Warmup-09-10-Nervous System
The arachnoid has two parts:
A layer of connective tissue adjacent to the dura mater, and a network of collagen and fibroblasts, connected to the pia mater.
The blood-brain barrier is made up of capillary endothelium in which the cells are tightly connected and allow almost no passage of substances. The capillaries are enveloped in a basement membrane. The third component is
A layer of perivascular astrocytic "feet"
Sensory nerve fibers are
Afferent
Which of these substances can pass through the blood-brain barrier?
Alcohol
Which of these is true?
Arachnoid villi release excess CSF into the blood
The choroid plexus consists of ependyma and vascularized pia mater. It functions as a type of barrier between
Blood and the CSF
What protects neurons and glia from bacterial toxins, infectious agents, etc., and maintains the composition and balance of ions in the interstitial fluid?
Blood-Brain barrier
Typically, a spinal nerve has
Both sensory and motor fibers
Ganglia are clusters of neuron cell bodies in the PNS. In the CNS, clusters of neuron cell bodies are called
Cerebral nuclei
One of the functions of the sub-arachnoid space is to
Cushion the CNS from damage
Which of these has only sensory fibers?
Dorsal root of spinal cord
What are the components of the choroid plexus?
Ependyma and pia mater with blood vessels.
Around the spinal cord, the dura mater is separated from the periosteum of the vertebrae by the
Epidural space
In a ___________________, blood from the middle meningeal artery accumulates between the skull bones and the dura mater.
Extradural hemorrhage
Where in the nervous system do most synapses occur?
Gray matter
Which region is marked by the letter A?
Gray matter
The autonomic nervous system regulates or manages
Homeostasis
The Nodes of Ranvier contribute to saltatory conduction. Which is true?
In saltatory conduction the action potential is faster than that in unmyelinated fibers.
Where is the choroid plexus found?
In the roofs of the 3rd and 4th brain ventricles
What does the Node of Ranvier do?
It aids in conduction of the action potential along axons.
The pia mater is closely applied to the entire surface of the CNS tissue. What is its function?
It forms a physical barrier separating CNS tissue from CSF in the subarachnoid space.
What is the caudal equina?
It is the collection of the spinal nerves searching the lumbar, coccygeal, and sacral regions.
From where does the arachnoid layer get its name?
It resembles a spider web.
Myelin is composed of
Lipids and proteins
Which of the glial cells is in the immune system?
Microglia
The anterior horns of the spinal cord contain mainly cell bodies of
Motor neurons
In the PNS, bundles of myelinated axons are called
Nerves
Which of these is true? Ganglia are made of clusters of nerve cell bodies in the PNS All of these are true. Tracts are part of the CNS only, not the PNS Nerves are part of the PNS only, not the CNS.
Nerves are part of the PNS only, not the CNS.
The central canal of the spinal cord and the ventricles of the brain are formed from the embryonic
Neural tube
A bundle of myelinated axons is called a fascicle. It is covered by
None of these
How many pairs of thoracic nerves are there in humans?
None of these.
Which cells form the myelin sheathes of cells in the CNS?
Oligodendrocytes
The dura mater is
One of the meninges of the CNS
Ganglia are clusters of nerve cell bodies (as opposed to axons and dendrites). Where are ganglia found?
Only in the peripheral nervous system,
Which meningeal layer lies between the CSF and the tissue of the CNS
Pia mater
The blood-brain barrier protects the CNS from harmful agents. It also
Prevents passage of some clinically important drugs.
A subarachnoid hemorrhage may result from a
Saccular aneurysm
Which type of glial cells are associated with ganglia?
Satellite cells
Which cells form myelin sheathes of axons in the PNS?
Schwann Cells
What is filled with CSF and cushions and protects the CNS?
Subarachnoid space
White matter is white because of
The lipid content of the cell membrane sheaths
What is the clinical advantage of knowing where the dermatomes are located on the body?
This knowledge can help diagnose which spinal nerves may be damaged.
In the CNS, bundles of myelinated axons are called
Tracts
What happens at the tissue level in Multiple Sclerosis?
White blood cells penetrate the blood-brain barrier and attach the myelin sheath.
The epineurium
Wraps the entire nerve in a layer of connective tissue
The ventricles of the brain are filled with
cerebrospinal fluid