Activity 4: Examining the Ventral Body Cavity
Starting with the most superficial structures and working deeper the following are structures of the thoracic cavity.
Thymus - the endocrine system
An irregular mass of glandular tissue overlying the heart. (rat dissection only)
Heart - the cardiovascular system
Medial oval structure enclosed within the pericardium (serous membrane sac)
Bronchi - the respiratory system
Following the trachea into the thoracic cavity it divides into these two passages.
Esophagus - the digestive system
Internal (behind) the trachea this is a food chute; the part of the digestive system that transports food from the pharynx (throat) to stomach.
Diaphragm - the muscular system
A thin muscle attached to the inferior boundary of the rib cage; separates the thoracic and abdominal cavities
Stomach - the digestive system
Follow the esophagus through the diaphragm to its junction with this curved organ important in food digestion and temporary food storage.
Greater omoentum - the _______________system
A superficial structure of the abdominopelvic cavity this is an extension of the peritoneum that covers the abdominal viscera.
Small intestine - the digestive system
Continuing from the stomach and ending just before the sac-like cecum (human cadaver)
Large intestine - the digestive system
A large muscular tube connected to the small intestine and ending at the anus.
Cecum - the digestive system
The initial portion of the large intestine. Follow the course of the large intestine to the rectum which is partially covered by the urinary bladder.
Rectum - the digestive system
Terminal part of the large intestine; continuous with the anal canal.
Mesentery - the ______________ system
Lift the small intestine with the forceps to view this apron-like serous membrane; suspends many of the digestive organs in the abdominal cavity. Notice that it is heavily invested with blood vessels and, more likely than not, riddled with large fat deposits. The remaining abdominal structures will be found in/under it.
Pancreas - the endocrine system, accessory organ of the digestive system.
A diffuse gland; rests dorsal (behind) to and in the mesentery between the first portion of the small intestine and the stomach. You will need to lift the stomach to view the pancreas.
Speen - the lymphatic system
A dark red organ curving around the left lateral (away from the midline) side of the stomach; considered to be part of the lymphatic system and often called the "red blood cell graveyard".
Liver - the digestive system
Large and brownish red; the most superior organ in the abdominal cavity, directly beneath the diaphragm.
Deeper structures of the abdominopelvic cavity
Found by moving the stomach and intestines to one side.
Kidneys - the urinary system
Located along the posterior (back) wall of the abdominal cavity these bean shaped organs are retroperitoneal (or behind the peritoneum)
Adrenal glands - the endocrine system
Large endocrine glands that sit astride the superior (upper) margin of each kidney.
Ureter - the urinary system
Tube running from the indented region of a kidney to the urinary bladder, found by striping away part of the peritoneum with forceps then follow one of these to the bladder.
Inferior vena cava - the cardiovascular system
In the midline of the body cavity and lying between the kidneys are the two principal abdominal blood vessels. This is one of them, the large vein that returns blood to the heart from the lower regions of the blood.
Descending aorta - the cardiovascular system
In the midline of the body cavity and lying between the kidneys this is the other principal abdominal blood vessel, deep (behind) the inferior vena cava and the largest artery of the body and carries blood away from the heart down the midline of the body.
Rat: Scrotum, testis, ductus deferens and penis - the male reproductive system
Observing the ventral (front) body surface beneath the tail of the rat. Two openings indicate male.