meso-, mes-, mesi- +

(Greek: middle, intermediate; close to a center line; between)

brachymesophalangia
Abnormal shortness of the middle phalanges.
circumesophagal
In zoology, surrounding the esophagus; a reference to the nerve commissures and ganglia of arthropods and mollusks.
dolichoeuromesocephalus
A person having a long skull that is significantly broad in the temporal regions or the temples of the head (the parts of each side of the head between the eyes and the ears).
mesencephalic
A reference to the middle section of the embryonic (pre-birth) vertebrate brain or midbrain.
mesencephalon, midbrain
1. The middle section of he embryonic (animal or human before it is born) vertebrate brain which is a highly complex organ consisting of sensory and motor systems that constitutes part of the nervous system.

The vertebrate brain is in all of the brain systems that are found in mammals and occur in birds, reptiles, and amphibians, as well as in fish and sharks.
2. The part of the brain developed from the middle cerebral vesicle (hollow organ in the body containing fluid) and consisting of the tectum (part in the body that forms a covering; especially, the back upper section of the midbrain) and cerebral peduncles (neurons joining different parts of the brain), and traversed by the cerebral aqueduct.

The cerebral aqueduct is a narrow opening in the brain that connects the third ventricle with the fourth ventricle, allowing cerebrospinal fluid to flow between these two areas.

Ventricles are openings in the brain that provide a pathway for cerebrospinal fluid is the cushiony fluid that protects the brain and spine from trauma.

The cerebral aqueduct drains cerebrospinal fluid from the third ventricle to the fourth ventricle where the third ventricle is a narrow, four-sided, irregularly shaped opening in the middle of the brain.

The fourth ventricle is a wide, flat open space located in the back bottom part of the brain.

mesencephalotomy
Surgical incision of the spinothalamic tract in the mesencephalon, formerly used to control intractable pain, now in disuse because of resulting dysesthesia.
mesenchyma
The part of the mesoblast which gives rise to the connective tissues and blood.
mesenchymal
Having to do with, consisting of, or derived from mesenchyme which is that part of the mesoderm consisting of cells set in a gelatinous matrix.

A reference to the interaction between the mesenchymal and epithelial components (tissue that forms a thin protective layer on exposed bodily surfaces and forms the lining of internal cavities, ducts, and organs) in the development of the pancreas, skin, liver, salivary glands, lungs, and other bodily organs.

mesenchyme
1. Embryonic cell mass including the cells within the embryo (pre-fetal development) that develop into connective tissue, bone, cartilage, blood, and the lymphatic system.
2. The part of the embryonic mesoderm, consisting of loosely packed, unspecialized cells set in a gelatinous ground substance, from which connective tissue, bone, cartilage, and the circulatory and lymphatic systems develop.
3. Etylmology: from Greek meso-, "middle, between" + Greek enchyma, "infusion"; from en-, "in, into" + Greek chymos, "juice"; from cheein, "to pour, to spill".

The term mesenchyme was introduced into embryology by the German embryologists Oskar Hertwig (1849-1922) and his brother Richard (1850-1937) in 1881.

mesenterectomy
A surgical operation which results in the resection of the mesentery or a membrane that supports an organ or body part; especially, the double-layered membrane of the peritoneum attached to the back wall of the abdominal cavity that supports the small intestine.

The peritoneum is the smooth transparent membrane that lines the abdomen and doubles back over the surfaces of the internal organs to form a continuous container or sac.

mesenteric
1. Referring to a fold or membrane which envelops and supports an internal organ; such as, the vertebrate mesentery (a membrane which holds the spinal column together).
2. Pertaining to the mesentery which is a membranous fold attaching various organs to the body wall; such as, a fatty membrane placed in the middle of the intestines, and to which they are attached.

This prevents them from becoming entangled with each other by convolutions (coiling or twisting or winding together).

mesenteriopexy
Fixation or attachment of a torn or incised mesentery (the membranes, or one of the membranes which connect the intestines and their appendages with the dorsal wall of the abdominal cavity).
mesenteron
1. The middle section of the digestive tract in a vertebrate embryo from which the ileum, jejunum, and portions of the duodenum and colon develop.
2. The middle section of the embryonic intestine, which develops into the stomach, small intestine, and most of the large intestine.
3. The middle portion of the digestive tract of certain invertebrates; such as, arthropods, lined with an enzyme-secreting tissue and serving as the main site of digestion and absorption.
mesentery
1. A fold or membrane which envelops and supports an internal organ, attaching it to the body wall or to another bodily organ.
2. Etymology: from Greek mesenterion, from mesos, "middle" + entern, "intestine".
mesiad
Directed or proceeding toward the median sagittal plane of the body or, specifically, following the dental arch toward the center line.