Posterior Abdominal Wall- Exam III Flashcards
Describe the physical barrier between the abdominal and pelvic cavities?
No physical barrier- only arbitrary
What creates the ceiling, floor, and walls of the abdominopelvic cavity?
Ceiling- diaphragm
Floor- pelvic organs (bladder, uterus, rectum)
Posterior wall- bones of vertebral column (lumbar region), and muscles
Anterior lateral wall- muscle & connective tissue
Abdomen + pelvis =
One continuous space
Sheet of skeletal muscle and connective tissue that forms a physical barrier between the thorax & abdomen:
Diaphragm
What vertebra comprise the posterior abdominal wall?
T12-L5
Where do we consider the posterior abdominal wall to stop at?
Disc between L5 & sacrum
What does the hip bone break down into?
Ileum, Ischium, & pubis
Where does the inguinal ligament stretch between?
Pubic tubercle to iliac spine
Where is the obturator foramen & what passes through it?
Holes on either side of pubis & passageway for nerves
Part of the bony pelvis that is connected to the sacrum:
Ilium
Part of upper margin of ilium that is a blunt, curving, long ridge:
Iliac crest
The concavity below the iliac crest, facing the midline of the body:
Iliac fossa
Where the iliac crest comes to a point:
Anterior superior iliac spine
What do we consider our hip bones?
Anterior superior iliac spine
Label 1-8:
- Iliac crest
- Iliac fossa
- Anterior superior iliac spine
- Inguinal ligament
- Ilium
- Sacrum
- Obturator foramen
- Pubic tubercle
How far does the diaphragm come down into the abdominal cavity?
Rib 12
What muscle will form a large portion of the posterior abdominal wall?
Diaphragm
Describe the shape of the diaphragm:
Highly curbed arching dome
What do the upper abdominal organs attach to?
Posterior abdominal wall by sticking to the diaphragm
What two muscles of the posterior abdominal wall both attach to the transverse processes of lumbar vertebra?
Psoas major & quadratus lumborum
What posterior abdominal wall muscles function in lower limb movement?
(Muscles that cross the hip joint) Iliacus & psoas major
The quadratus lumborum primarily functions in what type of movement?
Primarily a lateral flexor of trunk
What is the practical function of the quadratus lumborum:
Trunk stabilization
Long & thick strong muscle that will originate from the transverse processes of the lumbar vertebra & 12th thoracic vertebra
Psoas major
A cylindrical muscle that comes from multiple origins on individual vertebra
Psoas major
Muscle that acts across the hip join & produces motions of the lower limb (although found in the abdominal & pelvis) and function mainly in lower limb movement
Psoas major
The psoas major comes down and narrows into a _____ that will cross the hip joint and insert into the ___.
Tendon; femur
Muscle that is located on the surface of the psoas major
Psoas minor
Thin mostly fibrous muscle that does NOT cross the hip joint, inserts on the front of the pelvis and may be associated with proprioception and some people don’t even have these
Psoas minor
Fan shaped muscle that is located within the iliac fossa
Iliacus
The iliacus crosses the hip joint to function in ____ limb movement and functions to _____.
Lower limb movement; flex the hip
Two posterior abdominal wall muscles that have the exact same function.
Iliacus & psoas major
Iliacus + psoas major
Iliopsoas
Tendons of what two posterior abdominal wall muscles fuse together?
Iliacus and psoas major
Muscle of the lower back that is lateral to the psoas minor:
Quadratus lumborum
The quadratus lumborum is named for:
It’s shape and location
What muscle has an origin coming off of the iliac crest
Quadratus lumborum
The quadratus lumborum has a free lateral margin that:
Doesn’t attach to anything
The quadratus lumborum has multiple insertions including:
12th rib & transverse processes of lumbar vertebra
On the transverse processes of the lumbar vertebra, describe the attachments of the quadratus lumborum and psoas major:
Psoas major attaches in front of the quadratus lumborum attachments
We tend to use the quadratus lumborum on:
One side at a time
When using the QL, we flex the trunk laterally toward:
The side where the QL is contracted
Does the QL function in lower limb movement? Why?
No, does not cross the hip joint
Origin of QL?
Iliac crest
The origin of the quadratus lumborum is considered _____. This is involved in teacup movement.
Stationary
The QL is active when _____ to help stabilize the trunk and control your center of gravity
Walking
Label
- Diaphragm
- Rib 12
- Iliac crest
- Iliacus
- Psoas minor
- Psoas major
- Quadratus lumborum
Are posterior abdominal wall deep intrinsic back muscle or hypaxial muscle?
Hypaxial muscles
because the posterior abdominal wall muscles are all hypaxial muscles they are all innervated by:
Ventral rami of spinal nerves
The muscles of the posterior abdominal wall need input from :
Multiple spinal cord levels
The quadratus lumborum is innervated by:
Ventral rami of spinal nerves T12- L4
How many different spinal cord levels are responsible for innervating the quadratus lumborum
5 levels
Both the psoas major and psoas minor are innervated by:
Ventral rami of spinal nerves L1 - L3
The iliacus is innervated by:
The femoral nerve
The femoral nerve is a combination of spinal cord levels:
L2, L3, L4
- Quadratus lumborum
- Psoas major
- Iliacus
The psoas major and iliacus tendons fuse together an go ______ to the hip joint.
Anterior
The psoas major originates off both:
Bodies and transverse processes of vertebra
Once the tendons of iliacus and psoas major fuse, where do they attach?
Lesser trochanter of femur
All of the muscles of the posterior abdominal wall are anterior to the:
Deep intrinsic back muscles
What two muscles are anterior to the QL?
Iliacus & psoas major
What is the origin of the QL?
Iliac crest near midline
Where does the QL instert/attach?
12th and transverse processes of lumbar vertebra
- Anterolateral abdominal wall mm
- Thoracolumbar fascia
- Quadratus fascia
- Psoas fascia
- Quadratus
- Iliocostalis
- Longissimus
4.multifidus - Psoas
Envelope that surrounds the deep intrinsic back muscles:
Thoracolumbar fascia
What are the muscles inside the thoracolumbar fascia innervated by?
Dorsal ramus of one or more spinal nerves
What are the muscles outside of the thoracolumbar fascia innervated by?
Ventral rami of one or more spinal nerves
Thickened epimysium covering the psoas major
Psoas fascia
Where is the psoas minor relative to the psoas fascia?
Outside
Thickened epimysium layer covering the quadratus lumborum:
Quadratus fascia
Both the psoas major and QL are outside of the thoracolumbar fascia so they are considered to be ____ muscles, and innervated by ____.
Abdominal muscles; ventral rami
What are both the psoas fascia and QL important for?
Diaphragm
What is the left crus attached to?
L1 & L2 vertebra
What is the right crus attached to?
L1-L3 vertebra
Posterior attachment of the diaphragm:
Vertebral bodies (bone)
Laterally & anteriorly where does the diaphragm attach to?
Ribs & costal cartilages
When there is no bone in front (anteriorly), in order to strengthen the attachments of the diaphragm, what occurs?
Thickened fascia in the form of psoas fascia and QL fascia
What are the 3 areas of which the diaphragm itself is thickened:
- Median actuate ligament ligament
- Medial arcuate ligaments
- Lateral arcuate ligament
Opening in the midline of the diaphragm? What is the thickened fascia around this?
Aortic hiatus; median arcuate ligament
What is the thickened area of the diaphragm that crosses the quadratus lumborum?
Lateral arcuate ligament
Thickened lower border of diaphragm that crosses the psoas major: (one on either side)
Medial arcuate ligament
Connective tissue that surrounds the aortic hiatus involving the two crura of the diaphragm:
Median arcuate ligament
- Lateral arcuate ligament
- Medial arcuate ligament
- Median arcuate ligament
What is the lumbar plexus?
Set of B/L nerves made of the ventral rami of T12-L5 spinal nerves.
What spinal cord levels are involved in the ventral rami of the lumbar plexus?
T12-L5
What type of information does the lumbar plexus carry?
Somatic motor, Somatic sensory, sympathetics
Most of the nerves of the lumbar plexus carry axons from:
More than one spinal cord level
All plexuses in general are collections of axons that come off of:
Ventral rami of spinal nerves
The somatic motor axons of the lumbar plexus innervate:
Hypaxial derived skeletal muscle
The somatic sensory axons of the lumbar plexus innervate/ supply:
Skin (touch, temp, pain, pressure)
What axons respond to touch, temp, pain, & pressure in the skin?
Somatic sensory axons
Example of somatic sensations:
Touch , temp, pressure, pain
The sympathetic axons of the lumbar plexus innervate:
Visceral body wall structures (sweat glands & smooth muscle axons)
Why is the lumbar plexus necessary?
Because the muscles of the lower limbs are larger, they are derived from multiple myotomes which in turn requires innervation from the corresponding multiple spinal cord levels
A group of muscles that is innervated by a single spinal cord root:
Myotomes
How many myotomes are the muscles from the lower limbs derived from?
Multiple
The multiple myotomes comprising the muscles of the lower limbs require innervation from:
Multiple corresponding spinal nerves (multiple levels)
Describe the patches of skin supplied by nerves that come out of the plexus:
Bigger, larger, irregular shaped patches of skin (not nice & neat)
What type of nerves are innervating the skin that covers the limbs?
Somatic sensory
The patterns of somatic sensory supply to the skin of the lower limbs differs when comparing it to:
Dermatomes to nerves
In the limbs, we need to make more complex, larger muscles and we do this by combining _____ together during development
Somites
What is the motion of picking up a limb and moving it forward?
Flexion of hip
What is the motion of straightening a limb and moving it backwards? (Posteriorly)
Extension of hip
What is the motion of moving a limb laterally away from the midline (outward)?
Abduction of hip
What is lateral motion of moving a limb inward toward the midline?
Adduction of hip
If the knee is posteriorly bent backwards in an “L” shape
Flexion of knee
When leg and knee are straightened out (thigh + knee + ankle in a straight line)
Extension of knee
We have ventral rami that come out from T12-L5 of spinal cord and as soon as these ventral rami get out of the posterior abdominal wall, they:
Establish connections between eachother
The connections of the ventral rami are making nerves that will be able to:
Supply muscles from multiple spinal cord levels
The whole point of having the lumbar plexus:
To make big nerves from multiple spinal cord levels that can supply big muscles and big areas of skin
The subcostal nerve involves what ventral ramus?
T12 ventral ramus
The subcostal nerve is basically a ____ however its named differently because of its inferior location
Intercostal nerve
What type of nerve is the subcostal nerve?
Mixed nerve
What type of information does the subcostal nerve carry?
Somatic motor, Somatic sensory, Sympathetics
The somatic motor function of the subcostal nerve innervates:
Abdominal wall muscles
The somatic sensory function of the subcostal nerve innervates:
T12 dermatomes of abdominal wall
The sympathetic function of the subcostal nerve innervates:
Sweat glands, cutaneous vasculature, and smooth muscle that needs supply from autonomics
Superior branch of nerve coming out of L1 ventral ramus
iliohypogastric nerve
Inferior branch of nerve coming out of L1 ventral ramus
Ilioinguinal
The L1 nerves is considered to be a ____ nerve
mixed nerve
What type of information is carried in the L1 nerve? (both superior and inferior branches)
Somatic motor, somatic sensory, & sympathetics
What are the 2 branches of the L1 nerve of the lumbar plexus
iliohypogastic nerve & ilioinguinal nerve
What branch of the L1 nerve is most superior?
iliohypogastric
What does the somatic motor component of the L1 nerve innervate (both iliohypogastric and ilioinguinal)
muscles of the anterior abdominal wall
What does the somatic sensory component of the L1 nerve innervate? (both iliohypogastric and ilioinguinal)
L1 dermatome
What does the sympathetic component of the L1 nerve innervate? (both iliohypogastric and ilioinguinal)
L1 dermatome
The iliohypogastric branch of the L1 spinal nerve tends to stay above _____ up into the ____
iliac crest & up into the abdominal wall
The ilioinguinal branch of the L1 spinal nerve tends to extend downward further to the:
medial and anterior portions of the thigh & external genetalia
What branch of the L1 spinal nerve extends downward inferiorly & is longer?
inlioinguinal nerve
Nerve combining axons from L1 to L2
Genitofemoral nerve
The genitofermoral nerve is unusual because: (2)
males & females have different combinations of axons in this nerve & passes through a large chunk of muscle (psoas major)
The genitofemoral nerve passes through:
psoas major msulce
In females, the genitofemoral nerve contains what type of axons?
sensory + small amount sympathetics
In males, the genitofermoral nerve contains what type of axons?
mainly motor, + small amounts of sympathetics
The genitofemoral nerve innervates:
skin of external genitalia & skin on medial part of thigh
The fact that the genitofemoral nerve has motor axons in males but not females implies:
males have an additional muscle that females do not
Because the genitofemoral nerve passes through the psoas major, any damage to the muscle has the risk of causing:
compression of the nerve
Nerve that runs underneath the inguinal ligament & right across the iliacus
lateral femoral cutaneous nerve
The lateral femoral cutaneous nerve isa combination of spinal cord levels:
L2 & L3
In both sexes, the lateral femoral cutaneous nerve contains purely ____ axons with a little bit of ____ axons.
sensory; sympathetics
What nerve innervates a patch of skin on the lateral part of the thigh
lateral femoral cutaneous nerve
Very large nerve that supplies a lot of motor innervation to the lower limb muscles
femoral nerve
The femoral nerve is made of axons coming off of:
L2, L3, L4
The femoral nerve is considered what type of nerve?
mixed nerve
What does the somatic motor portion of the femoral nerve innervate?
muscles of the anterior compartment of thigh
The muscles of the anterior compartment of thigh work to:
act as hip flexors; extend knee
What motion describes the actions of the anterior compartment of thigh muscles?
kicking a ball
The somatic sensory component of the femoral nerve innervates:
skin that covers the anterior compartment thigh muscles
The ____ component of the femoral nerve innervates the surrounding skin
sympathetic
nerve that comes off of the same spinal cord levels as the femoral nerve:
obturator nerve
The obturator nerve combines axons from what spinal cord levels?
L2, L3, L4
The obturator nerve comes down into the ____ and through the ____
pelvis and through the obturator foramen
The obturator nerve ends up in the:
medial compartment of thigh (part of thigh that faces midline)
The obturator nerve functions in the innervation of the medial compartment of thigh which is involved in what motion?
adduction of hip (moving back toward midline)
The lumbosacral trunk combines axons from :
L4 & L5
What contributes to the sciatic nerve?
Lumbosacral trunk
The sciatic nerve is a major nerve supply to the:
lower limbs
The lumbosacral trunk is considered to be a ____ nerve, carrying _____ axons.
mixed nerve- motor, sensory, sympathetics
The sympathetic trunk extends from ____ to ____.
Thorax down into abdomen
The sympathetic trunk contains _____ running in front of the psoas major and in front of the transverse processes:
paravertebral ganglia
- Subcostal
- Iliohypogastric
- Ilioinguinal
- Lateral femoral cutaneous
- Genitofemoral
- Femoral
- Sympathetic trunk
- Lumbosacral trunk
- Obturator
Tuberculous is caused a bacteria in the lungs but can commonly spread to:
Spine
When TB spreads to the spine it can form little pockets of pus forming between vertebra often called:
Military tuberculosis