Anatomy Final Exam

External Nares

Openings in the nasal region to allow air to enter the nasal cavity.

Nasopharynx

The upper portion of the throat that connects to the nasal cavity and allows air to travel from the external nares to the lower portion of the throat or pharynx.

Larynx

Also known as the voice-box. It is located inferior to the pharynx. It contains vocal folds that allow us to speak when they vibrate.  It fine-tunes ventilation, assists in the cough reflex and can prevent foreign substances from traveling to the lungs.

Vocal Folds

Flaps made of muscle and other tissues located in the larynx that vibrate when we exhale to produce sound. They also regulate the flow of air into our lungs.

Trachea

A respiratory passageway that connects the larynx to the lungs and facilitates the travel of air to the lungs. It is surrounded by cartilaginous rings which prevent the collapse of the trachea. It has contains cilia and mucus which help to purify, moisten, and warm the air.

Bronchial Tubes

A system of tubes is often called the respiratory tree as they branch from the Primary bronchi to the secondary bronchi, to the bronchioles, and end at the alveoli. They function to facilitate the travel of air from the trachea to the alveoli deeper in the lungs. Primary Bronchi have cartilaginous rings.

Lungs

Large lobed organs that are the site of external respiration where oxygen and carbon dioxide are exchanged. Respiratory gases are exchanged between alveoli and pulmonary capillary beds located in this organ.

Diaphragm

A large muscle that separates the thoracic and abdominal cavity. It will contract or relax to aid in ventilation as the lungs cannot expand or contract on their own. When it contracts the thoracic cavity expands and we inhale. When it relaxes the thoracic cavity shrinks and we exhale.

Incisors

Flat or Narrow edged teeth that function to cut, tear, and rip food as it enters the mouth.  They have one root. They work to perform the function of mastication and are an important first step of digestion as they physically break down food into a bolus.

Canines

Teeth with a singular pointed cusp that functions to bite and tear into food.  They have one root. They work to perform the function of mastication and are an important first step of digestion as they physically break down food into a bolus

Premolars

Also known as bicuspids.  These teeth function to grind and tear food.  They have two, more rounded cusps. They work to perform the function of mastication and are an important first step of digestion as they physically break down food into a bolus.

Hard Palate with Transverse Ridges

A plate of bone covered by a layer of soft and durable tissue that secretes small amount of mucus.  It separate the oral and nasal cavity.  It aids the break down of food as the transverse ridges hold food in place so the tongue can mash it into a bolus. 

Salivary Glands

Glands around the tongue and pharynx that release a solution called saliva that consist of mucus, salivary amylase, lysozymes, and antibodies.  Saliva helps to soften food into a bolus that can be swallowed, breaks down carbs, and inhibits bacterial growth.

Tongue

A muscular organ in the mouth that functions to mash food into a bolus that can be swallowed down the esophagus.  It also aids in speaking and breathing.  Taste buds are located here and have gustatory cells that help us taste.  

Masseter Muscles

Muscles that function to elevate the jaw and aid in mastication by crushing food.

Digastric Muscles

Muscles that function to depress the jaw and open the mouth. Aids in chewing.

Epiglottis

This structure is a flap made out of elastic cartilage that covers the trachea when swallowing so that food and liquid don’t get into the trachea and/or lungs. It is superior to the larynx.

Esophagus

Muscular tube that moves bolus (mashed food) into the stomach by peristalsis. It allows for the passage of material from the mouth and throat to the stomach

Stomach

A muscular sac-like structure that acts like a temporary storage tank and is a site of chemical and physical break down of food. It contains sphincters at both ends to control how food enters and exits. It has three muscular layers that function to churn and compress food and mix it with gastric juice to form chyme. Proteins are broken down here by pepsin.

Rugae

Folds in the stomach that allow the stomach to expand when full and can also compress to aid in digestion.

Liver

The largest gland in the body that has digestive, metabolic, and regulatory functions. It makes bile to break down fats. It processes nearly every kind of nutrient. It stores amino acids, fatty acids, and glucose (as glucagon). It detoxifies drugs and alcohol and breaks down drugs. It makes cholesterol, blood proteins, bile, and lipoproteins and houses phagocytic cells.

Gall Bladder

A thin walled, green sac that functions to store excess bile and release it into the duodenum when food needs to be broken down.

Common Bile Duct

This structure is the tube where cystic duct and hepatic duct join. It allows bile from the liver and gallbladder to enter the duodenum.

Pancreas

This organ functions to release NaHCO3 into the duodenum to neutralize the acidic chyme, It also releases enzymes to break down all classes of macromolecules. It also release insulin and glycogen to regulate blood sugar. These functions make it a very important gland in the body.

Duodenum

The first portion of the small intestine where acidic chyme is neutralized, all classes of macronutrients are broken down by pancreatic enzymes, and where bile emulsifies fat

Jejunum

The second portion of the small intestine. Here proteins and carbs continue to be broken down by brush border enzymes and lipids are absorbed by lacteal and lymph vessels. This is also where these nutrients are absorbed by the mesentery and taken into the blood stream.

Ileum

The third portion of the small intestine. Proteins and carbs continue to be broken down. This is where nutrients are absorbed by the mesentery and taken into the bloodstream. This portion of the small intestine is connected to the cecum by the ileocecal valve.

Mesenteric Blood Vessels

These absorb nutrients broken down in the small intestine into the bloodstream where they can be transported throughout the body to other tissues.

Hepatic Portal Vein

This structure carries nutrient rich blood from the intestines to the liver where nutrients can be processed and stored.

Large Intestine

This structure includes several sections including the cecum. It functions to absorb water, vitamins, and some ions. Bacteria that live in this structure metabolize nutrients and release gas and some vitamins.

Anal Opening

This structure functions to allow waste to leave the body. It is surrounded by both smooth and skeletal sphincter muscles that allow us to excrete waste voluntarily.

Pericardium

A double layered serous membrane surrounding the heart while allowing it to move smoothly.  

Heart

An organ within the thoracic cavity that functions to pump blood throughout the body and along the pulmonary and systemic circuits. 

Coronary Vessels

These function to supply the myocardium with oxygenated blood.

Right Atrium

This structure is a collecting chamber for deoxygenated blood entering the heart from the vena cavas.  

Right Ventricle

The chamber of the heart that functions to pump deoxygenated blood to the pulmonary artery and towards the lungs.

Left Atrium

This structure is a collecting chamber for oxygenated blood returning from the lungs.

Left Ventricle

This chamber functions to pump oxygenated blood to the aorta and along the systemic circuit to the body tissues.

Anterior Vena Cava

This vessel brings deoxygenated blood from the bodily tissues in the anterior portion of the cat back towards the heart. It is located anterior to the heart.

Posterior Vena Cava

This vessel brings deoxygenated blood from the bodily tissues in the posterior portion of the cat back to the heart. It is located posterior to the heart.

Pulmonary Trunk

This vessel transports deoxygenated blood from the right ventricle to the lungs.

Aortic Arch

This is a portion of the vessel that is the largest artery in the body and is responsible for bringing oxygenated blood to the body’s tissues. It carries oxygenated blood along the systemic circuit. This portion is anterior to the heart in the cat and curves posteriorly. It branches into the brachiocephalic artery along with the left subclavian and carotid artery.

Brachiocephalic Artery

This vessel branches off from the aortic arch and Carries oxygenated blood away from the heart towards the anterior portion of the cat including the head and arms. It splits into the right carotid and subclavian artery.

Left Subclavian Artery

This vessel stems from the aortic arch and lies just below the left clavicle, delivering oxygenated blood to the arms with minor contributions to the head and neck

Carotid Arteries

This vessel stems from the aortic arch (left) and the brachiocephalic artery (right). It is the main blood supply to the head and neck- primary vessel for the brain and face

Jugular Vein

This vessel carries deoxygenated blood from the head and neck back to the anterior vena cava.

Brachial Vessels

These vessels supply blood to the tissue in the arm, elbow, and hand.

Descending Aorta

This is a portion of the vessel that is the largest artery in the body and is responsible for bringing oxygenated blood to the body’s tissues. It carries oxygenated blood along the systemic circuit. This portion runs laterally to the heart and is in the thoracic cavity.

Abdominal Aorta

This is a portion of the vessel that is the largest artery in the body and is responsible for bringing oxygenated blood to the body’s tissues. It carries oxygenated blood along the systemic circuit. This portion is located in the abdominal cavity and continues to branch off to supply abdominal organs with blood containing oxygen and nutrients.

Femoral Vessels

These vessels function to supply the lower limbs with blood starting at the inner groin and branching off towards the back of the knee.

Kidneys

The structure that is main organ of the urinary system that functions to filter blood and bodily fluids.  They contain millions of nephrons which function to filter the blood. They are responsible for removing waste,also regulating blood volume and blood ph, balancing water and electrolytes, and producing hormones.

Renal Artery

This vessel brings oxygenated blood that contains waste and need to be filtered to the kidney.

Renal Veins

This vessel brings filtered blood from the kidneys back towards the heart.

Ureters

Tubes that function to transport urine via peristalsis from the renal pelvis in the kidney to the urinary bladder.

Urinary Bladder

This structure is a storage site for urine and is able to expand to store from 500-700 ml of urine until it is convenient to void 

Urethra

A hollow tube that transports urine from the bladder to outside the body. It is surrounded by both voluntary and in voluntary sphincter muscles which allow for controlled micturition.

Urogentital Opening

Most mammals except for primates have this opening which leads to both the urethra and vagina. For female cats urine leaves the body through this opening. It is also the opening where sperm can enter the reproductive tract, where the endometrium exits the body and where babies leave the body during childbirth.

Ovary

This organ is the female gonad and functions to produce and release ovum, release hormones, and help regulate the menstrual cycle. It is this structure where oogenesis is performed and ovum are produced and mature. This structure releases estrogen and progesterone.

Uterus

This structure is a muscular, hollow organ that functions to house, protect, and nourish developing offspring. The embryo will implant into it’s innermost layer the endometrium if fertilization occurs and continue to develop. If no fertilization occurs the endometrium will be shed during menses. When in labor the myometrium will function to expel the baby from the body.

Uterine Horns

These structures branch away from the main body of the uterus and extend towards the ovaries. They are much larger in cats as they are needed to house multiple fetuses. The fetuses are arranged in rows and will be moved down into the body of the uterus and out of the body during labor.

Testis

The male gonad where sperm are created and mature. Spermatogenesis occurs in the seminiferous tubules within this structure and sperm mature in the epididymis. Also, the interstitial cells of this structure produce testosterone. It is surrounded by a sac called the scrotum.

Penis

This structure makes up apart of the external male genitalia and functions to allow urine to leave the body and also functions to insert sperm into the vagina during intercourse. It is contains the urethra, erectile tissue, the prepuce and also the glans penis which acts as the sensory portion.

Spermatic Cord

This tube contains the vas deferens, nerves, and blood vessels. The nerves and blood vessels bring blood to the testis and also carry nerve impulses. The vas deferens within this tube carries sperm from the testis, to the prostate gland, where they are activated and sent through the urethra.

Sciatic Nerve

The longest nerve in the human body that starts in the lower back and runs down the back of each leg.  It is a mixed nerve that contains both motor and sensory fibers.  It transfers nerve impulses to the leg including the back of the thigh, part of the lower leg, and the sole of the foot.  This allows us to walk, run and even stand.  

Tibial Nerve

First terminal branch of the sciatic nerve.  It begins above the knee and runs through the foot.  It is a mixed nerve that sends sensory and motor impulses to the posterior leg and foot.  It aids in movement of the the hip, knee, ankle, and toes and sends sensory information about the leg, heel, and foot. It runs more posteriorly, closer to the center of the leg.

Peroneal Nerve

Another terminal branch of the sciatic nerve.  A mixed nerve that supplies movement and sensation to the lower leg, foot and toes. It branches from the the sciatic nerve in the distal femoral region and runs more laterally and anteriorly, closer to the outside of the leg/calve.

Intercostal Nerves

Nerves that run lateral to the costals and aid in the contraction of intercostal muscles and the return of sensory information from the lungs and pleura. 

Mesenteric Lymph Nodes

These structure house white blood cells (lymphocytes) and macrophages and filter substances entering from the small intestine to prevent bacteria and viruses from spreading and infecting the body.

Spleen

This structure not only stores blood and extra platelets but it also contains lymphocytes and functions to filter bacteria, viruses, and other debris out of the blood passing through. It also destroys old red blood cells to recycle them.

Adrenal Gland

This structure is functions to produce hormones like adrenaline and aldosterone. Aldosterone targets the kidneys to retain sodium and water which also helps maintain blood volume and pressure. It also increases the amount of potassium and hydrogen ions lost in urine.