The part of a plant embryo that develops into the primary root.
Reversal of the natural direction in which contents flow through a tube or a cavity in the body. During rumination, rumen contents are regurgitated through the esophagus in the mouth for further mastication.
The first two stomachs of a ruminant comprised of the reticulum and the rumen. A microbial population lives in the rumen and enable the cow to digest dietary fiber. The digesta in the rumen and the reticulum is being exchanged once about every 50 to 60 seconds under the influence of a rhythmic cycle of contraction which also results in passage of some digesta from the reticulum into the omasum through the reticulo-omasal orifice.
The second stomach of a ruminant in which folds of the mucous membrane form hexagonal cells. Also called honeycomb stomach. The reticulum is joined to the omasum by the reticulo-omasal orifice.
A type of bacteria that live in association with the roots of legume plants and make the nitrogen of the air available to the plants.
A root-like usually horizontal stem growing under or along the ground that sends out roots from its lower surfaces and leaves or shoots from its upper surface.
A deficiency disease resulting from a lack of vitamin D or lack of sunshine exposure, characterized by defective bone growth.
Part of the plant, usually under ground that maintain the plant, withdraw water and other nutrient from the soil, and sometimes accumulate reserves of nutrients.
The large first compartment of the stomach of a ruminant from which food is regurgitated and in which cellulose in broken down by the action of the symbiotic bacterial, protozoa, and fungal populations.