Avian Internal Anatomy and Reproductive System

Beak

Prehension

Mouth

Entrance to GI tract (Birds do NOT have teeth)

Oropharynx

Combined oral and pharnygeal space

Pharyngeal space

Joint area for digestive and respiratory systems

Salivary glands

Secretes mucin, bicarbonate, and water (no salivary amylase)

Infundibular cleft

Common opening of the Eustachian tubes

Eustachian tubes

Pressure equalization in flight, middle ear

Laryngeal cleft

Block food from entering the larynx

Larynx

Allows passage of air (No vocal cords)

Sprinx

Responsible for vocalization, Y-shaped organ, base of the trachea

Crop

Feed storage area, soaks feed

Proventriculus

Glandular stomach, secretes pepsinogen, HCl, mucous and gastrin (chemical and enzymatic breakdown)

Ventriculus

Grinds food, muscular part, rocks and pebbles are lodged, functions similarly to teeth

Small intestine

Duodenum, Jejunum, Ileum (doe not produce lactase)

Mechel’s diverticulum

Marks the juncture of jejunum and ileum

Large intestine

Ceca and colonH

How many ceca does a chicken have

2

Cloaca

Juncture of ureters, colon, and reproductive system

Testes

Male gonads, produces sperm and testosterone

Epididymis

Increase sperm motility and increases fertilizing capacity

Vas deferens

Sperm storage, maximizing motility and fertilizing capacity of the sperm, sperm maturation, and adding accessory fluid to the sperm (two vas deferens, each connects one testis)

Cloaca

Receives sperm from the vas deferns

Ovary

responsible for ova production and estrogen production

follicles

At least 2,000 follicles (largest follicle is named F1)

Stigma Line

Site of ovulation, there are no blood vessels in this area, no bleeding when ovulation occurs

Oviduct

Infundibulum, Magnum, Isthmus, Uterus, V*gina

Infundibulum time

¼ hour

Infundibulum

Catches the ova when it is ovulated, location of sperm storage, and fertilization

Magnum time

3 hoursM

Magnum

Secretes the albumen protein, or egg white

Isthmus time

1 ¼ hour

Isthmus

The two shell membranes are deposited

Uterus time

20 ¾ hours

Uterus

Plumping, the taking up of water, occurs. Egg shell and shell pigment deposited

V*gina time

¼ hour

V*gina

Rotates the egg from pointed end down to round end down