Unit 5: Lecture 1 (Part 1: Cranium & Scalp)

Neurocranium (braincase)

What encloses the brain and forms the cranial vault and base?

Calvaria (skullcap) and basicranium (cranial base)

What are the two components of the neurocranium (braincase)?

Calvaria (skullcap)

What part of the neurocranium (braincase) is comprised of the frontal, parietal, and parts of the occipital bones?

Basicrainium (cranial base)

What part of the neurocranium (braincase) includes the sphenoid, ethmoid, parts of the occipital, and temporal bones?

Neurocranium (braincase) and viscerocranium (facial skeleton)

What are the two principal components of the skull?

Viscerocranium (facial skeleton)

What forms the anterior portion of the skull and supports the face?

True

(T/F) Although the sphenoid and ethmoid are primarily considered neurocranial bones, they also contribute to the facial skeleton.

Frontal, parietal, temporal, occipital, sphenoid, and ethmoid

What 8 bones make up the neurocranium?

Mandible, vomer, maxillae, zygomatics, nasals, lacrimals, inferior nasal conchae, palatines

What 15 bones make up the viscerocranial bones?

Suture

What is a fibrous joint between skull bones that ossify with age?

Coronal suture

What suture is formed between the frontal and parietal bones?

Sagittal suture

What suture is found between the two parietal bones?

Lambdoid suture

What suture is found between the parietals and occipital bones?

Squamosal suture

What suture is formed between the parietal and temporal bones?

Fontanelle

What is a fibrous membrane-filled gap between the bones of the skull in an infant where the sutures intersect?

Fontanelles

What are the soft spots that allow for flexibility of the skull during birth (to pass through the birth canal) and postnatal brain growth in the first years of life?

Anterior (frontal)

What fontanelle closes around 18 months of age?

Posterior (occipital)

What fontanelle closes around 2 months of age?

Sphenoidal (anterolateral)

What fontanelle closes around 6 months of age?

Mastoid (posterolateral)

What fontanelle closes around 6-18 months of age?

Temporomandibular joint (TMJ)

What is the synovial modified hinge joint between mandibular condyle and mandibular fossa of temporal bone?

Elevation, depression, protrusion, retrusion, and lateral deviationWhat

What movements occur at the temporomandibular joint?

Frontal, maxillary, and sphenoidal sinuses and ethmoidal air cells.

What are the four paranasal sinuses?

Frontal sinus

What paranasal sinus is in the frontal bone; variable in size?

Maxillary sinus

What paranasal sinus is the largest; drains superiorly into the middle meatus?

Ethmoidal air cells

What paranasal sinus is between nasal cavity and orbit?

Sphenoidal sinus

What paranasal sinus is deep, near the sella turcica?

Paranasal sinuses

What are air-filled spaces that lighten the skull and enhance voice resonance?

Anterior cranial fossa

What cranial fossa houses the frontal lobes?

Middle cranial fossa

What cranial fossa contains temporal lobes and features the sella turcica?

Posterior cranial fossa

What cranial fossa accommodates the cerebellum and brainstem?

32

How many teeth do adults have?

Incisors, canines, premolars, molars

What are the 4 classifications of teeth?

Enamel

What part of the tooth is the hardest tissue that covers the crown?

Dentin

What part of the tooth supports enamel?

Cementum

What part of the tooth covers the root?

Pulp cavity

What part of the tooth contains nerves and vessels

Deciduous teeth (20)

What type of teeth begin erupting ~6 months and are replaced by permanent teeth between ages 6-12?

Craniosynostosis

What refers to the premature fusion of one or more cranial sutures, altering normal skull growth patterns and potentially impacting brain development?

Sagittal synostosis (scaphocephaly)

What type of craniocynostosis is the most common; elongated skull anteroposteriorly?

Coronal synostosis (anterior plagiocephaly)

What type of craniocynostosis can be unilateral or bilateral; results in flattened forehead and brow?

Metopic synostosis (trigonocephaly)

What type of craniocynostosis is a triangular-shaped forehead due to premature closure of the metopic suture?

Lambdoid synostosis (posterior plagiocephaly)

What type of craniocynostosis least common;

asymmetry in the occipital region?

Multifactorial — genetic syndromes (e.g., Apert, Crouzon),

intrauterine constraints, or idiopathic.

What are the causes of craniosynostosis?

Some patients remain asymptomatic, while others may experience increased intracranial pressure, developmental delays, seizures, or optic nerve compression.

What are the potential complications with craniosynostosis?

Cleft lip and cleft palate

What are congenital deformities caused by incomplete fusion of embryonic facial structures during weeks 6-12 of gestation?

Cleft lip

What results from failed fusion of the maxillary and medial nasal processes and can be unilateral or bilateral?

Cleft palate

What is caused by failure of palatal shelves to fuse and may involve only the soft palate, or both soft and hard palate?

Feeding difficulties, speech delay, recurrent otitis media, and dental issues.

What are the common complications with cleft lip and cleft palate?

Torus palatinus and torus mandibularis

What are benign bony exostoses (growths) occurring along the midline of the hard palate and the lingual aspect of the mandible?

Skin, connective tissue, aponeurosis, loose areolar connective tissue, pericranium

What are the layers of the scalp?

Skin

What layer of the scalp contains hair follicles, sebaceous and sweat glands and is well-vascularized and innervated?

25%

How large is a baby brain compared to the adult brain?

True

(T/F) In the first 6 months of life, the brain doubles in size.

Connective tissue (dense)

What layer of the scalp is richly vascularized and innervated and anchors vessels and nerves?

Aponeurosis (epicranial aponeurosis or galea aponeurotica)

What layer of the scalp is a tough fibrous sheet connecting the frontalis and occipitalis muscles (collectively called the occipitofrontalis muscle)?

Loose areolar connective tissue

What layer of the scalp allows movement of the scalp proper (layers 1-3) over the calvaria? This is the "danger area" due to potential spread of infections into cranial cavity via emissary veins.

Pericranium

What layer of the scalp is comprised of periosteum of the calvarial bones; firmly attached but removable during surgical dissection?

SCALP

What is the mnemonic to remember the layers of the scalp?

Supratrochlear and supraorbial arteries

What arteries from the internal carotid artery via the ophthalmic artery supply the scalp?

Superficial temporal, posterior auricular, and occipital arteries

What arteries from the external carotid artery supplies the scalp?

Dense connective tissue layer (2nd layer of the scalp)

What binds the vessels supplying the scalp, making scalp lacerations prone to profuse bleeding due to retraction resistance?

Supratrochlear, supraorbital, zygomaticotemporal, and auriculotemporal nerves

What branches of the trigeminal nerve (CN V) supplies the anterior and lateral scalp?

Trigeminal nerve (CN V)

Branches of what nerve innervates the anterior and lateral scalp?

Greater and lesser occipital nerves

What nerves innervate the posterior scalp?

Greater or lesser occipital nerves

Tension headaches and occipital neuralgia may involve entrapment or irritation of what nerves? These can refer pain to the upper neck, scalp, and behind the eyes.

Pterion

What is the H-shaped suture where 4 different bones come together?

Females

Is cleft palate more common in males or females?

Males

Is cleft lip more common in males or females?

Pterion

What landmark of the skull is very weak and prone to fracturing?

6 months to 3 years

Around what age should baby teeth come in?

12-13

Around what age should permanent teeth all be in by?

False

(T/F) Because teeth are ossified tissue, they are considered bone.

Fibrous

What type of joint is tooth and socket?