sensation of the back

Ventral ramus

supplies front and sides of trunk, supplies limbs, forms nerve plexuses

Ramus communicans

branch between nerve and sympathetic chain, contains autonomic nerve fibers

Dura mater

outermost layer, dense fibrous connective tissue, protects and surrounds the spinal cord

Arachnoid

middle layer, thin, encloses CSF

Pia mater

innermost layer, thin and delicate, closely covers spinal cord

Denticulate ligaments

extensions of the pia mater, anchors spinal cord to dura mater

Subarachnoid space

between arachnoid and pia mater, contains CSF, cushions and protects the spinal cord

Epidural space

between dura mater and vertebral canal, contains fat, provides cushioning

Cervical enlargement

contains extra neurons that control upper limbs

Lumbar enlargement

contains extra neurons that control the lower limbs

Conus medullaris

cone shaped end of the spinal cord

Filum terminale

a thin strand of pia mater extending downward from the conus medullaris

Cauda equina

extension of conus medullaris, carries sensory and motor info to and from the lower body

Sympathetic chain

2 vertical chains of ganglia along the spine, contains sympathetic autonomic nerves, distributes sympathetic signals throughout the body

Sympathetic chain ganglia

small clusters of neural cell bodies along sympathetic chain, contain bodies of sympathetic postganglionic neurons, serve at relay stations where preganglionic sympathetic neurons communicate with postganglionic neurons

Cervical plexus

provides sensation to neck and ear

Phrenic nerve

controls diaphragm, allows breathing

Brachial plexus

provides motor and sensory innervation to the upper limbs

Radial nerve

controls extensions of elbow, wrist, and fingers; sensation of arm

Median nerve

controls forearm flexors and sensation to hand

Ulnar nerve

controls small hand muscles, sensation to pinky and ring finger

Musculocutaneous nerve

controls elbow flexion, provides sensation to forearm

Lumbar plexus

functions lower ab wall and thighs

Lateral femoral cutaneous nerve

provides sensation to outer thigh

Femoral nerve

controls hip flexion and knee extension, provides sensation to leg

Obturator nerve

controls thigh adduction and sensation to medial thigh

Sacral plexus

supplies buttocks, thigh, lower leg, and foot

Sciatic nerve

controls muscles of posterior thigh and lower leg/foot

Tibial nerve

controls plantar flexion and toe flexion, sensation to sole of foot

Common peroneal (fibular) nerve

controls dorsiflexion and eversion, sensation to lower leg and top of foot

Sural nerve

sensation to lower leg

Intercostal nerves (thoracic nerves)

helps with breathing, sensation to chest and abdominal wall

Left brain

artistic and empathy

Right brain

logic and language

Beta waves

active thinking

Alpha waves

relaxed alertness

Theta waves

early stages of sleep

Delta waves

deep sleep

Cerebrum

conscious thought processes, intellectual functions, memory storing and processing, conscious/subconscious regulation of skeletal muscle contractions

Frontal lobe

controls voluntary movement, involved in planning, decision making, personality, problem solving

Parietal lobe

physical sensations; processes touch, pain, pressure, temperature

Occipital lobe

processes visual info

Temporal lobe

involved in hearing, memory, and language comprehension

Insula

involved in taste, internal body sensations, emotion, awareness of body’s internal condition

Longitudinal fissure

deep groove separating right and left hemispheres

Lateral sulcus

separates temporal lobe from frontal and parietal

Parieto-occipital sulcus

separates parietal and occipital lobes

Central sulcus

separates frontal and parietal lobes

Precentral gyrus

controls voluntary skeletal muscle

Postcentral gyrus

receives sensory info

Caudate nucleus

regulates voluntary movement, involved in learning and motor control

Internal capsule

carries info between cerebral cortex and lower parts of nervous system

Globus pallidus

regulates movement, controls the intensity of movements

Putamen

regulates voluntary movement

Transverse fissure

deep groove separating cerebrum from cerebellum

Cerebellum

coordinates voluntary movements, maintains balance and posture, helps make movements smooth and accurate

Cerebellar hemispheres

coordinate movement and motor activity

Vermis

coordinates posture and movements of trunk

Folia

increases surface area of cerebral cortex

Arbor vitae

carries signals to and from the cerebellar cortex

Middle cerebellar peduncle

carries info from pons to cerebellum

Superior colliculi

visual reflexes, coordinates eye and head movements in response to visual stimuli

Inferior colliculi

auditory reflexes, processes sound and coordinates responses to sounds

Cerebral peduncles

carry motor signals from cerebrum toward brainstem and spinal cord

Substantia nigra

produces dopamine, regulates voluntary movement

Pons

helps regulate breathing, carries signals from brain to the spinal cord

Medulla oblongata

relays sensory info to the thalamus and brainstem, autonomic centers relay visceral function, regulates heart rate, blood pressure, breathing, swallowing, coughing/vomiting reflexes

Pyramids of medulla

Cranial nerves (I – XII)

Olfactory bulb

processes smell info

Olfactory tract

carries smell info from olfactory bulb to brain

Optic nerve

visual info from retina to brain

Optic chiasm (chiasma)

allows visual info from both sides to be processed by both sides of the brain