reticulum

reticulum /re·tic·u·lum/ (rĕ-tik´u-lum) pl. retic´ula   [L.]

1. a small network, especially a protoplasmic network in cells.

2. reticular tissue.

---

endoplasmic reticulum  an ultramicroscopic organelle of nearly all higher plant and animal cells, consisting of a system of membrane-bound cavities in the cytoplasm; occurring in two types, rough-surfaced (granular r.), bearing large numbers of ribosomes on its outer surface, and smooth-surfaced (agranular r.) .

sarcoplasmic reticulum  a form of agranular reticulum in the sarcoplasm of striated muscle, comprising a system of smooth-surfaced tubules surrounding each myofibril.

stellate reticulum  the soft, middle part of the enamel organ of a developing tooth.

---

re·tic·u·lum (r-tky-lm)

n. pl. re·tic·u·la (-l)

1. A fine network formed by cells, by certain structures within cells, or by connective-tissue fibers between cells.

2. See neuroglia.

3. The second compartment of the stomach of ruminant mammals, lined with a membrane having honeycombed ridges.

---

reticulum [rĕ-tik´u-lum] (L.)

1. a small network, especially a protoplasmic network in cells.

2. reticular tissue.

agranular reticulum smooth-surfaced endoplasmic reticulum.

endoplasmic reticulum an ultramicroscopic organelle of nearly all higher plant and animal cells, consisting of a system of membrane-bound cavities in the cytoplasm, occurring in two types: granular or rough-surfaced, bearing large numbers of ribosomes on its outer surface, and agranular or smooth-surfaced.

granular reticulum rough-surfaced endoplasmic reticulum.

sarcoplasmic reticulum a form of agranular reticulum in the sarcoplasm of striated muscle, comprising a system of smooth-surfaced tubules surrounding each myofibril.

---

reticulum

pl. reticula [L.]

1. a small network, especially a protoplasmic network in cells.

2. reticular tissue.

3. the smallest, most cranial section of the compound stomach of ruminants, lined with mucous membrane folded into a hexagonal pattern. Called also honeycomb. It communicates cranially with the esophagus and caudally with the rumen.

---

reticulum (1) cell

see reticular1 cells.

reticulum (1) cell leukemia

see malignant histiocytosis.

reticulum (1) cell sarcoma

see cutaneous lymphosarcoma.

endoplasmic reticulum (1)

an ultramicroscopic organelle of nearly all higher plant and animal cells, consisting of a system of membrane-bound cavities in the cytoplasm, occurring in two types: granular or rough-surfaced, bearing large numbers of ribosomes on its outer surface, and concerned mainly with protein production, and agranular or smooth-surfaced, concerned with lipid and glycogen synthesis and cholesterol metabolism. See also rough endoplasmic reticulum.

sarcoplasmic reticulum (1)

a form of agranular reticulum in the sarcoplasm of striated muscle, comprising a system of smooth-surfaced tubules surrounding each myofibril.

transmissible reticulum (1) cell tumor

see canine transmissible venereal tumor.

transmissible venereal reticulum (1) cell tumor

see canine transmissible venereal tumor.