5.1 Organization of the Brain (Dental Decks also used) Flashcards
The white matter of the spinal cord contains tracts that provide and recieve information to and from the brain. What is the function of the ascending tracts and descending tracts?
ascending travels toward the brain - sensory
descending travels away from the brain - motor
Which ascending (sensory) tract of the spinal cord has the function of: pain, temperature, and crude touch to the opposite side?
Lateral spinothalamic
Which ascending (sensory) tract of the spinal cord has the function of: crude touch and pressure?
Anterior spinothalamic
Which ascending (sensory) tract of the spinal cord has the function of: discriminating touch and pressure sensations?
DCML
Fasciculus gracilis
Fasciculus cuneatus
Which ascending (sensory) tract of the spinal cord has the function of: unconscious kinesthesia?
Anterior and posterior spinocerebellar
What lies in the longitudinal fissure and separates the cerebral hemispheres?
Falx cerebri
What separates the occipital lobe of the cerebrum and the cerebellum?
Tentorium cerebelli
What separates the two lobes of the cerebellum?
Falx cerebelli
contains occipital sinus
What is the epidural space?
over the dura matter
epidermal hematoma = accumulation of blood from a torn meningeal artery
What is the subdural space?
a closed space between the dura matter and the arachnoid membrane
often the site of hemorrhage after head trauma, associated vessel is the bridging vein
What is the associated vessel in a subarachnoid hemorrhage?
Circle of Willis
Berry Aneurysm
What CN’s arise in the pons?
- Trigeminal - CN V
- Abducens - CN VI
- Facial - CN VII
5,6,7
What CN’s are attached to the medulla oblongata?
- Glossopharyngeal - CN IX
- Vagus - CN X
- Spinal Accessory - CN XI
- Hypoglossal - CN XII
9 - 12
What in the midbrain helps to control movement, a lession of it will cause Parkinson’s Disease?
substantia nigra
What part of the brain serves as an exit tract for CN V?
Pons “bridge”
What area in the medulla oblongata, is involved in regulating sleep and arousal, pain perception, and includes vital centers that regulate breathing and heart activity?
reticular formation
central core of gray matter
Where are the inferior and superior sagittal sinuses found?
Falx cerebri
What contains the straight, transverse, and superior petrosal sinuses?
Tentorium cerebelli
What is the thin, wrinkled gray matter covering each cerebral hemisphere?
cerebral cortex
What layer of the cerebrum is a thick core of white matter?
cerebral medulla
What is the function of the cerebellum?
control of movement and balance
What lines most of the ventricular system of the CNS?
ependymal cells
What cells provide structural support in the CNS?
astrocytes
What are modified ependymal cells that form the inner layer of the choroid plexus, and secrete CSF into the ventricles?
Choroidal Cells
What support cell bodies in ganglia within the PNS?
satellite cells
What is the NT of preganglionic sympathetic neurons?
acetylcholine
In which system of the ANS are the preganglionic neurons relatively short and the postganglionic axons relatively long?
Sympathetic
What is the NT of the postganglionic sympathetic axons?
NE except for adrenal medulla and sweat glands
What nerves is the parasympathetic system dervided from?
- CN III
- CN VII
- CN IX
- S2-S4
Through what opening do the lateral ventricles communicate with the 3rd ventricle?
interventricular foramen (foramen of Monro)
The third ventricle is continous with the forth ventricle via?
cerebral aqueduct (aqueduct of Sylvius)
traverese the midbrain
Where is the third ventricle?
diencephalon
What provides communication between the fourth ventricle and the subarachnoid space?
a median aperture (foramen of Magendie) and two lateral apertures (foramina of Luschka)
Where and how and when does absorption fo the CSF into the bloodstream occur?
- superior sagital sinus
- via arachnoid granulations (arachnoid villi)
- one way valves
- when CSF pressure is > venous pressure
What do the lateral ventricles use to communicate to each other?
septum pellucidum
What muscle fibers do the alpha motor neurons innervate?
Extrafusal muscle fibers
most numerous
involved in muscle contraction
What muscle fibers do the gamma motor neurons innervate?
intrafusal muscle fibers
together with sensory afferents compose muscle spindles
sense body position (proprioception)
In the 3rd week of prenatal development, what cells develop from the neuroectoderm, and migrate to disperse whithin the mesenchym. They are involved in the development of many face and neck structures, such as branchial arches?
neural crest cells
What is neurulation?
The stage in vertebrae embryos during which the neural tube is transformed into the primitive structures that will become the CNS.
Begining in the 3rd week with the folding of ectoderm creating the indentation known as the neural groove.
What nerve fibers carry information related to proprioception?
A-alpha
What nerve fibers carry information related to touch?
A-beta
What nerve fibers carry information related to pain and temperature?
A-delta
What nerve fibers carry information related to pain, temperature, and itch?
C-nerve
All autonomic preganglionic synapses have what as a neurotransmitter and receptor?
Ach
nicotinic receptors
All postganglionic parasympathetic synapses have what as a NT and receptor?
Ach
muscarinic receptors
Most postganglionic sympathetic synapses have what as the NT, with which receptors?
NE
adrenergic
What is the sympathetic preganglionic NT at adrenal medulla?
Ach
nicotinic receptor
What is the sympathetic postganglionic NT and associtated receptor at sweat glands?
Ach
muscarinic
What dysfunction of the cerebellum causes a disturbance that alters the direction and extent of voluntary movements; abnormal gait and uncoordinated movements?
Ataxia
What dysfunction of the cerebellum causes an altered range of motion (misjudged distance)?
Dysmetria
What dysfunction of the cerebellum causes oscillating motion, especially of head during movement?
Intention tremor
What dysfunction of the cerebellum causes nystagmus, head tilt?
Vestibular signs
What cerebellar cortex cells are the only output neuron from the cortex to utilize GABA to inhibit neurons in deep cerebellar nuclei?
Purkinje cells
Intrinsic cells of cerebellar cortex; use glutamate as an excitatory transmitter; excites Purkinje cells via axonal branches called “parallel fibers”
Granule Cells
Inhibitory interneuron; utilizes GABA to inhibit Purkinje cells.
Basket Cells
What descending tract of the spinal cord’s major function is: voluntary movement, contraction of individual or small groups of muscles?
Lateral Corticospinal (crossed pyramid)
Upper and Lower Limbs
What descending tract of the spinal cord’s major function is: voluntary movement, contraction of individual or small groups of muscles of the same side?
Anterior Corticospinal (direct pyramidal)
Trunk
What descending tract of the spinal cord’s major function is: mainly facilitary influence on motor neurons to skeletal muscles?
Lateral reticulospinal
What descending tract of the spinal cord’s major function is: mainly inhibitory influence on motor neurons to skeletal muscles?
Medial reticulospinal
What descending tract of the spinal cord’s major function is: coordination of body movement and posture?
Rubrospinal
What descending tract of the spinal cord’s major function is: mediates the influences of the vestibular end organ and the cerebellum upon extensor muscle tone?
Vestibulospinal
What descending tract of the spinal cord’s major function is: coordination of head, neck and eye movements?
Tectospinal tract (colliculospinal)
