Neuroanatomy Flashcards
Central Nervous System (anatomical)
Brain (cerebrum, cerebellum, brain stem, subthalamus, basal ganglia) and spinal cord.
Peripheral Nervous System (anatomical)
12 cranial nerves and 31 spinal nerves and sensory receptors
Autonomic Nervous System (functional)
INVOLUNTARY
Sympathetic: arousing/fight or flight - controls organs, smooth muscle, heart muscle.
Parasympathetic: calming - controls organs, smooth muscle, heart muscle.
Somatic Nervous system (functional)
VOLUNTARY
Sensory (Afferent): Vision, hearing, touch, pressure pain -controls skeletal muscle
Motor (Efferent): Generating motor responses -controls skeletal muscle
prosencephalon (forebrain)
Diencephalon - Thalamus, Hypothalamus, Pituitary gland, Optic tract, Third Ventricle.
Telencephalon - Cerebral hemispheres, white matter beneath, basal ganglia, olfactory tract.
Sulci
on cerebral cortex. grooves between raised area.
Gyri
on cerebral cortex. raised areas.
Fissure
If Sulci groove is deep we call it a fissure instead
Mesencephalon (midbrain)
Approx. 2cm long.
Major part of the brainstem.
aids in controlling movement and sensory process such as vision and hearing.
Rhombencephalon (hindbrain)
Includes cerebellum, medulla, and pons.
Cerebrum
Two cerebral hemispheres connected by corpus collosum. The Cerebral cortex (outer layer or bark).
CONSCIOUS. Perception, awareness, motor planning and prep., cognitive function, attention, decision making, voluntary motor inhibition, language function, speech function
Pons
receives information from visual areas to control eye and body movements. Also plays a role in controlling patterns of sleep and arousal
Corpus Callosum
connects the two cerebral hemispheres.
Cerebellum
“little brain” with Pons, controls movement and maintains equilibrium.
Medulla
controls unconscious yet essential body functions such as breathing, swallowing, blood circulation and muscle tone
Plexus
Network of nerves
ganglia
group of nerve cell bodies (usually in PNS)
glial cells
nutrients to neurons, support, myelin. COMMUNICATING tissue.
neuron
ind. nerve fiber
What composes the brain stem?
Midbrain, Pons, Medulla
what are the two types of neural responses?
Excitation: a stimulation that causes an increase of activity of the tissue stimulated
inhibition: refers to stimulation of a neuron that reduces the neuron’s output. (when a neuron is inhibited, it reduces its activity - ex: hearing a siren at a traffic light).
What is gray matter?
A high concentration of cell bodies.
What is white matter referred to as?
Myelin - communication to different areas of your brain.
Unipolar Neuron
Neuron with single bifurcating process arising from the soma (SENSORY except hearing and smell) - afferent
Bipolar Neuron
Neuron with two processes (SENSORY hearing and smell) - afferent
Multipolar Neuron
Neuron with more than two processes (MOTOR) - efferent
Afferent
signals carried towards the brain
Efferent
signals carried away from the brain
Types of Meningeal linings covering the brain
- Dura Mater - tough bi-layered lining. most superficial.
- Arachnoid Mater - spider like, filled with cerebrospinal fluid and creates a suspension system
- Pia Mater - Thin, membranous covering that closely follows the contour of the brain.
What is the function of the meningeal linings?
Protect the brain, holding structures in place during movement, provide support for structures.
Cerebrospinal Fluid
cushions brain, serves as transport system, inadequate flow leads to hydrocephalus. Removes waste.
volume is approx. 125 mL
replenished every 7 hours.
The Cerebral Cortex is considered the _____ of the brain
Bark. it is between 2 and 4 mm thick.
Pyramidal System
the voluntary motor pathway that we use for moving in space/producing speech. (two major efferent tracts)
Extra-pyramidal System
Not a discreet anatomical entity in the brain.
involves cerebellum and basal ganglia - maintain coordinated movements.
provides background tone and movement supporting the primary acts; involves basal ganglia and reticular formation.
upper motor neurons
begin in cortex and travel down to brain stem or spinal cord. “excitatory and inhibitory”
lower motor neurons
begin in spinal cord and go on to innervate muscles throughout the body. “excitatory”
Circle of Willis
part of Cerebrovascular system. Arteries that come together at the base of the skull.
What are 3 types of trauma that can lead to Cerebrovascular accidents (CVA’s)?
- Thrombosis - foreign body obstructs blood vessel
- Embolism - blood clot that arrives via bloodstream
- Aneurysm - dilation or ballooning of blood vessel, which can rupture and bleed.
what makes up a motor unit?
Lower motor neurons + Endplate within muscle.
what are ventricles?
spaces in the brain through which the Cerebrospinal fluid flows.
Brodmann Map
localized areas of the brain are dominated by specific cell types. Pertaining to Cerebral layers.
what are pyramidal cells?
large, pyramid-shaped cells involved in motor function.
cerebral longitudinal fissure
separates left and right cerebral hemispheres
frontal lobe
Planning, starting and preventing voluntary movements (Issues with it can lead to impulsive behavior)
parietal lobe
Somatosensory reception - contains association areas that integrate responses to auditory, visual, and somatosensory stimuli.
occipital lobe
Primary visual reception area
temporal lobe
auditory reception
insular lobe
hidden lobe. You would have to pull the temporal lobe up to see it.
Taste, auditory processing, emotion, homeostasis, self awareness, cognitive functioning.
limbic system
6th “virtual lobe”
no anatomical area, just a conglomerate of a # of distinct anatomical areas that can be considered a system/lobe because of their function.
motivation, sex drive, emotional behavior.
Wernicke’s area
Auditory comprehension. interpreting spoken language.
Heschls Gyrus
primary auditory processing area.
Broca’s area
Producing spoken language - motor speech
Projection fibers
connect the cortex with distant locations. (ex. corona radiata)
association fibers (white matter)
provide communication between regions of the same hemisphere.
short - connect neurons of one gyrus to the next
long - connect lobes of brain within same hemisphere.
commissural fibers (white matter)
connects the cerebral hemispheres (ex. corpus collosum)
Basal ganglia (white matter)
a group of cell bodies intimately related to the control of background movement and initiation of movement patterns.
Cerebrovascular System
the vascular system of the brain maintains constant circulation required by the nervous system.
Thalamus
Gray matter sensory relay station
Hypophysis
pituitary gland = makes essential hormones
affects of lesions on cranial nerves
Paralysis: gross limitation of movement
paresis: partial paralysis
hemiplegia: one-sided paralysis
corticospinal tract
descends from motor cortex to spinal column. (EFFERENT)
corticobulbar tract
descends from motor cortex to the brain stem. (EFFERENT)
what happens if there is a lesion on the Lower Motor Neuron?
Loss of excitation, hypotonia (loss of muscle tone)
what happens if there is a lesion on the upper motor neuron?
Loss of inhibition, hypertonia (excess of tone)
cranial nerves are controlled?
bilaterally and by upper motor neurons. so if one side is damaged at the upper motor neuron level, there may still be control because the other side is intact.
spinal nerves are controlled?
contralateral and by lower motor neurons. Affects can be more marked in that case.
arcuate fasciculus
connects Broca’s area and Wernicke’s area
Anterior spinothalamic tract
pathway from spinal nerves to cortex, carries somatosensory info. to the thalamus (AFFERENT)
A visual representation of the proportion of the precentral gyrus devoted to various parts of the body
motor homunculus
spinal arc reflex
Fundamental responses that take place at the spinal or brainstem level. (doesn’t require higher processing in the thalamus)
Dysarthria
Difficulties in the production of speech
Resulting from: Paralysis, weakness, or dyscoordination of speech musculature.
Flaccid, Spastic, Ataxic
Dyspraxia/Apraxia
Difficulties finding right words and initiating speech process (can come along with dysarthria)
resulting from: damage to supplementary motor area, insular cortex
Wernicke’s Aphasia
difficulty processing what is heard “word salad”
Aphasia
problem with language in the brain as a result of a problem in brain.
brain damage
Broca’s Aphasia
you an comprehend what you hear you just have difficulty producing speech
Conduction Aphasia
damage to arcuate fasciculus. a person can comprehend speech and written material but cannot repeat what is heard.
