BMB 1 - Brain & Spinal Cord Flashcards
How many neurons does the brain have?
80 - 100 billion
The brain uses what percent of the body’s O2, ATP, blood supply?
20%
Ventral in the brain is the same as _________ (alternate name for the same direction).
Ventral in the spinal cord is the same as _________ (alternate name for the same direction).
Ventral in the brain is the same as inferior.
Ventral in the spinal cord is the same as anterior.
Dorsal in the brain is the same as _________ (alternate name for the same direction).
Dorsal in the spinal cord is the same as _________ (alternate name for the same direction).
Dorsal in the brain is the same as superior.
Dorsal in the spinal cord is the same as posterior.
From your left to your right, give the names of each of these three cuts.
Transverse;
coronal;
mid-saggital
True/False.
The unfolded brain (i.e. the gyri and sulci all stretched out) is about the size of a car.
False.
More like a pizza.
The brain ‘hills’ are called ______, and the ‘valleys’ are called ______.
The brain ‘hills’ are called gyri, and the ‘valleys’ are called sulci.
Are cells in the cerebral cortex typically myelinated or unmyelinated?
Unmyelinated
What are the main functions of the frontal lobe?
Motor + higher cognitive functions
What are the main functions of the parietal lobe?
Somatosensory processing
What are the main functions of the temporal lobe?
Auditory processing,
memory,
language understanding
What are the main functions of the occipital lobe?
Visual processing
What are the main functions of the insula lobe?
Taste processing;
some elements of visceral pain processing, consciousness, empathy, compassion, self-awareness, and more…
Which cortical lobe is most associated with memory?
Temporal
What sulcus separates the frontal lobes from the parietal lobes?
What sulcus separates the frontal and parietal lobes from the temporal lobes?
What sulcus is in the mid-saggital line between the two brain hemispheres?
The central sulcus;
the lateral (Sylvian) fissure;
the longitudinal fissure
What cortical structure lies between the outer cortex and the corpus callosum?
The cingulate gyrus
The insula lobe can be exposed by removing what portion of the cerebral cortex?
The anterior portion of the temporal lobe
Identify the functions of the following Brodmann areas:
8 -
6 -
4 -
Identify the functions of the following Brodmann areas:
8 - Frontal eye fields
6 - Premotor cortex
4 - Primary motor cortex
Identify the functions of the following Brodmann areas:
3 -
1 -
2 -
Identify the functions of the following Brodmann areas:
3 - Primary somatosensory cortex
1 - Primary somatosensory cortex
2 - Primary somatosensory cortex
Identify the functions of the following Brodmann areas:
17 -
22 -
41 -
Identify the functions of the following Brodmann areas:
17 - Primary visual cortex
22 - Auditory association cortex (Wernicke’s area)
41 - Primary auditory cortex (with 42)
Identify the functions of the following Brodmann areas:
42 -
45 -
44 -
Identify the functions of the following Brodmann areas:
42 - Primary auditory cortex
45 - Broca’s area (in dominant hemisphere only)
44 - Broca’s area (in dominant hemisphere only)
Identify the functions of the following Brodmann areas:
9 -
10 -
11 -
12 -
Identify the functions of the following Brodmann areas:
9 - Prefrontal cortex
10 - Prefrontal cortex
11 - Prefrontal cortex
12 - Prefrontal cortex
Identify the Brodmann area(s) associated with each of the following cerebral structures:
Premotor cortex -
Primary motor cortex -
Identify the Brodmann area(s) associated with each of the following cerebral structures:
Premotor cortex - 6
Primary motor cortex - 4
Identify the Brodmann area(s) associated with each of the following cerebral structures:
Frontal eye fields -
Primary somatosensory cortex -
Identify the Brodmann area(s) associated with each of the following cerebral structures:
Frontal eye fields - 8
Primary somatosensory cortex - 3, 1, 2
Identify the Brodmann area(s) associated with each of the following cerebral structures:
Primary visual cortex -
Auditory association cortex (Wernicke’s area) -
Identify the Brodmann area(s) associated with each of the following cerebral structures:
Primary visual cortex - 17
Auditory association cortex (Wernicke’s area) - 22
Identify the Brodmann area(s) associated with each of the following cerebral structures:
Primary auditory cortex -
Broca’s area -
Identify the Brodmann area(s) associated with each of the following cerebral structures:
Primary auditory cortex - 41, 42
Broca’s area - 44, 45
Identify the Brodmann area(s) associated with each of the following cerebral structures:
Prefrontal cortex -
Identify the Brodmann area(s) associated with each of the following cerebral structures:
Prefrontal cortex - 9, 10, 11, 12
Describe the motor homunculus.
Describe the sensory homunculus.
Name the structures which derive from the following embryonic structures:
Telencephalon
Diencephalon
Cerebral cortex, lateral ventricles;
thalami, third ventricles
Name the structures which derive from the following embryonic structures:
Mesencephalon
Midbrain, cerebral aquaduct
Name the structures which derive from the following embryonic structures:
Metencephalon
Myencephalon
Pons, cerebellum;
medulla oblongata
__________ fibers link two areas of the brain that have separate functions in order to produce some higher function.
Association fibers link two areas of the brain that have separate functions in order to produce some higher function.
__________ fibers allow communications between ipsilateral areas of the brain.
__________ fibers allow communications between contralateral areas of the brain.
Connection fibers allow communications between ipsilateral areas of the brain.
Commissural fibers allow communications between contralateral areas of the brain.
What structure in the brain is made almost entirely of commissural fibers?
The corpus callosum
What structure connects the visual pathway to the amygdala (among other locations)?
What structure connects the auditory pathway to the amygdala (among other locations)?
The lateral geniculate nucleus;
the medial geniculate nucleus
_______lateral structures are on the same side of the body.
_______lateral structures are on opposite sides of the body.
Ipsilateral structures are on the same side of the body.
Contralateral structures are on opposite sides of the body.
____________ is the term for when a group of nerve fibers cross the midline and terminate contralateral to the side of origin.
Decussation is the term for when a group of nerve fibers cross the midline and terminate contralateral to the side of origin.
Where do most sensory nerves decussate?
The medial lemniscus
Where do motor nerves typically decussate?
The medullary pyramids
Commissures, peduncles, brachias, pyramids, capsules, and stria are all forms of what?
Nerve fiber tracts
Gyri, olives, pyramids, and colliculi are all forms of what?
Raised areas formed by underlying neurons / fibers
Groups of neuronal cell bodies in the brain are called _________.
Groups of neuronal cell bodies in the spinal cord are called _________.
Groups of neuronal cell bodies in the brain are called nuclei.
Groups of neuronal cell bodies in the spinal cord are called ganglia.
Which sensations (if any) are always unconscious (sensed by our brains but below the level of consciousness)?
Visceral reflexes;
muscle coordination
What term refers to a sensations of limb position and motion?
Proprioception
In the spinal cord, ______ matter makes outer portion and ______ matter makes up the internal portion.
In the spinal cord, white matter makes outer portion and gray matter makes up the internal portion.
What structure connects the two halves of spinal cord gray matter and allows for nerves to pass between the two?
The gray commissure
The central canal in the spinal cord pierces (and runs through) what structure?
The gray commissure
Cells of similar morphology in the spinal cord cluster into columns known as ________.
Cells of similar morphology in the spinal cord cluster into columns known as nuclei.
Spinal cord gray matter forms structures called _______, while spinal cord white matter forms structures called _______.
Spinal cord gray matter forms structures called horns, while spinal cord white matter forms structures called funiculi.
_________________ refers to a pale area of lightly-myelinated neurons spanning the entire length of the spinal cord that are tasked with discriminating pain and temp.
Substantia gelatinosa refers to a pale area of lightly-myelinated neurons spanning the entire length of the spinal cord that are tasked with discriminating pain and temp.
Describe the location and function of the Substantia gelatinosa.
Location: (see image) along the entire length of the spinal cord
Function: discriminating pain and temperature
Name some of the major nuclei present in the posterior horn of the spinal cord.
- Substantia gelatinosa*,
- proper sensory nucleus*,
- dorsal nucleus (of Clarke)*
Name the major nucleus that occupies the lateral horn of the spinal cord?
The intermediolateral nucleus
_________________ refers to the cell bodies of the spinothalamic tract (a collection of pain fibers in the spinal cord traveling to the anterolateral system).
Proper sensory nucleus refers to the cell bodies of the spinothalamic tract (a collection of pain fibers in the spinal cord traveling to the anterolateral system).
Describe the location and function of the Proper sensory nucleus.
Location: (See image)
Function: pain transmission (part of the spinothalamic tract)
_________________ refers to the spinal cord gray matter containing sympathetic and preganglionic (general visceral efferent) neurons. It is only present at the thoracic levels.
Intermediolateral nucleus refers to the spinal cord gray matter nucleus containing sympathetic and preganglionic (general visceral efferent) neurons. It is only present at the thoracic levels.
The intermediolateral nucleus makes up what structure?
The lateral horn
Describe the location and function of the Intermediolateral nucleus.
Location: (See image) only present at thoracic levels
Function: sympathetic activity
_________________ refers to the spinal cord gray matter containing neuron bodies involved in nonconscious input to the cerebellum via dorsal spinocerebellar tracts (NOTE: found at levels C8 - L2).
Dorsal nucleus (of Clarke) refers to the spinal cord gray matter containing neuron bodies involved in nonconscious input to the cerebellum via dorsal spinocerebellar tracts (NOTE: found at levels C8 - L2).
Describe the location and function of the Dorsal nucleus (of Clarke).
Location: (See image) present at levels C8 - L2
Function: nonconscious input to the cerebellum via dorsal spinocerebellar tract
Describe the locations of the gracile and cuneate fasciculi in the spinal cord (i.e. which is medial and which is lateral; in which portion they reside).
Gracile fasciculus - medial
Cuneate fasciculus - lateral
Both in the posterior funiculus
The dorsal columns of the spinal cord are made up by what two structures?
The gracile fasciculus and the cuneate fasciculus
Fiber tracts known as ________ occupy the spinal cord funiculi.
Fiber tracts known as fasciculi occupy the spinal cord funiculi.
Some ascending tract fibers (e.g. some pain and temperature) decussate in the spinal cord via the ________________.
Some ascending tract fibers (e.g. some pain and temperature) decussate in the spinal cord via the anterior white commissure.
What structure connects the posterior horn of the spinal cord to the posterolateral sulcus?
The tracts of Lissauer
Describe some of the fasciculi of the spinal cord.
The dorsal columns (the fasciculus gracilis and fasciculus cuneatus) are also known as the _____________ tracts.
The dorsal columns (the fasciculus gracilis and fasciculus cuneatus) are also known as the spino-medullary tracts.
Which are the main three categories of ascending tracts in the spinal cord?
(Hint: spino-__________, spino-__________, and spino-__________)
Spinomedullary (a.k.a. the dorsal columns)
Spinocerebellar (dorsal and ventral)
Spinothalamic (lateral and ventral)
Describe the locations of the spinocerebellar tracts.
Dorsal
+
ventral
Describe the locations of the spinothalamic tracts.
Lateral
+
ventral
(hence why it is called the anterolateral system)
Name the main six categories of descending spinal tracts.
(HINT: _______spinal, _______spinal, _______spinal, _______spinal, and _______spinal)
Corticospinal
Olivospinal
Reticulospinal
Rubrospinal
Vestibulospinal
Tectospinal
(A corrvette can go downhill real fast.)
Which of the descending spinal tracts (corticospinal, olivospinal, reticulospinal, rubrospinal, vestibulospinal, tectospinal) are pyramidal tracts?
Coritcospinal only
(anterior and lateral)
Which of the descending spinal tracts (corticospinal, olivospinal, reticulospinal, rubrospinal, vestibulospinal, tectospinal) are extra__pyramidal tracts?
Olivospinal, reticulospinal, rubrospinal, vestibulospinal, tectospinal
(all but coritcospinal)
Ascending tracts leading to conscious sensation are composed of a _______-neuron chain.
Ascending tracts leading to conscious sensation are composed of a three-neuron chain
(first-, second-, and third-order neurons).
In the three-neuron chain leading to conscious sensation (e.g. touching the skin on the back of your hand), where are the three cell bodies (bold the two synapse locations)?
The DRG;
the dorsal horn;
the thalamus
True/False.
The dorsal columns contain fibers for discriminative sense.
True.
Describe the somatotropic organization of the dorsal columns (i.e. which body regions are represented in specific regions of spinal cord).
_______ (rostral/caudal) fibers form the (lateral) fasciculi cuneatus.
_______ (rostral/caudal) fibers form the (medial) fasciculi gracilis.
Rostral fibers form the fasciculi cuneatus (lateral).
Caudal fibers form the fasciculi gracilis (medial).
The fasciculus gracilis carries information from the lower body, and the fasiculus cunateus carries information from the upper body.
What spinal level is the dividing line between the two?
T6
The fasciculus gracilis fibers are _________ (medial/lateral) to the fasiculus cuneatus fibers.
The spinothalamic fibers from the leg are _________ (medial/lateral) to those from the upper body.
The fasciculus gracilis fibers are medial to the fasiculus cuneatus fibers.
The spinothalamic fibers from the leg are lateral to those from the upper body.
Why are fasciculus gracilis fibers medial to the fasiculus cuneatus fibers?
They are pushed medially by axons entering at higher levels (i.e. those representing the upper trunk)
Why are spinothalamic fibers from the leg lateral to the other spinothalamic fibers?
Axons of the spinothalamic tracts representing the trunk and leg are deflected laterally by crossing the midline at successively higher levels
(and thus continually pushing the lower fibers that are first to decussate further and further out)
Descending motor tracts leading to skeletal muscle contraction are composed of a _______-neuron chain.
Descending motor tracts leading to skeletal muscle contraction are composed of a three-neuron chain
(first-, second-, and third-order neurons).
In the three-neuron chain leading from the cerebrum to skeletal muscle contraction, where are the three cell bodies (bold the two synapse locations)?
The cerebral cortex;
generic spinal cord (an interneuron);
the anterior horn
Starting in the cerebral cortex, name the three generic names of the neurons involved in motor contraction.
I. Upper motor neuron
II. Interneuron
III. Lower motor neuron
True/False.
Gray and white matter proportions stay more or less consistent along the length of the spinal cord.
False.
Proportion of gray and white matter varies between spinal cord levels.
The anterior horns expand laterally at the _________ and _________ enlargements to accommodate neurons necessary to innervate somatic muscles.
The anterior horns expand laterally at the cervical and lumbosacral enlargements to accommodate neurons necessary to innervate somatic muscles.
The lateral horn of the spinal cord is only present at which spinal column levels?
T1 - L2
Ascending funiculi _________ progressively.
Ascending funiculi enlarge progressively (as fibers are added to the spinal cord).
Descending funiculi __________ progressively.
Descending funiculi decrease progressively (as fibers leave the spinal cord).
Will there be more or less white matter in the distal spinal cord vs. the proximal?
Less
In the spinal cord, the neurons involved in somatic innervation to flexors are in which portion of the anterior horn?
Dorsal
(but still within the anterior horn)
In the spinal cord, the neurons involved in somatic innervation to axial (midline) muscles are in which portion of the anterior horn?
Medial
In the spinal cord, the neurons involved in somatic innervation to extensors are in which portion of the anterior horn?
Anterior
In the spinal cord anterior horn, the innervation to proximal musculature is ________ (location), and the innervation to the distal musculature is ________ (location).
In the spinal cord anterior horn, the innervation to proximal musculature is anteromedial, and the innervation to the distal musculature is posterolateral.
Which tracts innervate the axial portion (medial) of the anterior horn (as shown in the image below)?
Vestibulospinal and reticulospinal tracts
(involved in posture and balance)
Which tracts innervate the flexors and extensors in the anterior horn (as shown in the image below)?
Corticospinal and rubrospinal tracts
(involved in movement control)
Which general category of sensory fibers ascends ipsilaterally and decussates in the medulla?
Which general category of sensory fibers decussates near immediately in the spinal cord and ascends contralaterally?
Dorsal columns;
spinothalamics
How many anterior spinal arteries are there?
And posterior?
One;
two
Where do the two posterior spinal arteries originate?
The posterior inferior cerebellar arteries
Where does the anterior spinal artery originate?
The vertebral arteries
Which portion(s) of the spinal cord are supplied by the posterior spinal arteries only?
The dorsal columns
A patient has a blockage in his posterior spinal arteries. Which of the following do you expect to be affected?
Motor control, somatic sensation, pain and temperature sense
Somatic sensation
(the lateral corticospinal tract and spinothalamics have a dual supply)
