10/2 - Brainstem Nuclei in the Midbrain-Diencephalon

Question 1

BRAINSTEM AS AN INTEGRATIVE CENTER:

Answer 1

BRAINSTEM NUCLEI IN THE MIDBRAIN

Question 2

TRIGEMINAL NUCLEUS – SENSORY COMPONENTS

Answer 2

Somatic sensory conveying information on touch, pain, proprioception from all parts of the face

The trigeminal nerve has a general sensory components that is divided among 3 nuclei. The neurons that carry these sensations, for the most part, are located within the trigeminal ganglion.

Axons carrying sensory information on touch or pressure terminate in the main sensory nucleus, which is located at the level of the brainstem where the axons enter in the mid pons.

Axons carrying information on pain and temperature enter at the mid pontine level, but then descend to the caudal medulla forming the spinal trigeminal tract. Axon leave this tract at all levels from the pons to the medulla and synapse on neurons in the underlying spinal nucleus of V.

The third nucleus is the mesencephalic nucleus of V. This is a bit unique as the neurons conveying this information are NOT located in the trigeminal ganglion, but rather are located within this nucleus. This is an exception to the rule that all sensory neurons are located outside the CNS. There also is a motor nucleus related to V that contains the neurons that innervate the muscles of mastication. These are derived from pharyngeal arches and thus are branchiomeric. Thus the motor nucleus of V will be located a bit more lateral and ventral compared to somatic motor nuclei. It is located medial to the main sensory nucleus of V.

Question 3

Main sensory (principal) nucleus of V

Answer 3

touch, pressure

Located in mid pons at point of entry of V.

Question 4

Spinal nucleus of V

Answer 4

pain & temperature

Extends from mid pons (point of entry of V) to rostral spinal cord.

Question 5

Mesencephalic nucleus of V

Answer 5

proprioception from muscles of mastication and mechanoreceptors in teeth and jaw.

Long thin nucleus extending from caudal pons into midbrain

Neurons are within the CNS. The only sensory neurons that are not located in a peripheral ganglion.

Question 6

Proprioception

Answer 6

from Latin proprius, meaning “one’s own,” “individual”; perception is the sense of the relative position of neighbouring parts of the body and strength of effort being employed in movement.

The ability to sense stimuli arising within the body regarding position, motion, and equilibrium. Even if a person is blindfolded, he or she knows through proprioception if an arm is above the head or hanging by the side of the body.

Question 7

General Sensation

Answer 7

Main Nucleus of V

Question 8

Motor V

Answer 8

Trigeminal’s Motor innervation to muscles of mastication.

Question 9

TRIGEMINAL NUCLEUS: MOTOR COMPONENT

Answer 9

Branchial Motor Component

Motor nucleus is located immediately medial to main sensory nucleus in mid pons at point of entry of V.

Innervates muscles of mastication

Question 10

CAUDAL MEDULLA- DORSAL

Cross Section

Answer 10

We still see the Nucleus gracilis medially, the nucleus cuneatus lateral to it, and the spinal nucleus and tract of V, most lateral. The nuclei are getting larger and the fiber tracts are getting smaller as they terminate in their respective nuclei. The fasciculus gracilis is almost completely gone, whereas there are still some axons remaining in the fasciculus cuneatus. The Spinal Tract of V is actually getting larger as we go rostrally due to the fact that it enters the brainstem at the level of the pons and descends to the medulla; this was discussed in the presentation on the cranial nerves. Thus as we move, rostrally, we will encounter more and more of these axons.

Question 11

CAUDAL MEDULLA- DORSAL

Cross Section

Answer 11

We see the Nucleus Gracilis medially, the Nucleus Cuneatus lateral to it, and the spinal nucleus and tract of V, most lateral. The nuclei are getting larger and the fiber tracts are getting smaller as they terminate in their respective nuclei. The fasciculus gracilis is almost completely gone, whereas there are still some axons remaining in the fasciculus cuneatus.

The Spinal Tract of V is actually getting larger as we go up rostrally due to the fact that it enters the brainstem at the level of the pons and descends to the medulla. Thus as we move, rostrally, we will encounter more and more of these axons.

Question 12

CRANIAL NERVE NUCLEI

of the Rostral Medulla

Answer 12

In this schematic diagram, we see the location of cranial nerve nuclei that have motor components. The 4th ventricle is present. Starting with motor nuclei. On the midline of the cross section, there is a pair of hypoglossal nuclei. This corresponds to the hypoglossal trigone on the image of the gross brain. In the cross section, it is represented by the pair of nuclei located immediately adjacent to the midline called the hypoglossal nucleus. This is the nucleus of origin for the axons in the hypoglossal nerve. Just lateral to the hypoglossal trigone is the vagal trigone.
This corresponds to the dorsal motor nucleus of X. This is the nucleus that contains the neurons that give rise to axons in the vagus nerve that innervate smooth muscle; that is these are the preganglionic parasympathetic neurons. The one exception are the neurons that innervate the heart. These are located in another nucleus. Continuing laterally, we move into areas occupied by cranial nerve nuclei that relay sensory information to the thalamus. In this diagram, we see the relative position of cranial nerve nuclei that carry sensory information.

The axons that project to the nucleus form a dense bundle. The neurons are located around the tract forming a donut like structure. The donut hole contains the axons and the outer rim are the neurons. Finally, we can see another cranial nerve related nucleus at this level. It also is very long and is depicted as the brown structure in the diagram labeled sensory. This is the vestibular nuclear complex. It also extends from the medulla to the pons. We continue to see a nucleus and fiber tract we have been following from the caudal medulla this is the spinal nucleus and tract of V. We see more axons here as we are getting closer to the site where they enter the brainstem.
The rest of the tegmentum is called the reticular formation.

Question 13

CRANIAL NERVE NUCLEI

of the Rostral Medulla

Answer 13

In this schematic diagram, we see the location of cranial nerve nuclei that have motor components. The 4th ventricle is present. Starting with motor nuclei. On the midline of the cross section, there is a pair of hypoglossal nuclei. This corresponds to the hypoglossal trigone on the image of the gross brain. In the cross section, it is represented by the pair of nuclei located immediately adjacent to the midline called the hypoglossal nucleus. This is the nucleus of origin for the axons in the hypoglossal nerve. Just lateral to the hypoglossal trigone is the vagal trigone.
This corresponds to the dorsal motor nucleus of X. This is the nucleus that contains the neurons that give rise to axons in the vagus nerve that innervate smooth muscle; that is these are the preganglionic parasympathetic neurons. The one exception are the neurons that innervate the heart. These are located in another nucleus.

Continuing laterally, we move into areas occupied by cranial nerve nuclei that relay sensory information to the thalamus. In this diagram, we see the relative position of cranial nerve nuclei that carry sensory information.

The axons that project to the nucleus form a dense bundle. The neurons are located around the tract forming a donut like structure. The donut hole contains the axons and the outer rim are the neurons.

We continue to see a nucleus and fiber tract we have been following from the caudal medulla: the spinal nucleus and tract of V. We see more axons here as we are getting closer to the site where they enter the brainstem.

The rest of the tegmentum is called the reticular formation.

Question 14

nucleus solitarius

Answer 14

The long one nucleus that extends from the rostral medulla into the pons is called the nucleus solitarius. On the cross section, it is located just lateral to the dorsal motor nucleus of X. It has a very characteristic appearance that allows it to be easily recognized.

CRANIAL NERVE NUCLEI
of the Rostral Medulla

Question 15

nucleus ambiguus

Answer 15

Just dorsal to the inferior olive is a vague collection of neurons called the nucleus ambiguous for obvious reasons. This is a nucleus that contains motor neurons related to cranial nerves IX, X and XI. These neurons innervate branchial musculature in the larynx, pharynx, the neck (sternocleidomastoid and trapezius).

Also, the preganglionic parasympathetic neurons that innervate the heart are located in this nucleus. Remember, cardiac muscle is neither smooth or skeletal. It is its own special type of muscle.

CRANIAL NERVE NUCLEI
of the Rostral Medulla

Question 16

vestibular nuclear complex

Answer 16

It is very long and is sensory. It extends from the medulla to the pons.

CRANIAL NERVE NUCLEI
of the Rostral Medulla

Question 17

MIDBRAIN

Answer 17

This is the smallest part of the brainstem and extends from the rostral pons to the mammillary bodies.

Question 18

What is the Roof of the Cerebral Aquaduct, or the Roof of the Midbrain?

Answer 18

the Tectum

Question 19

What part of the ventricular system is associated with the midbrain?

Answer 19

the central aqueduct

Question 20

What structures are associated with the Midbrain?

Answer 20

From those that start most Rostrally to those that begin most Caudally:

Brachium of the Inferior Colliculus

Oculomotor Nucleus

Periaqueductal Gray

Red Nucleus

Substantia Nigra

Superior Colliculus

Trochlear Nucleus

Question 21

DORSAL MIDBRAIN, Tectum is associated with what nerve?

Answer 21

Trochlear Nerve

CN IV

Question 22

TECTUM

Answer 22

Inferior Colliculus and Superior Colliculus

Question 23

Inferior Colliculus

Answer 23

Relays auditory information

Question 24

Superior Colliculus

Answer 24

Receives input from retina.

Reflex reactions.

Question 25

Which structure is associated with Blind Sight?

Answer 25

Superior Colliculus

In Blind Sight, legally blind individuals walk without hitting obstacles. The visual cortex is not involved.

Question 26

PONS-MIDBRAIN JUNCTION / CAUDAL MIDBRAIN

Answer 26

Cross Section through the caudal midbrain, at the junction of the pons.

On this section ventrally, there are some remnants of the rostralmost part of the basilar pons.

Laterally there is a large fiber tract called the cerebral peduncle. This fiber tract contains the axons that formed the corticospinal tract in the pons and the pyramids in the medulla. It is all one continual tract that originated in the cerebral cortex. We’re following it backward through the sections.

Dorsally, we are primarily seeing midbrain structures.

At this level, the trochlear nucleus related to cranial nerve IV is evident. Since it only innervates one muscle, it is a very small nucleus.

The 4th ventricle has closed down to form the cerebral aqueduct which is surrounded by grey matter called the periaqueductal grey. The function of this grey matter involves the pain pathway.

Other landmarks in the tegmentum include a very large fiber bundle called the superior cerebellar peduncle, which arose from the cerebellum and entered the midbrain. At this point the axons from the right and left cerebellum are crossing to the opposite side or decussating.

Another new addition is a roof over the midbrain: the tectum. At this level we see that it is fairly light indicating it is a collection of cell bodies. These are called the inferior colliculus, and they are part of the auditory system.

Question 27

Periaqueductal Gray

Answer 27

Contains neurons that give rise to descending pain-control pathway. Neurons express numerous opiate receptors.

Activation of these receptors by opiates results in analgesia (the inability to feel pain).

Question 28

TROCHELAR NUCLEUS AND NERVE

Answer 28

IV indicates axons forming the trochlear nerve as they course dorsally.
Trochelar nerve is the only one that exits from dorsal aspect of brain. Also, only cranial nerve that crosses to innervate contralateral muscle.

The axons of the trochlear nerve course dorsally, crossing in the midline.

Question 29

PERIAQUEDUCTAL GREY and

TROCHELAR NUCLEUS & NERVE

Answer 29

Cross Section of the dorsal, caudal midbrain in the area of the cerebral aqueduct.

The nuclear group surrounding the cerebral aqueduct is the periaqueductal grey. The neurons in this region give rise to a descending pathway that is involved in modulating pain input at the level of the spinal cord. These neurons express opiate receptors and activation results in analgesia.

Just below the central canal, the trochlear nucleus is evident. Axons leaving the trochlear nucleus course dorsally where they cross on the midline. This is the only cranial nerve that is crossed, as well as the only one that exits from the dorsal surface of the brainstem. This nerve innervates the superior oblique muscle in the orbit.

Question 30

LOCUS CERULEUS

Answer 30

Cross Section of caudal, dorsal Midbrain.

In the lateral region of the periaqueductal grey, there is a group of neurons that have a darker color. This is the locus ceruleus. It is important because this is the major source of the transmitter Norepinephrine to the brain.

Collection of neurons in the lateral part of PAG that have a darker appearance. The locus ceruleus is the primary source of norepinephrine to the brain. Important in alerting responses.

Question 31

MIDBRAIN PROPER

Answer 31

Cross Section through the middle of the midbrain.

As in the medulla and pons, the ventral part of the midbrain has a motor function.

The large myelinated fiber bundle that forms the base of the midbrain (like a foot) is the cerebral peduncle. Axons in this fiber tract continue through the pons and medulla as they course to the spinal cord. These are the corticospinal axons.

The nuclear group located just dorsal to the cerebral peduncle is the substantia nigra. This nuclear group is related to a group of nuclei in the forebrain called the basal ganglia; they are involved in modulating motor output from the cerebral cortex.

Moving dorsally, we enter the tegmentum which contains the oculomotor nucleus. Neurons in this nucleus give rise to axons in the oculomotor nerve that innervate all but 2 of the muscles that control eye movement. The myelinated axons of the oculomotor nerve are seen as they course through the tegmentum and exit the midbrain between the two cerebral peduncles in a space called the interpeduncular fossa.

One nucleus is almost obscured by myelinated axons that arose in the cerebellum and crossed in the caudal midbrain. This is the superior cerebellar peduncle. The underlying nucleus is the red nucleus. Many of the axons in the superior cerebellar peduncle terminate in the red nucleus.

The periaqueductal grey is still present around the cerebral aqueduct.

The tectum is still evident. However, the neurons in this more rostral part of the tectum form a structure called the superior colliculus. These neurons are involved in processing visual information.

Question 32

Substantia Nigra

Answer 32

related to motor control and basal ganglia.

Source of dopamine to basal ganglia (Motor Control; lost in Parkinson’s Disease)

Question 33

Ventral Tegmental area

Answer 33

Source of dopamine to forebrain.

Goes to Reward Centers
Is involved in higher cognition

Question 34

MIDBRAIN - DORSAL

Answer 34

Dorsal midbrain proper.

The oculomotor nucleus is visible on the midline and axons arising from neurons in the nucleus can be seen leaving it and coursing ventrally.

A picture of the dorsal surface of the midbrain on a gross specimen allows you to visualize the tectum. The 2 caudal “hillocks” are the inferior colliculi. They are involved in relaying information in the auditory system.

The rostral hillocks are called the superior colliculi. They are involved in processing visual information.

Cranial nerve IV exits the dorsal surface of the brainstem. To find it on a gross specimen, look just below the inferior colliculi.

Question 35

What is another name for the tegmentum?

Answer 35

Another name for the tegmentum is the Reticular Formation

Question 36

What is another name for the tegmentum?

Answer 36

Another name for the tegmentum is the Reticular Formation

Question 37

RETICULAR FORMATION IN MEDULLA, PONS AND MIDBRAIN

Answer 37

There is a lot going on in the tegmentum of the medulla, pons and midbrain. There appear to be additional nuclei that are not clearly defined. This diffuse area of the brainstem, at all levels, is the reticular formation.

Question 38

BLOOD SUPPLY TO THE MIDBRAIN

Answer 38

Major blood supply to the midbrain. The basilar artery terminates by splitting into a right and left posterior cerebral artery at the rostral end of the pons. Arising from the posterior cerebral artery are perforating branches that penetrate the midbrain to supply underlying structures. In addition, branches arise from the posterior communicating artery that links the internal carotid artery to the posterior cerebral artery contribute vascular supply to the midbrain.

Question 39

Major Blood Supply to Midbrain is via Perforating branches of ___ and ____.

Answer 39

Major Blood Supply to Midbrain is via Perforating branches of Posterior Cerebral Artery and Posterior Communicating Artery.

Question 40

BRAINSTEM AS AN INTEGRATIVE CENTER:

Answer 40

the DIENCEPHALON

Question 41

What kind of nerve is Cranial Nerve IV, and how is it situated in the brain.

Answer 41

Trochlear Nerve is Somatic Motor, so it’s located medially.

Question 42

What does the term Cerulus refer to?

Answer 42

refers the Locus Cerulus’ naturally blue color

Question 43

4 PARTS ALL WITH TERM “THALAMUS” IN THEIR NAMES:

Answer 43

DORSAL THALAMUS (The REAL THALAMUS)

HYPOTHALAMUS

EPITHALAMUS = PINEAL GLAND

SUBTHALAMUS (lateral to thalamus)

Question 44

What does “thalamus” mean in Greek?

Answer 44

INNER CHAMBER

Question 45

HYPOTHALAMUS

Answer 45

Involved in autonomic, endocrine, emotional, and somatic functions that are designed to maintain the internal environment within a physiological range. For example, it is involved in:

• VASODILATION
• FEEDING BEHAVIOR
• REGULATION OF PITUITARY FUNCTION

More complex interactions involved in drives and emotional behavior:

• RAGE
• SLEEP
• SEXUAL BEHAVIOR

Question 46

HYPOTHALAMIC NUCLEI

Answer 46

THE HYPOTHALAMUS IS DIVIDED INTO SEVERAL NUCLEI.

One pathway involves input to the mammilary body from the hippocampus (limbic system) via the fornix.
Output of this pathway is to the anterior nucleus of the thalamus via the mammilothalamic tract.

Suprachiasmatic Nucleus:
Circadian Cycle Regulation

Question 47

Suprachiasmatic Nucleus

Answer 47

Circadian Cycle Regulation

Nucleus of the Hypothalamus

Question 48

EPITHALAMUS

Answer 48

MADE UP OF PINEAL GLAND (think PINECONE)

Midline, unpaired structure located rostral to superior colliculus that resembles a pinecone.

This is an endocrine gland that secretes melatonin in response to light cues.

There’s only one; it’s not bilateral.

Question 49

LIGHT ALTERS MELATONIN RELEASE

Answer 49

Light coming into the eye can effect release of a hormone from a gland buried deep in the brain. The pathway is very circuitous.

Let’s start at the pathway that induces release of melatonin. Since it is a gland, it is under control of the autonomic nervous system. Preganglionic sympathetic neurons located in the thoracic region project to and excite postganglionic sympathetic neurons in the most rostral part of the chain ganglia; this is the superior cervical ganglion. These postganglionic neurons send their axons back into the skull to the pineal gland via blood vessels where they induce release of melatonin. How does light affect this pathway? Light coming into the eye activates ganglion cells neuron in the retina. Most of the light information is transmitted to the thalamus, in particular to the lateral geniculate nucleus, via the optic tract. From there, it is relayed to the occipital lobe of the cerebral cortex for visual processing.

There is also a side path that we will now follow. Some retinal ganglion cells project to a nucleus in the hypothalamus of the diencephalon called the suprachiasmatic nucleus. It’s name tells you where it is located. Axons from neurons in this nucleus project to the spinal cord where they release an inhibitory neurotransmitter that suppresses the activity of the preganglionic sympathetic neurons. This in turn removes the previous excitatory drive on the postganglionic neurons reducing their activity. Reduction in activity in the postganglionic neurons reduces their excitation of the pineal gland and thus leads to a suppression of melatonin release. When it gets dark, the process reverses and melatonin is released again.

Question 50

LIGHT ALTERS MELATONIN RELEASE

in other words

Answer 50

Receives light information via circuitous pathway involving several relays:
Light sensitive ganglion cells in the retina start the circuit.

1. Retina to Hypothalamus (suprachiasmatic nucleus; SCN)
2. SCN output suppresses preganglionic sympathetic neurons in the spinal cord.
3. This removes excitatory drive on post ganglionic sympathetic neurons in peripheral ganglion.
4. Normally, post ganglionic sympathetic neurons project to the pineal gland and induce release of melatonin. If they are not active, there is a reduction in the secretion of melatonin.

In dark, SCN is not activated and inhibition is removed. Thus melatonin is secreted.

In non-primate mammals, decreased melatonin leads to an increase in gonadal function (i.e., mating in Spring).
Not as clear as to its role in humans. Loss of pinealocytes leads to precocious puberty as antigonadal effects of melatonin are removed.

Question 51

BORDERS OF THE DIENCEPHALON

Answer 51

Dorsal – Lateral Ventricle

Medial – Third Ventricle

Lateral – Internal Capsule

Question 52

THALAMUS

Answer 52

Makes up 80% diencephalon.

Serves as a gatekeeper for transmitting information to the cerebral cortex.

All general and special sensory pathways relay in the thalamus.

Circuits used by motor pathways arising in the cerebellum and basal ganglia involve thalamic relays.

Circuits used by limbic system involve thalamic relays.

There are reciprocal connections between thalamus and cerebral cortex.

Each system uses specific portions of the thalamus thus it is functionally divided into several nuclei.

Exception to rule: Chemically defined afferents such as serotonin from raphe and noradrenergic fibers from locus ceruleus reach cerebral cortex directly.

Question 53

Internal medullary lamina (thin sheet myelinated fibers) subdivides _____ into medial and lateral groups of nuclei.

Answer 53

Internal medullary lamina (thin sheet myelinated fibers) subdivides thalamus into medial and lateral groups of nuclei.

Internal medullary lamina splits anteriorly to define an anterior region.

Question 54

THALAMIC NUCLEI

Answer 54

Relationships between the thalamus and the cerebral cortex.
~~~~~~~~~~~~~~~~~~~~
The medial group, consisting of the anterior nucleus and the dorsomedial nucleus, form reciprocal connections with the prefrontal cortex and the limbic system.
~~~~~~~~~~~~~~~~~~~~~
The lateral group has 2 different thalamocortical relationships.

The Ventral Anterior (VA) and Ventral Lateral (VL) relay motor information to the motor cortex (precentral gyrus) from the basal ganglia and cerebellum, respectively.

The Ventral Posterior Lateral (VPL) and Ventral Posterior Medial (VPM) relay general and special sensory information to the postcentral gyrus in the parietal lobe.

~~~~~~~~~~~~~~~~~~~~~~~
In the posterior group, the medial geniculate nucleus projects to the auditory cortex located in the temporal lobe. The lateral geniculate projects to the primary visual cortex in the occipital lobe.

The Pulvinar projects to areas of the cerebral cortex called Association areas. These integrate information from different regions of the cerebral cortex and add more complex information about an input.

Question 55

THALAMIC NUCLEI:

Medial Group

Answer 55

Anterior Nucleus (A), Dorsomedial Nucleus (DM).

Reciprocal Connections With Prefrontal Cortex And Limbic System.

Question 56

THALAMIC NUCLEI:

Lateral Group:

Answer 56

Ventral Anterior (VA) and Ventral Lateral (VL) Relay Motor Information to Precentral Gyrus in Frontal Lobe.

Ventral Posterior Lateral (VPL) and Ventral Posterior Medial (VPM) are Related To Relaying General And Special Sensory Information from Body (VPL) and Face (VPM) to the Parietal Lobe.

Question 57

THALAMIC NUCLEI:

Posterior Group

Answer 57

Lateral Geniculate (LG) and Medial Geniculate (MG) Relay Special Sensory Information of Vision (LG) to the Occipital Lobe and Audition (MG) to the Temporal Lobe, respectively.

Pulvinar (Pul) Projects to Association Areas in Temporal, Occipital and Parietal Lobes.

Question 58

Relay Motor Information to Precentral Gyrus in Frontal Lobe.

Answer 58

Lateral Group: 
Ventral Anterior (VA), Ventral Lateral (VL)

Question 59

Reciprocal Connections With Prefrontal Cortex And Limbic System.

Answer 59

Medial Group: 
Anterior Nucleus (A), Dorsomedial Nucleus (DM).

Question 60

Related To Relaying General And Special Sensory Information from Body to the Parietal Lobe.

Answer 60

Ventral Posterior Lateral (VPL)

Question 61

Related To Relaying General And Special Sensory Information from the Face to the Parietal Lobe.

Answer 61

Ventral Posterior Medial (VPM)

Question 62

Relay Special Sensory Information of Vision to the Occipital Lobe.

Answer 62

Lateral Geniculate (LG)

Question 63

Relay Special Sensory Information of Audition to the Temporal Lobe.

Answer 63

Medial Geniculate (MG)

Question 64

Projects to Association Areas in Temporal, Occipital and Parietal Lobes.

Answer 64

Pulvinar (Pul)

Question 65

THALAMUS:

CORONAL SECTION - ANTERIOR THALAMUS

Answer 65

First the INTERNAL MEDULLARY LAMINA (IML) enclosing the anterior nucleus rostrally. The large dorsomedial nucleus is seen medial to the IML. At this level only VL is evident laterally.

Question 66

THALAMUS:

CORONAL SECTION –POSTERIOR THALAMUS

Answer 66

Caudal section. The main thalamic nucleus at this level is the pulvinar. The medial and lateral geniculate nuclei are apparent on the ventral surface of the thalamus. LGN can often be distinguished by the presence of what appear to be bands or layers.

Question 67

Blood Supply To Diencephalon Is Primarily From Perforating Branches Of _____ And Branches Of _____ .

Answer 67

Blood Supply To Diencephalon Is Primarily From Perforating Branches Of Posterior Cerebral Artery And Branches Of Posterior Communicating Artery.

Question 68

What functional grouping do the mammary bodies belong?

Answer 68

The Limbic System