CELL IN THE NERVOUS SYSTEM AND BLOOD BRAIN BARRIER

Everything the brain does depends on the detailed anatomy of its neurons and ______.

glia

Cells that fire together, “wire together” refers to neurons active at the same time becoming ______.

connected

True or False: The brain can connect dendrites or axons even if they cannot find each other.

False

Our behavior emerges from the communication among ______.

neurons

Neurons receive information and convey it to other cells. The nervous system also contains ______.

glia

Neurons contain the same internal structures as other ______ cells.

animal

The four major parts of a neuron are the cell body (or soma), ______, an axon, and presynaptic terminals.

dendrites

Who established that the nervous system is composed of separate cells, now known as neurons?

Santiago Ramón y Cajal

Name the neuron found only in the cerebellum.

Purkinje cell

What type of neuron carries signals from the skin to the spinal cord?

Sensory neuron

What type of cell is found in the motor area of the cerebral cortex?

Pyramidal cell

What type of neuron is found in the retina of the eye?

Bipolar cell

What is the name of the neuron from a honeybee?

Kenyon cell

What glial cell wraps around synapses of functionally related axons to shield them from chemicals?

Astrocytes

Astrocytes help synchronize closely related neurons by taking up and releasing ______ and _____.

ions and transmitters

Astrocytes can generate rhythms such as your rhythm of ______.

breathing

Astrocytes dilate blood vessels to bring more ______ into brain areas with heightened activity.

nutrients

In a tripartite synapse, an axon releases chemicals that cause the neighboring ______ to release chemicals of its own.

astrocyte

What tiny cells act as part of the immune system, removing viruses and fungi from the brain?

Microglia

After brain damage, microglia remove ______ neurons.

dead or damaged

Microglia also contribute to learning by removing the ______ synapses.

weakest

In the brain and spinal cord, ______ build the myelin sheaths that insulate axon

Oligodendrocytes

In the periphery of the body, ______ build the myelin sheaths that insulate axons.

Schwann cells

What type of glial cell guides the migration of neurons, axons, and dendrites during embryonic development?

Radial glia

The ______ is a mechanism that excludes most chemicals from the vertebrate brain.

blood–brain barrier

Why can’t the brain afford to sacrifice infected neurons like skin or blood cells?

The brain does not replace damaged neurons.

The brain’s blood vessels are lined with tightly packed ______ that keep out viruses, bacteria, and harmful chemicals.

cells

Name a virus that evades the blood–brain barrier and infects the brain, leading to death.

Rabies virus

What disease results when the spirochete penetrates the blood–brain barrier?

Syphilis

What condition may appear decades later when the chicken pox virus re-emerges from spinal cord cells?

Shingles

The virus responsible for ______ hides in the nervous system and periodically causes new infections.

genital herpes

The blood–brain barrier depends on the ______ cells that form the walls of capillaries.

endothelial

Outside the brain, such cells are separated by small gaps, but in the brain, they are joined so ______.

tightly

Small, uncharged molecules such as ______ and ______ cross the barrier freely.

oxygen, carbon dioxide

What fat-soluble vitamins can cross the blood–brain barrier?

Vitamins A and D

Water crosses through special ______ channels in the wall of endothelial cells.

protein

The brain’s main fuel, actively transported across the barrier, is _____.

glucose

Aside from glucose, name one other chemical actively transported across the barrier. (5)

amino acids, purines, choline, vitamins, iron

True or False: Insulin crosses the blood–brain barrier in at least small amounts.

True

In conditions like Alzheimer’s disease, the endothelial cells lining blood vessels ______, allowing harmful chemicals to enter

shrink

The blood–brain barrier poses a difficulty in treating ______ because most drugs fail to cross it.

brain cancers

Vertebrate neurons depend almost entirely on ______ for nutrition

glucose

Metabolizing glucose requires ______.

oxygen

Although the brain makes up only 2% of body weight, it uses about ______% of oxygen and ______% of glucose.

20, 25

To use glucose, the body needs vitamin ______, also known as ______.

B1, thiamine

Prolonged thiamine deficiency can lead to neuron death and a condition called ______ syndrome, marked by severe memory impairments.

Korsakoff’s