Lecture 17: Neck 1 Flashcards
2 boundaries of the neck
-thoracic inlet
-skull
thoracic inlet definition
space bounded by 1st ribs, sternum (1st sternabrae) and T1 vertebrae
what is the primary passageway for structures between neck and thorax
thoracic inlet
vertebral column and axial musculature attach to __________
occipital bone of caudal skull
caudal most portion of the skull (hint: bump)
external occipital protuberance
ridge on skull resulting from neck muscle attachment
nuchal crest
hypoglossal canal: definition, what structure passes through
hole in occipital bone
hypoglossal nerve runs through
jugular foramen: location, what goes through
between occipital and temporal bones
conveys jugular artery and vein
hyoid apparatus: definition, what 3 structures are supported by apparatus
series of bones running from temporal bones of skull into neck and supporting the tongue, larynx and pharynx
is the hyoid apparatus associated with vertebral musculature
no
laryngeal cartilages
set of cartilages at cranial end of airway (before joining pharynx)
C1 aka
atlas
C2 aka
axis
which cervical vertebrae has the largest transverse processes
atlas/C1
which cervical vertebrae has articular facets for occipital condyles
atlas/C1
what is the palpable landmark for atlas/C1
wings
what is the palpable landmark for axis/C2
spinous process
does atlas really have spinous processes
no
why can’t the spine of axis be palpated in horses and ruminants
ligamentum nuchae is very cranial
fatty crest present in horses
what can be used as reliable substitute for body composition/indicator of metabolic health issues in horses
size and shape of fatty crest
3 components/bones of hyoid apparatus
stylohyoid
basihyoid
thyrohyoid
stylohyoid: location, paired vs unpaired
most dorsal
articulates with temporal bone of skull next to mastoid process via the tympanohyoid cartilage
paired
basihyoid: paired vs unpaired, definition
unpaired bone anchored in musculature of the base of the tongue
what helps support the weight of the tongue in horses and ruminants
lingual process that is cranially directed
thyrohyoid: paired vs unpaired, definition
articulates with thyroid cartilage
attaches to larynx
paired
epaxial muscles of vertebral column attachment site
occipital bone
3 epaxial muscles of vertebral column
spinalis cervicis
semispinalis
longissimus
what is an epaxial muscle that is unique to the head and neck
splenius
splenius: OINA
O: T1-T3 spines
I - nuchal crest and mastoid
N - dorsal rami
A - extend head and neck, some lateral bending
what are the 2 most ventral/hypaxial cervical vertebral muscles
longus
scalenus
does spinalis have a capitis portion
no
scalenus is a group of how many muscles
3
long muscle of the neck =
longus colli/longus cervicis
location of longus colli/longus cervicis
along cranial thoracic vertebral bodies and cervical bodies and transverse processes
what are the 2 longus muscles
capitis
cervicis/colli
location of longus capitis
lateral to longus colli/cervicis from transverse processes of cervical vertebrae to ventral part of skull
location of scalenus muscles
from caudal cervical vertebrae to cranial ribs
6 capitis muscles that are specific to fine control of atlantoaxial (C1-C2) and atlantooccipital (C1-occipital bone) joints
rectus capitis dorsalis major
rectus capitis dorsalis minor
rectus capitis lateralis
rectus capitis ventralis
obliquus capitis cranialis
obliquus capitis caudalis
rectus capitis dorsalis major vs minor attachment
major: C2 to skull
minor: C1 to skull
of the 4 rectus muscles of vertebral column, which 2 are epaxial
rectus capitis dorsalis major and minor
obliquus capitis cranialis vs caudalis: attachment
cranialis: axis/c1 –> occipital bone
caudalis: atalas/C2 –> occipital bone
3 fascia compartments of the neck
carotid sheath
pretracheal fascia
prevertebral fascia
of the 3 fascia compartments of the neck, which one is a possible route of infection
prevertebral fascia
carotid sheath: 3 structures contained
common carotid artery
internal jugular vein
vagosympathetic trunk
pretracheal fascia contains (6)
muscles and viscera of ventral neck = esophagus, thyroid, omohyoideus, sternohyoid, larynx, brachiocephalicus
prevertebral fascia: structures
all muscles associated with vertebral column (rectus capitis muscles, longus colli, etc)
what happens to prevertebral fascia as ventral vertebral muscles (longus colli) pass into the thorax
blends with endothoracic fascia
2 primary cutaneous muscles that cover the neck
cutaneous colli
platysma
cutaneous colli definition
cervical portion of general cutaneous muscle
platysma definition, origin and insertion
muscle of facial expression
originates in neck and passes cranially to reach the head
cutaneous colli level of development: dogs/cats vs ungulates
not well developed in dogs or cats
well developed in ungulates
what does cutaneous colli form in horses (and why is this clinically important)
thick cover over caudal part of jugular groove
covers jugular vein so you have to stick higher up
what is the most ventral of the non cutaneous neck muscles
sternocephalicus
sternocephalicus: location(relative to another muscle), OINA
takes up position along ventral edge of brachiocephalicus
O: 1st sternabrae (manubrium)
I: mastoid and nuchal crest
N: CNXI/accessory nerve
A: unilateral lateral flexion of neck, bilateral ventral flexion of neck
unique role of sternocephalicus in other animals (related to different insertion)
inserts on mandible to help open the jaw
cranial group of muscles that control position of hyoid apparatus (3 general locations)
muscles of oral cavity, tongue and pharynx
4 muscles within caudal group that control position of hyoid
sternohyoideus
omohyoideus
sternothyroideus
thyrohyoideus
which of the 4 caudal muscles that control hyoid is NOT present in dogs and cats
omohyoideus
