This document describes the anatomy of the lumbar region. It discusses the lumbar vertebrae, joints of the vertebral column including the vertebral bodies and vertebral arches. It also describes the muscles of the lumbar region including the erector spinae, quadratus lumborum, and abdominal wall muscles. The ligaments of the lumbar vertebrae are listed including the ligamentum flavum, interspinous ligament, and anterior longitudinal ligament. Finally, the blood supply and innervation of the lumbar vertebrae are explained, noting the four paired lumbar arteries and sinuvertebral nerve.

1. Anatomy of lumbar region
By : Muhamad Afif bin Roslan
BHAL17047118
PBL GROUP 6
MBBS UniSZA
1
Learning Outcomes:
I. Describe the lumbar vertebrae
II. List the joints of vertebral column
III. Describe the muscles of lumbar region
IV. List the ligaments of lumbar vertebrae
V. Explain the blood supply and innervation of lumbar region

2. I. Lumbar vertebrae
▪ Body- kidney shaped body
▪ Pedicles- longer and wider than
thoracic;oval shaped
▪ Spinous process- prominent
posterior projection
▪ Transverse process- projects
laterally from each pedicle
provide attachment for intrinsic
muscle and ligaments
▪ vertebral foramen- opening
▪ Pedicles- sides of vertebral arch
▪ Laminae- flat root
plates,complete arch posteriorly
2
Posterior
Posterior
Anterior
Anterior

3. II. Joints of vertebral column
I. Joints of vertebral body:
▪ Symphyses ( secondary cartilaginous joint)
1. Annulus fibrosus  fibrous ring consists
of concentric lamellae of fibrocartilage
forming circumference of IV disk
▪ Inserted into epiphyseal rims of the
articular surface of vertebral bodies
2. Nucleus pulposuscore of the IV disk
II. Joints of vertebral arch:
1. Zygapophysial joint(facet jt)
▪ Articulation: plane synovial joint between
sup and inf articular process of adjacent
vertebra
▪ Surrounded by thin joint capsule
▪ Permits gliding between articular process
3
Anterior
Posterior
Posterior

4. III. Muscles of the lumbar region
Group of muscle Name of muscle Action
Posterior Thoracolumbar fascia Ant layer- transmit tension produced by contraction
of hip extensors to spinous process
Post layer- actv by contraction of transversus
abdominis
Erector spinae:
1. Iliocostalis
2. Longissimus
3. Spinalis
- Primary extensor of lumbar region when acting
bilaterally
- Unilaterally laterally flex the trunk and
contribute to rotation
Multifundus - Produce lumbar extension
Lateral Quadratus lumborum - Stabilization in horizontal plane
- Laterally flex the spine and control rotational
motion
Anterior Rectus abdominis - Flexor of trunk
- Provide stability inacorset manner around trunk
Abdominal wall - Stabilize lumbo-pelvic region
Psoas major - Flexion of hip
4

5. POSTERIOR
5

6. IV. Lumbar ligaments
▪ Ligamentum flavum join laminae of adjacent vertebral arch
▪ Interspinal ligament connect adjoining spinous process,attaching from
root to apex
▪ Supraspinous ligament connects the tip of spinous process from C7 to
sacrum
▪ Anterior longitudinal ligament strong broad fibrous band that connects
and cover anterolateral aspect of vertebral bodies and IV disc
▪ Posterior longitudinal ligament attached to the IV disc and posterior
aspect of vertebra bodies from C2 to sacrum 6

7. V. Blood supply and innervation of lumbar
vertebrae
▪ Blood supply:
- Four paired of lumbar arteries
that arise from post aspect of
aorta
▪ Nerve supply:
- Sinuvertebral nerve major
sensory nerve
- Innervates:
1. Post longitudinal ligament
2. Superficial layer of anullus
fibrosus
3. Posterior vertebral
periosteum
7

8. THANK YOU
REFERENCES:
1. Keith L.Moore ,Arthur F.Daley ,Anne M.R Agur ;Clinically
oriented anatomy sixth edition
2. www.slideshare.net/mobile/venus88/biomechanics-of-lumbar-
spine
3. Atlas of human anatomy; F Netter
8