A Diagram of a Chicken: Anatomy and Body Parts Explained

For backyard chicken keepers, having a basic understanding of chicken anatomy and being able to identify different body parts is essential. Knowing the names and locations of feathers, organs bones and muscles allows you to better care for your flock, whether it’s keeping them healthy grooming them properly or even cooking them.

In this article, we’ll provide a detailed chicken diagram with descriptions of all the major external and internal body parts of a chicken.

External Anatomy of a Chicken

Let’s start by looking at the outside of a chicken Here are the main elements of a chicken’s external anatomy

Head

• Comb: The fleshy, red crest on top of a chicken’s head. Comes in various shapes and sizes depending on the breed. Helps chickens regulate body temperature.

• Beak: Hard, bony structure used for eating, grooming, digging, vocalizing, and defense. Very sensitive. Continues growing throughout a chicken’s life.

• Nostrils: Paired openings on either side of the beak used for breathing.

• Wattles: Paired flaps of skin that dangle under the beak. Help regulate body temperature.

• Eyes: Allow chickens to see color and movement. Chickens have better close-up vision than distance vision.

• Earlobes: Flap of skin below each ear. Vary in color by breed.

• Ears: Openings covered in feathers that lead to the inner ear. Chickens have excellent hearing.

• Neck hackles: Long feathers on the neck, especially prominent in roosters.

Body

• Shoulders: Where the wings attach to the body. Covered in feathers.

• Breast: Muscular area of the chest containing major organs. Larger and more prominent in hens.

• Back: Area between the neck and tail covered in feathers. Contains the spinal column.

• Wings: Used for balance, flying, cooling, and courtship displays. Contain long flight feathers.

• Saddle: Area on the back before the tail where roosters have specialized feathers.

• Tail: Contains steering feathers and large, decorative feathers in roosters. Used for balance and courtship displays.

• Vent: Opening under the tail where eggs are laid and feces are expelled.

• Abdomen: Belly area containing digestive and reproductive organs. Covered in soft feathers.

Legs

• Thighs: Upper segments attaching the legs to the body. Contain large muscles.

• Hocks: Knees of a chicken. Thighs connect to shanks here.

• Shanks: Lower leg segments between the hock and foot. Scaly and featherless.

• Spurs: Pointed claws protruding from the back of rooster’s shanks used for fighting.

• Toes: Chickens have four toes, three pointing forward and one pointing back.

• Claws: Pointy toenails on the end of each toe used for scratching, grasping, fighting, and roosting.

Internal Anatomy of a Chicken

Now let’s look inside a chicken and identify its major internal organs and body systems:

Skeletal System

• Skull: Bone structure surrounding the brain. Connects to the beak.

• Spinal column: Long column of small bones down the back encasing the spinal cord.

• Shoulder bones: Bones supporting the wings, includes the humerus, radius and ulna.

• Keel bone: Breastbone chickens are attached to major muscle groups.

• Pelvis: Hip area where the legs attach to the backbone.

• Leg and wing bones: Thighs, drumsticks, shanks and wings contain long bones.

Muscular System

• Breast muscle: Large, thick chest muscle responsible for wing movement.

• Leg/thigh muscles: Muscles that allow for locomotion and kicking.

• Neck muscles: Allow flexibility and range of motion of the head.

• Wing muscles: Responsible for allowing wings to lift, flap, and tuck against the body.

Respiratory System

• Trachea: Windpipe conducting air from the mouth down into the lungs.

• Lungs: Paired organs where oxygen is absorbed into the bloodstream.

• Air sacs: Thin-walled sacs attached to lungs that supplement gas exchange.

Digestive System

• Beak and tongue: Used to manipulate, consume and taste food.

• Esophagus: Tube connecting the mouth to the stomach. Pushes food via contractions.

• Crop: Storage pouch along the esophagus where food is moistened before digestion.

• Stomach: Thick-walled organ containing acids and digestive enzymes to break down food.

• Liver: Secretes bile used for fat digestion and metabolizes carbohydrates and proteins.

• Pancreas: Gland that produces enzymes for digestion.

• Small intestine: Long, narrow tube where digestion is completed and nutrients are absorbed.

• Ceca: Paired small pouches near the intestinal-cloaca junction that ferment fiber.

• Cloaca: Chamber connecting the intestinal, urinary and reproductive tracts.

Circulatory System

• Heart: Four-chambered muscle pumping blood to the body systems.

• Arteries: Thick, muscular vessels carrying blood away from the heart.

• Veins: Thin vessels carrying blood back to the heart.

• Capillaries: Tiny vessels diffusing nutrients and gases between blood and body tissues.

Nervous System

• Brain: Control center interpreting sensory information and coordinating systems.

• Spinal cord: Pathway transmitting nerve signals between brain and body.

• Nerves: Bundle of fibers carrying signals to and from the brain.

• Eyes: Pair of complex organs receiving and processing visual stimuli.

• Ears: Openings catching sound waves and transmitting to the brain.

Reproductive System

Hens

• Ovary: Produces and releases egg yolks.

• Oviduct: Passage eggs travel down. Sections include:

  • Infundibulum: Collects released yolk

  • Magnum: Forms egg white

  • Isthmus: Forms shell membranes

  • Uterus: Mineralizes shell

  • Vagina: Adds cuticle and pigments shell

• Cloaca: Eggs exit body here

Roosters

• Testes: Produce sperm

• Vas deferens: Tubes carrying sperm

• Cloaca: Site where sperm is released

This covers all the major external and internal parts of a chicken. Being able to identify the different components on a chicken diagram will help you better understand chicken anatomy and physiology. Use this as a handy reference next time you are observing your flock.