Dissection 2.1 - Superficial Thorax

Body of the sternum

Part of sternum between manubrium and xiphoid process

Cephalic vein

Vein located between deltoid and pectoralis major

Path of cephalic v. to R atrium

Cephalic v. → Axillary v. → Subclavian v. → Brachiocephalic v. → Superior vena cava → Right atrium

Clavicle

Bone located superficial to structures of the neck and thorax but deep to muscles of the thoraxWh

What muscles attach to the clavicl?

SCM and Platysma

Corpus (body) of the mandible

Section of the mandible between the mental protuberance and ramus

Costal cartilage

Hyaline cartilage that connects the ribs to the sternum

Costal groove

Groove located on the inferior border of ribs 2 to 12H

How is the costal groove formed

By pulsations of the intercostal a.W

What lays within the costal groove

Intercostal VAN

Costal margin

Inferior border of the ribcage

Costochondral joint

Short bar of costal cartilage located between the anterior ends of the 1st rib and articulates with the manubrium (sternochostal joint)

Dermatome

Strip of skin innervated by dorsal and ventral cutaneous nerves from a single spinal nerve

External intercostal membrane

The most medial part of the external intercostal m. that is a semi-transparent membrane (directly superficial to the internal intercostal m.)

External intercostal muscle location

Muscles lateral to the costochondral joint

Directions of external intercostal muscle fibers

Inferior medially

Function of external intercostal m

Elevate ribs and expand the chest cavity (inhilation)

Genu/symphysis of the mandible

Point of fusion where the 2 halves of the mandible join together during development (midline - near chin)

Gonial angle

Inferior angle of the mandible

Path of intercostal a. from arch of aorta (L side)

Arch of aorta → L subclavian a. → Costocervical trunk → Intercostal a.

Path of intercostal a. from arch of aorta (R side)

Arch of aorta → R brachiocephalic a. → R subclavian a. → Costocervical trunk → Intercostal a.

Where do intercostal nerves arise from?

Ventral rami of 1st 11 thoracic n.

Internal intercostal muscle location

Lateral to sternum and deep to external intercostal membrane

Direction of internal intercostal muscle fibers

Inferior and laterally

Function of internal intercostal muscle

Pull ribs down and in (reducing volume of thoracic cavity)

Lateral pectoral n.

Supplies innervation to pectoralis major (located medially in pectoralis major)

What is the lateral pectoral nerve a branch of?

Lateral cord of brachial plexu

Manubrium

Superior portion of the sternum

Medial pectoral n.

Supplies innervation to pectoralis major (located laterally - pierces into to pectoralis minor)

What is the lateral pectoral n. a branch of?

Branch of medial cord of brachial plexus

Pectoralis major

Superficial muscle in thorax (innervated by medial and lateral pectoral nerves)

Pectoralis minor

Deep to pectoralis major (innervated by medial pectoral n.)

Platysma

Thin muscle embedded in the superficial fascia deep to the skin of the anterior neck (innervated by CN VII)

Sternocostal joint

Joint between manubrium and costal cartilage which joins the anterior ends of the 1st rib

Subcostal n.

Ventral ramus of T12 that lies below the 12th rib

Suprajugular notch

Notch at the superior margin of the manubrium

Fiber types in ventral rami

SS, SS, ANS

Xiphoid process

Inferior portion of the sternum