Exam I: Neurons & Structure Flashcards
1
Q
Binding Site
A
“key hole”
location on a receptor protein to which a ligand binds
2
Q
Ligand
A
“Key”
chemical that binds with the binding site of a receptor
3
Q
• How many neurons?
A
- 100 Billion neurons in human nervous system, most common estimate (book)
- 100-1000 Billion neurons estimated (according to lecture notes)
4
Q
• Multipolar neuron
A
*Focus studies on this one, know what it looks like
o A neuron with one axon and many dendrites attached to its soma
o Building block
o Most abundant in CNS, diversity of presentations
o what they are,
o what they do
o Motor Neuron
• Located within CNS
• Controls contraction of muscle or secretion of gland, efferent response)
• Efferent: moving outward, moving potentials outward from the CNS
5
Q
Meninges
A
Three membranes that cover the brain and spinal cord, consisting of the Dura mater, pia mater, and arachnoid mater
6
Q
What are the three membranes that cover brain and spinal cord?
A
Meninges
Dura mater, pia mater, and arachnoid mater
7
Q
1) Dura Mater
A
Thick, outermost layer of the meninges surrounding and protecting the brain and spinal cord
8
Q
3) pia mater
A
The third layer of the meninges, located nearest to the brain and spinal cord
9
Q
2) arachnoid mater
A
Which resembles a spider web, is the second layer of the meninges and is located between the Dura mater and the pia mater
10
Q
Subarachnoid Space
A
A space in the meninges beneath the arachnoid membrane and above the pia mater that contains the cerebrospinal fluid
11
Q
Cerebrospinal Fluid
A
A clear fluid the circulates around through the brain and spinal cord that helps to physically support the brain and act as a shock absorber, and that also exchanges nutrients and wastes with the brain and spinal cord
12
Q
Major Division of the Nervous System
A
CNS: Brain and Spinal Chord PNS: Nerves and Peripheral Ganglia
13
Q
Ventricle
A
One of the hollow spaces within the brain, filled with cerebrospinal fluid.
14
Q
Lateral Ventricle
A
One of the two ventricles located in the center of the telencephalon.
15
Q
Third Ventricle
A
The ventricle located in the center of the diencephalon
16
Q
Cerebral Aqueduct
A
A narrow tube interconnecting the third and fourth ventricles of the brain, located in the center of the mesencephalon
17
Q
Fourth Ventricle
A
The ventricle located between the cerebellum and the dorsal pons, in the center of the metencephalon.
18
Q
Choroid Plexus
A
The highly vascular tissue that protrudes into the ventricles and produces cerebrospinal fluid.
19
Q
Arachnoid Granulation
A
Small projections of the arachnoid membrane through the Dura mater into the superior sagittal sinus; CSF flows through them to be reabsorbed into the blood supply
20
Q
Superior Sagittal Sinus
A
A venous sinus located in the midline just dorsal to the corpus callosum, between the two cerebral hemisphere.
21
Q
The CSF route
A
Choroid plexuses of the lateral ventricles produce cerebrospinal fluid and it flows into the third ventricle. More CSF is produced in this ventricle which then flows through the cerebral aqueduct to the fourth ventricle where still more CSF is produced. The CSF leaves the fourth ventricle through small openings that connect the subarachnoid space surrounding the brain where it is reabsorbed into the blood supply.
22
Q
forebrain
A
The most rostral of the three major divisions of the brain; includes the telencephalon and diencephalon.
23
Q
cerebral hemisphere
A
One of two major portions of the forebrain, covered by the cerebral cortex
24
Q
subcortical region
A
The region located within the brain, beneath the cortical surface.
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neocortex
The phylogenetically newest cortex, including the primary sensory cortex, primary motor cortex, and association cortex
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fissure
A major groove in the surface of the brain, larger than a sulcus.
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sulcus
A groove in the surface of the cerebral hemisphere, smaller than a fissure.
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gyrus
A convolution of the cortex of the cerebral hemispheres, separated by sulci or fissures.
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frontal lobe
The anterior portion of the cerebral cortex, rostral to the parietal lobe and dorsal to the temporal lobe.
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parietal lobe
The region of the cerebral cortex caudal to the frontal lobe and dorsal to the temporal lobe.
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temporal lobe
The region of the cerebral cortex rostral to the occipital lobe and ventral to the parietal and frontal lobes.
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occipital lobe
The region of the cerebral cortex caudal to the parietal and temporal lobes.
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limbic system
A group of brain regions including the anterior thalamic nuclei, amygdala, hippocampus, limbic cortex, and parts of the hypothalamus, as well as their interconnecting fiber bundles.
34
What makes up the limbic system?
anterior thalamic nuclei, amygdala, hippocampus, limbic cortex, and parts of the hypothalamus, as well as their interconnecting fiber bundles.
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limbic cortex
Phylogenetically old cortex, located at the medial edge (“limbus”) of the cerebral hemispheres; part of the limbic system.
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cingulate gyrus
A strip of limbic cortex lying along the lateral walls of the groove separating the cerebral hemispheres, just above the corpus callosum
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hippocampus
A forebrain structure of the temporal lobe, constituting an important part of the limbic system; includes the hippocampus proper (Ammon’s horn), dentate gyrus, and subiculum.
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amygdala
A structure in the interior of the rostral temporal lobe, containing a set of nuclei; part of the limbic system.
emotion, survival, memory
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fornix
A fiber bundle that connects the hippocampus with other parts of the brain; including the mammillary bodies of the hypothalamus; part of the limbic system.
memory
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mammillary bodies
A protrusion of the bottom of the brain at the posterior end of the hypothalamus, containing some hypothalamic nuclei; part of the limbic system
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Basal ganglia
collection of subcortical nuclei that lie just under the anterior aspect of the lateral ventricles
makes sustantia negra, thus dopamine, important to parkinsons
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afferent neurons
(AKA sensory neurons)
they bring the stimuli from the sensors (e.g., skin, eyes, ears) TOWARD the CNS. The efferent neurons are also known as motor neurons: they bring the responses from the brain to the muscles and the glands.
43
thalamus
both process and relay sensory information selectively to various parts of the cerebral cortex, as one thalamic point may reach one or several regions in the cortex. The hypothalamus regulates certain metabolic processes and other activities of the Autonomic Nervous System
sensory, motor system relay
consciousness and sleep
44
Neurogenesis
(birth of neurons) is the process by which neurons are generated from neural stem cells and progenitor cells. It plays a central role in neural development. Neurogenesis is most active during pre-natal development and is responsible for populating the growing brain with neurons
45
efferent neurons
(AKA motor neurons, motoneuron, motor nerve fiber, motor neuron)
they bring the responses from the brain to the muscles and the glands.
a neuron conducting impulses outwards and AWAY from the brain or spinal cord
a nerve that conveys impulses toward or to muscles or glands
46
Broca's Area
Broca's (expressive or motor) Aphasia. Damage to a discrete part of a the brain in the left frontal lobe (Broca's area) of the language-dominant hemisphere has been shown to significantly affect use of spontaneous speech and motor speech control.
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Broca's Aphasia
Trouble speaking fluently but comprehension relatively preserved
Non-fluent or expressive aphasia.
Difficulty producing grammatical sentences, speech is limited, laborious process
May understand speech relatively well when simple
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Wernicke's Aphasia
Fluent Aphasia
Ability to grasp the meaning of spoken words is impaired, while producing connected speech is not much affected.
speech is not normal, don't necessarily make sense,
Reading and writing are often severely impaired.
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What are brain ventricles?
The ventricles of the brain are a communicating network of interconnected cavities filled with (CSF), also produced there via region of choroid plexus
2 lateral ventricles, the third ventricle, the cerebral aqueduct, and the fourth ventricle
The ventricular system is a set of four interconnected cavities (ventricles) in the brain, where the cerebrospinal fluid (CSF) is produced.
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Lateral Ventricles
The right and left lateral ventricles are structures within the brain that contain cerebrospinal fluid. Along with the structures known as the third ventricle and the fourth ventricle, they are part of the body's ventricular system.
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3rd Ventricle
forebrain, diencephalon
| CSF from lateral ventricles via foramen
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cerebral aqueduct
mesencephalon
| CSF from 3rd to 4th ventricle
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fourth ventricle
metencephalon
| CSF from aqueduct, through medial foramen into subarachnoid space, diffuses to brain, spinal cord
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Choroid plexus
Within each ventricle is a region of choroid plexus, a network of ependymal cells involved in the production of CSF.
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Medulla Oblongata
the continuation of the spinal cord within the skull, forming the lowest part of the brainstem and containing control centers for the heart and lungs.
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Pons
the part of the brainstem that links the medulla oblongata and the thalamus.
The pons contains nuclei that relay signals from the forebrain to the cerebellum, along with nuclei that deal primarily with sleep, respiration, swallowing, bladder control, hearing, equilibrium, taste, eye movement, facial expressions, facial sensation, and posture.
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Cerebellum
the part of the brain at the back of the skull in vertebrates. Its function is to coordinate and regulate muscular activity.
The cerebellum receives information from the sensory systems, the spinal cord, and other parts of the brain and then regulates motor movements. The cerebellum coordinates voluntary movements such as posture, balance, coordination, and speech, resulting in smooth and balanced muscular activity.
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Tegmentum
The midbrain tegmentum is the part of the midbrain extending from the substantia nigra to the cerebral aqueduct in a horizontal section of the midbrain. It forms the floor of the midbrain that surrounds the cerebral aqueduct.
The VTA is the origin of the dopaminergic cell bodies of the mesocorticolimbic dopamine system and is widely implicated in the drug and natural reward circuitry of the brain. It is important in cognition, motivation, orgasm,[2] drug addiction, intense emotions relating to love, and several psychiatric disorders.
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tectum
The tectum is located in the dorsal region of the mesencephalon (mid brain). It consists of the superior colliculi (visual receptors) and inferior colliculi (auditory receptors).
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Thalamus
send signals all around the structures
sensory and motor signal relay
regulation of consciousness and sleep.
smell, all other sensory processes
thalamic nucleus receiving signal, direct it
controlling the motor systems (voluntary bodily movement and coordination)
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The cingulate gyrus
The cingulate gyrus is the part of the cerebrum that lies closest to the limbic system, just above the corpus callosum. It provides a pathway from the thalamus to the hippocampus, seems to be responsible for focusing attention on emotionally significant events, and for associating memories to smells and to pain.is the part of the cerebrum that lies closest to the limbic system, just above the corpus callosum. It provides a pathway from the thalamus to the hippocampus, seems to be responsible for focusing attention on emotionally significant events, and for associating memories to smells and to pain.
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The ventral tegmental area
The ventral tegmental area of the brain stem (just below the thalamus) consists of dopamine pathways that seem to be responsible for pleasure. People with damage here tend to have difficulty getting pleasure in life, and often turn to alcohol, drugs, sweets, and gambling.
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The basal ganglia
The basal ganglia (including the caudate nucleus, the putamen, the globus pallidus, and the substantia nigra) lie over and to the sides of the limbic system, and are tightly connected with the cortex above them. They are responsible for repetitive behaviors, reward experiences, and focusing attention.
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The prefrontal cortex,
The prefrontal cortex, which is the part of the frontal lobe which lies in front of the motor area, is also closely linked to the limbic system. Besides apparently being involved in thinking about the future, making plans, and taking action, it also appears to be involved in the same dopamine pathways as the ventral tegmental area, and plays a part in pleasure and addiction.
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Function of Limbic system
a complex system of nerves and networks in the brain, involving several areas near the edge of the cortex concerned with instinct and mood. It controls the basic emotions (fear, pleasure, anger) and drives (hunger, sex, dominance, care of offspring).
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Structures of the Limbic System
The primary structures within the limbic system include the amygdala, hippocampus, thalamus, hypothalamus, basal ganglia, and cingulate gyrus. The amygdala is the emotion center of the brain, while the hippocampus plays an essential role in the formation of new memories about past experiences.
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Anatomical Subdivisions of the Brain: Forebrain
Lateral & 3rd Ventricles
Telencephalon & Diencephalon
Cerebral Cortex, Basal Ganglia, Limbic System
Thalamus, Hypothalamus
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Anatomical Subdivisions of the Brain: Midbrain
Cerebral Aqueduct
Mesencephalon
Tectum
Tegmentum
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Anatomical Subdivisions of the Brain: Hindbran
4th Ventricle
Metencephalon & Myelencephalon
Cerebellum, Pons, Medulla Oblongata
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hypothalamus
a region of the forebrain below the thalamus that coordinates both the autonomic nervous system and the activity of the pituitary, controlling body temperature, thirst, hunger, and other homeostatic systems, and involved in sleep and emotional activity
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Basal Ganglia
The substantia nigra is the source of the striatal input of the neurotransmitter dopamine, which plays an important role in basal ganglia function. The subthalamic nucleus receives input mainly from the striatum and cerebral cortex, and projects to the globus pallidus.
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ipsilateral
same side
e.g. smell, taste, some vision
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contralateral
movement
| touch and other sensation, some vision
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Idiopathic = Don’t know what it is
How would you go about diagnosing something that is unknown?
Onset, course, symptoms and signs. How important is the cause?
Normal pressure hydrocephalous-enlarged ventricles, wacky, wet, wobbly
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choroid plexus
The highly vascular tissue that protrudes into the ventricles and produces cerebrospinal fluid.
76
obstructive hydrocephalus
A condition in which all or some of the brain’s ventricles are enlarged; caused by an obstruction that impedes the normal flow of CSF.
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arachnoid granulation
Small projections of the arachnoid membrane through the dura mater into the superior sagittal sinus; CSF flows through them to be reabsorbed into the blood supply.
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superior sagittal sinus
A venous sinus located in the midline just dorsal to the corpus callosum, between the two cerebral hemispheres.
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CSF Flow
1. CSF formed in lateral ventricles, passes to:
2. Interventricular foramina (of Monro) to:
3. 3rd Ventricle through:
4. Cerebral Aqueduct to (structural landmark)
5. 4th Ventricle
6. Foramen of Magendie; Foramina of Lushka
(Medial | Lateral)
7. Cisterna Magna, Pontine Cistern
8. Tentorial Notch, Cerebral Hemispheres
9. Arachnoid Villi (site at which we see CSF finding way back)
*subarachnoid space, arachnoid granulation to superior sagittal sinus
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Tectum
Midbrain tectum. The tectum (Latin: roof) is a region of the brain, specifically the dorsal part of the mesencephalon (midbrain). This is contrasted with the tegmentum, which refers to the region ventral to the ventricular system. The tectum is responsible for auditory and visual reflexes.
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Tegmentum
Controls Motor Functions
Regulates Awareness and Attention
Regulates Some Autonomic Functions
The tegmentum is the area within the brainstem that forms the base of the mesencephalon (mid brain). It consists of the cerebral aqueduct, periaqueductal gray, reticular formation, substantia nigra and the red nucleus.
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3 Theoretical Contributors to Hydrocephalus
Excess CSF Production (e.g., as result of papilloma/choroid plexus tumor)
Obstruction of CSF Circulation
Deficiency in CSF Reabsorption (In arachnoid villa)
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CNS
The Forebrain
The Midbrain
The Hindbrain
The Spinal Cord
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Stages of Brain Development
Cell Birth (Neurogenesis)
Cell Migration
To intended destination before they differentiate
Cell Differentiation
Cell Maturation (Dendrite/Axon growth)
Synaptogenesis
Cell Death/Synaptic Pruning
Apoptosis: programmed cell death, natural
Myelogenesis
Evidence that this continues throughout adolescence
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Neural Tube
A hollow tube, closed at the rostral end, that forms from the ectoderm tissue early in embryonic development; serves as the origin of the central nervous system.
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Ventricular Zone
A layer of cells that line the inside of the neural tube; contains founder cells that divide and give rise to the central nervous system.
Early phases of brain and spine
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Cerebral cortex
The outermost layer of gray matter of the cerebral hemispheres.
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Radial Glia
Special glia with fibers that grow radially outward from the ventricular zone to the surface of the cortex; provide guidance for neurons migrating outward during brain development.
Scaffold for neurons to climb to specific destination
Radial glial cells help to guide migration of newly formed neurons
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CNS Development: Days 18, 21, 28, 30
CNS development occurs ~18 days post-conception
Portion of ectoderm thickens, forms plate; ridges in plate form ridges in rostral-caudal manner; fuse to form neural tube day 21
Neural tube gives rise to brain and spinal cord
~Day 28: Rostral end of neural tube forms 3 chambers (to become ventricles)
Cortex surrounding chambers become: 1 month post conception
(1) forebrain
(2) midbrain
(3) hindbrain
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Brainstem includes:
Midbrain, Pons, Medulla
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Founder Cells
Cells of the ventricular zone that divide and give rise to cells of the central nervous system.
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Symmetrical Division
Division of a founder cell that gives rise to two identical founder cells; increases the size of the ventricular zone and hence the brain that develops from it.
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Asymmetrical Division
Division of a founder cell that gives rise to another founder cell and a neuron, which migrates away from the ventricular zone toward its final resting place in the brain.
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Apoptosis
Death of a cell caused by a chemical signal that activates a genetic mechanism inside the cell.
Programmed cell death, instrumental in pruning process
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Gyri, Sulci, and Fissures
Gyri=hills
Sulci=valleys
Fissures=really big valleys
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Early Developmental Malformations
```
If Neural Tube Fails to Close
(1) Completely
Cranioarchishosis (Fatal)
(2) Rostrally
Anencephaly (may result from deficient folic acid)
(3) Caudally
Spina Bifida (Myelomeningocele)
```
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Multiple Scleroses
scleroses are lesions/wounds/scar tissue areas on brain where a person's immune system started attacking their own myelin sheaths, prevents certain messages, action potentials to be carried out, loss of function
autoimmune disease possibly caught in childhood
98
Wata Test
anesthetize one hemisphere of brain
requires brain mapping
locate "hemisphericity" of language
99
Generally, 3 Critical Age Divisions in Determination of Effects of Early Lesions:
5 years: Little or no sparing of function
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cerebral hemisphere
One of two major portions of the forebrain, covered by the cerebral cortex.
101
forebrain
The most rostral of the three major divisions of the brain; includes the telencephalon and diencephalon.
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subcortical region
The region located within the brain, beneath the cortical surface.
103
neocortex
The phylogenetically newest cortex, including the primary sensory cortex, primary motor cortex, and association cortex. Visual cortext, outwardly presented
Newest of evolution
*primary=initial analysis of information, secondary, tertiary cortices offer backup and further processing
104
Fissure
A major groove in the surface of the brain, larger than a sulcus.
Midsagettal fissure—separates hemisphere
105
Sulcus
A groove in the surface of the cerebral hemisphere, smaller than a fissure.
106
Gyrus
A convolution of the cortex of the cerebral hemispheres, separated by sulci or fissures.
107
Insula
is a portion of the cerebral cortex folded deep within the lateral sulcus (the fissure separating the temporal lobe from the parietal and frontal lobes).
108
primary visual cortex
The region of the posterior occipital lobe whose primary input is from the visual system.
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lateral fissure
The fissure that separates the temporal lobe from the overlying frontal and parietal lobes.
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calcarine fissure
A fissure located in the occipital lobe on the medial surface of the brain; most of the primary visual cortex is located along its upper and lower banks.
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primary auditory cortex
The region of the superior temporal lobe whose primary input is from the auditory system.
112
primary somatosensory cortex
The region of the anterior parietal lobe whose primary input is from the somatosensory system.
113
primary motor cortex
The region of the posterior frontal lobe that contains neurons that control movements of skeletal muscles.
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central sulcus
The sulcus that separates the frontal lobe from the parietal lobe.
115
insular cortex
A sunken region of the cerebral cortex that is normally covered by the rostral superior temporal lobe and caudal inferior frontal lobe. Deep, critical role in hyp. formation
Learning and memory
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sensory association cortex
Those regions of the cerebral cortex that receive information from the regions of the primary sensory cortex.
117
corpus callosum
A large bundle of axons that interconnect to corresponding regions of the association cortex on each side of the brain.
118
motor association cortex
The region of the frontal lobe rostral to the primary motor cortex; also known as the premotor cortex.
119
prefrontal cortex
The region of the frontal lobe rostral to the motor association cortex.
planning complex cognitive behavior, personality expression, decision making, and moderating social behaviour.
120
limbic system
A group of brain regions including the anterior thalamic nuclei, amygdala, hippocampus, limbic cortex, and parts of the hypothalamus, as well as their interconnecting fiber bundles.
121
limbic cortex
Phylogenetically old cortex, located at the medial edge (“limbus”) of the cerebral hemispheres; part of the limbic system.
122
cingulate gyrus
A strip of limbic cortex lying along the lateral walls of the groove separating the cerebral hemispheres, just above the corpus callosum.
Key structure
123
Hippocampus, seahorse
A forebrain structure of the temporal lobe, constituting an important part of the limbic system; includes the hippocampus proper (Ammon’s horn), dentate gyrus, and subiculum.
New memories
124
Amygdala, almond
A structure in the interior of the rostral temporal lobe, containing a set of nuclei; part of the limbic system. emotion
Just posterior to hippocampus
125
fornix
A fiber bundle that connects the hippocampus with other parts of the brain; including the mammillary bodies of the hypothalamus; part of the limbic system.
Verniquis corsecough syndrom, degen of mam bodies, alcohol addiction, amnesia
126
mammillary bodies
A protrusion of the bottom of the brain at the posterior end of the hypothalamus, containing some hypothalamic nuclei; part of the limbic system.
127
Basal Ganglia
predoimant role in regulation of extrapyramidal movement
| 5 Major Nuclei
128
5 Major Nuclei of Basal Ganglia
1-3 for sure; 4-5 sometimes added
(1) Putamen
(2) Caudate nucleus
(3) Globus Pallidus
(4) Subthalamic nucleus
(5) Substantia Nigra (both compact and reticular parts) technically in midbrain but in same network as BG; parkinsons, becomes bleached bc cell death
129
Basal Ganglia crucial role in movement, involvement contributes to variety of involuntary movement disorders contributing to:
Dystonia,
Athetosis, Chorea, Hemiballismus (throwing of given extermity)
Parkinson’s disease and other parkinsonian conditions
Huntington’s disease
130
Hypothalamus
Diencephalic nuclei beneath thalamus
involved in regulation of ANS, pituitary, and integration of species-typical behaviors.
Hypothalamus=fight flight feed fornicate, primitive, old structure, important adaptively
HPA axis, activate release of
131
Thalamus
Largest portion of the diencephalon (3rd ventricle),
located above the hypothalamus;
contains many nuclei that project information to specific regions of the cerebral cortex and receive information from it.
Thalamus grand central station
Primary inputs, primary outputsvision audition motor functions
Not olfactionfast track to limbic
132
Thalamic Nuceli
Lateral geniculate nucleus (LGN)
medial geniculate nucleus (MGN)
Ventrolateral nucleus
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Lateral geniculate nucleus (LGN)
Thalamic nucleus that receives fibers from the retina and projects fibers to the primary visual cortex.
One of many nucleus in Thal that is input/output site
134
medial geniculate nucleus (MGN)
Thalamic nucleus that receives fibers from the auditory system and projects fibers to primary auditory cortex.
135
ventrolateral nucleus
Thalamic nucleus that receives inputs from cerebellum and sends axons to the primary motor cortex
136
Diencephalon
```
Thal, Hypothal
Third ventricle
optic chiasm
neurosecretory cell
anterior pituitary gland
posterior pituitary gland
```
137
neurosecretory cell
A neuron that secretes a hormone-like substance.
138
optic chiasm
An X-shaped connection between the optic nerves, located below the base of the brain, just anterior to the pituitary gland.
Adolescent male cranial tumors; visual disturbance, lose lateral aspects of visual fields, activate pituitary gland, gigantism,
139
anterior pituitary gland
The anterior part of the pituitary gland; an endocrine gland whose secretions are controlled by the hypothalamic hormones.
140
posterior pituitary gland
The posterior part of the pituitary gland; an endocrine gland that contains hormone-secreting terminal buttons of axons whose cell bodies lie within the hypothalamus.
141
Midbrain
Mesencephalon, a region of the brain that surrounds the cerebral aqueduct; includes the tectum and the tegmentum, brain stem, reticular formation, periaqueductal gray matter, substantia nigra, red nucleus, periaqueductal gray matter
142
Tectum (pp notes)
in midbrain, more dorsally in mb
The dorsal part of the midbrain; includes the superior and inferior colliculi.
superior colliculi
Protrusions on top of the midbrain; part of the visual system.
Orienting for visual
inferior colliculi
Protrusions on top of the midbrain; part of the auditory system
Same orienting role for aud stimuli
Tectum two bumps on top, two on bottom
Important role in same entwork
Facilitating oreinting to visual information
Real rich interconnectivity
143
tegmentum (pp notes)
The ventral part of the midbrain; includes the periaqueductal gray matter, reticular formation, red nucleus, and substantia nigra (in midbrain, closely alligned with BG)
Cortex immediately surrounding aquedcut
144
brain stem
The “stem” of the brain, from the medulla to the diencephalon, excluding the cerebellum.
145
reticular formation
A large network of neural tissue located in the central region of the brain stem, from the medulla to the diencephalon.
Crucial for attention and arousal, stroke dev. delirium
146
periaqueductal gray matter
The region of the midbrain surrounding the cerebral aqueduct; contains neural circuits involved in species-typical behaviors.
147
red nucleus
A large nucleus of the midbrain that receives inputs from the cerebellum and motor cortex and sends axons to motor neurons on the spinal cord.
148
substantia nigra
A darkly stained region of the tegmentum that contains neurons that communicate with the caudate nucleus and putamen in the basal ganglia.
149
hindbrain
The most caudal of the three major divisions of the brain; includes the metencephalon and the myelencephalon.
cerebellum, cerebellar cortex, deep cerebellar nuclei
150
cerebellum
A major part of the brain located dorsal to the pons, containing two cerebellar hemispheres, covered with the cerebellar cortex; an important component of the motor system.
Own little brain, sophisticated, complex structure
Coordinating movements
151
cerebellar cortex
The cortex that covers the surface of the cerebellum.
152
deep cerebellar nuclei
Nuclei located within the cerebellar hemispheres; receives projections from the cerebellar cortex and send projections out of the cerebellum to other parts of the brain.
153
spinal cord
The cord of nervous tissue that extends caudally from the medulla.
Also includes: cauda equina, dorsal root, ventral root
154
cauda equina
A bundle of spinal roots located caudal to the end of the spinal cord.
caudal block
The anesthesia and paralysis of the lower part of the body produced by injection of a local anesthetic into the cerebrospinal fluid surrounding the cauda equina.
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dorsal root
The spinal root that contains incoming (afferent) sensory fibers.
156
ventral root
The spinal root that contains outgoing (efferent) motor fibers.
157
PNS
Spinal Nerves
Cranial Nerves
The Autonomic Nervous System
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spinal nerve
A peripheral nerve attached to the spinal cord.
159
afferent axon
An axon directed toward the central nervous system, conveying sensory information.
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efferent axon
An axon directed away from the central nervous system, conveying motor commands to muscles and glands.
161
dorsal root ganglion
A nodule on a dorsal root that contains cell bodies of afferent spinal nerve neurons.
162
cranial nerve
outside but essential
| A peripheral nerve attached directly to the brain (12 in total)
163
vagus nerve
The largest of the cranial nerves, conveying efferent fibers of the parasympathetic nervous system to organs of the thoracic and abdominal cavities.
164
olfactory bulb
The protrusion at the end of the olfactory nerve; receives input from the olfactory receptors.
165
somatic nervous system
The part of the peripheral nervous system that controls the movement of skeletal muscles or transmits somatosensory information to the central nervous system.
166
autonomic nervous system
The portion of the peripheral nervous system that controls the body’s vegetative functions.
167
sympathetic division
The portion of the autonomic nervous system that controls functions that accompany arousal and expenditure of energy.
168
sympathetic ganglia
Nodules that contain synapses between preganglionic and postganglionic neurons of the sympathetic nervous system.
169
sympathetic chain
Nodules of a pair of groups of sympathetic ganglia that lie ventrolateral to the vertebral column.
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preganglionic neuron
The efferent neuron of the autonomic nervous system whose cell body is located in a cranial nerve nucleus or in the intermediate horn of the spinal gray matter and whose terminal buttons synapse upon postganglionic neurons in the autonomic ganglia.
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postganglionic neuron
Neurons of the autonomic nervous system that form synapses directly with their target organ.
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adrenal medulla
The inner portion of the adrenal gland, located atop the kidney, controlled by sympathetic nerve fibers; secretes epinephrine and norepinephrine.
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parasympathetic division
The portion of the autonomic nervous system that controls functions that occur during a relaxed state.
