Trunk and Pelvis 2 Flashcards
(52 cards)
What is the purpose of the ischial tuberosity?
It is the location of attachment of the hamstring muscles.
What structure forms from the ischial spine’s protrusion?
The lesser sciatic notch
Where is the pubic crest located?
Anterolaterally to the pubic symphysis
What does the pubic crest do?
Provides attachment point for the abdominal muscles
What line of the pelvic inlet is formed by the pubis?
The pectineal line
What 2 structures are joined by the inguinal ligament?
The anterior superior iliac spine and the pubic tubercle (lateral side of the pubic crest)
What structures are joined by the sacrotuberous ligament?
The ischial tuberosity and the sacrum (posterior part of the sacrum and ilium)
What structures are joined by the sacrospinous ligament?
The ischial spine and the sacrum
What does origin and insertion typically refer to?
Origin refers to the more stable end of the attachment
Insertion refers to mobile end of attachment
What do erector spinae muscles do?
They extend the trunk
What are the main parts of the erector spinae muscles?
Spinalis muscles are near the midline. (Spinalis cervicis are located in cervical part and spinalis thoracis is located in the thoracic part)
Longissimus muscles are more lateral to the spinalis and contain thick fascia (include longissimus capitis, cervicis, and thoracis)
Iliocostalis is the most lateral part (cervicis, thoracis, and lumborum)
What are the abdominal muscles?
External oblique
Internal oblique
Transversus abdominis
rectus abdominis
What do external oblique muscles do?
Most superficial and fibers run downwards in V shape towards pelvis and they flex + rotate the trunk.
What do the internal oblique muscles do?
They run towards the ribcage in A shape. They also flex and rotate the trunk. External and internal obliques work together
What do the transversus abdominus muscles do?
They compress and constrict the abdomen. Important role in maintaining core stability.
What are the main muscles of respiration?
Diaphragm (controls intrathoracic pressure)
Internal and external intercostals
Innermost intercostals
Where are the external and internal intercostals located relative to thoracic cavity?
External intercostals are located more posteriorly near the spinal cord
Internal intercostals are located more anteriorly near the sternum
What is the function of quadratus lumborum?
Connects the iliac crest with L1 - L4 and last rib. It is responsible for lateral flexion of the trunk
Where does iliacus originat and insert? What is the resulting action?
Origin: Iliac fossa
Insertion: Lesser tuberosity of the femur
It flexes the thigh
Where does psoas major originate and insert? What is the resulting action?
Origin at T12 - L5
Insertion at joint tendon with iliacus onto lesser tuberosity of the femur
What is the clinical significance of the origin and insertion of psoas?
Hypertrophy in psoas can result in lower back pain because the muscle pulls on the vertebrae of the lower back.
What is the origin and insertion of psoas minor?
Origin: T12 - L1
Insertion: Iliopectineal eminence
Action: Weak flexion of the trunk.
Psoas minor is an inconsistent muscle and is absent in many people
Where does gluteas maximus originate and insert and what is its action?
Originates from posterior glueteal line of sacrum and coccyx.
Inserts onto gluteal tuberosity of femur and fascia lata (iliotibeal tract)
It extends the thigh
Where does gluteas medius originate and insert and what is its action?
Originates between posterior and anterior gluteal lines and inserts onto greater trochanter of the femur.
It abducts the thigh. it also holds the hip in place when walking.
