80 terms

Q7 - Head & Neck

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alveolus (alveoli)
These depressions are found in both of the maxillary bones and the mandible. They are functionally imporatant as the teeth are cemented into these depressions.
anterior triangle of the neck
The digastric muscle, sternohyoid muscle and the sternocleidomastoid muscle in humans define this area. In the cat there is no sternocleidomastoid muscle, rather the sternomastoid muscle defines it.
arytenoid cartilages
This cartilage is the only one of cartilages of the larynx that we will study that is split into two pieces. It forms the walls of the glottis and anchors the vocal cords.
bone collagen
The intercellular matrix of the tooth and bone tissue is made of hydroxyapatite (mostly) and this material. These protein fibers add stability to the matrix as steel reinforcement rods add stability to cement in the construction of large objects.
cells
These are the live portion of the tooth. They are capable of repairing the tooth when it is damaged. They require a blood supply to stay alive.
cementum
This is a hard material (calcified connective tissue) that helps secure the tooth into its alveolus by attaching the tooth to the periodontal membrane (ligament).
clavicle
This bone is part of the appendicular skeleton. It articulates with the scapula and the manubrium of humans while in cats it floats. In humans it acts as a brace for the scapula, It serves as origin and insertion for a number of muscles.
clavotrapezius muscle
This is a cat muscle that corresponds to the superior division of the human counterpart. This muscle elevates and retracts (adducts) the scapula. It is served by the spinal accessory nerve. It inserts on the clavicle
cleidomastoid muscle
This muscle combines with the sternomastoid muscle in humans, but in cats it remains separate. It is at least partially covered by the clavotrapezius of the cat.
common carotid artery
These arteries (left and right) are normally branches of the brachiocephalic artery, or less frequently branches of the bicarotid trunk in cats. In humans the right vessel is a branch of the brachiocephalic artery, but the left is a branch of the aorta. They are found in the carotid sheath on each side with the vagosympathetic trunk and the internal jugular vein. They have a number of branches. One of particular interest is the internal carotid artery.
common carotid artery
These vessels (left and right) are normally branches of the brachiocephalic artery, or less frequently branches of the bicarotid trunk in the cat. In the human the left vessel is a branch of the aorta while the right is a branch of the brachiocephalic artery. They are found in the carotid sheath on each side with the vagosympathetic trunk and the internal jugular vein. They have a number of branches that we study in lab.
cranial laryngeal artery
This vessel is a medial branch of the common carotid artery. It serves the cranial end of the larynx.
cranial thyroid artery
This artery is the first medial branch of the common carotid artery that we will study in the cat. It serves the thyroid gland.
cricoid (signetring) cartilage
This cartilage of the larynx is the only cartilage that forms a complete ring. It is narrow anteriorly and wide posteriorly. It is connected superiorly to the thyroid cartilage and inferiorly to the trachea. It forms most of posterior wall of the larynx.
crown
This is the exposed part of a healthy tooth. A thin layer of enamel (between 2 and 2.5 mm) covers it. Under the enamel we find dentin. Cells live in the intercellular matrix. In the center of the tooth is the pulp cavity filled with pulp. This part of the tooth meets the root at the neck close to the gingiva (gum).
dentin
This material underlies the enamel in the crown of the tooth and forms the hard part of the root of the tooth. It is about 64.5% hydroxyapatite, this being harder than bone. It is more porous than enamel.
digastric muscle
This muscle depresses the mandible. When one opens their mouth they are depressing the mandible.
enamel
This is the hardest material in a human unless you have foreign objects in you, not that there is anything wrong with that. It is about 92% hydroxyapatite, accounting for its hardness. It is about 2 to 2.5 mm thick on the outside of the crown.
esophagus
This organ begins at the inferior end of the pharynx. It passes through the cervical region, then through the thoracic cavity, through the diaphragm at the level of thoracic vertebra 10 body at midinhalation, and on to the stomach. Functionally it is important as it transports food from the pharynx to the stomach.
Exocrine Gland
This is the name for an organ that produces secretions that pass through a duct (except for one-celled goblet cells). The secretions pass into a cavity or onto the surface of the body.
external carotid artery
This branch of the common carotid artery has many branches that we study. They include the sublingual artery and the external maxillary artery. It brings blood to the areas of the head external to the cranial cavity
external jugular vein
This vein may be observed as it emerges from the deep side of the muscles in the neck and runs caudally until it meet the subclavian vein on the same side in the cat. This union forms the brachiocephalic vein on each side. Before that union occurs the internal jugular vein, which often does not take the dye, joins it. This vein receives blood from the head region except the cranial cavity.
external maxillary artery
This vessel is a medial branch of the external carotid artery that arises cranial to the lingual (sublingual) artery in the cat. It runs deep to the digastric muscle and supplies blood to the salivary glands and the masseter muscle.
external nares
These are the external openings on each side that lead into the nasal cavities. These openings are normally used to allow air into and out of the nasal cavities
Facial nerve (VII)
This nerve is a cranial nerve. It is both motor and sensory. It also has parasympathetic functions controlling the lacrimal gland, as well as the mandibular and sublingual salivary glands. It exits from the skull via the stylomastoid foramen. We will observe this nerve on the lateral portion of the face where the two branches bracket the masseter muscle.
gingiva
When we were in nursery school we called this the gum. Functionally it is important because it forms a seal around the neck of the tooth that keeps food and bacteria away from the surface of the root where there is no enamel and the dentin would otherwise be exposed. If the dentin is exposed it is more susceptible to the decay process.
glosso pharyngeal (IX)
This is a cranial nerve that controls the parotid salivary gland. It leaves the cranium by way of the jugular foramen. It includes both motor and sensory neurons, as well as parasympathetic neurons.
glottis
This the name for the opening between the vocal cords that leads into the trachea.
hard palate
This structure is the bony portion of the roof of the oral cavity. It is formed anteriorly by the palatine processes of the two maxillary bones and posteriorly by the horizontal plates of the two palatine bones. Functionally it is important because it separates the nasal cavities from the oral cavity. This separation is important to keep food out of the air passages and it also is essential to form suction as when drinking with a straw.
hydroxyapatite
This mineral makes up the majority of the intercellular matrix of the tooth and bone tissue. It is a calcium phosphate base with one hydroxide group for every 5 calcium atoms and 3 phosphate ions. It is very hard, but it is susceptible to reacting with acid and dissolving. The other component of the intercellular matrix is bone collagen
hyoid bone
This bone does not articulate with any other bones. It is held in place by ligaments to the styloid process of the temporal bone and the thyroid cartilage of the larynx. It also has muscle attachments. In spite of the fact that it is not attached to the skull, it is considered part of the axial skeleton, specifically part of the skull. It has a shape similar to the mandible, suggesting a common origin. Functionally it is important because it is the origin of muscles that move the larynx during the act of swallowing.
hypoglossal nerve (XII)
This cranial nerve is a motor nerve that serves the muscles of the tongue. It runs with the sublingual artery.
internal carotid artery
Although this vessel is too small to find in the cat, it is of particular significance as it is one of two vessels on each side that carry blood to the brain. They enter the cranium by passing through the carotid canal of the temporal bone.
internal jugular vein
This vessel is part of the carotid sheath, which also includes the common carotid artery and the vagosympathetic trunk. It usually joins the external jugular vein before the junction with the subclavian vein.
internal nares
These openings are on each side of the nasal septum. They lead from the nasal cavities into the nasopharynx. These openings are normally used to allow air into and out of the nasal cavities. Normally the soft palate prevents food or liquids from entering the nasal cavities during the act of swallowing by blocking them
laryngopharynx
This cavity is the inferior division of the pharynx, extending from the epiglottis inferiorly and posteriorly to the larynx to the openings of the esophagus and larynx. Functionally it is important because both food and air pass through this space.
laryngopharynx
This area is the inferior division of the pharynx, extending from the epiglottis inferiorly and posteriorly to the larynx to the openings of the esophagus and larynx. Functionally it is important because both food and air pass through this space.
larynx
This structure is made up of four major cartilages and houses the vocal cords. Functionally it is important because it connects the pharynx with the trachea, as well as being the structure where sound is produced. It extends between C4 and C6. Superiorly it is attached to the hyoid by the thyrohyoid ligament and inferiorly it is continuous with the trachea.
mandible
This is a single bone of the face. It articulates with the mandibular fossa of the temporal bone and irritation of this joint leads to the condition known as TMJ syndrome. When we were in nursery school we called it the lower jaw. It has a number of landmarks associated with it including: rami, alveoli, coronoid and condyloid processes, mandibular fossa, body, and the mandibular (sigmoid) notch. It also houses two important foramina, the mandibular and mental foramina. We find that it is actually two bones in the fetus.
mandibular nerve (v3)
This nerve is a branch of the trigeminal nerve (V). It is a sensory nerve to the skin of the face, oral cavity, and the teeth of the mandible. It passes through three foramina as it leaves the brain. In order they are the foramen ovale of the sphenoid bone, the mandibular foramen of the mandible, and the mental foramen of the mandible.
masseter muscle
This muscle, which is the prime elevator (closer) of the mandible, originates on the inferior margin of the zygomatic arch. It inserts on the mandible. In the cat it is partly covered by the parotid salivary gland. The dorsal and ventral facial nerves brackett the muscle in the cat as well.
mastoid process
This landmark is part of the temporal bone. It is the insertion for the sternocleidomastoid muscle. In fact it is this muscle that causes this landmark to develop. Several other muscles that you will not be responsible for also attach to this landmark. As a group these muscles are responsible for rotation or extension of the head.
maxillary bone
There are two of these bones and they are considered part of the face. They form the upper jaw, as well as the anterior two thirds of the hard palate. They also form the lateral walls of the nasal cavities, and a portion of the bony orbit of the eye. They have a number of landmarks including: sinuses, alveoli, and the palatine processes. In addition they have the infraorbital foramina and form part of the inferior orbital fissure. All facial bones except the mandible articulate with these bones.
maxillary nerve (v2)
This nerve is a branch of the trigeminal nerve (V). It is a sensory nerve to the skin of the face, oral cavity, and the teeth of the maxillary bones. It passes through three foramina as it leaves the brain. In order they are the foramen rotundum of the sphenoid bone, the inferior orbital fissure of the maxilla, palatine, sphenoid and zygomatic bones, and the infraorbital foramen of the maxillary bone.
mouth
This cavity extentds from the outside to the oralpharynx. It contains the tongue and the teeth.
muscular artery (branch)
This vessel is a lateral branch of the common carotid artery. It leaves the common carotid close to the cranial thyroid artery and supplies blood to the muscles of the cervical region.
nasal septum
This structure is a wall between the two nasal cavities. It is made of two bones (inferiorly the vomer and superiorly the perpendicular plate of the ethmoid) and anteriorly by a septal cartilage. It is covered by mucous membranes on both sides. Anteriorly it separates the external nares and posteriorly it separates the internal nares.
nasopharynx (nasalpharynx)
This space is the superior/posterior division of the pharynx. It is superior and posterior to the soft palate. Normally air passes through this space on its way to or from the trachea. The pharyngeal and tubal tonsils are found in this space. Also, we find the eustachian (pharyngotympanic) tube from the middle ear in this space.
oropharynx (oralpharynx)
This space is the superior/anterior division of the pharynx. It is posterior to the oral cavity and extends from the soft palate to the epiglottis. Functionally it is important because both food and air pass through this space. There are two tonsils in this space - the pair of palatine tonsils (laterally) and the lingual tonsil (posterior surface of the tongue).
parasympathetic nerves
These nerves form one of the two functional subdivisions of the autonomic nervous system. They are responsible for the 'feed or breed' response. These nerves are responsible for preparing the body for digestion and gestation. Slower heart rate and sleepiness are characteristic of their activity (for example, it is active after you have eaten 40 pounds of food at Thanksgiving dinner).
Parotid salivary gland
This gland is the largest of the salivary glands. It lies superficial to the masseter muscle and its duct passes across the masseter to deliver the saliva lateral to the second upper molar. As with most glands, it has a rough texture. It is an exocrine gland. Its secretions are controlled by the glossopharyngeal nerve (XII).
periodontal ligament (membrane)
This structure is primarily connective tissue and it surrounds the root of the tooth. The cementum actually secures the tooth to this structure and this holds the tooth in its alveolus. It is continuous with the periosteum that surrounds the bone.
periosteum
This organ is primarily a fibrous connective tissue membrane that surrounds all bones, except at the articular surfaces where articular cartilage is formed. This layer has the ability to produce or remove bone tissue from the surface of the bone, and is responsible for the increase in diameter of bones as they grow longer. It has nerves incorporated in its structure which is why a broken bone hurts so much. It also has a blood supply that is connected to the blood supply of the bone it is associated with. This organ is attached to the bone by rootlets (Sharpey's fibers or perforating fibers). This is important because the tendons from muscles actually attach to it, not the bone surface. It is also continuous with the periodontal membrane of the tooth and the joint capsule of synovial joints.
posterior triangle of the neck
The sternocleidomastoid muscle, trapezius, and clavicle in humans define this area. In the cat there is no sternocleidomastoid muscle, rather the cleidomastoid muscle defines it.
pulp cavity
This is the space within the crown and root of the tooth that is occupied by the pulp.
root
This part of the tooth is the portion that is in the alveolus (socket). Cells live in the intercellular matrix. In its center is the pulp cavity filled with pulp. The outer portion is made of dentin. It is held in place by cementum. It meets the crown at the neck close to the gingiva (gum).
root canal
This is the narrow part of the pulp cavity that is primarily within the root of the tooth. It is occupied by the pulp
saliva
This material is an exocrine secretion. It contains water, electrolytes, mucus, and salivary amylase (ptyalin). Functionally it is important because it moistens the mouth, helps control bacteria (mucus and enzymes), helps regulate the mouth's pH to be about 7.2, helps lubricate the food, among other things. When we were in nursery school we called it spit.
salivary amylase (ptyalin)
This enzyme is found in saliva. It converts starch into disaccharides. This answer does not begin with the letter "P".
soft palate
This structure is muscular tissue. Functionally it is important because during the act of swallowing it block the internal nares so that food and liquids do not move into the nasal cavity.
spinal accessory nerve (XI)
This cranial nerve is somewhat unusual because it controls muscles that attach to the skull and the scapula. It controls the sternocleidomastoid muscle and the trapezius muscle. It is also unusual because it leaves the cranium by way of the foramen magnum and the jugular foramen. Most cranial nerves leave the cranium by one foramen.
sternocleidomastoid muscle
This muscle is a human muscle. It inserts on the mastoid process and originates on the clavicle and sternum. This muscle forms part of the boundaries for both the anterior and posterior triangles of the neck in a human. If both the right and left muscles contract the head bends. If only one side contracts the head rotates.
sternohyoid muscle
This muscle originates on the sternum and inserts on the hyoid bone. It depresses the larynx and mandible.
sternomastoid muscle
This is a cat muscle that originates on the sternum and inserts on the mastoid process. If both this muscle contracts on both sides the snout is depressed, while if only one of them contracts it depresses the snout and turns the head
subclavian artery and vein
The answer here is a pair of vessels from each side. On the right one of these vessels is a branch of the brachiocephalic artery. On the left one of these vessels is the fourth branch of the aorta. They run through the thoracic outlet to become the axillary arteries. The other vessels help form the two brachiocephalic veins when they join the external jugular veins. They drain blood from the upper limb back toward the heart.
sublingual (lingual) artery
This vessel is a medial branch of the external carotid artery. It runs with the hypoglossal nerve along the medial margin of the digastric muscle. Functionally it is important because it supplies the tongue with blood.
sublingual salivary gland
In the cat this structure is situated deep to the submaxillary duct and the digastric muscle. It has its own ducts that open ventral to the tongue. Its secretions are controlled by the facial nerve (VII).
sympathetic trunk
This nerve runs along each side of the vertebral column. It receives neurons from anterior rami of the spinal nerves via the sympathetic trunk ganglia. It serves many organs from the head to the pelvis. Because it receives nerves from the intervertebral foramina it is difficult to lift away from the body wall. It runs with the vagus nerve (X) in the cervical region.
thyroid cartilage
This structure is the largest of the laryngeal cartilages and larger in sexually mature males due to the effect of sex hormones. It is sometimes described as plow or shield shaped. It forms part of the walls of the glottis and is the insertion for the sternothyroid muscle.
thyroid gland
This structure is a bilobate endocrine gland. It is located inferior to the thyroid cartilage of the larynx and lateral to the trachea. It is the largest purely endocrine gland in the body. Notice: in the cat they look like rice peel offs. In fact, this may be where rice peel offs come from!
tongue
This organ is attached to the floor of the oral cavity. It is the primary organ responsible for the sense of taste. It also aids in the mastication of food. Its base is attached to the hyoid bone. It is responsible for modifying the sound produced by the vocal cords into words.
tonsils
These are lymphoid organs. There are four groups of them. Functionally they are important because they remove pathogens that enter the pharynx. Cells in them are part of our immune system. When they become inflamed they are sometimes called adenoids.
tooth
These organs project from the mandible and two maxillary bones into the oral cavity. They are functionally important as they help break food into small pieces.
trachea
This is a tube connecting the larynx with the primary bronchi. This structure is reinforced with 16 to 20 "C" shaped cartilaginous rings to prevent it from collapsing when the pressure inside drops. The diameter of the rings is approximately 1.5 inches. It is lined with ciliated epithelial cells that sweep mucous upward toward the pharynx. The superior end is found at the level of cervical vertebra 6 body. Inferiorly it extends to the level of the sternal level when the subject is supine and to thoracic vertebra 7 when standing.
trapezius muscle
This human muscle is served by the spinal accessory nerve (XI). It is one of the muscles of the scapula. It elevates, depresses, adducts (retracts), and rotates the scapula.
uvula
This structure is a conical projection. The zoological root means small grape. It assists the soft palate in blocking the internal nares during swallowing.
vagosympathetic trunk
This nerve runs along each side of the trachea in the carotid sheath, which also includes the common carotid artery and the internal jugular vein. It is formed where the vagus nerve and sympathetic trunk run adjacent to each other. They do not actually become one structure, and can be separated with a probe.
vagus nerve (X)
This nerve is cranial nerve X. It is the only cranial nerve to pass into the body cavities below the neck. It is primarily parasympathetic in nature and is the major nerve affecting the heart and most of the gastrointestinal tract. It slows the heart down and speeds up the activity of the gastrointestinal tract. As this nerves approach the heart is runs parallel to the respective phrenic nerve.
vocal cords
These structures are anchored to the arytenoid cartilages of the larynx. They are spread apart to facilitate breathing, but when they are closed they vibrate as air passes over them. This results in sound production. The sound is modified by the tongue to produce words.
vomer
This bone is a single bone of the face. It Is of functional importance because it forms the inferior portion of the nasal septum. It starts as a large portion of that septum posteriorly and then narrows to a point at is anterior end, often being called plow shaped. Anteriorly the septum is cartilage.