Muscles of the Trunk and Neck

Question 1

also called axial muscles and are classified morphologically into hypaxial and epaxial groups:

Answer 1

MUSCLES OF THE
TRUNK AND NECK

Question 2

lie dorsal to transverse process of the vertebrae; function mainly as extensors of the vertebral column

Answer 2

EPAXIAL

Question 3

include the muscles of the abdominal and thoracic walls

Answer 3

HYPAXIAL

Question 4

*Muscles of the Neck

arises from transverse processes of cervical vertebrae and inserts on the ventral surface of basioccipital bone of the skull

Answer 4

longus capitis

Question 5

*Muscles of the Neck

covers the ventral surfaces of the vertebral bodies from the sixth thoracic vertebrae to the atlas; can be felt when you insert your finger into the thoracic inlet because of its location

Answer 5

longus colli

Question 6

*Muscles of the Thoracic Wall

a muscle of inspiration which attaches to the first few ribs and the transverse processes of the cervical vertebrae; divided into several slips

Answer 6

scalenus

Question 7

*Muscles of the Thoracic Wall

large, fan-shaped muscle with extensive origin on the neck and trunk; inserts on the serrated face of the scapula

Answer 7

serratus ventralis

Question 8

*Muscles of the Thoracic Wall
*Serratus dorsalis

arises from thoracolumbar fascia and inserts on the
craniolateral surfaces of the ribs. It lifts ribs during inspiration.

Answer 8

serratus dorsalis cranialis

Question 9

*Muscles of the Thoracic Wall
*Serratus dorsalis

arises from the thoracodorsal fascia and inserts on caudal borders of the last 3 ribs; draws the last 3 ribs caudally during expiration

Answer 9

serratus dorsalis caudalis

Question 10

*Muscles of the Thoracic Wall

fibers run caudoventrally from the caudal border of one rib to the cranial border of the rib behind. They draw the ribs together during respiration.

Answer 10

external intercostal muscles

Question 11

*Muscles of the Thoracic Wall

can be differentiated from external intercostal muscles because their fibers run cranioventrally from the cranial border of one rib to the caudal border of the rib in front of it; draw the ribs together

Answer 11

internal intercostal muscles

Question 12

*Muscles of the Thoracic Wall

thin triangular muscles deep the transversus abdominis; crosses the space between the 1st few lumbar transverse processes and the last rib; arises from thoracolumbar fascia

Answer 12

retractor costae

Question 13

*Muscles of the Thoracic Wall

lies on inner surface of sternum and the sternal costal
cartilages (2nd to last segment); fibers came from sternum and insert into costal cartilages; aids expiration

Answer 13

transversus thoracis

Question 14

*Muscles of the Thoracic Wall

flat to rectangular muscle that runs caudoventral from 1st rib and inserts by a fascia at distal end of 3rd and 4th rib; moves forward during inspiration

Answer 14

rectus thoracis

Question 15

*Muscles of the Thoracic Wall

spindle-shaped muscles; arise from transverse processes of first 12 thoracic vertebrae and run caudolaterally to insert on adjacent rib

Answer 15

levatores costarum

Question 16

*Muscles of the Thoracic Wall

a tendinous central sheet; fibers attach along costal arch;

Answer 16

diaphragm

Question 17

*Muscles of the Abdominal Wall

covers the ventral half of the lateral thoracic
wall and the lateral part of the abdominal wall; fibers run caudoventrally; in the ventral abdominal wall it forms a wide aponeurosis that inserts on the linea alba

Answer 17

external abdominal oblique

Question 18

is the midventral aponeurosis of the abdominal muscles from xiphoid cartilage to prepubic tendon

Answer 18

linea alba

Question 19

a slit between the abdominal muscles from the deep to the superficial inguinal ring

Answer 19

Inguinal canal

Question 20

1. vaginal tunic – a thin membrane beneath the abdominal muscles which is an extension of the peritoneum
2. testes and spermatic cord – enclosed by the vaginal tunic
3. external pudendal artery and vein
4. genitofemoral nerve

Answer 20

Structures that enter the inguinal canal
In the male animal:

Question 21

1. vaginal process
2. round ligament of the uterus – enveloped by the vaginal process
3. external pudendal artery and vein
4. genitofemoral nerve

Answer 21

Structures that enter the inguinal canal In the female animal:

Question 22

*Muscles of the Abdominal Wall

fibers run cranioventrally; fibers from caudal border of this muscle form the cremaster muscle which accompanies the vaginal tunic

Answer 22

internal abdominal oblique

Question 23

*Muscles of the Abdominal Wall

fibers run transversely; lies medial to the internal
abdominal oblique and rectus abdominis

Answer 23

transversus abdominis

Question 24

*Muscles of the Abdominal Wall

extends from the pubis to the sternum; has distinct
transverse tendinuos intersections; right and left muscles are separated by linea alba

Answer 24

rectus abdominis

Question 25

Actions of Abdominal Muscles (2)

Answer 25

a. contract to increase abdominal pressure in defecation, urination, expiration and parturition
b. flex vertebral column

Nerve Supply: ventral branches of spinal nerves

Question 26

Epaxial Muscles 3 divisions

Answer 26

1. iliocostalis system
2. transversospinalis system
3. longissimus system

Question 27

*ILIOCOSTALIS SYSTEM

arises from wing of ilium and inserts on the transverse
processes of the lumbar vertebrae and the last 4 or 5 ribs; fused with longissimus lumborum at the lumbar region.

Answer 27

iliocostalis lumborum

Question 28

*ILIOCOSTALIS SYSTEM

arises from the 12th rib to the transverse processes of C7

Answer 28

iliocostalis thoracis

Question 29

• most medial and deep epaxial muscle mass
• extends from the sacrum to the head; includes spinalis, semispinalis, multifudus, rotators, interspinalis, intertransversarii

Answer 29

TRANSVERSOSPINALIS SYSTEM

Question 30

*TRANSVERSOSPINALIS SYSTEM

dorsolateral surface of the neck under rhomboideus capitis and serratus dorsalis cranialis; extends from spines of first three thoracic vertebrae and inserts on nuchal crest and mastoid part of the temporal bone

Answer 30

splenius

Question 31

*TRANSVERSOSPINALIS SYSTEM

cervical portion of the transversospinalis group; lies deep to the splenius and extends from the thoracic vertebrae; consists of:

◦ biventer cervicis – from thoracic vertebra and inserts on the caudal surface of the skull; has tendinous intersection
◦ complexus – ventral to the biventer and arises from cervical vertebra and inserts on the nuchal crest

Answer 31

semispinalis capitis