brain Flashcards
1
Q
What structure forms during the 3rd and 4th week of embryological development?
A
The neural tube forms during the 3rd and 4th week of embryological development.
2
Q
What happens to the cranial end of the neural tube during development?
A
The cranial end of the neural tube bulges and separates into three primary vesicles during development.
3
Q
How many secondary vesicles are eventually produced from the cranial end of the neural tube?
A
Two of the three primary vesicles divide further, eventually producing five secondary vesicles.
4
Q
What structures do the secondary vesicles at the cranial end give rise to?
A
The secondary vesicles at the cranial end will give rise to the cerebrum.
5
Q
What structures arise from the vesicle caudal to those forming the cerebrum?
A
The vesicle caudal to those forming the cerebrum will give rise to the thalamus and hypothalamus.
6
Q
What do the remaining three vesicles eventually form?
A
The remaining three vesicles will eventually form the brainstem and cerebellum.
7
Q
How many “primary vesicles” does the cranial end of the neural tube separate into?
A
The cranial end of the neural tube separates into three “primary vesicles”.
8
Q
What happens to two of the primary vesicles during development?
A
Two of the primary vesicles further sub-divide during development, giving rise to five “secondary vesicles”.
9
Q
What do the walls of these vesicles form?
A
The walls of these vesicles form specific regions of the brain.
10
Q
What do the fluid-filled cavities within these vesicles form?
A
The fluid-filled cavities within these vesicles form the ventricles and canals of the brain.
11
Q
What is the largest region of the brain?
A
The largest region of the brain is the highly folded cerebrum.
12
Q
What is located inferior to the posterior end of the cerebrum?
A
Inferior to the posterior end of the cerebrum is the cerebellum.
13
Q
What is the name of the stock-like structure that extends from the inferior surface of the brain?
A
The stock-like structure is the brainstem.
14
Q
What is located at the cranial end of the brainstem?
A
At the cranial end of the brainstem is the diencephalon.
15
Q
What structures form the walls and ceiling of the diencephalon?
A
The walls and ceiling of the diencephalon form the thalamus.
16
Q
What structure forms the floor of the diencephalon?
A
The floor of the diencephalon forms the hypothalamus.
17
Q
What are the three sections of the brainstem?
A
The three sections of the brainstem are the midbrain, pons, and medulla oblongata.
18
Q
what is the largest potion of the brain?
A
cerebrum
19
Q
What is the core composition of the cerebrum?
A
The cerebrum contains a core of white matter surrounded by a layer of highly folded gray matter.
20
Q
What is white matter composed of?
A
White matter is composed of myelinated axons.
21
Q
What is gray matter composed of?
A
Gray matter is composed of unmyelinated axons and cell bodies.
22
Q
What are the elevated ridges on the surface of the cerebrum called?
A
The elevated ridges on the surface of the cerebrum are referred to as gyri.
23
Q
What are the depressions between the gyri called?
A
The depressions between the gyri are referred to as sulci or fissures.
24
Q
How is the cerebrum divided?
A
The cerebrum is divided into left and right hemispheres.
25
What separates the left and right hemispheres of the cerebrum?
The left and right hemispheres of the cerebrum are separated by a deep depression called the longitudinal fissure.
26
What is located at the base of the longitudinal fissure?
At the base of the longitudinal fissure is a mass of white matter called the corpus callosum.
27
What structure is located at the "floor" of the longitudinal fissure?
At the "floor" of the longitudinal fissure is the corpus callosum, a mass of transversely running axons that connect the left and right hemispheres.
28
What does the cerebral white matter consist of?
The cerebral white matter consists of several tracts of axons that transmit signals between various portions of the cerebrum.
29
What do association tracts connect?
Association tracts connect regions of the same hemisphere.
30
What do commissural tracts connect?
Commissural tracts connect analogous regions of the two hemispheres, with the largest being the corpus callosum.
31
What do projection tracts carry signals between?
Projection tracts carry signals between the cerebrum and other portions of the brain and spinal cord.
32
What is the function of the corpus callosum?
The corpus callosum is the largest of the commissural tracts whose axons transmit signals between the left and right hemispheres.
33
Besides commissural tracts, what other types of tracts are found in the cerebrum?
In addition to commissural tracts, the cerebrum also contains association tracts whose axons transmit signals between regions of the same hemisphere.
34
What do association tracts do?
Association tracts transmit signals between regions of the same hemisphere.
35
What are projection tracts responsible for?
Projection tracts transmit signals between the cerebrum and other regions of the brain and spinal cord.
36
How is the cerebral grey matter (cortex) divided in each hemisphere?
In each hemisphere, the cerebral grey matter (cortex) is divided into 4 lobes that are separated by prominent sulci.
37
How are the cerebral hemispheres divided into lobes?
The cerebral hemispheres are divided into four lobes by prominent depressions, with their names mirroring the cranial bones superficial to them.
38
Which lobe of the cerebrum lies deep to the frontal bone?
The frontal lobes of the cerebrum lie deep to the frontal bone.
39
Which lobe of the cerebrum lies deep to the parietal bones?
The parietal lobes lie deep to the parietal bones.
40
Which lobe of the cerebrum lies deep to the temporal bones?
The temporal lobes lie deep to the temporal bones.
41
Which lobe of the cerebrum lies deep to the occipital bone?
The occipital lobes lie deep to the occipital bone.
42
What separates the frontal and parietal lobes in each hemisphere?
The frontal and parietal lobes in each hemisphere are separated by the central sulcus.
43
What separates the frontal and temporal lobes in each hemisphere?
The frontal and temporal lobes in each hemisphere are separated by the lateral sulcus.
44
What separates the parietal and occipital lobes in each hemisphere?
The parietal and occipital lobes in each hemisphere are separated by the parietal occipital sulcus.
45
What is the general function associated with the frontal lobe?
The frontal lobe is associated with motor functions and higher functions.
46
What are the major functional areas associated with each lobe of the cerebrum?
The major functional areas associated with each lobe of the cerebrum include motor functions and higher functions in the frontal lobe, and sensory functions in the parietal, temporal, and occipital lobes.
47
What is the general function associated with the parietal, temporal, and occipital lobes?
The parietal, temporal, and occipital lobes are generally associated with sensory functions.
48
What has allowed for the development of a map of functional areas specific to each lobe of the cerebrum?
The relatively constant organization of functional areas between individuals has allowed for the development of a map of functional areas specific to each lobe of the cerebrum.
49
What function is associated with the primary motor area of the frontal lobe?
The primary motor area of the frontal lobe is associated with the initiation of voluntary movements.
50
What is the function of the premotor area in the frontal lobe?
The premotor area in the frontal lobe serves as a "memory bank" of learned movements.
51
What functions are associated with the prefrontal cortex in the frontal lobe?
The prefrontal cortex in the frontal lobe is associated with "higher functions" such as intellect, learning, memory, planning, judgment, personality, and mood.
52
Besides voluntary movements, what other functions are associated with areas in the frontal lobe?
Areas in the frontal lobe are also involved in the articulation of speech and the recognition of olfactory stimuli (odours).
53
What areas are contained within each frontal lobe?
Each frontal lobe contains the primary motor area, pre-motor area, and prefrontal cortex.
54
Where is the primary motor area located within the frontal lobe?
The primary motor area is located in the precentral gyrus, immediately anterior to the central sulcus.
55
What is the function of the primary motor area?
The primary motor area is responsible for initiating voluntary movements
56
What does the motor homunculus represent?
The motor homunculus represents the portions of the cortex responsible for initiating movements in various regions of the body.
57
What is located anterior to the primary motor area?
Anterior to the primary motor area is the premotor area.
58
What is the function of the premotor area?
The premotor area serves as a storage site for learned movements and coordinates activity in the primary motor area to execute complex movements.
59
What is located anterior to the premotor area?
Anterior to the premotor area is the prefrontal cortex.
60
What functions are associated with the prefrontal cortex?
The prefrontal cortex contains areas associated with higher functions such as intellect, memory, and personality.
61
What areas are contained within each parietal lobe?
Each parietal lobe contains the primary somatosensory area and the common integrative area.
62
Where is the primary somatosensory area located within the parietal lobe?
The primary somatosensory area is located in the postcentral gyrus, immediately posterior to the central sulcus.
63
What is the function of the primary somatosensory area?
The primary somatosensory area is responsible for the perception of somatic sensations.
64
Somatic senses
also known as bodily senses, are the senses that allow us to perceive the physical world through touch, taste, smell, sight, and hearing.
65
What does the sensory homunculus represent?
The sensory homunculus represents the portions of the cortex responsible for receiving somatosensory input from various regions of the body.
66
What is located posterior to the primary somatosensory area?
The common integrative area is located posterior to the primary somatosensory area.
67
What is the function of the common integrative area?
The common integrative area receives and integrates information related to a variety of sensory inputs from the parietal, temporal, and occipital lobes.
68
What areas are contained within each parietal lobe?
Each parietal lobe contains the primary somatosensory area and the common integrative area.
69
Where is the primary somatosensory area located within the parietal lobe?
The primary somatosensory area is located in the postcentral gyrus, immediately posterior to the central sulcus.
70
What does the sensory homunculus represent?
The sensory homunculus represents the portions of the cortex responsible for receiving somatosensory input from various regions of the body.
70
What is the function of the primary somatosensory area?
The primary somatosensory area is responsible for the perception of somatic sensations.
71
What is located posterior to the primary somatosensory area?
The common integrative area is located posterior to the primary somatosensory area.
72
What is the function of the common integrative area?
receives and integrates information related to a variety of sensory inputs from the parietal, temporal, and occipital lobes.
73
What areas are contained within each temporal lobe?
Each temporal lobe contains the primary auditory area and the primary olfactory area.
74
What is the function of the primary auditory area?
The primary auditory area is responsible for the perception of auditory sensations.
75
What is the function of the primary olfactory area?
perception of olfactory sensations.
76
Besides auditory and olfactory sensations, what other functions are associated with areas in the temporal lobe?
Areas in the temporal lobe are also involved in the recognition of auditory stimuli and the recognition of faces.
77
what is the occipital lobe responsible for?
primary visual area. The perception of visual sensations and recognition of visual stimuli.
78
How does the structure of the cerebellum resemble that of the cerebrum?
The cerebellum, like the cerebrum, is separated into left and right hemispheres and contains a core of white matter surrounded by a layer of highly folded gray matter.
79
What are the main functions of the cerebellum?
refines voluntary movements.
It helps coordinate complicated movements.
It helps us keep our balance and posture steady.
It regulates how tense or relaxed our muscles are.
80
What is the cerebellum's role in regulating muscle tone?
The cerebellum regulates muscle tone, which is a muscle's resistance to passive stretch.
81
How does the size of the cerebellum compare to other brain structures?
The cerebellum is the second largest portion of the brain.
82
How is the cerebellum structured internally?
Like the cerebrum, the cerebellum is divided into left and right hemispheres and has a superficial layer of grey matter (cerebellar cortex) surrounding a core of white matter.
83
What is the name of the superficial layer of grey matter in the cerebellum?
The superficial layer of grey matter in the cerebellum is called the cerebellar cortex.
84
What is the main function of the thalamus?
The main function of the thalamus is to serve as the switchboard for incoming sensory signals destined for the cerebrum.
85
How does the thalamus function as a switchboard for sensory signals?
Signals from various sensory receptors are transmitted to the thalamus, whose nuclei then relay them to the appropriate areas of the cerebrum.
86
Can you provide an example of how the thalamus relays sensory signals to the cerebrum?
For example,
signals from visual receptors in the eye are transmitted to the thalamus, which then relays them to the primary visual area in the occipital lobe.
Similarly, signals from somatosensory receptors in the skin and muscles are transmitted to the thalamus, which then relays them to the primary somatosensory area in the parietal lobe.
87
What is the composition of the thalamus?
The thalamus is composed of a mass of nuclei (grey matter) and tracts (white matter) located in the walls of the diencephalon.
88
What are the major functions of the thalamus?
The major functions of the thalamus include relaying sensory impulses from the spinal cord, brain stem, and cerebellum to the cerebral cortex, and helping maintain consciousness.
89
What structure forms the floor of the diencephalon?
The hypothalamus forms the floor of the diencephalon.
90
How is the hypothalamus connected to the pituitary gland?
The hypothalamus is connected to the pituitary gland via a narrow stalk called the infundibulum.
91
What role does the hypothalamus play in relation to the pituitary gland?
The hypothalamus regulates the release of hormones from the pituitary gland.
92
what role does the hypothalamus play in regards to the autonomic nervous system?
regulates activity in the autonomic nervous system (ANS)
93
what are some other functions of the hypothalamus?
regulates emotions, behaviour, hunger, thirst, and body temperature.
94
What is the cranial portion of the brainstem called?
midbrain
95
what is the function of the nuclei in the midbrain?
initiates reflexive movement in response to visual and auditory stimuli.
96
Can you provide an example of a reflexive movement initiated by nuclei in the midbrain?
For example, if a bright light appears in your peripheral vision on one side, or a loud sound is detected on one side, the nuclei in the midbrain will initiate a reflexive head rotation to that side without any conscious input from the cerebrum.
97
What is the major function of the midbrain?
The midbrain generates motor reflex responses to visual and auditory stimuli and assists in the control of voluntary movements.
98
Where are the nuclei and tracts of the midbrain located?
The nuclei and tracts of the midbrain are located at the cranial end of the brainstem.
99
What is located caudal to the midbrain?
Caudal to the midbrain is the pons.
100
What function does the pons serve in relation to the cerebrum and cerebellum?
The pons relays signals from the cerebrum to the cerebellum.
101
What is the group of nuclei in the pons responsible for?
regulating breathing
102
What is the the respiratory center?
group of nuclei in the pons responsible for regulating breathing
103
Where is the pons located within the brainstem?
The pons is located in the middle of the brainstem.
104
What are the major functions of the pons?
relaying motor signals from the cerebral cortex to the cerebellum and helping control breathing.
105
What structure is located caudal to the pons?
the medulla oblongata.
106
What is the function of the cardiovascular center in the medulla oblongata?
he cardiovascular center in the medulla oblongata regulates cardiovascular function.
107
What sensory signals does the medulla oblongata relay from the spinal cord to the thalamus?
The medulla oblongata relays certain somatosensory signals from the spinal cord to the thalamus.
108
Where is the medulla oblongata located within the brainstem?
The medulla oblongata is a funnel-shaped mass of nuclei and tracts located at the caudal end of the brainstem that is continuous with the spinal cord.
109
What are the major functions of the medulla oblongata?
helping control breathing, heart rate, and blood vessel diameter, as well as controlling reflexes related to swallowing, sneezing, coughing, and vomiting.
110
What additional components are found in each part of the brainstem?
In addition to specific functions, each part of the brainstem contains nuclei that give rise to specific cranial nerves
111
What other structures are present in each part of the brainstem?
Each part of the brainstem contains sensory and motor tracts that carry signals between the brain and spinal cord.
112
What is the function of the blood-brain barrier?
The blood-brain barrier protects the brain from bloodborne pathogens and toxins by regulating the passage of substances into the brain tissue.
113
How is the blood-brain barrier formed and maintained?
The blood-brain barrier is formed and maintained by tight junctions between the endothelial cells of the blood vessels and processes extending out from astrocytes that wrap around the blood vessels.
114
what are endothelial cells?
Endothelial cells are a type of cell that lines the inner surface of blood vessels.
115
What substances are allowed free passage through the blood-brain barrier?
Some substances that are allowed free passage through the blood-brain barrier include oxygen, glucose, and alcohol.
116
What challenge does the blood-brain barrier present in drug delivery?
The blood-brain barrier presents a challenge in the delivery of certain drugs to the brain, requiring some drugs to be modified to allow them to pass through the barrier.
117
Blood-Brain Barrier
A special barrier is present around the vessels that carry blood to the brain
118
How do the brain and spinal cord develop?
The brain and spinal cord develop from the neural tube, which contains a fluid-filled cavity.
119
What structures develop from the neural tube cavity as different regions of the brain form?
Portions of the neural tube cavity expand and develop into chambers within the brain called ventricles.
120
Where are the lateral ventricles located?
The lateral ventricles form within the cerebral hemispheres.
121
Where does the third ventricle form?
The third ventricle forms within the diencephalon.
122
Where does the fourth ventricle form?
The fourth ventricle forms between the brainstem and cerebellum.
123
How are the ventricles connected to each other?
The ventricles are connected to each other via a series of canals.
124
What is the fourth ventricle continuous with inferiorly?
The fourth ventricle is continuous inferiorly with the central canal of the spinal cord.
125
What type of cells line the ventricles?
Ependymal cells line the ventricles.
126
What is the function of ependymal cells in the ventricles?
Ependymal cells produce cerebrospinal fluid (CSF).
127
What are some functions of cerebrospinal fluid (CSF)?
Functions of CSF include physically supporting the brain in space, acting as a cushion for nervous tissue, maintaining the ionic environment, and transporting and exchanging nutrients and wastes.
128
What are the three layers of connective tissue that surround the brain and spinal cord?
The three layers are the dura mater, arachnoid mater, and pia mater.
129
Describe the characteristics of the dura mater.
The dura mater is a tough, fibrous outer layer.
130
What is the composition of the arachnoid mater?
The arachnoid mater is a mesh-like middle layer.
131
What is the characteristic of the pia mater?
The pia mater is a thin inner layer that is firmly bound to the underlying nervous tissue.
132
What functions do the meninges serve?
The meninges provide physical stability and shock absorption to the brain and spinal cord.
133
How do the meninges relate to the spinal and cranial nerves?
The meninges extend out and are continuous with the epineurium of the emerging spinal and cranial nerves.
134
What is the epineurium?
The epineurium is the outermost layer of connective tissue that surrounds entire nerves, providing protection and support.
135
Describe the structure of the dura mater in the brain.
the dura mater has an outer layer fused to cranial bones and an inner layer attached to the arachnoid mater. Spaces between layers contain venous sinuses, draining blood from the brain.
136
What are the inward extensions of the dura mater in the cranial cavity?
The inward extensions include the falx cerebri, which separates the cerebral hemispheres; the falx cerebelli, which separates the cerebellar hemispheres; and the tentorium cerebelli, which separates the cerebrum and cerebellum.
137
What are the inward extensions of the dura mater used to separate within the brain?
The inward extensions of the dura mater physically separate the cerebrum and cerebellum, as well as the left and right hemispheres of these regions.
138
What is the space between the arachnoid mater and pia mater called?
The space between the arachnoid mater and pia mater is called the subarachnoid space.
139
Why is it clinically important that the meninges extend the entire length of the vertebral canal?
The meninges extending the entire length of the vertebral canal is clinically important because it allows for the testing of cerebral spinal fluid when infection or inflammation in the brain or meninges is suspected.
140
How is cerebral spinal fluid obtained for testing without risking damage to the spinal cord?
Cerebral spinal fluid is obtained for testing by inserting a needle into the vertebral canal in the lower lumbar region. This procedure, known as a lumbar puncture or spinal tap, draws CSF from the canal.
141
