Lower Limb Part 2

Question 1

Extrinsic muscles: superficial and intermediate muscles responsible for ___ and __ movements

• Intrinsic muscles: superficial, intermediate, and deep muscles that act directly on the __ __ to generate movement and maintain __. They are arranged in __, __, and __ layers

Answer 1

Extrinsic muscles: superficial and intermediate muscles responsible for respiration and limb movements

• Intrinsic muscles: superficial, intermediate, and deep muscles that act directly on the vertebral column to generate movement and maintain posture. They are arranged in superficial, intermediate, and deep layers

Question 2

superficial intrinsic back muscle

Answer 2

splenius

Question 3

3 intermediate intrinsic back muscles

Answer 3

erector spinae muscles

1. iliocostalis (most lateral)

2, longissimus (middle)

3. spinalis (closest to spine)

Question 4

recall:

Anterior/ventral ramus innervates the skin and muscle on the anterior aspect of the trunk ( innervate the hypaxial musculature, including the limb musculature that sits on the trunk)
→ the anterior (ventral) ramus and anterior (ventral) roots carry somatic motor nerve fibres to
the hypaxial musculature \

o Posterior/dorsal ramus innervates the post-vertebral muscles and the skin of the back. ( innervate the epaxial musculature)

Question 6

OIF of iliocostalis

Answer 6

• intermediate intrinsic back muscle (therefore it’s epaxial)

O; iliac crest, sacrum, sacral and inferior lumbar spinous processes, supraspinous ligament

I; ribs and cervical transverse process

F; stabilization of VC. Extension of vertebral column and head. Lateral flexion of vertebral column

Question 7

OIF of longissimus

Answer 7

intermediate group of intrinsic back muscles

O; iliac crest, sacrum, sacral and ingerior lumbar spinous processess, supraspinous ligament.

I; ribs, cervical and thoracic transverse processes, mastoif process

F: extension of vertebral column and head,, lateral flexion

Question 8

OIF of spinalis

Answer 8

O; iliac crest, sacrum, sacral and ingerior lumbar spinous processess, supraspinous ligament.

I; thoracic spinous processes

F; extenion of vertebral column and head.

• lateral flexion of vertebral column
• this is an intermediate intrinsic back muscle

Question 9

3 deep intrinsic EPAXIAL back muscles.

Answer 9

1. semispinalis
2. multifidus
3. rotatores
   - these are epaxial therefore, they are innervated by posterior rami

Question 10

OIF of semispinalis? epaxial or hypaxial

Answer 10

epaxial. deep intrinsic back muscle

O. transverse process

2. spinous process of superior vertebrae

F; stabilization of vertebral column, extension of vertebral column

Question 11

OIF of multifidus? epaxial or hypaxial?

Answer 11

epaxial. deep intrinsic back muscle

O; transverse process

I: spinous processes of superior vertebrae

F; stabilization of vertebral column, extension of vertebral column

Question 12

OIF of rotatores? epaxial or hypaxial?

Answer 12

epaxial. deep intrinsic back muscle

O; transverse process

I; spinous processes of superior vertebrae

F; stabilization of vertebral column, extension of vertebral column.

Question 13

deep HYPAXIAL intrinsic back muscles

Answer 13

1. psoas major
2. iliacus
3. quadratus lumborrum

Question 14

5 extrinsic back muscles for respiration and limb movement (recall that intrinsic back muscles are for vertebral column movement and stabilization)

Answer 14

1. trapezius
2. levator scapulae
3. rhomboid major and minor
4. serratus posterior
5. latissimus dorsi

Question 15

Answer 15

Question 16

Answer 16

Question 18

The deep epaxial intrinsic muscles are located underneath the erector spinae, and are known collectively as the __. They are a group of short muscles, associated with the transverse and spinous processes of the vertebral column. There are three major muscles in this group – the __, __ and __

Answer 18

The deep epaxial intrinsic muscles are located underneath the erector spinae, and are known collectively as the transversospinales. They are a group of short muscles, associated with the transverse and spinous processes of the vertebral column. There are three major muscles in this group – the semispinalis, multifidus and rotatores

Question 19

Answer 19