Lecture - General Plan of the Limbs Flashcards
Which body wall segments are in the upper limbs?
C5 to T1
Which body wall segments are in the lower limbs?
L2 to S3
Which rami control the limbs?
The ventral rami of the corresponding spinal nerves.
NOTE: all musculature is hypaxial
For the hands and feet, name a preaxial structure and a postaxial structure.
Preaxial – thumb and big toe
Postaxial – little toe/finger
For the upper limbs, what do flexion movements do?
Carry the distal part forwards.
NOTE: all anterior surfaces of the upper limbs are developmentally ventral (except the thumb).
For the lower limbs, which surfaces are developmentally ventral and which are dorsal?
At hip: anterior surface is developmentally ventral
Thigh & leg: anterior surface is developmentally dorsal
Foot: Sole (planta) is ventral, and top (dorsum) is dorsal
Describe the flexor/extensor muscles in the upper limbs.
- anterior = flexors
- posterior = extensors
Describe the flexor/extensor muscles in the lower limbs.
- anterior compartment of THIGH has flexors of hip and extensors of knee
- posterior compartment of THIGH has extensors of hip and flexors of knee
- abductors of the HIP = gluteal region
- adductors of HIP = significant medial compartment along inner thigh
- anterior compartment of (lower) LEG has extensors
- posterior compartment of (lower) LEG has flexors
What are the girdle bones?
Upper limbs = ‘pectoral girdle’
Scapula and Clavicle
Lower Limbs = ‘pelvic girdle’ Hip bone: a) Ilium b) Ischium c) Pubis
What are the two divisions of the ventral ramus?
Dorsal division: extensors
Ventral division: flexors
Describe the brachial plexus.
- 5 nerves, 4 from the neck
- 3 ‘trunks’
- each trunk has a posterior and an anterior division
- trunk divisions = ‘chords’. Anterior cord feeds flexor muscles, posterior cord feeds extensor muscles
Describe the lumbar and sacral plexuses.
- simpler pattern (no trunks or chords)
- Part of L4 and all of L5 join sacral nerves
- L2,3, and part of 4 for one plexus
- The rest of L4, L5, S1, S2 and S3 form another plexus
Where are epaxial muscles?
Muscles posterior to vertical column are epaxial. True ones are solely for functioning of vertebral column
Where is the proximal segment of a limb?
The segment immediate to the girdle i.e. the upper arm/thigh Has a single bone
Where is the distal segment of a limb?
Immediately attached to the proximal i.e. forearm or leg. Composed of two bones