Hanan Mohammed Tarabeh
Lecturer of Anatomy & Human Embryology
Faculty of Medicine, Helwan University
Objectives
Definition.
Boundaries.
Layers of pectoral region
Muscles of pectoral region.
Fasciae of pectoral region.
Vertical Lines of the body
1)-Midline:-
line passing through median sagittal plane of the body.
2)-Para-sternal line:line passing through lateral margin of the sternum.
3)-Mid-clavicular line:line passing through the middle of the clavicle.
4)-Anterior axillary line:line passing through anterior axillary fold.
5)-Mid-axillary line:line passing in the middle of the axilla.
6)-Posterior axillary line:line passing through posterior axillary fold.
Vertical Lines of the body
Definition
The pectoral region includes
the structures present on the
front of the upper part of chest
(anterior thoracic wall).
Boundaries
1) Above :
clavicle.
2) Below
: 6th rib.
3) Medially :
Midline.
4) Laterally :
Mid-axillary line.
Layers of the pectoral region
S.
1
P.
Mn.
2
P.
Mj.
3
1. Skin.
2. Fascia:1) Superficial fascia.
2) Deep fascia (pectoral fascia).
3) Clavipectoral fascia.
3. Muscles: (pectoral muscles)
1) Superficial layer:-Pectoralis major.
2) Deep layer:1. Above:- Subclavius.
2. Below:- Pectoralis minor.
Muscles of the pectoral region
Each pectoral region contains:
1.the pectoralis major.
2.pectoralis minor.
3.subclavius muscles.
All originate from the anterior thoracic wall
and insert into bones of the upper limb.
(1)-Pectoralis major
Origin:
1- clavicular head anterior surface
of medial half of clavicle
2- sternocostal head from anterior
surface of sternum; first seven
costal cartilages; aponeurosis of
external oblique.
Insertion :
Lateral lip of Intertubercular sulcus
(bicipital groove) of humerus
Nerve supply (N .S): Medial and
Lateral Pectoral nerves
ACTION
1-Adduction Of the arm
2-Flexion of arm
3-Medial rotation of
arm.
4-Accessory muscle of
inspiration [by drawing
the ribs
outwards
towards humerus].
(2)-Pectoralis minor
Origin :
Anterior surfaces and superior
borders of ribs III to V; and
from deep fascia overlying the
related intercostal spaces.
Insertion :
Coracoid process of scapula
(medial border and upper
surface)
N .S: Medial pectoral nerve
ACTION
1Protraction of scapula:pulls scapula downwards & forwards.
2Depresses shoulder.
[as it pulls coracoid process
downward]
3Accessory muscle of inspiration
[with scapula fixed, pulls ribs upwards]
(3)-Subclavius
Origin :
First rib at junction between
rib and costal cartilage
(costochondral joint).
Insertion :
Groove on inferior surface of
middle one third of
Clavicle (subclavius groove).
N .S : Nerve to subclavius
ACTION
Steadies the clavicle during
movements of shoulder girdle.
Protects the great vessels &
nerves from the bone (Acts as a
cushion).
Fasciae of pectoral region.
1) SUPERFICIAL FASCIA
It encloses:1. mammary
glands (breast).
2. Platysma.
3. Cutaneous
nerves.
CLAVIPECTORAL FASCIA
1) DEFINITION:A strong fibrous sheet lies deep to clavicular
head of pectoralis major.
2) SITE: Extends from pectoralis minor (below) to clavicle
(above) where it splits to enclose subclavius
3) ATTACHMENT Its upper border, along lower border of
subclavius,
• thickened to form costo-coracoid ligament that extends from
anterior end of 1st rib medially to coracoid process laterally.
Superiorly (bone):*It splits to enclose the subclavius muscle.
*It is attached to clavicle.
Inferiorly (soft tissue):*It splits to enclose the pectoralis minor.
*It continues downward as the suspensory ligament of the axilla
& joins the floor of axilla.
CLAVIPECTORAL FASCIA
4) STRUCTURES
FASCIA
=VEIN:-
PIERCING CLAVI-PECTORAL
(CALL)
Cephalic vein
terminates in axillary vein.
=ARTERY:- Acromiothoracic artery
branch from axillary artery.
=NERVE:- Lateral pectoral nerve
From lateral cord of brachial plexus.
=LYMPHATIC VESSELS:into infra-clavicular lymph nodes (L.N).
STRUCTURES PIERCING
CLAVI-PECTORAL FASCIA
MCQ
What is the innervation of pectoralis major?
• Medial and lateral pectoral nerves
• Intercostal nerves
• Long thoracic nerve
• Thoracodorsal nerve
The pectoralis major is comprised of two heads:
clavicular and sternocostal.
Which of the following movements is specifically
carried out by the clavicular head?
• Scapular rotation
• Shoulder abduction
• Shoulder flexion
• Lateral rotation of upper limb
Where on the scapula does pectoralis minor
attach?
• Acromion
• Glenoid fossa
• Subscapular fossa
• Coracoid process