Anatomy Course Module 3 Sample

Module Three Course Index

Lesson 1:

Vertebral column

Quiz

Lesson 2:

Anterolateral abdominal wall

Quiz

Lesson 3:

Muscles of the back

Quiz

Module Three Lesson One

Back and vertebral column

App: Click or copy the links to view.

1. Video on the spinal curves 2 min- https://3d4medic.al/3IBR19vk

2. Overview of vertebral column -https://3d4medic.al/a92XNVZN

TIP To investigate in detail any vertebral structure, try the following process

1. Turn off all viewing options in your bottom tool bar except “skeletal”

2. Click on a particular vertebra 3. Click “hide others”

Typical features of thoracic vertebra lateral features App: Click or copy this link to view a video on the features of the thoracic vertebrahttps://3d4medic.al/ALlQd7YW. An additional short video on the thoracic cage can be found here: https://3d4medic.al/3xAKTfMp

Lumbar vertebra typical features of App: Click or copy this link to watch a short video on the features of the lumbar vertebrahttps://3d4medic.al/TJzKubF8

Module Three Lesson Two

Anterolateral abdominal wall

App: Click or copy the link to watch a 4 min. video on the anteriolateral abdominal wallhttps://3d4medic.al/mLqL7jSc

• Although the abdominal wall is continuous, it is subdivided in the anterior wall, right and left lateral wall, and posterior wall for descriptive purposes.

• Because there is no definite boundary, the term anterolateral abdominal wall is often used.

Some structures, such as muscles and cutaneous nerves, are in both the anterior and lateral walls.

The anterolateral abdominal wall extends from thoracic cages to the pelvis.

Anatomy • There are five (bilaterally paired) muscles in the anterolateral abdominal wall (see images below).

• The two vertical muscles are the large rectus abdominis and the small pyramidalis.

• The three flat muscles are the external oblique, internal oblique, and transverse abdominis.

• Their attachments are listed, along with their nerve supply and main actions, in Table 1.

IMAGE O

IMAGE P

Image O. Lateral rectus abdominus

Quadratus lumbrorum • The Quadratus lumborum lies in the posterior abdominal wall.

• It is stretched however, with many of the stretches in this chapter, and therefore included here • The quadrilateral quadratus lumborum forms a thick muscular sheet in the posterior abdominal wall (images Q, R).

• It lies adjacent to the lumbar transverse processes and is broader inferiorly.

• Contracting bilaterally, the quadratus lumborum is an extensor of the lumbar region.

Its action is based on the line of force passing about 3.5 cm posterior to the medial-lateral axis of rotation at L3.

• Contracting unilaterally, the quadratus lumborum has very favorable leverage as a lateral flexor of the lumbar region. The axial rotation potential of the quadratus lumborum, however, is minimal.

• Clinically, the quadratus lumborum is often called a “hip hiker” when its role in walking is being described, especially for persons with paraplegia at or below the L 1 neurologic level. By elevating (hiking) one side of the pelvis, the quadratus lumborum raises the lower limb to clear the foot from the ground during the swing phase of brace-assisted ambulation.

IMAGE Q

Image Q. Anterior view of QL

IMAGE R

Image R. Posterior view of QL

Functions and actions of anterolateral abdominal muscles The muscles of the anterolateral abdominal wall: • Form a strong expandable support for the anterolateral abdominal wall.

• Support the abdominal viscera and protect them from most injuries.

• Compress the abdominal contents to maintain or increase the intra-abdominal pressure and, in so doing, oppose the diaphragm (increased intra-abdominal pressure facilitates expulsion).

• Move the trunk and help to maintain posture.

Module Three Lesson Three

The Muscles of the Back

Most body weight lies anterior to the vertebral column, especially in obese people; consequently, the many strong muscles attached to the spinous and transverse processes of the vertebrae are necessary to support and move the column.

There are two major groups of muscles in the back. The extrinsic back muscles include superficial and intermediate muscles that produce and control limb and respiratory movements, respectively.

The intrinsic (deep) back muscles include muscles that specifically act on the vertebral column, producing its movements and maintaining posture.

The section below will focus on the intrinsic back muscles.

App: Click or copy this link to view a 3 minute video on the erector spinae muscles, the intermediate layer of the intrinsic back muscles- https://3d4medic.al/iKrgpSEm Note/tip. Because of the number and complexity of the intrinsic spinal muscles, we have chosen not to provide images of all of them. Rather, we have provided examples. Use your anatomy software program to explore each region. Click in individual muscles, isolate them, highlight them, strip layers away or use labels to explore their origins, insertions and actions.

IMAGE 8

IMAGE 9

IMAGE 10

Image 9.

The multifidus running from the sacrum cranially to the skull.

Image 10.

The rotatores muscles are the deepest of the transversospinalis group.

They are present thought out the spine but more develop in the thoracic region.

IMAGE 2

IMAGE 3

Image 2. Splenius capitis

Image 3. Splenius cervicis

Table 1. Superficial layer of intrinsic back muscles Muscle Splenius

Proximal Attachment

Distal Attachment

Nuchal ligament and spinous processes of C7T3 or T4 vertebrae

Splenius capitis: fibres run superolaterally to mastoid process of temporal bone and lateral third of superior nuchal line of occipital bone Splenius cervicis: tubercles of transverse processes of C1C3 or C4 vertebrae

Nerve Supply Posterior rami of spinal nerves

Main Action Acting alone: laterally flex neck and rotate head to side of active muscles Acting together: extend head and neck

IMAGE 5

Image 5. Iliocostalis lumborum