Head and Neck Anatomy

Oral Cavity

Lips to the palatoglossal arch; contains teeth and tongue

Palatoglossal

Arch Mucosal fold from soft palate to tongue (bilateral)

Oral Cavity

Roof Hard palate (rostral), soft palate (caudal)

Nasal Cavity

Opens respiratory tract; from nares to choana

Choana

Where nasal cavities join to form nasopharynx

Nasal Conchae Turbinate

bones that increase surface area; warm and humidify air

Nasopharynx

Choana to laryngopharynx

Oropharynx

Oral cavity to laryngopharynx

Laryngopharynx

Leads to esophagus or larynx

Pathway of Food Oral

cavity → oropharynx → laryngopharynx → esophagus

Pathway of Air External

nares → nasal cavity → nasopharynx → laryngopharynx → larynx → trachea

Temporomandibular Joint Synovial

joint between mandible and temporal bone; used for chewing

Atlanto-occipital Joint.

Between skull and first vertebra (C1); allows "yes" movement

Sinuses

Air-filled skull spaces (maxillary recess, frontal sinus); warm air

Dental Formula (Dog/Cat).

I 3/3 C 1/1 P 4/4 M 2/3 = 10/11 total

Tooth Root

Embedded in jaw

Tooth Crown

Exposed part of tooth

Brachydont.

Teeth Fully enamel-covered, don't grow continuously

Hypsodont

Teeth Continue growing; opposite of brachydont

Digastricus Muscle

Opens the jaw

Masseter, Temporalis, Pterygoids

Close the jaw

Orbicularis Oris

Muscle around lips; controls mouth/lip movement

Orbicularis Oculi

Muscle around eye; allows blinking

Intrinsic Tongue Muscles.

Both attachments within the tongue

Extrinsic Tongue Muscles

One attachment outside tongue; control position

Parotid Salivary Gland

Located at base of ear

Mandibular Salivary Gland.

Base of jaw

Sublingual Salivary Gland

Runs under the tongue

Zygomatic Salivary Gland

Medial to zygomatic bone, near eye

Gland Duct Openings.

Zygomatic and parotid open into cheek; sublingual and mandibular open under tongue

Mandibular Lymph Nodes

Only palpable head lymph nodes; under mandibular salivary glands

Function of Lymph Nodes

Filter lymphatic fluid

Fibrous Tunic of Eye

Sclera and cornea; connective tissue

Vascular Tunic of Eye

Ciliary body, choroid, iris; blood supply

Nervous Tunic of Eye

Retina and optic nerve; for vision

Extraocular Muscles

Control eye movement

Periorbita

Connective tissue cone around eye

Vertebra Components

Dorsal spinous process, transverse processes, articular processes, arch, pedicle, lamina, body

C1 (Atlas)

Supports skull

C2 (Axis)

Rotational vertebra

C5

Typical cervical vertebra

Larynx Function

Regulates airflow, protects trachea, enables vocalization

Laryngeal Cartilages

Epiglottis, thyroid, arytenoid, cricoid

Laryngeal Muscles

Cricoarytenoideus dorsalis/lateralis, cricothyroideus, thyroarytenoideus

Esophagus

Transports food to stomach; smooth & skeletal muscle

Trachea

Airway with cartilaginous rings; ventral to esophagus

Neck Muscles.

Sternohyoideus, sternothyroideus, sternocephalicus, omotransversarius, brachiocephalicus

Superficial

Cervical Lymph Node Only palpable lymph node in neck

Thyroid Gland

Below larynx; makes metabolic hormones

Parathyroid Gland

On thyroid lobes; regulates calcium/phosphate

Carotid Artery

Main artery to head

External Jugular Vein

Main vein draining head/neck

CN I (Olfactory)

Smell and pheromone detection

CN II (Optic)

Vision

CN III (Oculomotor)

Controls most eye muscles

CN IV (Trochlear)

Controls superior oblique eye muscle

CN V (Trigeminal)

Main sensory nerve of face; 3 branches

CN V - Ophthalmic

Branch Sensory to forehead and eye

CN V - Maxillary

Branch Sensory to upper jaw and cheek

CN V - Mandibular.

Branch Sensory & motor to lower jaw

CN VI (Abducens)

Moves eye laterally

CN VII (Facial)

Motor to facial expression muscles

CN VIII (Vestibulocochlear)

Balance and hearing

CN IX (Glossopharyngeal)

Motor/sensory to pharynx

CN X (Vagus)

Motor to larynx

CN XI (Accessory)

Motor to neck muscles

CN XII (Hypoglossal)

Motor to tongue

PLR (Pupillary Light Reflex)

Afferent: CN II (optic), Efferent: CN III (oculomotor); both pupils constrict to light

Palpebral Reflex

Afferent: CN V (trigeminal); Efferent: CN VII (facial); blink when canthus touched

Menace Response

Afferent: CN II (optic); Efferent: CN VII (facial); blink to hand movement near eye