4.1 Flashcards
Label surface anatomy neck muscles
Bones of the neck
C1-C7
Hyoid
Manubrium
Clavicles
C1 is just inferior to the mastoid process.
The 1st rib traverses the neck region.
Superficial Cervical Fascia
Includes the platysma
Contains arteries, nerves, veins, and adipose tissue
Deep Cervical Fascia
Investing (red)
- deep to subcutaneous skin layer
- surround the entire neck
Pretracheal (blue)
- anterior hyoid –> inferior
- muscular and visceral
Carotid sheath (green)
- communicates with cranium and mediastinum
Prevertebral (orange)
- vertebral column
* retropharyngeal space just anterior
Boundaries of the anterior triangle
Anterior: median line of the neck
Posterior: anterior border of sternocleidomastoid
Superior: inferior border of mandible
Inferior: superior sternum
Roof: platysma
Floor: pharynx, larynx, thyroid gland
Contents of anterior triangle
Hyoid bone
- forms superior border of larynx
- located at C3
- important for pharynx and larynx movements
4 suprahyoid mm
- mylohyoid
- geniohyoid
- stylohyoid
- digastric
4 infrahyoid mm
- sternohyoid
- omohyoid
- thyrohyoid
- sternothyroid
Arteries
- common carotid bifurcates
- carotid sinus contains carotid body; a chemoreceptor for O2
Veins
- internal jugular that empties into subclavian
Nerves
- CN XII enters tongue
- CN IX (glossopharyngeal)
- CN X (vagus)
Lateral triangle boundaries
Anterior: posterior border of sternocleidomastoid
Posterior: anterior border of trapezius
Superior: merging of sternocleidomastoid and trapezius
Inferior: clavicle
Roof: platysma
Floor: muscles covered by prevertebral layer
Contents of lateral triangle
Floor overlies deep mm of the neck
Arteries
- thyrocervical trunk and branches
- subclavian artery traveling to arm
Veins
- external jugular
Nerves
- CN XI, spinal accessory to trapezius (motor)
- multiple sensory nerves
- Erb’s point
- ansa cervicalis (cervical plexus)
* nerve loop formed from C1-C3
* motor innnervation to neck muscles
Prevertebral muscles
Lie directly posterior to retropharyngeal space on anterior surface of vertebrae
Anterior mm:
- rectus capitis
- longus capitis
- longus coli
Lateral mm:
- scalene mm
- anatomical variation - an extra rib can be found at C7 and can predispose thoracic outlet syndrome
Root of the neck
Junction between neck, thorax, and upper limb
Inferior boundary: superior thoracic aperture
- manubrium, T1, 1st rib
Contents of the root of the neck
Prevertebral muscles
Phrenic, vagus, and recurrent layngeal nn.
Brachial plexus
Sympathetic trunk
Carotid sheath and contents
Subclavian vessels and branches
Apex of lungs
Trachea/ esophagus
Outlet syndrome
Group of entrapment syndromes of the brachial plexus and/or axillary artery and vein as they pass from trunk to axilla
Common sites:
* interscalene triangle - between anterior and middle scalene mm
* costoclavicular space - between 1st rib and clavicle
* intrapectoral space - under pectoralis minor tendon and coracoid process
Viscera of the neck (3 layers)
Organized into 3 layers from anterior to posterior:
1. endocrine layer - thyroid and parathyroid glands
- hormone producing layer
2. respiratory layer - larynx and trachea
3. alimentary layer - pharynx and esophagus
Viscera of the neck: superficial to deep
Laryngeal prominence: thyroid cartilage
- thyroid gland overlies the trachea
Trachea
Esophagus
Label the regions of the thorax
Bones of the anterior chest wall
Sternum
- manubrium
- body
- xiphoid process
12 pairs of ribs
- true (vertebrocostal) ribs (1-7)
- false (vertebrochondral) ribs (8-10)
- floating ribs (11-12)
12 thoracic vertebrae
Costal cartilages
Intercostal spaces
Superior thoracic aperture
Bound by T1, rib 1, and manubrium
Thoracic outlet syndrome
Inferior thoracic aperture
Bound by T12 and ribs 11-12
Anterolaterally: cartilage of ribs 7-10
- xiphisternal joint
- diaphragm
Label the parts of the rib
Label the joints of the rib
What are the cavities of the trunk?
Thoracic and abdominopelvic
Pleural cavity
Contains multiple cavities lined with connective tissue which forms separate compartments.
Serous membrane surrounding the lungs
- Visceral layer: clings to lung surface
- Parietal layer: lines cavity walls
- Pleural cavity: potential space between layers with serous fluid
The visceral layer is continuous with the parietal layer.
External interacostals
11 muscles
Costal tubercles –> costochondral junction
- does NOT extend to sternum
Attachments
- Superior: lower border of superior rib
- Inferior: upper border of inferior rib
- External intercostal membrane
Inferomedial fiber direction (hands in pockets)
Action: elevates ribs during inspiration; stabilizes chest wall
- N: intercostal nn.
- A: intercostal aa.
Internal intercostals
11 muscles, perpendicular to externals
Sternum –> costal angle
- does NOT extend to vertebrae
Attachments
- superior: lower border of superior rib
- inferior: upper border of inferior rib
Action: depresses ribs during expiration; stabilizes chest wall
N: intercostal nn.
A: intercostal aa.
Innermost intercostals
Deeper parts of internal intercostals
Doesn’t extend to sternum or vertebra (only lateral wall)
Separated from internals by intercostal artery, vein, and nerve
Diaphragm
Primary muscle for breathing
Dome shaped, flat muscle
Separates thoracic and abdominal cavities
Contractile fibers insert into central tendon
Structures of the diaphragm
Right and left dome
Central tendon
Right and left crus
Foramina in the diaphragm
Vena caval hiatus (inferior vena cava: T8
Esophageal hiatus: T10
Aortic hiatus: T12
Arteries and nerves of the diaphragm
Arteries
- superior surface: branches of the internal thoracic artery
- abdominal surface: right and left inferior phrenic
Nerve: phrenic nerve C3-C5
Chest wall movement
- Contraction of diaphragm
- Anterior rib movement: pendulum swinging anterior to posterior
- Transverse movement: lateral
Motor and sensory innervation of the chest wall
Intercostal nerves: ventral rami of spinal nerves T1-T11
Subcostal nerve (because no more ribs): ventral ramus of T12
Neurovasculature of the anterior chest wall
Subclavian artery: internal thoracic artery
- anterior intercostal arteries 1-6
- anterior intercostal arteries 7-9 form the musculophrenic artery
- distal internal thoracic becomes the superior epigastric artery - descends into rectus abdominis
Neurovasculature of posterior chest wall
Thoracic aorta
- posterior intercostal arteries 3-11
