Head & Neck

They produce chemical secretions needed for normal body functioning.

• Endocrine – ductless, secretions pour directly into vascular system 
• Exocrine – has a duct associated it with it. Secretions empty into various locations

• Produces watery fluid that lubricates the eye.
• Location – superiorly and laterally in orbit.
• Fluid flows inferiorly, and medially, enters tiny opening in medial canthus. Nasolacrimal duct drains into superior portion of nasal cavity.

• Parotid 
• Submandibular 
• Sublingual

• Buccal, labial, lingual, soft palate, hard palate, floor of mouth 
• Von Ebner’s glands – associated with the circumvallate papilla of tongue

• Largest 
• Produces only 25 % of salivary volume. Serous secretion (watery)
• Duct – called Stensen’s duct
• Nerve innervation – IX; Glossopharnygeal. Facial nerve goes through the gland
• Blood supply – branches from external carotid artery. 
• Lymph drainage – deep parotid lymph nodes

• Mumps - Viral infection of parotid gland. Swelling; facial pain. Vaccination - MMR 
• Salivary gland tumor 
• Blockage of Stensen’s Duct

• Second largest salivary gland 
• Produces 60-65 % of the salivary volume 
• Mixed salivary gland – both serous and mucous 
• Duct – Wharton’s Duct; opens at the sublingual caruncle under tongue 
• Nerve innervation – Efferent (parasympathetic ) fibers of chorda tympani (branch of facial nerve) and from submandibular ganglion of facial nerve. 
• Blood Supply – Branches from facial and lingual arteries

• Smallest of major salivary glands 
• Produces 10 % of salivary volume 
• Mixed secretions, but mostly mucous
• Nerve innervation – Same as submandibular 
• Blood Supply – Sublingual and submental arteries (small branches from lingual and mental arteries respectively) 

Mucocoele

Injury to major salivary glands causing blockage

• Largest endocrine gland 
• Secretes thyroxine – hormone that stimulates metabolic rate
• Enlargement – Goiter 

• Four small endocrine glands 
• Produce parathyroid hormone – regulates calcium and phosphorus levels in blood

• Part of immune system; T-cell lymphocytes mature in this gland. 
• Grows in size until puberty; then begins to shrink. 

Cell body, dendrite, and axon

Bundle of neural processes outside the CNS, and in the Peripheral Nervous system 

Collection of nerve cell bodies outside the CNS

Sensory nerve → CNS Analyzes 

Motor nerve → Periphery, muscles effects 

Difference between the positive charge outside the nerve membrane and the negative charge inside nerve membrane; measured in millivolts. Resting potential is  - 70 mV (negative 70 mV) 

• Outside of nerve membrane is high in Na+ 
• Inside of nerve membrane is high in K+ 
• Nerve stimulated, gates open, Na+ rushes in. 
• Depolarization occurs; i.e., becomes less negative by + charges rushing in 
• So, nerves goes from   - 70 mV → + 40 mV 
• Current begins to flow from the depolarized area to the adjacent resting area of   -70 mV. 
• Flow begins down nerve – Action potential or impulse propagation

Junction between two neurons, or between a neuron and an effector organ 

Brain + Spinal Cord

Two cerebral hemispheres. Coordinates sensory data and motor functions, intelligence, reasoning, learning and memory 

muscle coordination, muscle tone and posture and balance 

Medulla, pons, and midbrain

Regulation of heartbeat, breathing, vasoconstriction (blood pressure), reflex centers (vomiting, coughing, sneezing, swallowing and hiccupping) 

Connects medulla with cerebellum; *** cranial nerves V and VII cell bodies are found here 

relay stations for hearing, vision, and motor pathways

Thalamus and hypothalamus 

Central relay point for incoming nerve impulses 

Homeostasis: thirst, hunger, body temperature, water balance, blood pressure, links nervous system to endocrine glands 

• Afferent Nervous System (Sensory)
• Efferent Nervous System (Motor)

• Somatic Nervous System-All nerves controlling the muscular system and external sensory receptors. External sense organs are receptors, but the muscle fibers and glands associated with them are affected by this system. 
• Autonomic Nervous System- Operates without conscious control

• Sympathetic Nervous System “Fight or flight responses” In general, speeds things up; heart rate, blood pressure, dilation of eyes; One exception is salivary gland production; *DECREASES
• Parasympathetic Nervous System "Rest and digest" In general, slows things down; One exception is salivary gland production; * INCREASES

• 8- Cervical 
• 12 -Thoracic 
• 5- Lumbar 
• 5- Sacral 
• 1 -Coccygeal

Olfactory -Sensory only; smell; nerves enters skull through the cribriform plate of the ethmoid bone. Olfactory bulbs → olfactory tracts → brain

Optic -Sensory only; sight; retina → optic nerve → optic chiasma → optic tracts → brain 

Occulomotor -Motor Only; muscles of the eye

Trochlear -Motor only; muscle of the eye 

• Trigeminal -A mixed nerve – both motor and sensory 
• Three Divisions: V1 – Ophthalmic Nerve (Division) – Sensory Only; exits skull through the superior orbital fissure 
• V2 – Maxillary Nerve (Division) – Sensory only; exits skull through foramen rotundum 
• V3 – Mandibular Nerve (Division) – Mixed; motor and sensory; exits skull through foramen ovale

Abducens -Motor Only; muscle of the eye

Facial 

Auditory/Vestibulocochlear -Sensory only; hearing and balance 

Glossopharyngeal – Mixed (both); motor – stylpharyngeus muscle and parotid gland; sensory – skin around ear and tongue (taste and general sensation)

Vagus – Mixed (both); motor – muscles of soft palate, pharynx,  larynx and thorax and absominal organs; Sensory – skin around ear and epiglottis (taste)

Accessory – Motor only; two muscles in neck, sternocleidomastoid and trapezius, soft palate, pharynx 

Hypoglossal – Motor only; tongue muscles