Gluteal Region and Anal Triangle Flashcards
Label the bones of the gluteal region
What is important about the following structure?
Ligament of the head of the femur - has blood supply so if you tear the ligament you can cut off the blood supply to the head of the fermur and have necrosis of that joint.
What is the cutaneous innervation of the gluteal region and from which primary rami do they come?
Label the following muscles. What nerve branch innervates all of them?
Tensor fascia lata is the most anterior muscle innervated by the same nerves as the gluteal region (lateral to hip).
Innervated by mostly superior inferior gluteal nerves
What’s the innervation of the gluteal muscles? What nerves share the same spinal segements?
Most muscles innervated by nerves stemming from 3 spinal segments
Gluteus maximus = inferior gluteal nerve (L5, S1, S2)
Gluteus medius, gluteus minimus, tensor fascia lata = superior gluteal nerve (L4, S1, S2)
*quadratus femoris has same spinal segments as the superior gluteul nerve and obturator internus has the same spinal segements as the inferior gluteul nerve
**obturator internus and inferior gluteul
What are the nerves of the sacral plexus and their associated muscles?
How are the different nerves oriented around the piriformis?
Where is an important landmark for finding the superior gluteal nerve? the nerve to quadratus femoris?
*S2-S4 keep the perineum off the floor
**posterior femoral cutaneous does posterior side of the thigh and some of the perneal region - posterior scrotal branches
**sciatic nerve does virtually everything below the kneww - sensation and muscle innervation. Also does the posterior thigh (exits just below the piriformis)
Superior gluteal nerve above the piriformis. Inferior gluteal nerve, sciatic nerve, posterior femoral cutaneous, pudendal nerve all come below the piriformis.
The gluteus minimis and gluteus medias are separated by the superior gluteal nerve and vessels.
Nerve to quadratus femoris passes deep to the inferior gemellas and obterator internus
What is muscles of the gluteal region are supplied by the superior gluteal artery?
What is the pathway of the superior gluteal artery and from where does it come?
How do the superior gluteal nerve and superior gluteal artery differ?
Superior gluteal artery does more than the nerve does - the superficial branch of the artery does the gluteal maximus and the superior gluteal nerve doesn’t. The deep branch of the superior gluteal artery runs with the superior gluteal nerve.
What muscles of the gluteal region are supplied by the inferior gluteal artery?
What important anastamose is created around the hip joint? What critical blood supplies are being joined?
Descending branch off the inferior gluteal artery anastamoses with 3 other arteries: 2 femoral circumflexes and deep femoral. Form a cross.
2 femoral circumflexes and deep femoral come from femoral artery of the external iliac whereas inferior gluteal artery comes from the internal iliac. Important anastomose for the internal and external iliacs.
What three arteries do the gluteal region?
Superior gluteal artery, inferior gluteal artery and the internal pudendal artery.
*pudendal artery goes underneath the sacrotuberous ligament
What is the Trendelenburg sign?
When feet are fixed, the gluteus medius and gluteus minimus muscle hold the ilac crest to hip joint in place.
When lift left foot, right hip contracts so that the left hip stays up/level. When muscle not innervated, than left hip falls. This causes issues when a patient is walking and their superior gluteal nerve is injured, it causes the foot to drag.
The superior gluteal nerve (gluteus medius and minimus + tensor fascia lata)
What are the muscles of the posterior thigh? How are they innervated?
Which muscles of the posterior thigh have dual action?
What nerovascular bundle runs with these muscles?
*long head of the biceps femoris is on the pelvis (ishial tuberostiy) so it has some effect on the hip and inserts on the head of the fibula - crosses two joints so has dual action!
**shorter head of the biceps femoris only has one action on the knee joint. Origin on the femor and inserts on the lateral side of the fibula.
**Ischial tuberosity is the origin of 3 muscles: long head of biceps femoris, semitendinosus and semimembranosus. Only difference is that the semitendinosus and semi membranosus insert on the medial side of the knee (tibia). All have dual action!
**Semitendinosous has a more tendinosus insertion/distal end whereas the semimembranosous is flatter.
One of the cases where there is no neurovascular bundle - only sciatic nerve and perforating branches.
What is an antalgic gait and what are its causes?
What is gluteus maximus lurch and its causes?
Nerve affected: inferior gluteal nerve
Lean back to compensate for the lack of extension from the gluteus maximus. When “heal-strike” with right foot, body goes into full extension.
What are the lymphatics of the gluteal region?
What is an important landmark and its embryological relevance for lymphatic drainage?
Pectinate line delineates the junction between endodermal and ectodermal regions of the anal canal. At this line the epithelium changes from columnar to stratified squamous epithelium and drains differently
