bmeg 350 neuro 1

sagittal plane

middle through body

coronal plane

shoulder to shoulder

transverse/horizontal/axial plane

half

Dorsal

toward spine

ventral

toward belly

anterior

towards front

posterior

towards back

superior

towards top

inferior

towards bottom

anterior brain

front

posterior brain

back

superior brain

toward head

inferior brain

toward feet

dorsal brain

superior to brain

ventral brain

inferior to brain

rostral brain

toward noise; because of cephalic flexure

caudal brain

toward back of head/spinal cord

rostral SC

up

caudal SC

bottom

ventral SC

front

dorsal SC

back

peripheral nervous system

communication; cranial nerve and spinal nerve

central nervous system

processing; brain and spinal cord

gyri

surface folds of cerebrum; increase SA so more neurons and grey matter —> higher cognitive function

sulci

grooves; increase SA, organize regions of lobes

fissures

large sulci

frontal lobe

motor control (premotor cortex), problem solving (prefrontal area), speed (Broca’s area)

brainstem

midbrain/pons/medulla, auto control (breath, HR), conduit b/w brain and SC

temporal lobe

auditory processing (hearing), language comprehension (Wenicke’s area), memory/info retrieval

parietal lobe

touch perception (somatosensory cortex), body orientation and sensory discrimintation

occipital lobe

sight (visual cortex), visual reception and visual interpretation

cerebellum

balance, coordination

Precentral gyrus

primary mortar cortex (anterior)

Postcentral gyrus

 primary comatoesensory cortext

Somatosensory and motor homunculus

size of each region of the homunculi is related to its importance in sensory or motor function; fine motor control and dense sensory input (hands, lips, tongue = large cortical area).

Cerebrum

 conscious thought, voluntary movement, sensory perception

motor cortex

initiates voluntary movement

sensory cortex

processes sensory input

interneurons

neuron entirely within CNS; processing and linking sensory and motor neurons; reflexes and complex movement 

reflex path

stimulus → SC → motor neuron → muscle (brain notified after)

Gray matter

neuron cell bodies, butterfly-shaped center, processing and integration

White matter

myelinated axons, outer region, signal conduction 

Dorsal root

 into CNS; sensory input Ventral root: out of CNS, motor output 

Association fibers

 connects areas within same hemisphere

Commissural fibers

connect left and right hemispheres ex. Corpus collosom

Projection fibers

connect cortex → brainstem/spinal cord

Cervical SC

• concave posteriorly, secondary curvature 

thoracic SC

• convex posteriorly, concave anteriorly, primary curvature

Lumbar

•  concave possteriorly, secondary curvature

Sacral

• convex posteriorly, concave anteriorly; primary curvature 

Reflexes

• automatic, rapid, involuntary response to stimulus; for protection and speed (bypass brain); processed at SC

Reflex arc

• 1. Sensory receptor 2. Sensory neron 3. Integration center (SC) 4. Motor neuron 5. Effector (muscle)

Monosynaptic reflex

• one synapse, fastest; ex. Patellar 

Polysynaptic reflex

• multi synapse, involves interneurons; ex. Withdrawal 

Reciprocal inhibition

• when agonist muscle contracts, antagonist muscle is inhibited; prevents opposing F