What Are the Mammillary Bodies?

Like the amygdala, it is a part of the limbic system of the brain. The structure of the interbrain is a pair. It can be observed from the ventral side of the brainstem, below the pituitary, between the two brain feet, and related to emotional operation.

The papillary body is a gray-white round or oval-shaped bulge on the ventral side of the hypothalamus. It is located in front of the intercondylar fossa and behind the funnel; its trailing edge is the boundary mark between the midbrain and the midbrain. Contains the medial, medial, and lateral nucleus of the papillary body, the medial nucleus is the largest, and the median nucleus is the smallest. It mainly receives fornix fibers and emits the main bundle of nipples, which are divided into the nipple thalamus bundle and the nipple covered bundle, which stop at the anterior nucleus of the thalamus and the midbrain and are part of the limbic system.

Chinese name: Papillary body
Category: organ

Field: biological
Location: Edge of the brain

Papillary body anatomy

1. Nipple body:

The papillary body belongs to the hypothalamus. It is located behind the gray nodules, and is a pair of bulges in the midfoot fossa. They are the subcortical center of the limbic system. It is a pair of obvious spherical gray matter masses, which are located in the posterior perforator cranial fossa. The deep side of the nipple body is the nipple body nucleus. Consists of lateral, medial, and medial nuclei. The fibers from the hippocampus, the hippocampus, the septum, etc. finally nucleate, and then send out axons to form the papillary thalamus bundle and the papillary cover bundle to the anterior nucleus of the thalamus, the dorsal dorsum of the midbrain, and the ventral nucleus.

2. Hypothalamus:

The hypothalamus is a part of the midbrain, located below the hypothalamus sulcus, forming the side wall of the lower part of the third ventricle, and the lower part is connected to the pituitary. The hypothalamus is not large, but there are a large number of endocrine neurons (such as supraoptic nucleus, supraoptic nucleus, paraventricular nucleus, nodular nucleus, caudate nucleus, nodular papillary nucleus, etc.). Therefore, some people call it "neuroendocrine nuclear energy device". The hypothalamus is a high-level integration center of autonomic nerves and endocrine, is the control system of the hypothalamus-pituitary-target gland system; it is also an important contact point of the limbic system and reticular structure. It has important physiological functions such as regulating body temperature, feeding, drinking water, sexual function, cardiovascular, visceral activity, endocrine and emotional response. When the hypothalamus becomes diseased, the above-mentioned functional disorders constitute the so-called "hypothalamic syndrome".

The hypothalamus is located on the ventral side of the thalamus and below the hypothalamus sulcus, forming the side wall and bottom wall of the lower third ventricle. On the underside of the brain, the hypothalamus includes five parts, including the optic cross, gray nodules, papillary bodies, and funnels that extend downward from the gray nodules.

The hypothalamus is a high-level center under the vegetative neurocortex, which controls the activities of sympathetic and parasympathetic nerves. The hypothalamus is closely related to the reticular structure of the brainstem and the limbic system of the cortex. They jointly regulate various activities of the body and internal organs.

3. Midbrain:

The midbrain is the smallest of the six parts of the brain and still maintains the original shape of the neural tube. It is about 15-20 mm long and is located between the pontine and the midbrain. The upper boundary of the ventral side of the midbrain is the optic bundle, and the lower boundary is the upper edge of the pontine; there are bulges composed of large longitudinal fibers on both sides of the ventral side, called the brain feet; The optic nerve root comes out of the brain from the outer edge of the fossa; the dorsal side (also known as the tectum) has a quadruplex, consisting of two pairs of small round mounds. Is the white matter fiber) and the lateral geniculate body; the next symmetrical hypothalamus is the inferior cortical center, which is connected to the medial geniculate body by the hypothalamus arm (for white matter fibers). Below the inferior colliculus, there is a puncture nerve. There is a midbrain water pipe in the midbrain, which is connected to the third ventricle upward and to the fourth ventricle downward.

In the middle of the dorsal part of the midbrain cross section, there is a section of the midbrain water pipe, and there is a layer of gray matter around the midbrain water pipe, which is called central gray matter. The dorsal side of the gray matter is the quadruplex. The ventral side of the midbrain is the brain foot, and each side of the brain foot is divided into two parts by a layer of melanin-containing nerve cells (ie, substantia nigra): the dorsal part of the substantia nigra, called the cover, which contains a reticular structure, downward It is connected to the reticular structure of the pontine; the ventral part of the substantia nigra is a thick layer of nerve fiber plates called the soles of the feet.

Covered, consisting of gray and white matter. The central part of the cover has a red nucleus formed by the accumulation of cell bodies. This nucleus is the subcortical motor center. The cell processes cross each other and form the red nucleus spinal cord bundle. On the outside of the red nucleus, there are ascending fibers that conduct proprioceptive and cutaneous sensations. These fibers are collectively referred to as the medial thalamus and travel to the thalamus. The gap between the medial thalamus and the red nucleus is called the midbrain reticular structure, and the dorsal side has central gray matter. The midbrain water pipes pass through the central gray matter. On the base of the midbrain water duct, there are the oculomotor nucleus and the trochlear nucleus. The former is located in the superior colliculus plane and the latter is located in the inferior colliculus plane. On the inner side of the oculomotor nucleus, there is a Daksevich nucleus, and the protrusions from the cells in this nucleus form a medial longitudinal bundle that enters the spinal cord.

Papillary body and its fiber connection

(1) There are three gray matter nuclei in the nipple:

1, the inner nucleus of the nipple: this nucleus constitutes the majority of the papillary body, the ventral part is formed by light-stained small cells, and the dorsal part is formed by a thin layer of large spindle-shaped cells. This nucleus is connected to the caudal nucleus to the caudal side.

2. Lateral nucleus of the nipple: It is located on the ventral side of the mouth of the inner nucleus of the nipple. It is formed by large deep stained cells.

3. Papillary nucleus: It is located between the inner and outer nucleus of the nipple, and slightly back to the back. It is formed by dense small cells.

(2) Fibrous connections of the nipple body:

1. The fibers of the fornix: mainly the lateral part of the medial nucleus of the papillary body, the lateral nucleus of the papillary body, and the phrenic nucleus.

2. Nipple thalamus bundle: It mainly starts from the medial nucleus of the nipple body and finally the thalamus.

Papillary body and papillary body related diseases

Homen syndrome (post-concussion syndrome):

Overview of Nipple Body

Post-concussion syndrome was first reported by a scholar in 1890 and was caused by recurrent chronic brain trauma.

Causes of papillary body

Recurrent lenticular degeneration caused by chronic brain trauma, or the sequelae of progressive subacute encephalitis secondary to trauma.

Papillary body pathology

Bean-shaped nucleus degeneration, with transparent holes and cracks, atrophy of the papillary body, degeneration or disappearance of cerebral cortical nerve cells. Pathological changes can also be seen in the cerebellum and substantia nigra.

Clinical manifestations of papillary body

Adult men are more common and have a history of repeated brain trauma. Early manifestations include headache, insomnia, dizziness, irritability, etc., followed by vague speech, unstable gait and even stiff limbs, inattention, poor memory, mental retardation, decreased ability to calculate and understand, progressive dementia, Ataxia, tremor, paralysis, etc.

Papillary body diagnosis

Repeated history of traumatic brain injury, the clinical manifestations were initially manifested as vegetative neurological dysfunction, followed by progressive mental decline and dementia. Qi-brain and brain CT showed brain and cerebellar atrophy and hyaline septal abnormalities.