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Mitral (or Bicuspid) Valve

The bicuspid and tricuspid valves are both located between the atrium and the ventricle.   They are similar in appearance and can be difficult for beginning anatomists to identify accurately.  There are a couple of different ways to remember and then locate the valves.  First, you must remember …

Vitreous Humor of the Eye

This dissected eye shows the clear gel that fill the space between the lens and the retina of the eye.  In a preserved specimen, the fluid is cloudy and thick, having the consistency of gelatin.  When the eye is cut in half, the lens can be found floating …

Rat Dissection

Students in biology are often tasked with dissecting a frog, but there are many other vertebrate models that can provide a rich experience in learning anatomy.   Common specimens include the fetal pig, shark, mink, cat, and the rat.   Rats are fairly inexpensive and are raised for …

Heart – Systole and Diastole

During the cardiac cycle, two contractions occur.  Systole occurs when the muscles contract and diastole occurs when the muscles relax.   Atrial systole occurs when the atria contract and push blood into the lower ventricles.  During this point, the aortic valve is closed.   Ventricular contraction then occurs …

Video of a Brain Dissection

This video shows the major parts of the brain, starting with the external anatomy where the pituitary gland, optic chiasma (nerves) , olfactory lobes, dura mater, and the parts of the brain stem:  midbrain, pons, medulla, and spinal cord.   The brain is the cut along the longitudinal …

Cerebellum and Arbor Vitae

The cerebellum is located at the posterior end of the brain and is associated with motor control, balance and coordination.  It is only loosely attached to the cerebrum, and dissections of the brain reveal that removing the dura mater often result in the accidental removal of the cerebellum. …

Muscles of the Leg (Human)

The thigh muscles are often collectively called the quadriceps, which consist of four separate muscles:  rectus femoris, vastus lateralis, vastus medialis, and the vastus intermedius.  On most diagrams, the rectus femoris is shown as the front muscle that runs parallel to the femur.   The word “rectus” means …

Radius and Ulna

The lower arm consists of two bones, the radius and the ulna.  The ulna articulates with the humerus to form a hinge joint.  The radius articulates with the ulna at the radial notch and forms a pivot joint, allowing for the rotation of the wrist. This type of …

Ulna and Humerus

The ulna is one of two bones found in the forearm.  It forms a hinge joint with the humerus and a pivot joint with the radius, giving the lower arm the range of motion to bend and rotate the hands.   On anatomical drawings, the ulna and radius …

Stomach of a Cow

You may have heard that cows have 4 stomachs, but that is not actually accurate.  Cows, like all other vertebrates, have the same basic blueprint for the digestive system: mouth –> esophagus –>  stomach  –> small intestine –> large intestine  –> anus There is one stomach, but that stomach is …