Neurologic System: A&P Flashcards
Central Nervous System
includes the brain and spinal cord
Cerebral Cortex
the cerebrum outer layer of nerve cell bodies, humans’ highest functions - governing thought, memory, reasoning, sensation and voluntary movement
Cerebral Hemispheres
each half of the cerebrum is a hemisphere; the L hemisphere is dominant in most people
Frontal Lobe
area concerned with personality, behavior, emotions and intellectual function; precentral gyrus initiates involuntary movement
Broca’s Area
in frontal lobe, mediates motor speech
if damaged, expressive aphasia results and person cannot talk.
Parietal Lobe
post central gyrus is the primary center for sensation
Occipital Lobe
primary visual receptor center
Temporal Lobe
primary auditory reception center
taste and smell
Wernicke’s Area
in temporal lobe, is associated with language comprehension.
when damaged, receptive aphasia results - person hears but it has no meaning.
Basal Ganglia
- bands of gray matter buried deep within two cerebral hemispheres that forms the extrapyramidal system
- controls automatic associated movements of the body
Thalamus
main relay station for the nervous system where sensory pathways of the spinal cord, cerebellum, basal ganglia and brainstem form synapses.
has connections that are crucial to human emotion and creativity.
Hypothalamus
major control center with many vital functions
The hypothalamus controls what functions?
temperature*
heart rate
b/p control
sleep center
anterior and posterior pituitary gland regulator
coordinator of autonomic nervous system activity and emotional status
Cerebellum
a coiled structure located under the occipital lobe that is concerned with motor coordination of voluntary movements, equilibrium and muscle tone
it does not initiate movement but coordinates and smooths movement
Brain Stem
central core of the brain consisting of mostly nerve fibers
Midbrain
anterior part of brain stem that still has the basic tubular structure of the spinal cord
merges into thalamus and hypothalamus
Pons
enlarged area containing ascending and descending fiber tracts.
has two respiratory centers that coordinate with the main respiratory center in the medulla.
Medulla
continuation of the spinal cord in the brain, contains all ascending and descending fiber tracts connecting the brain and spinal cord, vital autonomic centers (respiration, heart and GI function)
Spinal Cord
- long cylindrical structure that occupies the upper 2/3 of the vertebral canal
- it is the main highway for ascending and descending fiber tracts that connect the brain to the spinal nerves and mediates reflexes
Cerebellar System
complex motor system coordinates movement, maintains equilibrium and helps maintain posture on a subconscious level
Upper Motor Neurons
all the descending motor fibers that can influence or modify the lower motor neurons
upper motor neurons are located completely with the CNS
know what diseases go along with which neurons?
Lower Motor Neurons
- located mostly in the peripheral nervous system, the cell body of the lower motor neuron is located in the anterior gray column of the spinal cord, but the nerve fiber extends from here to the muscle
- any movement must be translated into action by lower motor neuron fibers
- Know what diseases go along with which motor neurons
Peripheral Nervous System includes
includes the 12 pairs of cranial nerves, 21 spinal nerves and all their branches
Peripheral Nervous System
carries sensory messages to the CNS through afferent fibers
Cranial Nerves
- enter/exit the brain
- the 12 pairs of cranial nerves supply primarily the head and neck, except the vagus nerve - which travels to heart, respiratory muscles, stomach and gallbladder
Spinal Nerves
arise from the length of the spinal cord and supply the rest of the body - 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal - contains both sensory and motor fibers
Dermatome
circumscribed skin area that is supplied mainly from one spinal cord segment through a particular spinal nerve
Autonomic Nervous System
- the peripheral nervous system is composed of cranial nerves and spinal nerves
- these nerves carry fibers that can be divided functionally into two parts - somatic and autonomic
Somatic
somatic fibers innervate the skeletal (voluntary) muscles
Autonomic
innervate smooth (involuntary) muscles, cardiac muscles and glands, mediates unconscious activity, overall function is to maintain homeostasis of the body
Reflex Arc
reflexes are basic defense mechanisms of the nervous system
they are involuntary and help the body maintain balance and appropriate muscle tone
Reflexes include
Deep Tendon Reflexes - i.e patellar Superficial Reflexes - i.e cornea, abdominal Visceral Reflexes - i.e pupillary response to light Pathologic Reflexes (abnormal) - i.e. babinski
Lateral Spinothalamic Tract
contains fibers carrying pain and temperature sensations
Culture and Genetics
Racial/Ethnic Disparity noted relative to strokes: 4% African American, 6% Indians/Alaska Natives, 2.5% Hispanics
Geographic Disparity relative to strokes.
Anterior Spinothalamic Tract
sensations of crude touch form the anterior spinothalamic tract
Spinothalamic Tract
contains sensory fibers that transmit the sensations of pain, temperature, and crude or light touch.
Corticospinal fibers
aka pyramidal tract
mediate voluntary movement, particularly very skilled, discrete, and purposeful movements, such as writing.
