Veterinary Body Systems: Anatomy and Physiology Across Species

External Anatomy

Visible and palpable exterior features of an animal, essential for handling, restraint, and clinical assessments.

Directional Terminology

Standard terms used to describe locations on an animal: cranial, caudal, proximal, distal, dorsal, ventral, medial, and lateral.

Cranial

Toward the head.

Caudal

Toward the tail.

Proximal

Near to the body.

Distal

Farther away from the body.

Dorsal

Toward the back.

Ventral

Toward the belly.

Medial

Toward the midline.

Lateral

Away from the midline.

Rostral

Toward the nose, used often in reference to the head.

Monogastric

A type of digestive system with one main stomach chamber, as seen in dogs, cats, and pigs.

Ruminant

Animals with a four-compartment stomach, including the rumen, reticulum, omasum, and abomasum, such as cattle.

Hindgut Fermenter

An animal, such as a horse or rabbit, that ferments fiber primarily in the cecum and large colon.

Avian

Pertaining to birds, which lack teeth and have a unique digestive system involving a crop, proventriculus, and gizzard.

Neuron

The basic unit of the nervous system, consisting of dendrites, a cell body, and an axon.

CNS

Central nervous system, comprising the brain and spinal cord.

PNS

Peripheral nervous system, made up of cranial and spinal nerves.

Sympathetic Nervous System

Part of the autonomic nervous system that prepares the body for 'fight or flight' responses.

Parasympathetic Nervous System

Part of the autonomic nervous system that promotes 'rest and digest' activities.

Endochondral Ossification

Process where cartilage is replaced by bone during growth, especially in long bones.

Myelin

A protective sheath around axons that speeds up electrical signal conduction.

Osteoblasts

Bone cells responsible for building new bone.

Osteoclasts

Bone cells that resorb bone tissue and are involved in the remodeling process.

Cardiovascular System

The system responsible for the transportation of blood, nutrients, gases, and wastes throughout the body.

Minute Ventilation

The volume of air inhaled or exhaled per minute.

Nephron

The functional unit of the kidney, involved in urine formation through filtration, reabsorption, and secretion.

Prolactin

Hormone that stimulates milk production in mammals.

Oxytocin

Hormone that triggers milk let-down in mammals.

Colostrum

The first milk produced after giving birth, rich in antibodies for newborn immunity.

Adaptive Immunity

Specific immune response involving memory, coordinated by B and T lymphocytes.

Innate Immunity

Non-specific immune response that includes immediate defenses like barriers and phagocytes.