6b Flashcards
deep back muscles - there are 3
- innervated by dorsal rami
Generally named Erector Spinae, it consists of three muscles
Iliocostalis
- Illium to costalis
Longissimus
- Illium and attaches to transverse processes on vertebral column
- is long hence name
Spinalis
- Illium all the way up to the spine
Extend the trunk, maintain posture, balance
- Movement and stability of the spine, keep you erect/ upright
Thoracolumbar Fascia
Diamond shapes ligament where muscles attach to/ muscles come off of it.
There is no actual muscle but has a tendon coming off it
Many muscles originate off here.
Innervation of Muscle: Neuroscience meets Anatomy
ventral + dorsal horns
Most motor information is transmitted through the Ventral Root BUT for the deep back muscles, motor information travels via the Dorsal Root
When they come together they form Ramus (pl. Rami) which contains sensory and motor information
Spinal Cord (ventral and dorsal horns)
Ventral provides MOTOR (efferent)
Dorsal receives SENSORY (afferent)
deepest back musculature
Generally called the ‘Transverspinalis Muscles’
Intertransversarius
- Goes along the transverse processes (of T2 + T3???)
Rotatores
- Spinous process of vertebrae to the transverse process of the vertebrae
Multifidus
- Skips over an entire vertebrae and connects from transverse to spinous process
Interspinalis
- In between the spinous processes
Aid in extension, lateral flexion, and rotation of vertebrae
Innervated by dorsal rami
rectus abdominis
Has small little tendons that create bellies that give appearance to the 6 pack
Same muscle but one on each side of the midline
There are two of them
In between we have tendonous intersections and that is what they are called the linea alba
Superiorily it attaches to the xyphoid process and the costal margin or costal cartilage and the ribs with a broad attachment
- Inferiorily attaches at the 5-7 costal cartilages of these ribs
Inferiorily it goes all the way down to the pubic symphisis but this is its origin
- It also attaches to a ligament known as the inguinal ligament from the ASIS to the pubic tubercle.
other fun facts about the abdomen
Aponeurosis is a broad attachment across a bone.
The external, internal and transverse oblique muscles create a rectus sheath and where this ends as you approach the bottom is the inguinal ligament.
–> The inguinal ligament folds into itself to make the inguinal canal and this canal is the passageway for the testes.
obliques - in abdomen
Muscles adjacent to the rectus abdominas
These muscles are all coming together to the linear Alba the muscle that separates the two anterior rectus abdominis.
It is thick and this is because each tendon of the external, internal and the transverse and then they all surround this muscle after passing through the rectus abdominis as they wrap the linear alba 3 times.
external obliques
oblique means direction of the muscle fibers
These are most exterior and to find the direction of their fibres you make a V with your fingers.
Goes forward over the rectus to the linear alba
Past its attachment it keeps going to the inguinal region and goes down then attaches to the linear alba and then helps to create the inguinal ligament.
Inguinal ligament is an extension of the tendon and as it grows it starts to grow upon itself and it creates the inguinal canal inside itself. This canal is a passageway for the testes. *
It is a paper like and then it is an aponeurosis which is a broad attachment across a bone.
Testes go from the posterior abdominal cavity to scrotum where they can be positioned from the core of the body and the sperm need to grow further
The testes are attached to the Spermatic cord exists the abdominal cavity via the interior inguinal ligament and exists at the end to drop into the testes.
Inguinal hernia is a large lump is the intestine can pop through the canal and pop out near the spermatic cord and forces this to come out and at night it pop back in.
internal obliques
Inside the external obliques and their fibres run perpendicular from each other
Goes around the rectus abdominis muscle by splitting to get to the linear alba
abdomen - internal vs external - how to tell
external - fibres moving towards midline
internal - fibres moving outwards/ away from midline
transverse abdominal muscle
Deepest layer
Fibres run in a horizontal pattern.
Its tendon runs from the rectus abdominal muscle to get to the linear alba
tendinous intersections
little white lines between each ab
linea alba
Write on the midline and in the belly button
In-between the rectus muscle
It goes from the midline at the xiphoid process to the pubic symphysis.
Made of collagen connective tissue and is formed by the aponeurosis of the abdominal muscles
- This means it does not contain primary nerves or blood vessels.
side muscles
- layered like sheets of plywood
- follwo same pattern as intercostal muscles
- contraction laterally flexes body and increases intraabdominal pressure
intrabdominal pressure
Lift something and then this is how you can make a hernia and then it may cause intestine to pop out of the inguinal ligament
Hernia is when an organ is pushed through the muscle or tissue that holds it in place.
Used for excretion as you push intestines to remove unwanted materials.
transverse abdominal
Contraction laterally flexes body and increases intra-abdominal pressure
You use this pressure when you lift something or when you go to the bathroom.
intercostals
Lift up ribcage during inhalation and down during exhalation.
When they lift up we increase the space in the thoracic cavity then the lungs go where the ribs were.
On a pressure system airs is forced into the lungs.
- An increase in pressure causes air to flow out of the lungs.
Muscles of the thoracic cage have to put in work as it is not easy to move the ribs as they are solid structures.
Any muscle that attaches to the rib will assist in this process
external intercostal muscle
This is the first layer of muscle
Involved in inspiration
internal intercostal muscle
Expiration muscles
Just under the external ones to bring rib cages back down.
innermost intercostal muscle
3rd layer and it is an important region
Intercostal vessels and nerves lie between this an the internal intercostal muscles.
They are responsible for innervation and blood supply to these muscles here but they also innervate the oblique and the transverse, rectus abdominal muscles.
diaphragm
Has a central tendon
- Gives dome shape appearance
C 3,4,5 keep diaphragm alive
The phrenic nerve originals from C3,C4,C5 from this innervation to have unassisted breathing.
- Injury to the spinal cord below C5 can breathe on their own
- Above C3 you cannot breathe on your own
- In between C3 and C5 it would be partial breathing
diaphragm - stuctures + attachments
attachments:
- xiphoid
- ribs + costal cartilages
- lumbar vertebral bodies
In the diaphragm there are holes for structures to pass through
- Holes for the inferior vena cava, esophagus and aorta hole.
Aorta
- Runs through the aortic hiatus.
Esophagus
- Esophagial hiatus
Vena cava
- Runs through the vena cava hiatus
