An Overview of the Oral Cavity
The mouth, or oral cavity, includes your teeth, gums, the soft and hard palates, tongue, tonsils, and salivary glands. These oral structures allow you to eat and drink as well as breathe when your nose is plugged. Your mouth also works with the larynx to help you speak.
Anteriorly, the oral cavity begins behind the opening of the lips, called the oral fissure, and posteriorly it opens into the oropharynx.
The oral cavity is divided into the oral cavity proper and the vestibule.
Oral cavity proper: This space includes everything behind the teeth. The roof of the mouth is formed by the hard palate, and the floor is formed by the anterior two-thirds of the tongue and the mucous membrane that covers the sides of the tongue and attaches it to the mandible.
Vestibule: This space is between the cheeks and lips externally and the teeth and gums internally. Two muscular fleshy folds (the lips) surround the oral fissure. Skin covers the lips externally, and the interior is lined with a mucous membrane. Median folds of the mucous membrane called the labial frenulae connect the lips to the gums. The lips contain the orbicularis oris, which puckers the lips and is sometimes referred to as the kissing muscle. The little groove that runs from the upper lip toward the nose is called the philtrum.
The walls of the vestibule are formed by the internal surface of the cheeks, which contain the buccinator muscles, and are also covered internally with mucous membrane.
The teeth and gums
The teeth are firmly affixed to the upper and lower jaws in sockets called dental alveoli. Teeth are used for biting, chewing, and assisting with speaking. Children have 20 primary teeth, and adults have 32. Sixteen teeth are in each jaw. Most of these teeth erupt by the middle of the teenage years, but wisdom teeth may not erupt until the 20s.
The gingivae are made of fibrous connective tissue and covered with a mucous membrane. The gingivae are attached to the alveolar processes of the mandible and maxilla and the necks of the teeth.
The palate
The palate forms the roof of the mouth and the floor of the nasal cavities. It has two parts: a hard palate and a soft palate:
The hard palate forms the anterior part of the palate. It’s formed by the palatine process of the maxilla and the horizontal plates of the palatine bones. The hard palate is covered by a mucous membrane and has the following three foramina:
Incisive fossa: This opening is posterior to the central (incisor) teeth. It allows passage of the nasopalatine nerves.
Greater palatine foramen: This opening is located on the lateral portion of the palate. It allows passage of the greater palatine vessels and nerve.
Lesser palatine foramen: Posterior to the greater palatine foramen, this opening allows the lesser palatine nerves and vessels to pass through to the soft palate.
The soft palate extends posteriorly and inferiorly from the hard palate and is strengthened by the palatine aponeurosis, which is a tendinous sheet. A conical, fleshy process called the uvula hangs from the back of the soft palate and is visible when the mouth is open wide. Laterally, the soft palate connects to the wall of the pharynx. It’s joined to the tongue and the pharynx by the palatoglossal and palatopharyngeal arches. Clumps of lymphoid tissue called the palatine tonsils are located between these arches.
The soft palate works with the tongue to produce movements that help you swallow and force food into the esophagus. It also rises during swallowing to close off the opening between the oropharynx and the nasopharynx to prevent food and liquid from entering your nose. These five muscles also help with swallowing:
Tensor veli palatini: This muscle originates on the sphenoid bone and the cartilage of the pharyngotympanic tube and inserts onto the palatine aponeurosis. It’s innervated by the nerve to the medial pterygoid (CN V3) and tenses the soft palate and opens the pharyngotympanic tube when yawning or swallowing.
Levator veli palatini: Originating on the pharyngotympanic tube and part of the temporal bone, this muscle inserts onto the palatine aponeurosis. It’s innervated by the pharyngeal branch of the vagus nerve (CN X). It elevates the soft palate during yawning or swallowing.
Palatoglossus: This muscle originates on the palatine aponeurosis and inserts on the side of the tongue. It’s innervated by the pharyngeal branch of the vagus nerve and elevates the posterior part of the tongue while drawing the soft palate to the tongue.
Palatopharyngeus: Originating on the hard palate and palatine aponeurosis, this muscle inserts into the thyroid cartilage and the lateral wall of the pharynx. It’s innervated by the pharyngeal branch of the vagus nerve and tenses the soft palate and pulls the pharynx toward the oral cavity during swallowing.
Musculus uvulae: This muscle originates on the posterior nasal spine of the palatine bone and palatine aponeurosis and inserts into the mucosa of the uvula. It’s innervated by the pharyngeal branch of the vagus nerve, and it pulls the uvula upward.

Clinical Anatomy Glossary
abdomen
This region of the body starts along the bottom of the ribcage and extends to the hips. It’s visible from the front.

Clinical Anatomy Glossary
abdominopelvic splanchnic nerves
These sympathetic (fight-or-flight) nerves of the abdomen carry the presynaptic fibers to the abdomen and pelvis.

Clinical Anatomy Glossary
anastomose
To join together.

Clinical Anatomy Glossary
androgen hormones
Male sex hormones.

Clinical Anatomy Glossary
ankylosing spondylitis
An arthritic disease of the vertebral joints that results in hyperkyphosis and may restrict lung expansion if the disease spreads superiorly. It may lead to fusion of intervertebral joints and spinal column rigidity.

Clinical Anatomy Glossary
anterior
In clinical anatomy, closer to the front of the body. For instance, the abdominal muscles are anterior to the spine.

Clinical Anatomy Glossary
aponeurosis
The broad tendinous structure that attaches a muscle to another muscle.

Clinical Anatomy Glossary
articulate
In clinical anatomy, to form a joint.

Clinical Anatomy Glossary
ball-and-socket joint
A ball-shaped head that fits into a bony socket. The shoulder and hip are ball-and-socket joints. This type of joint allows for free movement in several directions, including flexion, extension, abduction, adduction, medial and lateral rotation, and circumduction.

Clinical Anatomy Glossary
bilateral
On both the left and right sides of the body, such as the eyes, the kidneys, and the arms and legs.

Clinical Anatomy Glossary
bladder
A thin-walled, bag-like organ that can hold up to two cups of urine.

Clinical Anatomy Glossary
bony process
A projection of bone that sticks out from the arch found in vertebrae.

Clinical Anatomy Glossary
brainstem
Connects the cerebrum with the spinal cord.

Clinical Anatomy Glossary
bursae
Fluid-filled sacs that help tendons glide over the bones and other tendons.

Clinical Anatomy Glossary
bursitis
An inflammation of a bursa, which is usually the result of repetitive motion injuries.

Clinical Anatomy Glossary
calcaneus
The part of the heel you stand on.

Clinical Anatomy Glossary
cardiovascular disease
Diseases of the heart and blood vessels.

Clinical Anatomy Glossary
cartilaginous joints
The joint surfaces in cartilaginous joints are covered with hyaline cartilage and have fibrocartilaginous discs between them. Like fibrous joints, cartilaginous joints can be immoveable.

Clinical Anatomy Glossary
cerebrum
The largest part of the brain; made up of the left and right cerebral hemispheres.

Clinical Anatomy Glossary
cervical
The neck region; starts below the head, ends at the thorax, and is visible from the front and rear from below the head to the shoulders.

Clinical Anatomy Glossary
circumduction
To move in a circular motion; doing arm circles, is circumduction.

Clinical Anatomy Glossary
condyloid joints
Joints with an oval surface on one bone that articulates with an oval-shaped depression in another bone. The metacarpophalangeal joints in the fingers are examples of condyloid joints.

Clinical Anatomy Glossary
contralateral
On opposite sides of the body. The right ear is contralateral to the left ear.

Clinical Anatomy Glossary
corpus callosum
A band of nerve fibers that allows the sides of the brain to communicate with the other.

Clinical Anatomy Glossary

Clinical Anatomy Glossary
dendrite
The receiving part of a neuron. The signal received at the dendrite is transmitted toward the cell body of the neuron in the form of an electrical impulse. The impulse is transmitted away from the cell body to another neuron, muscle, or gland by the axon.

Clinical Anatomy Glossary
dermis
The lower layer of the skin containing collagen and elastic fibers that give strength to the skin.

Clinical Anatomy Glossary
diencephalon
The central part of the brain, underneath the cerebrum.

Clinical Anatomy Glossary
distal
Farther from the trunk or from the point of origin. The elbow is distal to the shoulder.

Clinical Anatomy Glossary
dorsal
An anatomical region that runs from immediately below the neck down to the area below the waist. It doesn’t include the shoulders. It’s visible from the rear.

Clinical Anatomy Glossary
dorsiflex
To move your foot and toes up.

Clinical Anatomy Glossary
duodenum
The first segment of the small intestine.

Clinical Anatomy Glossary
dural venous sinuses
The spaces between the two layers of the dura matter that collect blood from veins on the surface of the brain.

Clinical Anatomy Glossary
elastic cartilage
Cartilage that contains elastic fibers in the matrix, so it’s more flexible than either hyaline or fibrocartilage; your ear has elastic cartilage.

Clinical Anatomy Glossary
endoneurium
The delicate layer that surrounds each individual nerve fiber in the peripheral nervous system.

Clinical Anatomy Glossary
epidermis
The tough layer outermost layer of skin. It gets its toughness from a protein called keratin.

Clinical Anatomy Glossary
epineurium
The thick layer of connective tissue that surrounds a bundle of fascicles in the peripheral nervous system.

Clinical Anatomy Glossary
esophagus
A muscular tube that extends from the pharynx to the stomach.

Clinical Anatomy Glossary
eversion
To move the bottom of your foot away from the midline of the body.

Clinical Anatomy Glossary
facet
In clinical anatomy, a smooth joint-forming surface.

Clinical Anatomy Glossary
fascia
A layer of fibrous connective tissue that covers muscle.

Clinical Anatomy Glossary
fibrocartilage
This cartilage has a larger number of collagen fibers and less matrix. It’s found in the discs in joint spaces including the temporomandibular joint, knee joint, and joints between the bodies of the vertebrae.

Clinical Anatomy Glossary
fibrous joints
The bones of a fibrous joint are connected by fibrous tissue. They range from being immovable (like joints between the bones of the skull) to being slightly moveable (joints between the tibia and fibula in the legs).

Clinical Anatomy Glossary

Clinical Anatomy Glossary
frontal planes
Imaginary vertical planes that clinical anatomy uses to define regions of the body. They pass through the body at right angles to the midsagittal plane, so they divide the body into front and back. Frontal (coronal) planes can divide the body at any point, so you need to use a reference point to know where exactly the plane passes.

Clinical Anatomy Glossary
ganglion
A collection of nerve-cell bodies similar to the nuclei of the central nervous system, except that these ganglia are only found in the peripheral nervous system.

Clinical Anatomy Glossary

Clinical Anatomy Glossary
hila
The plural of hilum, and the hilum is the part of the lung where the bronchus and pulmonary artery enter and the pulmonary vein exits the lungs.

Clinical Anatomy Glossary
hinge joint
A joint that allows flexion and extension (bending and straightening) of joints like the elbow and the knee.

Clinical Anatomy Glossary
hyaline cartilage
This durable type of cartilage covers most of the bone surfaces in synovial joints. It’s also found in the nasal septum, rings of the trachea, and costal cartilages of the ribs, and it forms the epiphyseal plates of growing bones.

Clinical Anatomy Glossary
hyperkyphosis
An abnormal increase in the thoracic curvature.

Clinical Anatomy Glossary
hypertension
A condition in which blood pressure remains elevated over time. Having high blood pressure increases the risk of heart disease, stroke, and kidney disease.

Clinical Anatomy Glossary
inferior
Closer to the feet. The chin is inferior to the nose.

Clinical Anatomy Glossary

Clinical Anatomy Glossary
intermuscular septa
The septa divide muscles into various groups.

Clinical Anatomy Glossary
inversion
To move the bottom of your foot toward the midline of your body.

Clinical Anatomy Glossary
investing fascia
This part of the fascia covers deeper structures, such as muscles and ligaments.

Clinical Anatomy Glossary
ipsilateral
On the same side of the body. For example, the right ear and the right eye are ipsilateral.

Clinical Anatomy Glossary
keratin
A major structural component of the outer layers of skin.

Clinical Anatomy Glossary
keratinocytes
These cells are constantly shed and replaced by cells from the lower layers of the epidermis. These cells have lost most of their internal structures and organelles.

Clinical Anatomy Glossary
kidneys
Organs that filter the blood and produce urine.

Clinical Anatomy Glossary
lateral
In clinical anatomy, away from the body’s midline. For example, the little toe is lateral to the big toe.

Clinical Anatomy Glossary
lateral epicondyle
A bony prominence located proximal to the lateral condyle.

Clinical Anatomy Glossary
lateral rotation
To move a body part around its long axis with the anterior surface moving away from the midline, like turning your whole lower extremity so your foot points out toward the side.

Clinical Anatomy Glossary

Clinical Anatomy Glossary
manubrium
The superior part of the sternum.

Clinical Anatomy Glossary

Clinical Anatomy Glossary
matrix
A structural component made of water, collagen fibers, and crystallized calcium salts.

Clinical Anatomy Glossary
medullary cavity
Open space inside the bone.

Clinical Anatomy Glossary
meninges
Coverings of the brain. They protect the brain by housing a fluid-filled space, and they function as a framework for blood vessels.

Clinical Anatomy Glossary
midsagittal plane
An imaginary vertical plane that clinical anatomy uses to divide the body into left and right halves.

Clinical Anatomy Glossary
multinucleated
Containing more than one nucleus.

Clinical Anatomy Glossary
myoblasts
Embryonic muscle cells.

Clinical Anatomy Glossary
myocardium
Muscle of the heart.

Clinical Anatomy Glossary
nasal mucosa
Membranous lining of the nasal cavity that secretes mucus.

Clinical Anatomy Glossary
neurocranium
The part of the cranium that holds the brain.

Clinical Anatomy Glossary
osteoblasts
Cells that build up bone.

Clinical Anatomy Glossary
osteoclasts
Cells that break down bone.

Clinical Anatomy Glossary
osteocytes
Cells that maintain bone and collagen fibers.

Clinical Anatomy Glossary
papillae
Small, rounded protuberances.

Clinical Anatomy Glossary
parasympathetic stimulation
Constricts the bronchi, dilates blood vessels, and increases glandular secretions.

Clinical Anatomy Glossary

Clinical Anatomy Glossary
perineurium
Dense connective tissue surrounding a bundle of nerve fibers called a fascicle in the peripheral nervous system.

Clinical Anatomy Glossary
periorbita
A covering of fibrous connective tissue.

Clinical Anatomy Glossary
pharyngotympanic tube
The eustachian tube.

Clinical Anatomy Glossary
pivot joints
Joints that include a bone shaped like a pivot and a ring made of bone or ligament. Pivot joints, such as the atlantoaxial joint of the cervical spine, have rotational movements.

Clinical Anatomy Glossary
plane joints
Joints with flat articular surfaces that allow for a sliding motion, such as the acromioclavicular joint of the shoulder.

Clinical Anatomy Glossary
plantarflex
To point your toes down.

Clinical Anatomy Glossary
popliteal fossa
A diamond-shaped space posterior to the knee joint, bordered by several muscles, skin, the popliteal fascia, the femur, and the joint capsule.

Clinical Anatomy Glossary
posterior
Closer to the rear. The spine is posterior to the abdominal muscles.

Clinical Anatomy Glossary
pronation
A medial rotation of the forearm so that the palm faces posteriorly (toward the rear).

Clinical Anatomy Glossary
proximal
Closer to the trunk or closer to the point of origin. The shoulder is proximal to the elbow.

Clinical Anatomy Glossary
retinacula
Band-like structures that hold tendons in place while joints move.

Clinical Anatomy Glossary
retrusion
To move backward.

Clinical Anatomy Glossary
rugae
Gastric folds that appear when the stomach muscle tissue is contracted.

Clinical Anatomy Glossary
saddle joints
Joints that have the appearance of a saddle. The carpometacarpal joint at the base of the thumb is an example of a saddle joint.

Clinical Anatomy Glossary
sagittal planes
Imaginary vertical planes that are parallel to the midsagittal plane and divide the body into unequal left and right portions. There are many possible sagittal planes, so you should always give a reference point where the plane passes through.

Clinical Anatomy Glossary
scapula
The shoulder blade.

Clinical Anatomy Glossary
sciatic foramen
The opening in the posterior portion of the pelvis formed by the sciatic notch of the ischium and the sacrospinous and sacrotuberous ligament.

Clinical Anatomy Glossary
scoliosis
A rotation and lateral flexion of the spine that may twist and turn the thoracic cage.

Clinical Anatomy Glossary
sebaceous glands
Glands connected to the hair follicles. They produce sebum, which is an oily substance that helps keeps the hair flexible.

Clinical Anatomy Glossary
skeletal muscles
The muscles responsible for making the skeleton move. They’re voluntary muscles because you can control whether the muscles move.

Clinical Anatomy Glossary
stratum basale
Forms the deepest layer of the skin. The cells of this layer continuously divide and form new keratinocytes to replace the ones that are constantly shed. This layer also contains melanocytes, which are the cells that produce skin coloring.

Clinical Anatomy Glossary
stratum corneum
Dead, mature skin cells called keratinocytes. These cells are constantly shed and replaced by cells from the lower layers of the epidermis. These cells have lost most of their internal structures and organelles.

Clinical Anatomy Glossary
stratum granulosum
The area of the skin where keratin is formed. The cells in this layer also produce materials that prevent evaporation, which helps waterproof the skin.

Clinical Anatomy Glossary
stratum lucidum
Found in thicker skin; helps reduce friction between the stratum corneum and the stratum granulosum. It’s composed of dead, flattened cells.

Clinical Anatomy Glossary
stratum spinosum
Contains keratin-producing cells that were formed in the stratum basale.

Clinical Anatomy Glossary
subcutaneous layer
Area below the skin; underneath the cutaneous layer and is sometimes called the hypodermis or superficial fascia.

Clinical Anatomy Glossary
subserous fascia
The part of the fascia that lies between the body walls such as the thoracic wall and the membranes that line corresponding body cavities.

Clinical Anatomy Glossary
superficial
Closer to the surface. For instance, the skin is superficial to the muscles.

Clinical Anatomy Glossary
superior
Closer to the top of the head. For example, the nose is superior to the chin.

Clinical Anatomy Glossary
superior oblique muscle
The muscle that turns the eyeball inferiorly and laterally.

Clinical Anatomy Glossary
supination
Lateral rotation of the forearm so the palm faces anteriorly.

Clinical Anatomy Glossary
sympathetic stimulation
Causes bronchodilation and constricts the blood vessels.

Clinical Anatomy Glossary
synapse
The junction in the brain where nerve impulses pass.

Clinical Anatomy Glossary
synovial joints
A typical synovial joint includes bones covered in hyaline cartilage and a joint cavity lined with a synovial membrane and filled with synovial fluid. A durable fibrous joint capsule surrounds the joint. Some synovial joints also have fibrocartilaginous discs between the bones.

Clinical Anatomy Glossary
thorax
The section of the body that starts immediately below the neck, at the clavicles, and ends along the bottom of the ribcage. It’s visible from the front.

Clinical Anatomy Glossary
transverse planes
Imaginary horizontal planes that pass through the body at right angles to the midsagittal and the frontal planes. They divide the body into upper and lower portions. You need to have a reference point to know exactly where a transverse plane lies.

Clinical Anatomy Glossary

Clinical Anatomy Glossary
tympanic membrane
The eardrum.

Clinical Anatomy Glossary

Clinical Anatomy Glossary
ureters
Two long tubes that lead to the urinary bladder.

Clinical Anatomy Glossary
ventral
Toward the abdomen.