Animal Body Systems for Equine Selection, Nutrition, and Management

Dorsal

Toward the back/spine.

Ventral

Toward the belly.

Cranial

Toward the head.

Caudal

Toward the tail.

Medial

Toward the midline of the body.

Lateral

Away from the midline.

Proximal

Closer to the body (upper limb).

Distal

Farther from the body (lower limb/hoof).

Muzzle/nostrils (nares)

Air intake and smell; noticeable respiratory effort in horses.

Poll (horse)

Area between/behind ears; important for handling and head posture.

Withers (horse)

Junction of neck and back; landmark for height and saddle fit.

Back/loin/croup (horse)

Weight-bearing and power transfer in locomotion.

Barrel (horse)

Ribcage region; relates to gut capacity.

Udder/teats (female mammals)

Milk delivery; important for nursing success.

Hindgut fermentation

Fermentation occurring after the small intestine, typical in horses.

Rumen

Large fermentation vat in ruminants where cellulose is digested.

Volatile Fatty Acids (VFAs)

Produced from the fermentation of fiber in ruminants.

Cecum

Major fermentation site in hindgut fermenters like horses.

Omasum

Absorbs water and VFAs in ruminants.

Abomasum

True stomach in ruminants where digestion occurs.

Fibrous joints

Joints with very little movement.

Synovial joints

Freely movable joints that allow for flexibility.

Osteoblasts

Cells that build bone.

Osteoclasts

Cells that resorb bone.

Cardiac Output (CO)

Heart Rate (HR) multiplied by Stroke Volume (SV).

Respiratory rate

Increases with exercise, heat stress, and stress.

Male reproductive system main structures

Testes, epididymis, vas deferens, and penis.

Female reproductive system main structures

Ovaries, oviducts, uterus, cervix.

Negative feedback

Mechanism that maintains hormone balance by reducing signals when levels rise.