Origin:

Clavicular Head: Originates from the anterior surface of the medial half of the clavicle (collarbone)

Sternocostal Head: Originates from the anterior surface of the sternum (breastbone), the superior six costal cartilages (cartilage connecting ribs to sternum), and the aponeurosis of the external oblique muscle

Insertion: Lateral lip of the intertubercular groove of the humerus

Innervation: Lateral and medial pectoral nerves

Action: Brings the arm towards the body, rotates the arm inward, assists in flexing and extending the shoulder joint

Origin: Upper border of a rib

Insertion: Lower border of rib above, coursing up and medially

Innervation: Intercostal nerves (T1-T11)

Action: Keeps the intercostal space from blowing outor sucking in during respiration

Origin: Lowerborder of a rib within an intercostal space

Insertion: Upperborder of the rib below, coursing, downward and medially

Innervation: Intercostalnerves (T1-T11)

Action: Keeps the intercostal space from blowing outor sucking in during respiration

Origin: Third to fifth ribs, adjacent to the costochondral junction

Insertion: Medial border and superior surface of the coracoid process of the scapula

Innervation: Medial pectoral nerve

Action: Draws the scapula anteroinferiorly against the thoracic wall, contributing to shoulder stability and Assists in elevating the ribs, playing a small role in breathing when the scapula is fixed

Origin: Lateral surfaces of the first to eighth or ninth ribs

Insertion: Anterior surface of the medial border of the scapula (shoulder blade)

Innervation: Long thoracic nerve (C5-C7)

Action:

Scapular Stabilization: It helps to hold the scapula against the rib cage, preventing it from "winging" (protruding away from the chest wall)

Scapular Protraction: It pulls the scapula forward, allowing for movements like pushing and reaching

Scapular Upward Rotation: It rotates the scapula upwards, enabling arm elevation above 90 degrees

Origin: Lower 8 ribs

Insertion: Linea alba, pubic crest & tubercle, anterior superior iliac spine & anterior half of iliac crest

Innervation: Intercostal nerves 7-11, subcostal, iliohypogastric and ilioinguinal nerves

Action: Flexes and laterally bends the trunk

Origin: Pubis and the pubic symphysis

Insertion: Xiphoid process of the sternum and costal cartilages 5-7

Innervation: Intercostal nerves 7-11 and subcostal nerve

Action: Flexes the trunk

Origin: Thoracolumbar fascia, anterior 2/3 of the iliac crest, lateral 2/3 of the inguinal ligament

Insertion: Lower 3 or 4 ribs, linea alba, pubic crest

Innervation: Intercostal nerves 7-11, subcostal, Iliohypogastric and ilioinguinal nerves

Action: Flexes and laterally bends the trunk

Origin: Originated from lower 6 ribs, thoracolumbar fascia, anterior 3/4 of the iliac crest, lateral 1/3 of inguinal ligament

Insertion: It inserted into linea alba, pubic crest and pecten of the pubis

Innervation:The muscle innervated by intercostal nerves 7-11, subcostal, iliohypogastric and ilioinguinal nerves

Action: It flexes and laterally bends trunk

Origin: Lateral surfaces of the first to eighth or ninth ribs

Insertion: Anterior surface of the medial border of the scapula (shoulder blade)

Innervation: Long thoracic nerve (C5-C7)

Action:

Scapular Stabilization: It helps to hold the scapula against the rib cage, preventing it from "winging" (protruding away from the chest wall)

Scapular Protraction: It pulls the scapula forward, allowing for movements like pushing and reaching

Scapular Upward Rotation: It rotates the scapula upwards, enabling arm elevation above 90 degrees

Origin: Originated from posterior surface of the sternum

Insertion: It inserted into sternum inner surfaces of costal cartilages 2-6

Innervation:The muscle innervated by intercostal nerves 2-6

Action: It compresses the thorax for forced expiration

Origin: Originated from posterior surfaces of both the manubrium and sternal end of the clavicle

Insertion: It inserted into lower border of the hyoid bone, medial to the omohyoid m. insertion

Innervation:The muscle innervated by ansa cervicalis

Action: It depresses/stabilizes the hyoid bone

Description: Curved bones that form the rib cage at the thoracic area

Location: Located at the sides of the torso, connecting the sternum in front to the spine in the back

Types:

True Ribs: Ribs 1-7, which connect directly to the sternum via cartilage

False Ribs: Ribs 8-12, which do not connect directly to the sternum

Floating Ribs: Ribs 11 and 12, which have no connection to the sternum

Functions:

Protection: Protect the lungs, heart, and other organs within the thoracic cavity.

Breathing: Expanding the chest cavity during inhalation and contracting during exhalation

Support: Support to the chest wall and contribute to the overall structure of the body

Description: The inferior part of the sternum. Xiphoid means "sword shaped"; it is variable in size, shape & ossification; it articulates with the body of the sternum superiorly

Description: A long, curved bone that connects the shoulder blade (scapula) to the sternum

Location: Located between the ribcage (sternum) and the shoulder blade (scapula)

Functions:

Acts as a strut to connect the sternum to the shoulder blade

Helps keep the shoulder blade in the correct position during movements

Transmits forces from the upper limb to the axial skeleton

Protects important nerves and blood vessels that run behind it

Description: It is a horizontal demarcation in the lower abdomen, located approximately midway between the umbilicus and the pubic symphysis marking the inferior end of the posterior rectus sheath.

Function: It is a key anatomical landmark, particularly for surgeons, as it marks where the inferior epigastric vessels enter the rectus sheath

Description: It is a horizontal demarcation in the lower abdomen, located approximately midway between the umbilicus and the pubic symphysis marking the inferior end of the posterior rectus sheath.

Function: It is a key anatomical landmark, particularly for surgeons, as it marks where the inferior epigastric vessels enter the rectus sheath

Description: A strong, fibrous midline structure in the anterior abdominal wall, formed by the fusion of aponeuroses (tendinous sheets) of the abdominal muscles, separating the right and left rectus abdominis muscles

Location: Runs vertically down the midline of the abdomen, extending from the xiphoid process (the lower end of the sternum) to the pubic symphysis

Functions:

Stabilizing the abdominal wall complex

An attachment point for other abdominal muscles, helping to anchor and stabilize the torso

Use as a point of entrance for open abdominal surgery due to its avascular nature and minimal blood loss

Description: A tough, fibrous compartment in the anterior abdominal wall that encloses the rectus abdominis and pyramidalis muscles

Location: Extends from the inferior costal margin and costal cartilages of ribs 5 to 7 to the pubic crest. .

Functions:

Protection of the anterior abdominal muscles and vessels

Provides support and compression of abdominal organs

Description: Type of hyaline cartilage that connects the ribs to the sternum and other ribs

Function: It contributes to the elasticity and mobility of the chest wall, allowing for expansion and contraction during breathing

Description: A flat, T-shaped bone located in the center of the chest, forming the anterior part of the rib cage and protecting vital organs

Types:

Manubrium: The broad, superior part of the sternum, forming the top part of the T-shape. It articulates with the clavicles (collarbones) and the first pair of ribs. Features the jugular notch (suprasternal notch) at its superior surface.

Body (or Gladiolus): The middle and longest part of the sternum, connecting the manubrium to the xiphoid process. It has facets on its lateral borders for articulation with the costal cartilages of the ribs.

Xiphoid Process: The narrow, inferior part of the sternum, forming the tip of the T-shape. It is the smallest and most distal part of the sternum.

Description: A curved line running from the 9th rib to the pubic tubercle that indicates the lateral border of rectus abdominis muscle

Function: It provides strength, mobility, and flexibility to the lateral abdominal muscles

Description: A fibrous bands that traverse the muscle, dividing it into distinct segments. Located on the anterior surface of the rectus abdominis muscle, which is a long, flat muscle that extends from the pubic bone to the xiphoid process and costal cartilages

Function: It gives the characteristic of "six-pack" appearance with well-developed rectus abdominis muscles. It also help to transmit forces generated by the muscle contractions