pectoral region

Question 1

what are 5 vertical lines used to locate position on chest wall?

Answer 1

1. midline(down the center of the sternum)
2. mid clavicular line (from the tip of acromion and midsternal line)
3. anterior axillary line(front of the armpit)
4. mid axillary line(widest part of thorax)
5. posterior axillary line

Question 2

how many ribs?

Answer 2

12 ribs and 11 pairs of intercostal spaces

1-7 are true ribs 8-12 are false ribs, 11-12 are floating ribs

Question 3

which ribs are attached to sternal body?

Answer 3

3-7 ribs attached to the sternal body
the first rib is hidden behind the clavicle
the second rib is the highest rib that can be identified by palpable

Question 4

origin of the pectoralis major

Answer 4

clavicle, sternum and costal cartilages

Question 5

insertion of the pectoralis major

Answer 5

attached to humerus

Question 6

function of the pectoralis major

Answer 6

shoulder horizontal adduction
medial rotation of the shoulder
flexion of the extended arm

Question 7

pectoralis minor

origin, insertion, function

Answer 7

origin is anterior surface 3,4 and 5th ribs
insertion medial aspect of the coracoid process of scapula
function, stabilize the scapula, and move shoulder forward or contract anteriorly and inferiorly (protraction)

Question 8

which nerves supply pectoralis major and minor?

Answer 8

medial and lateral pectoral nerves (C5Th1) comes off the brachial plexus supply major, (medial supply to minor)

Question 9

serratus anterior

fan-shaped muscles based on the lateral wall of thoracic

Answer 9

origin; 1st to 8th rib
insertion; medial border of the scapula
nerve supply, innervation; long thoracic nerve (C5-C7)
function: contraction leads to ventrolateral movement of scapula, stabilization of scapula, lifts the ribs and act as accessory inspiratory muscle

Question 10

deltoid muscle

upper shoulder muscles

Answer 10

origin; anteriorly to clavicular, posteriorly to acromial and spinal part of deltoid muscle
Insertion: deltoid tuberosity lateral part to humerus
innervation: Axillary nerve carries fibers from C5 to C6nerve roots of brachial plexus
function; flexion, internal rotation, abduction, extension and external rotation

Question 11

intercostal muscles

The gap between two ribs is closed by two intercostal muscles called external and internal intercostal

Answer 11

Intercostal nerves supply them
function is to support breathing, external IM, the elevation of ribs (inspiratory muscles). Internal IM, lower the ribs (expiratory breathing muscles)

Question 12

subclavius( nerve to subclavius)

Answer 12

origin-first costal cartilage
insertion-clavicle
action-depresses and stabilize the clavicle

Question 13

the rib articulates with the costal cartilage the cartilages are connected by which membrane?

Answer 13

Anterior intercostal membrane

Question 14

what lies in deep to the anterior thoracic wall?

Answer 14

Internal mammary artery(or internal thoracic artery) and veins. these vessels run vertically down behind the costal cartilages on the inside of the thoracic wall and onto supply the abdominal wall and diaphragm

Question 15

what nerve supply to diaphragm?

Answer 15

sole motor supply to the diaphragm is via phrenic nerve. the phrenic nerve also receives sensory input from mediastinal pleura, diaphragmatic pleura, and peritoneum