Lab List 2: Muscles

Question 1

Pectoralis major

Answer 1

Action: flexes and adducts arm, medially rotates arm
Innervation: medial and lateral pectoral nerves
Blood: pectoral branch of thoracoacromial trunk
Antagonist: deltoid

Question 2

Pectoralis minor

Answer 2

Action: depress tip of shoulder, protract scapula
Innervation: medial pectoral nerve
Blood: pectoral branch of the thoracoacromial trunk
Antagonist: trapezius, serratus anterior

Question 3

Subclavius

Answer 3

Action: draws clavicle down and forward
Innervation: nerve to the subclavius
Blood: clavicular branch of the thoracoacromial trunk
Antagonist:

Question 4

Serratus anterior

Answer 4

Action: holds scapula against thoracic wall, protracts scapula, and rotates scapula
Innervation: long thoracic (if thoracic nerve is cut then winged scapula)
Blood: lateral thoracic artery
Antagonist: rhomboid major and minor

Question 5

Transverse thoracic muscles

Answer 5

Action: compress thorax for forced expiration
Innervation: intercostal nerves 2-6
Blood: internal thoracic
Antagonist:

Question 6

External intercostal muscles

Answer 6

Action: keeps the intercostal space from blowing out or sucking in during respiration (inhale)
Innervation: intercostal nerve
Blood: intercostal
Antagonist: internal intercostals

Question 7

Internal intercostals

Answer 7

Action: keeps the intercostal space from blowing out or sucking in during respiration (exhalation)
Innervation: intercostal nerve
Blood: intercostal
Antagonist: external intercostals

Question 8

Innermost intercostal

Answer 8

Action: keeps the intercostal space from blowing out or sucking in during respiration
Innervation: intercostal nerve
Blood: intercost