Latissimus Dorsi

Question 1

Latissimus Dorsi is a large, wide ___-shaped muscle covering the ___ 1/2 of the back.
It is superficial to ___.

Answer 1

Fan-shaped, inf. 1/2
Serratus post. Inf.

Question 2

Lats pass from trunk to ___ and act ___ on shoulder joint and ___ on pectoral girdle

Answer 2

Humerus, directly, indirectly

Question 3

What is the site of origin of the Lats?

Answer 3

Thoracolumbar aponeurosis

Question 4

What is the attachment of the thoracolumbar aponeurosis?

Answer 4

SPs of T7-Sacrum
Post. Part of iliac crest
Lower 3-4 ribs via slips interdigitating w/ ext. oblique muscle

Question 5

What is the insertion site of the lats?

Answer 5

Lesser tubercle, bicipital groove of humerus

Question 6

What is the innervation of the lats

Answer 6

Thoracodorsal nerve (post. Cord of brachial plexus, C6-8 fibers)

Question 7

What is the blood supply of the lats

Answer 7

Thoracodorsal A. (Branch of subscapular A.)

Question 8

What are the actions of the lats?

Answer 8

Extension; Med. rotation; Adduction of arm (pull insertion toward origin)