Disorders of the Central Nervous System: Lecture Notes Review

Fill-in-the-blank flashcards covering key CNS topics such as membrane potentials, neuron and glial cell roles, barriers, CSF, autoregulation, spinal cord anatomy, and synaptic transmission.

At rest, the resting membrane potential is approximately __ mV.

-70

During an action potential, after depolarization, Na+ flows in, Na+ channels close and K+ channels open, leading to repolarization, and the membrane becomes briefly __.

hyperpolarized

The Na+/K+ ATPase pumps Na+ out of the cell and K+ into the cell, contributing to the membrane potential of about __ mV.

-70

The average neuron forms about __ synaptic connections.

1000

Glia outnumber neurons by about __ (to 1) but occupy ~50% of the CNS space.

3:1

Astrocytes contribute to isolation of the CNS by forming part of the __.

blood-brain barrier

In the CNS, oligodendrocytes produce the __ sheath that insulates multiple axons.

myelin

Microglia are the CNS immune cells that act as __.

phagocytes

Ependymal cells line the ventricles and central canal and form the __ that produces CSF.

choroid plexus

CSF maintains a constant external environment for neurons and glia; this is brain __.

homeostasis

The Blood–Brain Barrier is formed by microvascular endothelial cells, astrocytes, and __.

pericytes

The Blood–CSF Barrier is formed by the __ epithelium of the choroid plexus.

choroid plexus

The CSF normally consists of glucose, salts, enzymes and a few white blood cells; the CSF protein concentration is about __ mg/L.

200-400

Normal CSF WBC count is approximately __ per mL.

0-5

CSF glucose is about __ mM.

3

Motor neurons are located in the __ horn of the spinal cord.

ventral

Three functional types of neurons are sensory neurons, interneurons, and __.

motor neurons

Three main structures of the brain are the cerebrum, the cerebellum, and the __.

brainstem

The brain uses about __% of the body's total oxygen (O2) consumption.

20

MAP can vary from to mmHg while maintaining cerebral blood flow.

60-150

The brain represents about __% of body weight.

2

Neurons are post-mitotic, meaning they do not __ after reaching maturity.

divide

At a synapse, the influx of __ through voltage-gated channels triggers neurotransmitter release.

calcium

The three barrier sites in the CNS are the Blood–Brain Barrier, the Blood–CSF Barrier, and the __ Barrier.

arachnoid

In autoregulation, inhaling 5% CO2 increases cerebral blood flow by about __%.

50

In autoregulation, inhaling 7% CO2 increases cerebral blood flow by about __%.

100

Nodes of Ranvier are gaps in the myelin that boost the __ of the action potential.

amplitude

The spinal cord length is about __ cm in males.

45

Dendrites receive incoming signals; the axon conducts electrical signals; myelin speed of action potentials.

increases