"Quizable material" Quiz 1 Flashcards
What arteries provide the anterior cerebral circulation for the circle of willis?
Carotid arteries
What branch of the carotid arteries enter at the base of the skull?
The internal branch
What does the carotid artery of the circle of willis bifurcate into?
The external and internal carotid arteries
What artery supplies the eye from the circle of willis?
Ophthalmic artery
What does the circle of willis ultimately bifurcate into?
The anterior and middle cerebral arteries
What is the purpose of CSF?
Surrounds all exposed surfaces of CNS
Cushions, supports, and transports
What does the CSF interchange with?
Interchanges with interstitial fluid of the brain
What protrudes superiorly into dural sinus and permits CSF to be absorbed into venous blood?
Arachnoid villi
What is the flow of CSF?
Through ventricles
To arachnoid space
To dural sinuses (back to circulation)
Where is CSF Produced?
CSF is produced in the lateral ventricles and travels into the third ventricle via the interventricular foramina or Foramen of Monroe.
It subsequently transits through the cerebral aqueduct (aqueduct of Sylvius) into the fourth ventricle, and then into the space around the brain via the foramina of Luschka and Magendie.
Absorption of CSF into the dural venous sinuses occurs through what?
Arachnoid granulations
What produces CSF?
Choroid plexus in the ventricles
What increases CSF volume
Choroid plexus papilloma
Hyperthermia
Decreased serum osmolality
Increased CSF osmolality
What decreases CSF
Hypothermia
Increased hydrostatic pressure
Diamox
Increased serum osmolality
Decreased CSF osmolality
What makes up the CNS neuroglia (Glial cells)?
Astrocytes
Oligodendrocytes
Microglia
Ependymal cells
What makes up PNS neuroglia?
Schwann Cells
Satellite cells
What is the function of astrocytes?
Wrap around the nerve cell and support the cell
Predominate glial cell
Hypertrophy when cell is injuried
Create the Blood brain barrier
Provide structural support for neuron
Regulate metabolic environment
Where are the oligodendroglia and what is their function
Interposed between neuron and blood vessels
Create Myelin sheath around axons which transmits impulses faster than unmyelinated axons
What is the function of microglia
Small cells which move along inflamed or damaged brain cells
Function is phagocytosis of cellular waste and pathogens
Where are ependymal cells located and what is their function
line central canal of the spinal column and ventricular cavities;
they are ciliated and combine with endothelial cells to form a choroid plexus which secretes CSF
Where are schwann cells and what is their function
Surround axons in PNS and create neurilemma
Creates myelin sheath around most axons of PNS
the neurilemma allows for potential ________ of damaged axons
regeneration
Satellite cells support groups of cell bodies of neurons within _______ of the PNS
ganglia
What does the tentorium separate?
Tentorium is a horizontal folding of the dura separating the upper supratentorial cavity and lower infratentorial space
What is the supratentorial space divided into?
Divided into the right an left side for each cerebral hemisphere be an interhemispheric fissure occupied by an invagination of dura, the falx cerebri.
In what tentorial space is the cerebellum contained in?
Infratentorial
Divided into right and left cerebellar hemispheres by falx cerebelli
What divides the cerebellar hemispheres?
Falx cerebelli
What 4 parts make up the neuron stucture
Dendrites
Cell body
Axon
Synaptic terminals
Dendrites are stimulated by _____________ changes or the activities of other ______
Environmental changes
Other cells
The cell body of the neuron contains what?
Nucleus
Mitochondria
Ribosomes
Other organelles and inclusions
what conducts nerve impulses (action potential) toward synaptic terminals away from the cell body?
Axon
Vary in length and thickness
Nodes of Ranvier unmyelinated between Schwann cells
Neurolemma essential for peripheral nerve generation
Synaptic terminals affect what?
affect other neurons or effector organs (muscle or gland)
What are the structural classes of neurons?
Multipolar neuron
Bipolar neuron
Unipolar neurons
What structural class makes up the majority of CNS neurons?
Multipolar
Multiple dendrites and 1 axon
What are the rarest structural class of neurons? What three locations are they found
Bipolar neurons
Only in retina, ear, and olfactory
What structural class of neurons is found in DRG and cranial ganglial cells?
Pseudounipolar
Allows sensory input to travel from dendrite to axon without going through cell body
What are the functional classifications of neurons?
Sensory (afferent)
Motor (efferent)
Association (interneurons)
Afferent (sensory) neurons transmit sensory information from receptors of ___ toward the CNS
Most are unipolar a few are bipolar
PNS
Efferent (motor) neurons transmit motor information from the ___ to effector (muscles/glands/adipose tissue) in the periphery of the body
All are multipolar
CNS
What type of neuron transmits information between neurons within the CNS, analyzes inputs, and coordinates outputs?
Is the most common
Are all multipolar
Association (interneurons)
What is the perikaryon also known as?
Cell body
