Category: Anatomy

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Epiglottis

The epiglottis is elastic cartilage that is attached to the entrance of the larynx and prevents food and liquids from entering the airway.  In humans, the larynx is positioned much lower in body, which results in an increased risk of choking.  The position of the voice box also …

Body Planes

The planes of the body are one of the first topics in Anatomy and Physiology.   The concept relies on understanding the orientation of the specimen. Sagittal =  cuts the body into a left and right side  (red) Coronal = cuts the body into a front and back …

Osteocytes and the Bone Matrix

Osteocytes are bone cells  that sit within chambers called lacuna.   Lacuna are connective via tine canals called canaliculi and form concentric circles around a central haversian canal.   This coloring worksheet may help with your understanding of these relationships. It can be very difficult to develop a …

Clavicle

The clavicle is commonly called the collarbone and it located in the upper chest region.  The word “clavicle” is latin for “little key” because it rotates like a key when the shoulder and arm are extended.  The clavicle connects to the acromion process of the scapula and the …

Tibia and Fibula

The lower leg bones of the human consist of the large tibia, which is commonly called the shinbone, and the smaller fibula which is located laterally.  Several features of these bones are visible from the outside of the body.  The large tibial tuberosity, is visible as a bulge just …

Femur – Distal End

The lower end of the femur, called the distal end, articulates with the tibia of the lower leg.   It consists of two large structures called condyles, which is the greek word for “knuckle.”   In fact, if you go to a butcher shop, you can order a …

Femur – Proximal End

The proximal end of the femur articulates with the hip.  The rounded head of the femur fits within the acetabulum of the coxal bones, forming a ball-and-socket joint.  The fovea capitis is a small depression in the head serves as an attachment point for ligaments.   The greater trochanter …

Iliolumbar Artery

The iliolumbar arteries are named for their location, supplying blood to the lumbar region of the back and the ilium of the  of the pelvis.  They branch from the abdominal aorta just above where it splits into the external and internal iliac arteries.

Trachea

The trachea is also called the windpipe and it connects the mouth to the lungs.   It is distinguished from the nearby esophagus by the presence of cartilage rings which prevent the airway from collapsing.   At the top of the trachea is the larynx, or the voicebox. …

Greater Omentum

The greater omentum is a fold of visceral peritoneum that hangs down from the greater curvature of the stomach.   It stores fat and also has an immune function, you might notice white spots embedded in the tissue – macrophage collections. The lesser omentum is found in the …

Skull – Mandible

The mandible is the lower jaw and articulates with the skull at the coronoid process and the mandibular condyle.   Two perpendicular parts (creating a right angle) are called the rami (ramu, singular.)   A hole at the front of the mandible provide an opening for nerves and …

Stomach and Pyloric Sphincter Valve

The pyloric sphincter valve is found between the stomach and the duodenum of the small intestine.  It regulates the passage of food from the stomach into the small intestine.  On the dissected frog below, the black pin indicates the stomach and the red indicates the location of the …

Heart and Lungs

The heart and lungs of mammals are closely associated.  You can find the lungs located on either side of the heart and often toward the dorsal side of the thoracic cavity.  The lungs are soft, spongy tissue that are attached to the heart by the pulmonary artery and …

Gallbladder

The gallbladder is part of the biliary system (with the liver and the bile ducts) and has the primary job of storing bile.   Humans can live without a gallbladder, the removal of the organ is called a cholecystectomy.   Some animals don’t even have a gallbladder to …

Aorta and Pulmonary Vessels

Often students mistake the pulmonary artery for the aorta.  The pulmonary artery, or pulmonary trunk, is the most anterior vessel found on the heart; it is indicated below with a blue pencil.  The aorta lies behind the pulmonary trunk, indicated with the red pencil. When the heart is …

Brachiocephalic Artery in Cats

In humans, the arch of the aorta has three main branches that deliver blood to the head and arms.  The cat only has two vessels that branch directly from the aorta.   Many of the cat diagrams will show the following diagram to help you locate the brachiocephalic …

Celiac Trunk

The celiac trunk (artery) is the first major branch of the abdominal aorta, as shown in the photo below. The celiac artery then branches into the gastric artery, which goes to the stomach, the hepatic artery  that goes to the liver, and the splenic artery that goes to …

Iliac Artery

On the cat, the external iliac arteries bifurcate off the abdominal aorta, forming a Y.   The internal iliac arteries also form a Y on the inside of the external iliac arteries.    The external iliac arteries will continue into the hind limbs of the cat and become …