Neuroscience- 1

Question 1

The human nervous system comprises two kinds of cells

Answer 1

Neurons

Glia

Question 2

The human
brain contains approximately \_\_\_\_\_\_\_\_ individual neurons.
\_\_\_\_ in cerebral cortex.
\_\_\_\_ in cerebellum.
\_\_\_\_spina cord.

Answer 2

• 100 billion
• 12-15 billion
• 70 billion
• 1 billion

Question 3

Santiago Ramón y Cajal

Answer 3

In the late 1800s, the Spanish investigator Santiago Ramon y Cajal (1852-1934) was the first to demonstrate that the individual cells comprising the nervous system remained separate
àHe showed that they did not merge into each other (as previously believed)

Question 4

The Structures of an Animal Cell

Answer 4

– Membrane
– Nucleus
– Mitochondria
– Ribosomes
– Endoplasmic reticulum

Question 5

Membrane

Answer 5

separates the inside of the cell from the outside environment

Question 6

Nucleus

Answer 6

contains the chromosomes (DNA)

Question 7

Mitochondrion

Answer 7

performs metabolic activities and
provides energy
that the cells require
-requires fuel & oxygen to function

Question 8

Ribosomes

Answer 8

sites at which the cell synthesizes new protein molecules

Question 9

Endoplasmic reticulum

Answer 9

network of thin tubes that transports newly synthesized proteins to their
location
*-ribosomes may be attached to ER

Question 10

Components of Most Neurons

Answer 10

• Dendrites
• Soma (cell body)
• Axon
• Presynaptic terminals

Question 11

Dendrites- 3 points

Answer 11

Branching fibers with a surface lined with synaptic receptors: responsible for bringing information into the neuron
• Some also contain dendritic spines that further branch out and increase the surface area of the dendrite
The greater the surface area of the dendrite, the more information it can receive

Question 12

Cell Body/Soma- 3 points

Answer 12

.Contains the nucleus, mitochondria, and ribosomes
• Responsible for most of the metabolic work of the neuron (energy production)
• Covered with receptors (synapses) on its surface (in
many
neurons)

Question 13

Axons- 3 points

Answer 13

-Thin fiber(s) of a neuron responsible for transmitting nerve impulses to other neurons, organs, or muscles.
• May have a myelin sheath, an insulating material that contains interruptions in the sheath known as nodes of Ranvier
• Presynaptic terminals (at the end points of an axon) release chemicals (neurotransmitter (NT))
to communicate with other neurons

Question 14

Types of Signaling- 3

Answer 14

Affervent, Effervent, Interneurons or intrinsic

Question 15

Interneurons or intrinsic

Answer 15

neurons are those whose dendrites
and axons are
completely
contained within a
single structure

Question 16

Affervent

Answer 16

SENSORY- conducting or conducted inward or toward something (for nerves, the central nervous system; for blood vessels, the organ supplied).

Question 17

Effervent

Answer 17

MOTOR-conducted or conducting outward or away from something (for nerves, the central nervous system; for blood vessels, the organ supplied).
“efferent neurons carry impulses outwards to the effector organs”

Question 18

Variations Among Neurons

Answer 18

The function is closely related to the shape
of a neuron
– Example: Purkinje cells of the cerebellum branch extremely widely within a single plane

Question 19

The Blood-Brain Barrier (BBB)

Answer 19

• Surrounds the brain and blocks most chemicals from entering
– The immune system destroys damaged or infected cells throughout the body
(cells can regenerate)
– Because neurons in the brain
generally do not regenerate, it is vitally important for the BBB to block incoming viruses, bacteria, or other harmful material from entering

Question 20

Active Transport

Answer 20

The protein-mediated process that expends energy to pump chemicals from the blood into the brain
– Glucose, certain hormones, amino acids, and a few vitamins are brought into the brain via active transport

Question 21

Astrocytes - 5 points

Answer 21

Type of Glia
- Branches surround axon terminals
• Absorbs released NTs
• Temporarilyinhibits connected axons
• Ceasesinhibition
• Axons respond again
in synchrony

Question 22

Microglia- 2 points

Answer 22

– Remove waste material, viruses, and fungi from the brain (immune response)
– Account for 10-15% of all cells found within the brain (20% of glial cells)

Question 23

Oligodendrocytes- 2 points

Answer 23

-in the brain and spinal cord) and Schwann cells (in the periphery of the body)
– build the myelin sheath that surrounds and insulates certain vertebrate
axons

Question 24

Radial glia- 2 points

Answer 24

– Guide the migration of neurons and the growth of their axons and dendrites during embryonic development
– When embryonic development finishes, most radial glia differentiate into neurons and a smaller number differentiate into astrocytes and oligodendrocytes

Question 25

Ependymal Cell

Answer 25

Secretes cerebrospinal (CSF)

Question 26

Nourishment of Vertebrate Neurons- 2 points

Answer 26

• Vertebrate neurons depend almost entirely on glucose
= A sugar that is one of the few nutrients that can pass through the BBB
• Neurons need a steady supply of oxygen
– 20% of all oxygen consumed by the body is used by the brain

Question 27

Thiamine

Answer 27

The body needs a vitamin, thiamine, to use glucose.

Question 28

Thiamine deficiency

Answer 28

Prolonged thiamine deficiency leads to death of neurons as seen in Korsakoff’s syndrome, a result of chronic alcoholism and/or poor diet
– Korsakoff’s syndrome is marked by severe memory impairment

Question 29

Organization of the Nervous System

Central nervous system (CNS)

Answer 29

the brain and the spinal cord

Question 30

Organization of the Nervous System

Peripheral nervous system (PNS)

Answer 30

connects the brain and spinal cord to the rest of the body
– Somatic nervous system: consists of axons conveying messages from the sense organs to the CNS and from the CNS to the muscles & glands.
– Autonomic nervous system: neurons
© CengagetLheaarnintg c20o16 ntrol the heart, intestines, and other organs

Question 31

The Spinal Cord

Answer 31

CNS
The part of the CNS found within the spinal column
-Communicates with the sense organs and muscles, except those of the head.

Question 32

Bell Magendie law- 4 points

Answer 32

The part of the CNS found within the spinal column
– Communicates with the sense organs and muscles, except those of the head.
– Entering axons = dorsal roots: carry sensory information from organs
– Exiting ventral roots carry motor information to muscles and glands

Question 33

Spinal cord - Consists of two types of matter

Answer 33

Grey and white

Question 34

Gray matter

Answer 34

located in the center of the spinal cord and is densely packed with cell bodies and dendrites

Question 35

White matter

Answer 35

in the periphery, composed mostly of myelinated axons

that carry information from the gray matter to the brain or other areas of the spinal cord

Question 36

PNS: The Autonomic Nervous System

Answer 36

Sends and receives messages to regulate the automatic behaviours of the body (heart rate, blood pressure, respiration, digestion, etc.)
• Divided into 2 subsystems:
– The sympathetic nervous system
– The parasympathetic nervous system

Question 37

The Sympathetic Nervous System- 4 points

Answer 37

• “Fight or Flight” response system
• A network of nerves that prepares the
organs for rigorous activity
– Increases heart rate,
blood pressure, respiration, etc.
– Composed of ganglia on the left and right of the spinal cord

Question 38

The Parasympathetic Nervous System- 4 points

Answer 38

• Facilitates vegetative, nonemergency responses
– Decreases functions increased by the sympathetic nervous system
– Composed of long preganglion axons extending from the
spinal cord and short postganglionic fibers that
attach to the organs themselves
– Dominant during our relaxed states