Anatomy and Physiology Lab 6: Muscular System of Torso and Upper Limb

What are “Flexors”?

Muscles on the anterior forearm

What are “Extensors”?

Muscles on the posterior forearm

What are “Carpi”?

Tendons that stop at the wrist

What are “Digitorum”?

Tenons that diverge into digits 2-5

What are “Radialis?

Tendons that attach to radius, lateral forearm

What are “Ulnaris”?

Tendons that attaches to ulna, medial forearm

Major muscles v. minor muscles

Distinguishes between size and distance the muscles travel when compared

Long v. short heads

muscles that have multiple tendon attachments at either its proximal or distal ends. They are further distinguished by distance when compared

What is this muscle and where is it found?

• What? Pectoralis Major

• Attachment? clavicle, sternum ➡ intertubercular sulcus (humerus)

  * superficial/lies on top of pectoralis minor!

What does the Pectoralis Major do?

• Adduction of shoulder

• Flexion of shoulder

• Medial rotation of shoulder

What is this muscle and where is it found?

• What? Pectoralis Minor

• Attachment? ribs 3-5, coracoid process

  *Deep/lies underneath pectoralis major!

What does the Pectoralis Minor do?

• Stabilizes scapula

What is this muscle and where is it found?

• What? External Intercostals

• Attachment? superior rib

  *criss crosses with internal intercostals

What do the External Intercostals do?

lifting rib cage when I breath in

What is this muscle and where is it found?

• What? Internal Intercostals

• Attachment? inferior rib

  *criss crosses with external intercostals

What do the Internal Intercostals do?

depresses ribs when I breath out

What is this muscle and where is it found?

• What? Transversus Thoracis

• Attachment? internal surface of sternum

What does the Transversus Thoracis do?

depresses ribs during forced expiration

What is this muscle and where is it found?

• What? Serratus Anterior (finger-like/wing-like collection of muscles where each finger attaches to a rib)

• Attachment? Ribs 1-8 ➡ medial border of scapula

What does the Serratus Anterior do?

stabilize and protract scapula

What is this muscle and where is it found?

• What? Rectus Abdominis

• Attachment? pubic crest and symphysis ➡ costal cartilage and xiphoid process

What does the Rectus Abdominis do?

flex trunk

What is this muscle and where is it found?

• What? Linea Alba

• Where? The vertical line down the center of the abs

What does the Linea Alba do?

provides structural support and connects abdominal muscles

What is this muscle and where is it found?

• What? Tendinous Intersections

• Where? The horizontal lines across the abs

What do the Tendinous Intersections do?

wider range of motion and flexibility in the trunk

What is this muscle and where is it found?

• What? External Abdominal Oblique

• Where? on the side of the rectus abdominis muscles, one layer superior to the rectus abdominis

• Muscle fiber direction? downward slant; lateral to medial

What do the External Abdominal Oblique do?

• flex trunk

• rotate trunk

What is this muscle and where is it found?

• What? Internal Abdominal Oblique

• Where? same layer as the rectus abdominis on the sides of the rectus abdominis muscle

• Muscle fiber direction? fan pattern; lateral to medial

What does the Interna Abdominal Oblique do?

• flex trunk

• rotate trunk

What is this muscle and where is it found?

• What? Transversus Abdominis

• Where? Deep to rectus abdominis muscle; on the sides of where the rectus abdominis muscles would be

• Muscle fiber direction? horizontal

What does the Transversus Abdominis do?

• flex trunk

• rotate trunk

What is this muscle and where is it found?

• What? Trapezius (in the shape of a ZackBot lol)

• Attachment? C7-T12 spinous processes ➡ scapula, clavicle

What does the Trapezius do?

rotate, retract, elevate, depress scapula (POSTURE)

What is this muscle and where is it found?

• What? Rhomboid Major

• Attachment? T2-T5 spinus processes➡ medial border of scapula

  *inferior to rhomboid minor

  *deep to trapezius

What does the Rhomboid major do?

retract scapula

What is this muscle and where is it found?

• What? Rhomboid Minor

• Attachment? C7-T1 Spinus processes the ➡medial border of the scapula

  *superior to rhomboid major

  *deep to trapezius

What does the Rhomboid Minor do?

retract scapula

What is this muscle and where is it found?

• What? Levator Scapulae

• Attachment? C1-C4 Transverse processes ➡ superior/medial scapula

What does the Levator Scapulae do?

elevate scapula (shoulder shrug)

What is this muscle and where is it found?

• What? Supraspinatus

• Attachment? supraspinous fossa of scapula —> greater tubercle of the humerus

What does the Supraspinatus do?

10-15 degrees of shoulder abduction

What is this muscle and where is it found?

• What? Infraspinatus

• Attachment? Infraspinous fossa of scapula —> greater tubercle of humerus

What does the Infraspinatus do?

lateral rotation of shoulder

What is this muscle and where is it found?

• What? Teres Minor

• Attachment? lateral border of scapula —> greater tubercle of humerus

  *inferior/deep to infraspinatus

What does the Teres Minor do?

lateral rotation of shoulder (same as infraspinatus)

What is this muscle and where is it found?

• What? Subscapularis

• Attachment? Subscapular fossa —> lesser tubercles of humerus

What does the Subscapularis do?

medial ration of shoulder

Which muscles are part of the rotator cuff?

*SITS

• Supraspinatus

• Infraspinatus

• Teres minor

• Subscapularis

What is this muscle and where is it found?

• What? Teres Major

• Attachment? posterior/inferior scapula —> medial lip of intertubercular sulcus

What does the Teres Major do?

• adduction

• medial rotation of shoulder

What is this muscle and where is it found?

• What? Deltoid

• Attachment? Scapula and Clavicle —> deltoid tuberosity

What does the Deltoid do?

• flexion

• extension

• abduction of shoulder

What is this muscle and where is it found?

• What? Latissimus Dorsi

• Attachment? T7-sacrum, ilim, inferior ribs ➡ intertubercular sulcus

What does the Latissimus Dorsi do?

extension (agonist of pec major), adduction, medial rotation of shoulder

What is this muscle and where is it found?

• What? Iliocostalis

• Where? run down the length of the back

  *most lateral

What does the Iliocostalis do?

(together with longissimus and spinalis) extension of trunk/ leaning back

What is this muscle and where is it found?

• What? Longissimus

• Where? along length of back?

  *medial to Iliocostalis

  *lateral to spinalis

What does the Longissimus do?

(together with Iliocostalis and Spinalis) extension of trunk/ leaning back

What is this muscle and where is it found?

• What? Spinalis

• Where? runs along length of back

  *medial to Iliocostalis and Longissimus

What does the Spinalis do?

(together with Iliocostalis and longissimus) extension of trunk/ leaning back

What is this muscle and where is it found?

• What? Biceps Brachii Long Head

• Where? The Biceps Brachii has one origin point but branches off into two “head". The long head is lateral

• Origin/Insertion? superior rim of glenoid cavity —> Radial Tuberosity

What does the Bicep Brachii Long Head do?

• forearm supination

• flexion of elbow

What is this muscle and where is it found?

• What? Biceps Brachii Short head

• Where? The Biceps Brachii has one origin point but branches off into two “heads”. The short head is medial

• Origin/Insertion? Coracoid process of scapula → Radial tuberosity

What does the Bicep Brachii Short head do?

• supination of forearm

• flexion of elbow

What is this muscle and where is it found?

• What? Brachialis

• Origin/Insertion? shaft of humerus —> coronoid process of ulna

  *deep to bicep brachii muscles (in the picture I have removed the bicep brachii)

What does the Brachialis do?

flexion of elbow (crosses joint)

What is this muscle and where is it found?

• What? Coracobrachialis

• Origin/Insertion? Coracoid process of scapula —> shaft of humerus

What does the Coracobrachialis do?

flex shoulder

What is this muscle and where is it found?

• What? Tricep Brachii Long Head

• Where? There are three “heads” of the Tricep Brachii muscle. The long head is on medial

• Insertion? Olecranon process of ulna

What does the Tricep Brachii Long Head do?

extension of elbow

What is this muscle and where is it found?

• What? Triceps Brachii Lateral Head

• Where? The Tricep Brachii muscle has three “heads”. The lateral head is on the lateral side

• Insertion? olecranon process of ulna

What does the Tricep Brachii Lateral Head do?

extension of elbow

What is this muscle and where is it found?

• What? Triceps Brachii Medial Head

• Where? The Tricep Brachii muscle has three “heads”. The Medial Head is deep to the long head. It isn’t visible unless the long head is taken away.

• Insertion? olecranon process of ulna

What does the Triceps Brachii Medial Head do?

extension of elbow

What is this muscle and where is it found?

• What? Brachioradialis

• Origin/Insertion? Humerous —> radius styloid process

What does the Brachioradialis do?

flexion of elbow

What is this muscle and where is it found?

• What? Pronator Teres

• Origin/Insertion? Humerus —> radius

What does the Pronator Teres do?

pronates forearm

What is this muscle and where is it found?

• What? Flexor Carpi Radialis

• Origin/Insertion? medial epicondyle of humuers —> lateral (radius side) wrist

What does the Flexor Carpi Radialis do?

• flexion

• adduction of wrist

What is this muscle and where is it found?

• What? Palmaris Longus

• Origin/Insertion? medial epicondyle of humerus —> palmar region

What does the Palmaris Longus do?

flex wrist

What is this muscle and where is it found?

• What? Flexor Carpi Ulnaris

• Origin/Insertion? medial epicondyle of humerus —> medial (ulna side) wrist

What does the Flexor Carpi Ulnaris do?

• flex wrist

• adduction

What is this muscle and where is it found?

• What? Extensor Carpi Radialis

• Origin/Insertion? lateral epicondy of humerus —> carpals

What does the Extensor Carpi Radialis do?

• extend wrist

• abduct wrist

What is this muscle and where is it found?

• What? Extensor Digitorum

• Origin/Insertion? lateral epicondyl eof humerus —> digits 2-5

What does the Extensor Digitorum do?

extend digits 2-5

What is this muscle and where is it found?

• What? Extensor Carpi Ulnaris

• Origin/Insertion? latral epicondyle of humerus —> medial wrist

What does the Extensor Carpi Ulnaris do?

• extends wrist

• adduction of wrist

What is this muscle and where is it found?

• What? Thenar Eminence

• Where? base of thumb

What does the Thenar Eminence do?

allows for thumb movement

What is this muscle and where is it found?

• What? Hypothenar Eminence

• Where? base of pinky

What does the Hypothenar Eminence do?

movement of pinky

What is this muscle and where is it found?

• What? Flexor Retinaculum

  *looks like a wristband around the wrist that helps stabilize everything (tendons).\

• Where? Band on the front/anterior side

What does the Flexor Retinaculum do?

stabilizes wrist

What is this muscle and where is it found?

• What? Extensor Retinaculum

  *looks like a wrist band that helps organize tendons in the wrist

• Where? band on the back/posterior side

What does the Extensor Retinaculum do?

stabilization and organization of wrist tendons