Introduction to Anatomy and Physiology

Abdominal cavity

The space below the diaphragm that contains digestive, urinary, and reproductive organs

Anatomy

The study of body structures and their physical relationships.

Barrel

The midsection or ribcage area of a horse's body. This region encompasses the thoracic cavity and represents the widest part of the horse's torso.

Bilateral symmetry

Having left and right sides that mirror each other. Most animals have paired structures like legs, kidneys, and lungs that appear as approximate mirror images.

Brisket

The chest area of a horse between the front legs. This region corresponds to the front part of the thoracic cavity and sternum area.

Cannon

The lower leg region of a horse between the knee or hock and the fetlock joint. This area contains the cannon bone and supporting tendons.

Caudal

Toward the tail end of the body.

Cellular level

The organizational level where individual cells carry out specialized functions.

Cephalic vein

A major vein running along the front surface of the front leg

Cranial

Toward the head end of the body

Cranial cavity

The space within the skull that houses and protects the brain

Diaphragm

The large muscle that separates the thoracic and abdominal cavities and is essential for breathing. This muscle contracts and relaxes to change chest cavity pressure for respiration.

Distal

Farther away from the body's center or point of attachment. On limbs, distal structures are farther from where the limb attaches to the body.

Dorsal

Toward the back or upper surface of the body

Dorsal body cavity

The body cavity that contains the central nervous system, including the cranial cavity (brain) and spinal cavity (spinal cord).

Dorsal plane

An imaginary horizontal plane that divides the body into dorsal (back) and ventral (belly) portions.

Epithelial tissue

Tissue that covers body surfaces and lines body cavities, providing protection and sometimes absorption. These tightly packed cells form barriers against the environment.

Fetlock

The joint in a horse's leg located between the cannon bone and the pastern, similar to the knuckle in humans.

Flank

The side region of a horse between the last rib and the hip

Homeostasis

The body's ability to maintain stable internal conditions despite external changes. This involves coordinated responses from multiple body systems to keep temperature, pH, and fluid balance within normal ranges.

Hock

The joint in the middle of a horse's hind leg, equivalent to the human ankle. This complex joint allows for movement and weight bearing.

Knee

The joint in the middle of a horse's front leg, equivalent to the human wrist (carpus).

Lateral

Toward the side of the body, away from the midline. Structures positioned farther from the center line are described as lateral.

Macroscopic

Large enough to be seen with the naked eye, without magnification. Refers to structures visible during regular examination

Median plane

The imaginary plane that divides the body into equal left and right halves, running down the exact center from head to tail.

Medial

Toward the midline or center of the body.

Microscopic

Too small to be seen without magnification, requiring a microscope for visualization. Refers to cellular and subcellular structures.

Muzzle

The nose and mouth area of an animal, including the nostrils and lips

Nervous tissue

Specialized tissue that transmits electrical signals throughout the body for communication and control. Includes neurons and supporting cells that carry messages between body parts.

Organ level

The organizational level where different tissues work together to perform specific functions. Examples include the heart, kidneys, and liver.

Organism level

The complete living individual with all systems working together to maintain life. Represents the integration of all organizational levels

Palmar

The back surface of the front limb from the carpus (wrist) down to the paw, corresponding to the palm area in humans.

Pastern

The region of a horse's leg between the fetlock joint and the hoof, containing the pastern bones.

Peritoneum

The smooth membrane that lines the abdominal cavity and covers abdominal organs, providing protection and reducing friction.

Physiology

The study of how body parts function and work together

Plantar

The back surface of the hind limb from the tarsus (hock) down to the paw, corresponding to the sole area in humans.

Pleura

The smooth membrane that lines the thoracic cavity and covers the lungs, reducing friction during breathing movements.

Poll

The top of a horse's head between the ears, where the skull meets the neck

Proximal

Closer to the body's center or point of attachment. On limbs, proximal structures are nearer to where the limb connects to the body.

Rostral

Toward the nose, used specifically when describing structures on the head. This term replaces "cranial" when referring to facial features.

Sagittal plane

Any plane that runs lengthwise through the body, dividing it into unequal left and right portions. Multiple sagittal planes exist parallel to the median plane.

Spinal cavity

The space within the vertebral column that houses and protects the spinal cord

Stifle

The joint in a horse's hind leg equivalent to the human knee, located in the upper portion of the hind limb near the body.

Systemic anatomy

The study of body structures organized by organ systems, such as studying all parts of the digestive system together

Tailhead

The base of the tail where it attaches to the body, located at the top of the hindquarters in horses.

Thoracic cavity

The space above the diaphragm that contains the heart, lungs, and major blood vessels, all surrounded by the ribcage for protection.

Tissue level

The organizational level where similar cells group together to perform common functions. The four basic tissue types are epithelial, connective, muscle, and nervous.

Transverse plane

An imaginary plane that runs crosswise through the body, dividing it into cranial (head-end) and caudal (tail-end) sections.

Ventral

Toward the belly or underside of the body

Ventral body cavity

The large body cavity that contains most internal organs, divided by the diaphragm into thoracic and abdominal cavities.

Visceral

Relating to the internal organs within body cavities and their protective coverings. Visceral structures are the organs themselves and their associated membranes.

Withers

The highest point of a horse's back, located at the top of the shoulders between the neck and back where the shoulder blades meet.

Organ System Level

Multiple organs coordinating for major body functions