Week 1 - Skull, Fascia and Posterior Triangle Flashcards
What are the two points of movement in the skull ?
Temporomandibular joint and atlanto-occpitial joint.
How are flat bones formed and distinguished ?
Intramembranous ossification.
Distinguished by embryological origin.
How are irregular bones formed and distinguished ?
Endochondral ossification. Distinguished by embryological origin.
How are pneumatised bones distinguished ?
Presence of air spaces (air cells or sinuses).
What is the function of pneumatised bones in the skull ?
Reduce weight and add resonance to voice.
What are four examples of pneumatised bones in the skull ?
Frontal.
Temporal.
Sphenoid.
Ethmoid.
What is the difference between neurocranium and viscerocranium ?
Neurocranium - bony case of brain.
Viscerocranium - anterior part of cranium.
What does the neurocranium consist of ?
Cranial meninges.
Calvaria.
Cranial base.
What does the viscerocranium consist of ?
Oral cavity.
Nasal cavity.
Most of orbit.
What bones are separate to the skull ?
Mandible.
Three ossicles of ear.
What are the three ossicles of the ear ?
Malleus.
Incus.
Stapes.
What are the bones of the neurocranium ?
8 bones -
Frontal.
Occipital.
Sphenoid.
Ethmoid.
Parietal (x2).
Temporal (x2).
What are the bones of viscerocranium ?
Ethmoid.
Vomer.
Mandible.
Palatine (x2).
Lacrimal (x2).
Nasal (x2).
Zygomatic (x2).
Inferior nasal concha (x2).
Maxilla (x2).
What does superior and inferior temporal lines do ?
Provide attachment for temporalis and temporal fascia.
What is the superior border of temporal fossa ?
Superior temporal line.
What is the posterior border of temporal fossa ?
Inferior temporal line.
What is the anterior border of temporal fossa ?
Frontal process of zygomatic bone.
Zygomatic process of frontal bone.
What is the inferior border of temporal fossa ?
Infratemporal fossa crest deep to zygomatic arch.
What lies at the floor of temporal fossa ?
Pterion.
Craniometric points - what is the vertex ?
Superior point of neurocranium centred in middle of cranium (if cranium is orientated in Frankfort horizontal plane).
Craniometric points - what is bregma ?
Junction between sagittal and coronal sutures.
Craniometric points - what is lambda ?
Junction between sagittal and lambdoid sutures.
Craniometric points - what is inion ?
Most prominent external protuberance of occipital bone.
Craniometric points - what is asterion ?
Star-shaped junction between occipital, parietal and temporal bones.
Craniometric points - what is nasion ?
Junction between frontonasal and internasal sutures join.
Craniometric points - what is glabella ?
Most prominent hairless protuberance of frontal bone between two brows.
Craniometric points - what is pterion ? And why is it significant ?
Junction between sphenoid, squamous part of temporal, frontal and parietal bones. Structurally weakest part of the skull with significant arteries running in proximity.
What are wormian bones ?
Small islands of bone seen in cranial sutures.
When does frontal suture begin to and finally close ?
Starts at 2 years old.
Complete by 8 years old.
When does mandibular symphysis occur ?
At 2 years old.
What is a metric suture ?
Where frontal suture fails to close.
What is a fontanelle and their function ?
Fibrous membranes which separate cranial bones.
Facilitates cranial growth and aids in child birth.
Name the two clinically relevant fontanelles, their shape and when they close ?
Anterior fontanelle - diamond shaped, 18 months.
Posterior fontanelle - triangular shaped, no longer palpable by 2 years old.
What are the superior and inferior boundaries of the neck ?
Superior - inferior aspect of the mandible and cranial base.
Inferior - clavicle, manubrium, acromion of scapula, C7 (posteriorly).
What are the three compartments of the neck ?
Visceral, vascular, vertebral.
What does the visceral compartment of neck contain ?
Digestive system, respiratory system, trachea, endocrine gland i.e. thyroid and parathyroid gland.
What does the vascular compartment of the neck contain ?
Carotid sheath and contents - vagus nerve, IJV and CCA.
What does the vertebral compartment of the neck contain ?
Cervical vertebrae, spinal cord, muscles and cervical nerves.
What is the function of fascia ?
Containment and protection for muscles/viscera.
Conduit for neuromuscular structures.
Movement for internal structures.
What are the three layers of fascia ?
Investing layer, pre-trachael, pre-vertebral deep fascia.
What does the investing fascia enclose anteriorly ?
SCM, trapezius, parotid and submandibular glands, can include infra-hyoid muscles.
What are the superior attachments of investing fascia ?
Superior nuchal line of occipital bone.
Mastoid processes of temporal bones.
Zygomatic arches.
Inferior border of mandible.
What are the inferior attachments of investing fascia ?
Spine of scapula.
Acromion.
Clavicle.
Manubrium.
What is the anterior attachment of investing fascia ?
Hyoid bone.
What is the posterior attachments of investing fascia ?
Ligamentum nuchae.
Periosteum of C7 spinous process.
What is ligamentum nuchae ?
Fibrous septum between muscles on each side of the neck.
What does pre-tracheal fascia enclose ?
Visceral - trachea, oesophagus, thyroid.
Muscular - infrahyoid muscles.
What vessels pierce the pre-tracheal fascia ?
Thyroid vessels.
What vessels pierce the investing fascia ?
External and anterior jugular veins and cervical plexus.
What does pre-vertebral fascia enclose ?
Vertebral column and pre and post vertebral muscles i.e. scalenes and longus.
What pierces the pre-vertebral fascia ?
Cutaneous branches of cervical plexus.
What is enclosed by the carotid sheath ?
IJV, ICA, CNX.
What are the boundaries of the carotid sheath ?
Aortic arch to jugular foramen.
What nervous structure lies on the surface of the carotid sheath ?
Ansa cervicalis.
What are the boundaries of the posterior triangle ?
Posterior surface of SCM, posterior 1/3 of clavicle and anterior surface of trapezius.
What are the 3 main regions of the posterior triangle ?
Sternocleidomastoid region.
Posterior cervical region.
Lateral cervical region.
How is the lateral cervical region subdivided ?
Occipital and subclavian triangle via inferior belly of omohyoid.
What nerves, muscles and blood vessels are associated with the sternocleidomastoid region of the posterior triangle ?
SCM, great auricular and transverse cervical nerves, superior part of EJV.
What nerves and muscles are associated with the posterior cervical region ?
Trapezius, cutaneous branches of posterior rami of cervical spinal nerves.
What is the origin of the sternocleidomastoid ?
Sternal head - manubrium via rounded tendon.
Clavicular head - superior of middle third of the clavicle.
What is the insertion of the sternocleidomastoid ?
Lateral of mastoid process and superior nuchal line.
What is the motor innervation to the sternocleidomastoid ?
CNXI (accessory cranial nerve).
What is the sensory innervation to the sternocleidomastoid ?
C2 and C3.
What is the action of SCM when functioning bilaterally ?
Extension of the neck and head upwards from AO joint.
What is the action of SCM when functioning unilaterally ?
Flex neck laterally i.e. ear to shoulder.
What is the origin of the trapezius ?
Superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes of C7 to T12.
What is the insertion of the trapezius ?
Lateral third of clavicle, acromion, spine of scapula.
What is the insertion of the trapezius ?
Lateral third of clavicle, acromion, spine of scapula.
What is the innervation of the trapezius ?
CNXI (accessory cranial nerve).
What is the action of the trapezius ?
Movement of scapula.
In relation to the pre-vertebral fascia, where do the muscular and cutaneous branches of the cervical plexus lie ?
Muscular - deep to PV fascia.
Cutaneous - superficial to PV fascia.
What are the two key muscular branches of the cervical plexus ?
Phrenic nerve - C3, C4, C5.
Ansa cervicalis - C1, C2, C3.
What are the four key cutaneous branches of the cervical plexus ?
Lesser occipital - C2.
Great auricular - C2 and C3.
Transverse cervical - C2 and C3.
Supraclavicular nerves - C3 and C4.
What does ansa cervicalis supply ?
Pre-vertebral and vertebral muscles i.e. anterior, middle and posterior scalenes and infrahyoid muscles (with exception of thyrohyoid - innervated by independent branches of C2).
What does the external jugular vein drain into ?
Subclavian vein.
What is the function of the anterior jugular vein ? And where does it drain into ?
Drain anterior neck.
Drains into EJV then subclavian.
What 4 blood vessels are associated with the posterior triangle ?
EJV, AJV, IJV and transverse cervical artery.
What main blood vessel runs deep to SCM ?
IJV.
What 3 structures cross the sternocleidomastoid ?
EJV, greater auricular nerve, transverse cervical nerve.
What does the greater auricular nerve innervate ?
Cutaneous - skin over parotid, mastoid process, temporal bone and auricle of the ear.
What does the transverse cervical nerve innervate ?
Cutaneous - anterolateral neck (chin to sternal notch and clavicle).
What is the function of the brachial plexus ?
Motor and sensory supply to upper limb.
Where is the brachial plexus located ?
Between anterior and middle scalene beneath the clavicle - runs with subclavian artery.
The brachial plexus is associated with what spinal nerves ?
Ventral rami of C5-T1.
