Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PY299 > Bear et al: Chapter 7 > Flashcards

Bear et al: Chapter 7 Flashcards

1
Q

Why does the human brain appear complicated when compared to the brains of other mammals?

A

It is distorted as a result of the selective growth of some parts within the confines of the skull

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What brain structure is unique to mammals and proportionately largest in humans?

A

Cerebral neocortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the two divisions of the nervous system of all mammals?

A
  1. Central Nervous System (CNS)

2. Peripheral Nervous System (PNS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Anterior

A

Anatomical reference meaning toward the nose or rostral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Rostral

A

From the Latin for “beak”

Anatomical reference meaning toward the nose or anterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Posterior

A

Anatomical reference meaning toward the tail, or caudal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Caudal

A

From the Latin for “tail”

Anatomical reference meaning toward the tail, or posterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Dorsal

A

From the Latin for “back”

Anatomical reference meaning toward the back

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Ventral

A

From the Latin for “belly”

Anatomical reference meaning toward the belly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Bilateral symmetry

A

Property where the right side of the brain and spinal cord is a mirror image of the left side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Midline

A

An invisible line that bissects the nervous system into right and left halves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Medial

A

An anatomical reference meaning toward the midline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Lateral

A

An anatomical reference meaning away from the midline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Ipsilateral

A

An anatomical reference meaning on the same side of the midline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Contralateral

A

An anatomical reference meaning on opposite sides of the midline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

In the language of anatomists, what is a slice called?

A

Section

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

In the language of anatomists, how would you say ‘to slice’?

A

To section

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the standard approach to cut into a brain?

A

Parallel to one of the three anatomical planes of section

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the three anatomical planes of section?

A
  1. Midsaggital plane
  2. Horizontal plane
  3. Coronal plane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Midsaggital plane

A

An anatomical plane of section
through the midline that is perpendicular to the
ground. A section in the midsagittal plane divides
the nervous system into right and left halves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Saggittal plane

A

An anatomical plane of section that is

parallel to the midsagittal plane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Horizontal plane

A

An anatomical plane of section
that divides the nervous system into dorsal and
ventral parts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Coronal plane

A

An anatomical plane of section
that divides the nervous system into anterior and
posterior parts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Central nervous system (CNS)

A
  1. The brain (including
    the retinas) and spinal cord
  2. Consists of parts of the nervous system that are encased in bone (i.e. the brain lies entirely within the skull)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What three parts of the brain are common to all mammals?

A
  1. Cerebrum
  2. Cerebellum
  3. Brain stem
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Cerebrum

A
  1. Largest part of the forebrain; also called telencephalon

2. Rostral-most and largest part of the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Cerebral hemispheres

A

The two sides of the cerebrum,
derived from the paired telencephalic
vesicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What structure separates the two cerebral hemispheres?

A

Deep sagittal fissure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the function of the right cerebral hemisphere?

A

Receive sensations from and control movements of the LEFT side of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the function of the left cerebral hemisphere?

A

Receive sensations from and control movements of the RIGHT side of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Cerebellum

A
  1. Derived from the Latin for “little brain”
  2. A structure derived from the rhombencephalon,
    attached to the brain stem at the pons; an important movement control center
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the two primary functions of the cerebellum?

A
  1. Movement control center

2. Extensive connections with the cerebrum and spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Does the cerebrum or the cerebellum have more neurons?

A

Cerebellum contains as many as both cerebral hemispheres combined

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the function of the left side of the cerebellum?

A

Concerned with movements of the LEFT side of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the function of the right side of the cerebellum?

A

Concerned with movements of the RIGHT side of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Brain stem

A
  1. The diencephalon, midbrain, pons, and medulla. (Some anatomists exclude the diencephalon.)
  2. Complex nexus of fibers and cells that forms the stalk from which the cerebral hemispheres and the cerebellum sprout
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

From what view is the brain stem best observed?

A

Midsagittal view

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the two main functions of the brain stem?

A
  1. Site where vital functions are regulated, such as breathing, consciousness, and the control of body temperature
  2. Relay information from the cerebrum to the spinal cord and cerebellum,
    and vice versa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is considered the most primitive part of the mammalian brain?

A

Brain stem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What part of the mammalian brain is most vital to life and why?

A

Brain stem–because one can survive damage to the cerebrum and cerebellum, but damage to the brain stem is usually fatal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Spinal cord

A

The part of the central nervous system encased in the bony vertebral column and attached to the brain stem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is the primary function of the spinal cord?

A

It is the major conduit of information from the skin, joints, and muscles of the body to the brain, and vice versa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What does a transection of the spinal cord result in?

A

Anesthesia (lack of feeling) in the skin and paralysis of the muscles in parts of the body caudal to the cut. Paralysis in this case does not mean that the muscles cannot function, but they cannot be controlled by the brain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

The spinal card communicates with the body via the _____?

A

The spinal card communicates with the body via the SPINAL NERVES

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Spinal nerves

A

A nerve attached to the spinal cord

that innervates the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

How do spinal nerves exit the spinal cord?

A

Through notches between each vertebra of the vertebral column

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

How does each spinal nerve attach to the spinal cord?

A

By means of two branches:

  1. Dorsal root
  2. Ventral root
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Dorsal root

A

A bundle of sensory neuron axons that emerges from a spinal nerve and attaches to the dorsal side of the spinal cord. Dorsal root axons bring information
into the spinal cord.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Ventral root

A

A bundle of motor neuron axons that
emerges from the ventral spinal cord and joins sensory fibers to form a spinal nerve. Ventral root axons carry information away from the spinal cord.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Through which branches do axons enter and exit the spinal cord respectively?

A

Enter via the dorsal root

Exit via the ventral root

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Peripheral Nervous System (PNS)

A

The parts of the nervous system other than the brain and spinal cord. The PNS includes all the spinal ganglia and nerves, cranial nerves III–XII, and the auto- nomic nervous system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What are the two parts of the peripheral nervous system?

A
  1. Somatic PNS

2. Visceral PNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What commands muscle contraction?

A

Somatic motor neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Where do the somatic motor axons derive from?

A

Motor neurons in the ventral spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Where do the cell bodies and axons of motor neurons lie?

A

The cell bodies of motor neurons lie within the CNS but their axons are mostly within the PNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is the function of somatic sensory axons?

A

Innervate and collect information from the skin, muscles, and joints

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Through what branch do sensory somatic axons enter the spinal cord?

A

Via the dorsal roots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Where do the cell bodies of somatic sensory neurons lie?

A

Outside the spinal cord in clusters called dorsal root ganglion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

There is _____ dorsal root ganglion for each spinal nerve

A

There is ONE dorsal root ganglion for each spinal nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Dorsal root ganglion

A

A collection of cell bodies of the sensory neurons that are part of the somatic PNS. There is one dorsal root ganglion for each spinal nerve.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Visceral peripheral nervous system

A

The part of the peripheral nervous system that innervates the internal organs, blood vessels, and glands; also called autonomic nervous system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Autonomic nervous system (ANS)

A

A system of central and peripheral nerves that innervates the internal organs, cardiovascular system, and glands; also called visceral PNS. The ANS consists of sympathetic, parasympathetic, and enteric divisions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What are three other names for the visceral peripheral nervous system?

A
  1. Autonomic nervous system (ANS)
  2. Involuntary nervous system
  3. Vegetative nervous system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What do visceral sensory axons do?

A

Bring information about visceral functions to the CNS, such as the pressure and oxygen content of the blood in arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What do visceral motor fibers do?

A

Command the contraction and relaxation of muscles that form the walls of intestines and blood vessels (called smooth muscles), the rate of cardiac muscle contraction, and the secretory function of various glands

For example, the visceral PNS controls blood pressure by regulating heart rate and the diameter of blood vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What part of the nervous system mediates emotional responses beyond voluntary control (i.e. “butterflies in the stomach”, blushing)?

A

Visceral PNS (the ANS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

Afferent

A

Derived from Latin “carry to”

An axon coursing toward and innervating a given structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Efferent

A

Derived from the Latin “carry from”

An axon originating in and coursing away from a given structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Cranial nerves

A

Twelve pairs of nerves that arise from each side of the brain stem, innervate (mostly) the head) and are numbered from anterior to posterior. Cranial nerve I is actually the olfactory tract, and cranial nerve II is the optic nerve; both are parts of the central nervous system. Cranial nerves III–XII, which are in the peripheral nervous system, perform many diverse functions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Who were the cranial nerves originally numbered by and how long ago?

A

Galen, 1800 years ago

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Does the central nervous system come in direct contact with the overlying bone?

A

No

72
Q

What is the singular form of meninges?

A

meninx

73
Q

Meninges

A

From the Greek for “covering”

Three membranes that cover the surface of the central nervous system: the dura mater, arachnoid membrane, and pia mater. Singular: meninx.

74
Q

What protects the surface of the central nervous system?

A

Meninges

75
Q

Dura mater

A

From the Latin words “hard mother,” an accurate description of the dura’s leather-like consistency.

The outermost of the three meninges, the membranes that cover the surface of the central nervous system.

Forms a tough, inelastic band that surrounds the brain and spinal cord.

76
Q

Arachnoid membrane

A

From the Greek for “spider”, appropriately named for its appearance and consistency resembling a spider web.

The middle of the three meninges, the three membranes that cover the surface of the central nervous system.

77
Q

Is there space between the dura and arachnoid?

A

Normally no BUT if the blood vessels passing through the dura are ruptured, blood can collect here and form what is called a subdural hematoma

78
Q

What is a subdural hematoma, what does it do and how is it treated?

A

If blood vessels passing through the dura are ruptured, they can collect here and form a subdural hematoma.

Can disrupt brain function by compressing parts of the CNS.

Treated by drilling a hole in the skull and draining the blood.

79
Q

Pia mater

A

“Gentle mother”

The innermost of the three meninges, the membranes that cover the surface of the central nervous system.

A thin membrane that adheres closely to the surface of the brain.

80
Q

Along the _____ run many blood vessels that ultimately dive into the substance of the underlying brain.

A

Along the PIA MATER run many blood vessels that ultimately dive into the substance of the underlying brain.

81
Q

Is the arachnoid separates from the pia mater?

A

Yes, by a fluid-filled space (called the subarachnoid space)

82
Q

Cerebrospinal fluid (CSF)

A

In the central nervous system, the salty, clear fluid produced by the choroid plexus that flows through the ventricular system to the subarachnoid space.

83
Q

Ventricular system

A

The cerebrospinal fluid–filled spaces inside the brain, consisting of the lateral ventricles, third ventricle, cerebral aqueduct, and fourth ventricle

84
Q

What fluid runs in the ventricular system?

A

Cerebrospinal fluid (CSF), the dame fluid that runs in the subarachnoid space

85
Q

What produces cerebrospinal fluid (CSF)?

A

A special tissue, called the choroid plexus, in the ventricles of the cerebral hemispheres

86
Q

What is the normal flow of cerebrospinal fluid?

A

paired ventricles of the cerebrum—> series of connected, central cavities at the core of the brain stem—> exits the ventricular system and enters the subarachnoid spaces by way of small openings, or apertures, located near where the cerebellum attaches to the brain stem—> in the subarachnoid spaces, CSF is absorbed by blood cells at special structures called arachnoid villi

87
Q

What special structures in blood vessels absorb cerebrospinal fluid in subarachnoid spaces?

A

Arachnoid villi

88
Q

What happens if the normal flow of CSF is disrupted?

A

Brain damage…
Fluid will backup causing a swelling of the ventricles. This condition is called hydrocephalus, a term originally meaning “water head.”

89
Q

How did anatomists initially investigate the internal structures of the brain for centuries? (hint: four steps)

A
  1. Removed the brain from the skull
  2. Sectioned it in various planes
  3. Stained the sections
  4. Examined the stained sections
90
Q

What is the main limitation of the initial method in which anatomists investigated the internal structures of the brain?

A

Seeing how parts deep in the brain fit together in three dimensions

91
Q

CLARITY

A

A new method introduced by researchers at Stanford University in 2013 that allows for visualization of deep structures without sectioning the brain

92
Q

How does CLARITY work?

A
  1. Soak the brain in a solution that replaces light-absorbing lipids with a water-soluble gel that turns the brain transport
  2. If such a “clarified” brain contains neurons that are labeled with fluorescent molecules, such as green fluorescent protein (GFP), then appropriate illumination will reveal the location of these cells deep inside the brain
93
Q

Hydrocephalus

A

When flow of cerebrospinal fluid from the choroid plexus through the ventricular system to the subarachnoid space is impaired leading to fluid backing up and causing a swelling of the ventricles

94
Q

What happens when a baby is born with hydrocephalus?

A

Because the skull is soft and not completely formed, the head will expand in response to the increased intracranial fluid, sparing the brain from damage. Often this condition goes unnoticed until the size of the head reaches enormous proportions.

95
Q

Why is hydrocephalus much more serious in adults?

A

Because the skull cannot expand and intracranial pressure is increased as a result. The soft brain tissue is then compressed, impairing function and leading to death if left untreated. Typically, this “obstructive” hydrocephalus is also accompanied by severe headache, caused by distension of nerve endings in the meninges.

96
Q

How is hydrocephalus treated?

A

By inserting a tube into the swollen ventricle and draining off the excess fluid

97
Q

In treatment of hydrocephalus, where is the tube inserted through and where is the drainage tube usually introduced?

A

Tube is inserted into the ventricle through hole in skull

Drainage tube is usually introduced into peritoneal cavity and (if applicable) with extra length to allow for the growth of the child

98
Q

What is the entire central nervous system derived from and when is that formed?

A

The entire CNS is derived from the walls of a fluid-filled tube that is formed at an early stage in embryonic development. The inside of the tube becomes the adult ventricular system.

99
Q

What are six common names for describing collections of neurons?

A
  1. Gray matter
  2. Cortex
  3. Nucleus
  4. Substantia
  5. Locus
  6. Ganglion
100
Q

What are seven common names for describing collections of axons?

A
  1. Nerve
  2. White matter
  3. Tract
  4. Bundle
  5. Capsule
  6. Commissure
  7. Lemniscus
101
Q

Gray matter

A

A generic term for a collection of neuronal cell bodies in the CNS. When a freshly dissected brain is cut open, neurons appear gray.

102
Q

Cortex

A

Any collection of neurons that form a thin sheet, usually at the brain’s surface. Cortex is Latin for “bark.”

Example: cerebral cortex, the sheet of neurons found just under the surface of the cerebrum.

103
Q

Nucleus

A

A clearly distinguishable mass of neurons, usually deep in the brain (not to be confused with the nucleus of a cell). Nucleus is from the Latin word for “nut.”

Example: lateral geniculate nucleus, a cell group in the brain stem that relays information from the eye to the cerebral cortex.

104
Q

Substantia

A

A group of related neurons deep within the brain but usually with less distinct borders than those of nuclei.

Example: substantia nigra (from the Latin for “black substance”), a brain stem cell group involved in the control of voluntary movement.

105
Q

Locus

A

A small, well-defined group of cells. Plural: loci.

Example: locus coeruleus (Latin for “blue spot”), a brain stem cell group involved in the control of wakefulness and behavioral arousal.

106
Q

Ganglion

A

A collection of neurons in the PNS. Ganglion is from the Greek for “knot.”

Example: the dorsal root ganglia, which contain the cell bodies of sensory axons entering the spinal cord via the dorsal roots. Only one cell group in the CNS goes by this name: the basal ganglia, which are structures lying deep within the cerebrum that control movement

107
Q

Nerve

A

A bundle of axons in the PNS.

Only one collection of CNS axons is called a nerve: the optic nerve.

108
Q

White matter

A

A generic term for a collection of CNS axons. When a freshly dissected brain is cut open, axons appear white.

109
Q

Tract

A

A collection of CNS axons having a common site of origin and a common destination.

Example: corticospinal tract, which originates in the cerebral cortex and ends in the spinal cord.

110
Q

Bundle

A

A collection of axons that run together but do not necessarily have the same origin and destination.

Example: medial forebrain bundle, which connects cells scattered within the cerebrum and brain stem.

111
Q

Capsule

A

A collection of axons that connect the cerebrum with the brain stem.

Example: internal capsule, which
connects the brain stem with the cerebral cortex.

112
Q

Commissure

A

Any collection of axons that connect one side of the brain with the other side

113
Q

Lemniscus

A

A tract that meanders through the brain like a ribbon.

Example: medial lemniscus, which brings touch information
from the spinal cord through the brain stem.

114
Q

How does the embryo begin?

A

As a flat disk with three distinct layers of cells called endoderm, mesoderm, and ectoderm

115
Q

What does the endoderm give rise to?

A

Lining of many of the internal organs (viscera)

116
Q

What does the mesoderm give rise to?

A

Bones of the skeleton and muscles

117
Q

What does the ectoderm give rise to?

A

Nervous system and skin

118
Q

What is the first important step in the development of the nervous system?

A

Formation of a groove in the neural plate that runs rostral to caudal, called the neural groove

119
Q

Neural folds

A

Walls of the neural grooves

120
Q

What comes together and fuses to form the neural tube?

A

Neural folds

121
Q

Neural crest

A

The bits of neural ectoderm that are pinched off and come to lie lateral to the neural tube when the neural tube rolls up

All neurons with cell bodies in the peripheral nervous system derive from the neural crest

122
Q

What does the peripheral nervous system (PNS) develop from?

A

Neural crest

123
Q

Somites

A

Mesoderm that will give rise to much of the skeletal system and the muscles

Prominent bulges on either side of the neural tube

From which the 33 individual vertebrae of the spinal column and related skeletal muscles will develop

124
Q

What part of the ectoderm gives rise to the nervous system?

A

Neural plate

125
Q

At about 17 days from conception in humans, what does the brain consist of?

A

Only a flat sheet of cells

126
Q

Neural groove

A

Groove in the neural plate that runs rostral to caudal

127
Q

How is the neural tube formed?

A

When the walls of the neural groove, neural folds, move together and fuse dorsally thus forming the neural tube

128
Q

True or False?:

All neurons with cell bodies in the peripheral nervous system (PNS) derive from the neural crest.

A

True

129
Q

True or False?:

All neurons with cell bodies in the peripheral nervous system (PNS) derive from the neural crest.

A

True

130
Q

What does the neural crest develop in close association with?

A

Underlying mesoderm which, at this stage in development, forms prominent bulges on either side of the neural tube called somites

131
Q

From what does do the 33 individual vertebrae of the spinal column and related skeletal muscles will develop?

A

Somites

132
Q

What are the nerves that innervate the related skeletal muscles to the 33 individual vertebrae of the spinal column called?

A

Somatic motor nerves

133
Q

Neurulation

A

The formation of the neural tube from the neural ectoderm during embryonic development; the process by which the neural plate becomes the neural tube

134
Q

About how many days after conception does neurulation occur in humans?

A

Very early in embryonic development, about 22 days (~3 weeks) after conception in humans (when a mother may be unaware she is pregnant)

135
Q

True or False?:

A common birth defect is the failure of appropriate closure of the neural tube.

A

True

136
Q

What does recent research suggest about avoiding neural tube defects?

A

Most cases of neural tube defects can be avoided by ensuring proper maternal nutrition during this period (of neurulation)

137
Q

How common is the birth defect of failure of appropriate closure of the neural tube?

A

Approximately 1 out of every 500 live births

138
Q

What does a recent discovery of enormous public health importance trace many neural tube defects to?

A

Deficiency of the vitamin folic acid (or folate) in the maternal diet during the weeks immediately after conception. It has been estimate that dietary supplementation of folic acid during this period could reduce the incidence of neural tube defects by 90%.

139
Q

What does the formation of the neural tube depend upon? (List 3)

A
  1. Precise sequence of changes in the three-dimensional shape of individual cells as well as on changes in the adhesion of each cell to its neighbours.
  2. Timing of neurulation must be coordinate must be coordinated with simultaneous changes in non-neural ectoderm and mesoderm.
  3. At the molecular level, successful neurulation depends on specific sequences of gene expression that are controlled, in part, by the position and local chemical environment of cells.
    * Note: This process is highly sensitive to chemicals, or chemical deficiencies, in the maternal circulation.
140
Q

What is the order of fusion of the neural folds to form the neural tube?

A

Occurs first in the middle, then anteriorly and posteriorly

141
Q

What condition is a result of the failure of the anterior neural tube to close?

A

Anencephaly

142
Q

Anencephaly

A

Condition characterized by degeneration of the forebrain and skull that is always fatal

143
Q

What condition is a result of the failure of the posterior neural tube to close?

A

Spina bifida

144
Q

What is spina bifida characterized by in its most severe form?

A

Failure of the posterior spinal cord to form from the neural plate

145
Q

What Latin word meaning is bifida from?

A

Cleft in two parts

146
Q

What is spina bifida characterized by in its less severe forms?

A

Defects in the meninges and vertebrae overlying the posterior spina cord

147
Q

Is spina bifida fatal?

A

Spina bifida is usually not fatal but it does require extensive and costly medical care

148
Q

What is the role of folic acid?

A

Plays an essential role in a number of metabolic pathways, including the biosynthesis of DNA, which naturally must occur during development as cells divide

149
Q

Why does folic acid deficiency increase the incidence of neural tube defects?

A

We do not precisely understand why folic acid deficiency increase the incidence of neural tube defects but it is easy to imagine how it could alter the complex choreography of neurulation

150
Q

What Latin word is the name folic acid derived from and what does this reflect?

A

Derived from the Latin word for “leaf”

Reflects the fact that folic acid was first isolated from spinach leaves

151
Q

What are six good dietary sources of folic acid?

A
  1. Green leafy vegetables (i.e. spinach)
  2. Liver
  3. Yeast
  4. Eggs
  5. Beans
  6. Oranges
152
Q

What food is commonly fortified with folic acid?

A

Many breakfast cereals

153
Q

What is the folic acid intake of the average American and how does it compare to the recommended amount to prevent birth defects?

A

Folic acid intake of the average American is only half of what is recommended to prevent birth defects (0.4 mg/day)

154
Q

What does the U.S. Centers for Disease Control and Prevention recommend women take before planning pregnancy?

A

Multivitamins containing 0.4 mg of folic acid

155
Q

What does the U.S. Centers for Disease Control and Prevention recommend women take before planning pregnancy?

A

Multivitamins containing 0.4 mg of folic acid

156
Q

Differentiation

A

During embryonic development, the process by which structures become more complex and functionally specialized

157
Q

What is the first step in differentiation of the brain?

A

Development, at the rostral end of the neural tube, of three swellings called the primary vesicles

158
Q

The entire brain derives from the _____ _____ _____ of the neural tube.

A

The entire brain derives from the THREE PRIMARY VESICLES of the neural tube.

159
Q

Prosencephalon

A

Rostral-most of the three primary vesicles

Pro is Greek for “before”; encephalon is derived from the Greek for “brain”

Also called the forebrain

160
Q

Forebrain

A

Region of the brain derived from the rostral primary embryonic brain vesicle

Also called prosencephalon

Forebrain structures include the telencephalon and the diencephalon

161
Q

What vesicle lies posterior to the prosencephalon?

A

Mesencephalon or midbrain

162
Q

What vesicle lies posterior to the mesencephalon?

A

Rhombencephalon or hindbrain

163
Q

Midbrain

A

Region of the brain derived from the middle primary embryonic brain vesicle

Also called mesencephalon

Midbrain structures include the tectum and the tegmentum

164
Q

Hindbrain

A

Region of the brain derived from the caudal primary embryonic brain vesicle

Also called rhombencephalon

Hindbrain structures include the cerebellum, pons, and medulla

165
Q

The _____ connects with the _____ _____ _____, which gives rise to the _____ _____.

A

The RHOMBENCEPHALON connects with the CAUDAL NEURAL TUBE, which gives rise to the SPINAL CORD.

166
Q

Where do the next important developments after the development of the three primary brain vesicles?

A

Forebrain, where secondary vesicles sprout off on both sides

167
Q

What are the two secondary vesicles that sprout off on both sides of the prosencephalon called?

A
  1. Optic vesicles

2. Telencephalic vesicles

168
Q

What is the central structure that remains after the secondary vesicles have sprouted off?

A

Diencephalon or “between brain”

169
Q

After the sprouting of secondary vesicles off both sides of the prosencephalon, what does the forebrain consist of?

A
  1. Paired (two) optic vesicles
  2. Paired (two) telencephalic vesicles
  3. Diencephalon
170
Q

Diencephalon

A

“Between brain”

A region of the brain stem derived from the prosencephalon (forebrain). Diencephalic structures include the thalamus and hypothalamus.

171
Q

How do optic vesicles become the optic nerves and the two retinas in the adult?

A

Optical vesicles grow and invaginate (fold in) to form the optic stalks and the optic cups. The optic stalks will become the optic nerves, and the optic cups will become the retinas.

172
Q

What part of the nervous system do the retina and the optic nerve belong to?

A

Brain; NOT the PNS

173
Q

Where is the retina located?

A

Back of the eye

174
Q

What does the optic nerve contain?

A

Axons that connect the eye to the diencephalon and midbrain

175
Q

The _____ _____ develop into eyes.

A

The OPTIC VESICLES develop into eyes.

176
Q

Telencephalon

A

“Endbrain”

A region of the brain derived from the prosencephalon (forebrain). Telencephalic structures include the paired cerebral hemispheres
that contain cerebral cortex and the basal telencephalon.

177
Q

What four ways does the telencephalon?

A

1) The telencephalic vesicles grow posteriorly so that they lie over and lateral to the diencephalon

2) Another
pair of vesicles sprout off the ventral surfaces of the cerebral hemispheres, giving rise to the olfactory bulbs and related structures that participate
in the sense of smell

3) The cells of the walls of the telencephalon divide and differentiate into various structures.
4) White matter systems develop, carrying axons to and from the neurons of the telencephalon.

PY299 (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions