How many bones are in the skull?
(+6 = 28 but if asked, 22)
What is the only synovial joint of the skull?
What are the two types of non-synovial cartilagenous joints?
Synchondrosis and Symphysis
Explain how synchondrosis joints are formed and give an example of one in the skull.
They're formed by hyaline cartilege - type II colagen connective tissue. The cartilege appears in the growing phase and is then replaced by ossification or fibrous joint. Example: sphenoethmoidal synchondrosis.
True or false:
1. Symphysis joints don't allow any movement.
2. Symphysis joints can take compression, torsion and tension.
1. False. Think pubic symphysis and how it has to expand when women give birth to let the baby through. 2. True.
1. What're the three types of non-synovial fibrous joints?
2. Which are non-moveable and which are slightly moveable?
3. Which ones are in the skull?
4. Which one pertains direction to dentists and how?
1. Suture, gomphosis and syndesmosis. 2. Suture and gomphosis are non-movable. Syndesmosis is slightly moveable. 3. Sutures and gomphosis. 4. "Gum"phosis - dentoalveolar joint; joint between tooth and max/mand. Keeps your teeth in your head.
What's a previously studied example of syndesmosis?
Intermembranous ligament between radius and ulna.
1. What's the part of the skull that houses your brain?
2. What part of the skull is decorated with your face?
1. Neurocranieum. (Cranial cavity / brain case.) 2. Visceral cranium.
1. How many bones are in the neural cranium?
2. Is the ethmoid bone paired?
1. How many bones does the visceral cranium have?
2. Is the vomer paired?
The facial nerve enters ________ and exits ___________.
1. Internal acoustic meatus 2. Stylomastoid foramen.
Where are the cell bodies for Cranial Nerve 7?
Facial nerves gives _______ sensations from the anterior ____ of the __________.
1. Responsible for?
2. Exits where?
1. Smell 2. Ethmoidal foramina of the cribriform plate.
Which nerves exit skull through superior orbital fissure?
CN 3, 4, 5 (V1) and 6.
Occulomotor Trochlear Trigeminal V1 Abducens
What does the abducens nerve do?
Abducts the eye; innervates the lateral rectus muscle of the eye
1. This muscle of the eye has a trochlea.
2. This nerve innervates it.
1. Superior oblique muscle of the eye 2. Trochlear nerve.
Describe the course of the trigeminal nerve (its branches), where they go and if they're sensory or motor.
The branches of the trigeminal nerve come from the trigeminal ganglia. V1 goes through superior orbital fissure to supply the eye. V2 exits through foramen rotundum and makes its way onto the maxillary region of the face. V3 exits through foramen ovale and goes to the lower teeth where it's called the inferior alveolar nerve. When it comes out of the mental foramen, it's known as the mental nerve.
V1 & 2: Sensory V3: Sensory and Motor.
Which two nerves enter the internal acoustic meatus?
CN 7 (Facial) and CN 8 (Vestibulocochlear)
Which nerves exit the skull through the Jugular foramen?
CN 9 (Glossipharyngeal), 10 (Vagus) and 11(Spinal accessory)
Think 9-11 (as in 9 to 11). If you cut your jugular, it's a 911 emergency...thus 9-11 Jugular foramen.
Where does the middle meningeal artery come out of?
Foramen spinosum. The groove for the middle meningeal artery leads right to spinosum.
1. Physical increase in size and mass. 2. All changes from conception to adulthood; increase in complexity and ability to function. 3. Process of advancing towards the goal of adult size, shape and function; reproductive capacity is part of maturation.
What are the three types of growth? Define them and give an example?
Hyperplasia: Tissues increase in size via mitosis, i.e. cancer Hypertrophy: Individual cell undergoes enlargement. i.e. skeletal muscle Accretion: "accrete" means "to cause to adhere." Thus growth by adhesions of parts and particles. i.e. growth in thickness of bone.
What are the time frames for zygote, embryo, fetus, neonate and infant?
Zygote: 0-2 weeks Embryo: 2-8 weeks Fetus: 8-36 weeks Neonate: 0-1 months postnatal Infant: 1 year.
During which stage of development does rapid mitotic cell division occur and is vulnerable with respect to critical periods?
By what age is the skull almost adult sized?
1. What are the two mechanisms of bone formation? Describe each.
2. Which mechanism is used by the skull?
1. Endochondral: cartilege forms a model and then ossifies. "Endo" = within. Chondra = cartilage. Intramembranous: bone is laid out by osteoblasts directly. 2. Skull uses intramembranous ossification.
When is the metopic suture present?
Up until end of second year
What are the five layers of the scalp?
Skin : richly vascularized and well innervated Connective tissue : attaches frontalis and goes back to attach another muscle on the occipital Aponeurosis : allows the upper 3 layers to move Loose connective tissue : dense connective tissue over calvarium. Periosteum
If you pop a pimple on the scalp, which  layer is considered the "danger zone" and can allow the infection to spread to what structures  through which veins ?
1. Loose connective tissue 2. Meninges 3. Emissary veins.
In development, where do the muscles of facial expression develope?
Mesoderm in the 2nd pharyngeal (branchial) arches - block-like structures in the neck region of the embryo.
1. Which muscle wrinkles your forehead and gives you a surprised look?
2. How many bony attachments does this muscle have?
1. Occipito-Frontalis. 2. None.
What is another name for the epicranial aponeurosis?
What does the vestibulocochlear nerve control?
Balance and hearing. Vestibular part: balance Cochlear part: hearing.
Which nerve is CN 11 and what is its path?
CN 11 is the spinal accessory (stupid nerve!); it comes out of the jugular foramen, goes into the foramen magnum, comes back out and goes into the sternocleidomastoid muscle.
1. What is the function of the orbicularis oculi?
2. What does its orbital part do?
3. What does its palpebral part do?
4. What type of muscle is orbicularis oculi?
1. Closes eyelids 2. Surrounds the orbit and mediates forceful closure of the eyes (>_<) 3. Inner portion within the eyelid and mediates blinking. 4. Sphincter.
1. What are the function of the orbicularis oris?
2. What type of muscle is it?
1. Closes oral fissure, presses lips against teeth, protrudes lips 2. Sphincter
1. Which muscle lifts the angles of the mouth?
2. Which one depresses the angles of the mouth?
1. Levator anguli oris 2. Depressor anguli oris
Which muscle makes you laugh?
Which two muscles make you sneer? (Elevate the upper lip)
Levator labii superioris and zygomaticus minor. (Major laughter, minor sneers)
1. What does the mentalis muscle do?
2. What can cause the mentalis to hypertrophy?
1. Closes the lower lip; brings it up and forward. Like..pouting. 2. Type II malocclusion in children.
1. Which is the trumpeter muscle?
2. What is its function?
1. Buccinator 2. Presses cheek against molar teeth, pushes food onto occlusal surface of the teeth and prevents cheek from expanding when forcefully expelling air from the mouth.
1. Bells Palsy is caused by injecting anesthetics into what region?
2. Which muscles does Bells Palsy inactivate?
1. Parotid gland. 2. Orbicular oculi, orbicularis orsi, buccinator, musculature of the lips is weakened.
What muscle lies in the parotid region?
The TMJ acts as what type of joint?
Modified hinge joint
The hinge/rotary movement of the TMJ occurs in the ________ between the _____ and ______. It causes ________ and _________.
1. Inferior articular cavity 2. condyle 3. disc 4. elevation 5. depression
The gliding movement (aka ________) occurs in the _____________ between the upper surface of ____ and the _________ and ____________. It causes __________ and _____________.
1. translation 2. superior articular cavity 3. disc 4. mandibular fossa 5. eminence. 6. protrusion 7. retraction.
Aside from elevation and depression, and protrusion and retraction, what other movement can the TMJ perform?
Side to side aka lateral excursion.
Which nerve innervates the muscles of mastication?
Trigeminal; CN 5
What are the fuctions of temporalis?
1. Elevate the mandible (bilateral contraction) 2. Retracts the mandible (posterior fibers) 3. Ipsilateral lateral excursion
1. What is unique about the Masseter's origin?
2. What is the function of the masseter muscle?
1. It's the only muscle that does NOT originate from the temporal or infratemporal fossa. It's located in the parotid region. 2. Elevates and protracts the mandible. Also has minor action of retrusion and ipsilateral lateral excursion.
1. Which muscle is the mirror image of the masseter?
2. What is its functions?
1. Medial pterygoid 2. Forms sling around mandible; elevates and protrudes mandible and contralateral lateral excursion (pterygoid on the opposite sides are active)
What are the functions of the lateral pterygoid?
Depresses, protrudes and stabilizes the mandible, contralateral lateral excursion
Which muscles elevate the mandible?
: Elevation Masseter Medial Pterygoid Temporalis
EMMPT = "Elevation is empty"
What muscles depress the mandible?
Inferior head of the lateral pterygoid.
What muscles protrude the mandible?
: Protrusion Lateral pterygoid Masseter Medial Pterygoid.
What muscles retrude the mandible?
Temporalis and Masseter.
What muscles aide in lateral excursion of the mandible?
Right lateral excursion: right masseter, right temporalis, left medial and lateral pterygoids.
Muscles switch sides for the left lateral excursion.