sub occipital region Flashcards
which 2 nerves supply cutaneous sensory innervation to the skin of the suboccipital region?
the greater and lesser occipital nerves
what are the muscles in the superficial suboccipital region?
trapezius
part of levator scapulae
the proximal part of SCM
what are the muscles of the intermediate layer of the suboccipital region?
splenius capitis and splenius cervicis
where does splenius capitis run from / to?
for the nuchal ligament and C3-C7 spinous process to the occipital bone
where does splenius crevicis run from / to?
from T3-T6 sopinous processes to C1-C2 transverse processes
what is the innervation of splenius capitis and splenius cervicis?
both innervated by the posterior rami of C1-C6
what are the functions of splenius capitis and splenius cervicis?
bilateral = extend the head and neck
unilateral = flex and rotate to the same side
what muscle group lies beneath splenius capitis and splenius cervicis?
erector spinae
what are the 4 muscles that attach to the mastoid process?
SCM
the posterior belly of digastric
splenius capitis
longissimus capitis
where do the suboccipital muscles lie?
deep between C1-C2 and the occipital bone
what is the collective function of the suboccipital muscles?
extend the head (tilt it backwards)
what nerve innervates the suboccipital muscles?
the suboccipital nerve (one on either side)
where does the suboccipital nerve originate from?
the posterior ramus of C1
what are the muscles of the suboccipital region?
rectus capitis posterior major
rectus capitis posterior minor
obliquus capitis inferior
obliquus capitis superior
where does rectus capitis posterior major attach?
to C2 spinous process inferior to the nuchal line
where does rectus capitis posterior minor attach?
to C1 posterior tubercle inferior to the nuchal line
where to the obliquus capitis muscles lie in relation to the rectus capitis muscles?
the sit lateral to the rectus capitis muscles
which of the obliquus capitis muscles are larger?
obliquus capitis inferior
where does obliquus capiits inferior pass between?
C1 and C2
where in reaction to obliquus capiits inferior does obliquus capitis superior lie?
more laterally
what is the function of both of the obliquus capitis muscles?
both of them: extends the head
one of them: rotates the head to the same side
what nerve innervates obliquus capiits muscles?
the suboccipital nerve (posterior rami of C1)
why is the there no C1 dermatome?
because the suboccipital nerve (C1) has only motor fibres
what is the innervation to the skin and muscles of the neck?
the dorsal ramus of C3
what is the arterial supply to the suboccipital region?
supplied by the suboccipital artery
which 2 arteries form the subclavian artery?
the descending branch from the suboccipital artery and the deep cervical artery
where do the vertebral arteries lie?
in the suboccipital triangle bound by both obliquus caopitis muscles and rectus capitis posterior major
where do the vertebral arteries arise from?
the subclavian artery
how is the basilar artery formed?
the two vertebral arteries (one from either side) unite to form the basilar artery
what is the course of the vertebral arteries?
the ascend the neck and then enter the cranial cavity through the foramen magnum
where does the basilar artery supply?
it contributes to the posterior part of the circle of wills that supplies the brain
explain the venous drainage of the suboccipital region
the occipital veins drain the suboccipital region into the deep cervical vein
which 2 veins do the deep cervical veins communicate w/?
the vertebral veins and the brachiocephalic vein
what structure does the occipital vein run w/?
the suboccipital nerve
what is the posterior vertebral venous plexus?
many small veins communicating w/ each other
what vein does the posterior vertebral venous plexus join and how does it do this?
it joins the brachiocephalic vein via the deep cervical vein
what are the 2 movements that occur are the base of the head and the top of the cervical region?
head shaking
head nodding
describe how head nodding occurs
occurs between the atlas (C1) and the occipital condyles of the skull
describe how head sharking occurs
rotation between the arch of the atlas (C1) and the dens of the axis (C2)
what are the ligaments that stabilise the head on C1 and support the atlantoaxial joint?
the cruciate ligament
the alar ligament
the anterior and posterior longitudinal ligaments
what is the cruciate ligament?
the transverse ligament of the atlas combined w/ superior and inferior longitudinal bands that collectively form a cross shape between the axis and the occipital bone
where does the alar ligament pass from / to?
from the dens of the axis to the medial sides of the occipital condyles
where does the anterior longitudinal ligament attach to?
the occipital bone
where does the posterior longitudinal ligament attach to?
the posterior longitudinal ligament becomes the tectorial membrane that also attaches to the occipital bone
what are the 3 movements possible between the atlas (C1) and the occipital coondyles at the base of the skull?
flexion
extension
lateral flexion
what is the one movement that is possible between the atlas and axis?
movement from left to right
why is C1 (atlas) not a typical vertebrae?
because it does not have a vertebral body (has an anterior arch instead) and does not have spinous process (has lateral masses instead)
why is C2 (axis) not a typical vertebrae?
because it has a bony projection called the dens / odontoid process that articulates w/ the atlas and also has large spinous process
why is C7 (vertebrae prominens) not a typical vertebrae?
because it has a large monofid spinous process
what are the 4 movements of the cervical spine?
flexion
extension
lateral bending
rotation
