Gross Anatomy of the head and neck Flashcards
Talk about the head!
The head is the superior part of the body that is attached to the trunk by the neck. It is composed of the brain, the skull, the ears and the face.
The cranium is the skeleton of the head, and it is divided into 2, talk about these 2 parts
The cranium is divided into
1. Neurocranium: is the bony covering of the brain and itβs membranous coverings, the meninges, proximal parts of the cranial nerve & vasculature of the brain.
The Neurocranium consists of : A dome-like roof called the calvaria(skull-cap), and a floor (Basicranium)
- Viscerocranium: which comprises the facial bones, and forms anterior part of the cranium.
What bones form the neurocranium?
The neurocranium in adults is formed by 8 bones (from these 8 bones, 4 are singular bones, then 2 occur as bilateral pairs (i.e 2Γ2=4).
What are the 4 singular bones that make up the neurocranium?
- Frontal
- Ethmoidal
- Sphenoidal
- Occipital
What are the 2 bilaterally occurring pairs;
- Temporal bones
- Parietal bones
The Viscerocranium consists of how many bones?
15 irregular bones
Of the 15 irregular bones of the Viscerocranium, 3 are singular. Can you name them?
- Mandible
- Ethmoid
- Vomer
Of the 15 irregular bones of the Viscerocranium, 6 are bilaterally occurring pairs. Can you name them?
- The Maxillae
- Zygomatic
- Inferior nasal conchae
- Palatine
- Nasal
- Lacrimal bones
List the bones In the anterior aspect of the cranium?
- Frontal bone
- Zygomatic bone
- Orbits
- Nasal region
- Maxillae
- Mandible
Talk about the frontal bone?
The frontal is a squamous part that forms the fore Head. It articulates inferiorly with the nasal & zygomatic bones.
The supra orbital foramen is located on what bone and what is itβs use?
The supra orbital foramen is a passage for supra orbital vessels and nerves.
It is located on the frontal bone
What is the Glabella?
It is a slightly depressed area located between the superciliary arches
Three intersection of the frontal & nasal bones is called?
Nasion
Talk about the nasal region?
The nasal region is formed by a pair of nasal bones joined at the midline by the nasal septum
The frontal bone articulates with the paired parietal bones at ?
Coronal suture
The 2 parietal bones articulate with each other at?
Sagittal suture
The paired parietal bones articulate with the occipital bones at?
Lambdoid suture
The junction between the coronal suture and Sagittal suture is called?
Bregma
The junction between the Sagittal suture and lambdoid suture is called?
Lamda
Where is the obelion?
The Obelion is the region of the skull between the 2 parietal foramina where the closure of the Sagittal suture usually begins
What is malar flush
Malaria flush refers to the redness of the skin covering the zygomatic prominence.
Talk about the obliteration of cranial sutures
Obliteration of the cranial sutures between the bones of the calvaria usually begins between the age of 30-40 on the external surface of the cranium.
Obliteration begins at the Bregma, then continues to the Sagittal, coronal and lambdoid sutures.
Can you mention features of the skull a new born baby?
- No mastoid process at birth
- No styloid process
- The bones of the calvaria are separated by membranous intervals called fontanelles
There are 4 fontanelles in newborns (neonates), name them?
- Anterior fontanelle
- Posterior fontanelle
- Paired sphenoidal fontanelle
- Paired mastoid fontanelle
The premature closure of the cranial sutures is called?
Craniosynostosis.
Where is the Pterion?
The pterion is the junction where the frontal, parietal, sphenoid (greater wing) & temporal bones meet.
It is usually indicated by a H-shaped suture formation.
What are the parts of the temporal bone?
- A squamous part (which articulates with the greater wing of sphenoid).
- A zygomatic process (which articulates with zygomatic bone to form zygomatic arch)
- A tympanic part which has the acoustic meatus.
- A petrous part of the temporal bone called the Mastoid process.
The internal surface of the calvarium has 3 large depressions, name them?
- Anterior cranial fossa
- Middle cranial fossa
- Posterior cranial fossa
What part of the brain lodges in the anterior cranial fossa?
The frontal lobes of the cerebral hemispheres.
What part of the brain lodges in the middle cranial fossa?
In the lateral portion: Temporal lobe
In the midline: pituitary gland.
What part of the brain lodges in the posterior cranial fossa?
The brainstem and cerebellar hemispheres
What are the 3 bones that form the anterior cranial fossa?
- Frontal bone (orbital surface)
- Ethmoid bone
- 2 parts of the sphenoid bone
The ethmoid bone of the anterior cranial fossa consist of?
- Crista Valli
- Cribriform plate
What bones form the middle cranial fossa?
The sphenoid and parts of the temporal bone
What is the function of foramen rotundum?
Foramen rotundum allows for passage of the maxillary division of the trigeminal nerve
What is the function of foramen ovale?
Foramen ovale allows for passage of the mandibular division of the trigeminal nerve
What is the function of foramen spinosum?
Foramen spinosum allows for passage of the middle meningeal artery and meningeal branch of mandibular nerve
What is the function of foramen magnum?
Foramen magnum allows for passage of the spinal cord to continue with medulla oblongata, and
2 vertebral arteries
What is the function of the muscles of facial expression?
The primary role of the facial muscles is to regulate the facial orifices(orbits, nostrils, mouth and ear)
All facial muscles have embryological prison
They develop from the second pharyngeal arch
The scalp consist of 5 layers, name them?
Skin
Connective tissue
Aponeurosis
Loose connective tissue
Periosteum
The simple acronym to remember it is: SCALP
The arterial supply to the scalp is by?
- Ophthalmic artery
- External carotid artery
The veinous drainage of the scalp is by
- Superficial venous drainage
- Deep venous drainage is by pterygoid venous plexus
Innervation to the scalp is by?
- Trigeminal nerve
- Cervical nerve root
The facial nerves divides to give what branches?
- Posterior auricular
- Temporal
- Zygomatic
- Buccal
- Marginal mandibular
- Cervical
Write on foramen magnum?
Foramen magnum is located at the base of the skull in the occipital bone. It contains passage for spinal cord as it exits the cranial cavity to enter the vertebral canal.
It allows for passage of meninges, vertebral arteries, and spinal accessory nerves.
What is a foramina?
A Foramina is an opening in the skull that allows the passage of nerves, blood vessels and other structures.
Examples of foramina include;
1. Foramen magnum
2. Optic canal
3. Superior orbital fissure
4. Foramen ovale
5. Foramen rotundum
6. Foramen spinosum
Talk about the optic canal
The optic canal is located in the lesser wing of the sphenoid bone, near the apex of the orbit.
It allows passage of the optic nerve and ophthalmic artery.
Talk about the superior orbital fissure
The superior orbital fissure is located between the greater and lesser wings of the sphenoid bone. It allows passage of Occulomotor nerve, , trigeminal nerve, Abducens, and ophthalmic veins
Talk about Foramen ovale
Foramen ovale is located in the greater wing of the sphenoid bone, posterior and lateral to the superior orbital fissure.
It allows passage for maxillary division of the trigeminal nerve, occulomotor nerve, accessory meningeal artery and emissary veins.
Talk about Foramen rotundum
Foramen rotundum is located in the greater wing of the sphenoid bone, anterior and medial to the Foramen ovale.
It allows for passage for the maxillary division of the trigeminal nerve
Talk about Foramen spinosum
Foramen spinosum is located in the greater wing of the sphenoid bone, posterolateral to the Foramen rotundum. It allows for passage of the middle meningeal artery.
Explain the internal acoustic meatus?
It is located on the petrous part of the temporal bone.
It allows passage for facial nerve, vestibulocochlear nerve, labyrinthine artery.
Talk about the jugular Foramen?
The jugular Foramen is located between the petrous part of the temporal bone and the occipital bone.
It allows the passage of the Glossopharyngeal nerve, vagus nerve, accessory nerve, jugular vein, meningeal branches of the ascending pharyngeal artery.
Mention and explain the articulations in head and neck anatomy?
- Temporomandibular joint: is located bilaterally between the mandible and the temporal bone of the skull. It consist of the mandibular condyle, which articulates with the mandibular fossa of the temporal bone, and the articular tubercle and articular eminence.
- Atlantic occipital joint: is located between the occipital bone of the skull and the Atlas of the cervical spine it consist of the occipital condyles of the skull articulating with the superior facets of the Atlas.
- Atlanto-Axial joint: is located between the Atlas and axis of the cervical spine. It consist of the anterior and posterior arched of the Atlas articulating with the odontoid process of the axis.
What is the function of the Temporomandibular joint
The TMJ allows for opening and closing the mouth as well as movements such as chewing and speaking
What is the function of the of the Atlanto-occipital
The Atlantic occipital joint allows for nodding movements of the head such as flexion and extension
What is the function of Atlanto-Axial joint?
The Atlanto-Axial joint allows for rotational movements of the head, such as shaking side to side and rotation.
The muscles of facial expression are responsible for producing various facial expressions such as smiling, frowning, and squinting?
- Orbicularis occuli
- Orbicularis oris
- Buccinator
- Zygomaticus major/minor
- Frontalis
The muscles of mastication are involved in cheering and movements of the mandible. Name them?
- Masseter
- Medial pterygoid
- Lateral pterygoid
- Temporalis
The muscles of the pharynx are the muscles involved in swallowing and vocalization. Name them?
- Stylopharyngeus
- Palatopharyngeus
The muscles of the tongue is composed of intrinsic and extrinsic muscles that control itβs movement and shape?
The muscles include;
1. Genioglossus
2. Palatoglossus
3. Hyoglossus
4. Styloglossus
And the intrinsic muscles of the tongue
The muscles of the larynx are responsible for vocalization and maintaining airway patency. Name them?
- Cricothyroid
- Thyroarytenoid
- Posterior cricoarytenoid
- Stylopharyngeus
- Thyrohyoid
What is the origin and insertion for the masseter muscle?
Originates from zygomatic arch
Inserts in coronoid process of mandibular ramus and angle
What is the origin and insertion for the temporalis muscle?
Originates from temporal fossa
Inserts in the coronoid process of the mandible.
What is the origin and insertion for the medial pterygoid muscle?
Originates from medial surface of lateral pterygoid and maxillary tuberosity.
Inserts in medial surface of mandibular ramus and angle.
What is the origin and insertion for the lateral pterygoid muscle?
Originates from greater wing of sphenoid and lateral pterygoid plate
Inserts in articular disc and neck of mandible.
Mention the 4 major arteries supplying has and neck, name them?
- Common carotid artery
- Internal carotid artery
- Vertebral artery
- Branches of subclavian artery
List the 12 cranial nerves?
- Olfactory nerve
- Optic nerve
- Occulomotor nerve
- Trochlear nerve
- Trigeminal nerve
- Abducens nerve
- Facial nerve
- Vestibulocochlear nerve
- Glossopharyngeal nerve
- Vagus nerve
- Accessory nerve
- Hypoglossal nerve
Talk about the common carotid artery
The common carotid artery originates from the brachiocephalic trunk on the right side and directly from the aortic arch on the left side.
It ascends and bifurcates into the internal and external carotid artery at the level of the superior border of the thyroid cartilage.
Talk about the external carotid artery?
Originates from the bifurcation of the common carotid artery.
It runs superiorly and anteriorly giving of several branches that supply the superficial structures of the face, scalp, muscles of mastication and neck
Talk about the internal carotid artery?
Originates from the bifurcation of the common carotid artery.
It ascends through the neck, enters the cranial cavity through cranial canal and supplies blood to the brain, orbit
Talk about the vertebral artery?
The vertebral artery arises from the subclavian artery.
It supplies blood to the brainstem , cerebellum, and posterior parts of the brain.
Mention the major branches of the external carotid artery?
- Superficial artery
- Ascending pharyngeal artery
- Lingual artery
- Facial artery
- Occipital artery
- Maxillary artery
- Superficial temporal artery
Mnemonic: Some Anatomist Like Freaking Out Medical Students
What veins drain the head and neck?
The internal and external jugular vein
What are the lymphatic drainages?
- Superficial lymph node
- Submental lymph node
- Preauricular lymph node
- Cervical lymph node
What is the thoracic duct?
The Thoracic duct is the largest lymphatic vessel in the body. It drains lymph from the entire body below the diaphragm, the left side of the head and neck, left upper limb and left thorax.
List the organs and structures of the neck?
- Thyroid gland
- Parathyroid glands
- Lymph node
- Carotid arteries
- Jugular vein
- Trachea and esophagus
What are the compartments of the neck
- Anterior triangle: is formed by the anterior border of the sternocleidomastoid, the midline of neck, indoor border of the mandible.
- Posterior triangle: is formed by the posterior border of the sternocleidomastoid, anterior border of trapezius muscle and middle third of the clavicle.
What are the subdivisions of the anterior triangle?
- Submandibular triangle
- Submental triangle
- Carotid triangle
- Muscular triangle
What are the boundaries and contents of the submandibular triangle?
The submandibular triangle is formed by the anterior and posterior bellies of the digastric muscle, inferior border of mandible.
The contents are;
1. Submandibular gland
2. Lymph nodes
3. Facial artery and vein
What are the boundaries and contents of the submental triangle?
Formed by anterior bellies of the digastrtic muscles, hyoid bone.
The contents are
1. Lymph node
2. Branches of facial artery
What are the boundaries and contents of the carotid triangle?
Formed by anterior border of the sternocleidomastoid, posterior belly of digastric muscle, hyoid bone.
The contents are:
1. Carotid artery
2. Internal jugular vein
3. Vagus nerve
4. Hypoglossal nerve
The posterior triangle is sub divided into?
- Occipital triangle
- Subclavian triangle
What are the boundaries and contents of the muscular triangle
It is formed by anterior border of sternocleidomastoid muscle, superior belly of omohyoid muscle, and midline of the neck.
The contents are:
1. Infrahyoid muscle (strap muscles)
2. Thyroid gland
3. Parathyroid gland
4. Arteries of thyroid and parathyroid gland.
What are the boundaries and contents of the occipital triangle?
It is formed by the posterior border of the sternocleidomastoid, superior border of trapezius muscle and inferior border of the occipital bone.
Contents are;
1. Sub occipital muscles
2.vertebral artery
3. Sub occipital nerve
4. Greater occipital nerve
What are the infra hyoid (strap muscles)?
the sternohyoid, the sternothyroid, the omohyoid, and the thyrohyoid.
What are the suprahyoid muscles?
geniohyoid, mylohyoid, stylohyoid, hyoglossus, and the anterior belly of the digastric muscle
List some clinical applications of head and neck anatomy?
- Tonsillectomy
- Thyroidectomy
- Facial nerve palsy
- Temporomandibular joint disorders