Pectoral Muscles

Question 1

Name the 4 muscles of the pectoral region?

Answer 1

PECTORALIS MAJOR
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PECTORALIS MINOR
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SUBCLAVIUS
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SERRATUS ANTERIOR

Question 2

What are the two divisions of pectoralis major?

Answer 2

UPPER FIBRES (CLAVICULAR HEAD)
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LOWER FIBRES (STERNOCOSTAL HEAD)

Question 3

Medial attachment (upper fibres):
MEDIAL 1/2 OF THE ANTERIOR CLAVICLE
Medial attachment (lower fibres):
STERNUM, ANTERIOR COSTAL CARTILAGES OF RIBS 2 - 6

Lateral attachment (both heads):
LATERAL LIP OF THE BICIPITAL GROOVE

Actions:
G - H MEDIAL ROTATION
G - H ADDUCTION
G - H HORIZONTAL ADDUCTION
G - H FLEXION (FROM DEEP EXTENSION)
G - H EXTENSION (FROM DEEP FLEXION)

Answer 3

PECTORALIS MAJOR

Question 4

Superior attachment:
CORACOID PROCESS

Inferior attachment:
RIBS 3 - 5

Actions:
S - T PROTRACTION
S - T DEPRESSION
S - T DOWNWARD ROTATION
IF THE SCAPULA IS FIXED, PM HELPS TO ELEVATE THE RIBS WITH FORCED INHALATION

Answer 4

PECTORALIS MINOR

Question 5

What causes a tipping scapula?

Answer 5

TIGHT PECTORALIS MINOR

Question 6

What are the actions of pectoralis major?

Answer 6

G - H MEDIAL ROTATION
G - H ADDUCTION
G - H HORIZONTAL ADDUCTION
G - H FLEXION (FROM DEEP EXTENSION)
G - H EXTENSION (FROM DEEP FLEXION)

Question 7

What is the medial attachment for the upper fibres of pectoralis major?

Answer 7

MEDIAL 1/2 OF THE ANTERIOR CLAVICLE

Question 8

What is the medial attachment for the lower fibres of pectoralis major?

Answer 8

STERNUM, ANTERIOR COSTAL CARTILAGES OF RIBS 2 - 6

Question 9

What is the lateral attachment for both heads of pectoralis major?

Answer 9

LATERAL LIP OF THE BICIPITAL GROOVE

Question 10

What are the actions of pectoralis minor?

Answer 10

S - T PROTRACTION
S - T DEPRESSION
S - T DOWNWARD ROTATION
IF THE SCAPULA IS FIXED, PM HELPS TO ELEVATE THE RIBS WITH FORCED INHALATION

Question 11

What is the superior attachment for pectoralis minor?

Answer 11

CORACOID PROCESS

Question 12

What is the inferior attachment for pectoralis minor?

Answer 12

RIBS 3 - 5

Question 13

What is it called when the inferior angle of the scapula moves posteriorly off of the rib cage?

Answer 13

TIPPING SCAPULA

Question 14

Medial attachment:
1ST RIB AND ITS COSTAL CARTILAGE

Lateral attachment:
MIDDLE 1/3RD OF THE INFERIOR SURFACE OF THE CLAVICLE

Action:
ANCHORS, DEPRESSES AND DRAWS THE CLAVICLE MEDIALLY

Answer 14

SUBCLAVIUS

Question 15

Medial attachment:
ANTERIOR SURFACE OF THE MEDIAL BORDER OF THE SCAPULA

Lateral attachment:
LATERAL SURFACES OF THE UPPER 8 RIBS

Action:
S - T PROTRACTION
S - T UPWARD ROTATION (LOWER FIBRES ONLY)

*** KEEPS THE MEDIAL BORDER OF THE SCAPULA FLAT AGAINST THE RIBS, IF MUSCLE IS WEAK, WINGING SCAPULA CAN OCCUR.

Answer 15

SERRATUS ANTERIOR

Question 16

What 3-part action does subclavius cause to the clavicle?

Answer 16

ANCHORS, DEPRESSES AND DRAWS THE CLAVICLE MEDIALLY

Question 17

What is the medial attachment for subclavius?

Answer 17

1ST RIB AND ITS COSTAL CARTILAGE

Question 18

What is the lateral attachment for subclavius?

Answer 18

MIDDLE 1/3RD OF THE INFERIOR SURFACE OF THE CLAVICLE

Question 19

What are the actions of serratus anterior?

Answer 19

S - T PROTRACTION
S - T UPWARD ROTATION (LOWER FIBRES ONLY)

*** KEEPS THE MEDIAL BORDER OF THE SCAPULA FLAT AGAINST THE RIBS, IF MUSCLE IS WEAK, WINGING SCAPULA CAN OCCUR.

Question 20

What is the medial attachment for serratus anterior?

Answer 20

ANTERIOR SURFACE OF THE MEDIAL BORDER OF THE SCAPULA

Question 21

What is the lateral attachment for serratus anterior?

Answer 21

LATERAL SURFACES OF THE UPPER 8 RIBS

Question 22

Weak serratus anterior can result in _________ _________.

Answer 22

WINGING SCAPULA