Gross Anatomy - Hypaxial Muscles Of The Neck And Thorax

Front 1

What are axial muscles associated with? What are the two divisions?

Back 1

Axial muscles are the muscles of the trunk and neck.
1) Epaxial
2) Hypaxial

Front 2

Where are epaxial muscles found? What is their function?

Back 2

Lie dorsal to the transverse processes of the vertebrae.
Extensors of vertebral column.

Front 3

Where are hypaxial muscles found?

Back 3

Lie ventral to the transverse processes of the vertebrae.

Front 4

What are the hypaxial muscles of the neck?

Back 4

Longus capitis
Longus colli mm.

Front 5

Origin, Insertion, Innervation, Action....
Longus capitus m.

Back 5

O: C2-C6 transverse processes
I: Basioccipital bone (tubercle)
N: Ventral brs. cervical spinal nn
A: flex atlanto-occipital joint and draw neck down

Front 6

Origin, Insertion, Innervation, Action....
Longus colli m. (thoracic portion)

Back 6

O: convex ventral surfaces of T1-T6
I: C6 and C7
N: Ventral brs. of initial 6 spinal nn
A: draw neck down

Front 7

Origin, Insertion, Innervation, Action....
Longus colli m. (cervical portion)

Back 7

O: ventral border of transverse processes of C6 to C3
I: ventral spine of preceding vertebra
N: ventral brs. of cervical spinal nn
A: draw neck down

Front 8

Origin, Insertion, Innervation, Action....
Scalenus m.
(two parts to this muscle)

Back 8

O: C4 and C5 transverse processes
I: 3rd or 4th rib (dorsalis) and 6th to 8th rib (medius)
N: ventral brs. of cervical and thoracic spinal nn.
A: draw ribs cranially; inspiration

Front 9

Origin, Insertion, Innervation, Action....
Serratus Dorsalis cranialis m.

Back 9

O: Broad aponeurosis of thoracolumbar fascia arising from tendinous raphe of the neck and spinous processes of the 1st 6 to 8 thoracic vertebrae
I: craniolateral ribs 2-10
N: intercostal nn.
A: lift ribs for inspiration

Front 10

Origin, Insertion, Innervation, Action....
Serratus dorsalis caudalis m.

Back 10

O: broad aponeurosis from thoracolumbar fascia
I: caudal border of ribs 11-13 (10?)
N: Intercostal nn.
A: Draw last 3-4 ribs caudally for expiration

Front 11

Origin, Insertion, Innervation, Action....
Rectus Thoracis m.

Back 11

O: 1st rib
I: ventral ends of ribs 2-4
N: Intercostal nn.
A: Aid in inspiration

Front 12

What are the hypaxial muscles of the thoracic wall?

Back 12

Scalenus, Serratus ventralis cerficis and thoracis, serratus dorsalis cranialis and caudalis, external/internal intercostal, rectus thoracis mm.

Front 13

What are the general two actions of hypaxial muscles of the thoracic wall?

Back 13

1) Inspiration - origin cranial to insertion; decrease thoracic volume by moving ribs out and cranially
2) Expiration - origin caudal to insertion; decrease thoracic volume by pulling ribs in and caudally

Front 14

What are the two parts of the Scalenus m.? What third part does a horse have?

Back 14

Scalenus dorsalis m.
Scalenus medius m.
Scalenus ventralis m. (horse)

Front 15

Origin, Insertion, Innervation, Action....
External intercostal mm.

Back 15

O: Caudal border of rib
I: Cranial border of next caudal rib; caudoventral fibers
N: Intercostal nn.
A: Inspiration

Front 16

Origin, Insertion, Innervation, Action....
Internal intercostal mm.

Back 16

O: Cranial border of rib
I: Caudal border of next caudal rib; Cranioventral fibers
N: Intercostal nn.
A: Expiration