[001] Organisational Patterns Of Limbs Flashcards
What are stylopods, zeugopods and autopods?
Stylopods - single, most proximal elements (humerus, femur)
Zeugopods - double, middle element (radius/ulna, tibia/fibula)
Autopods - multiple elements, most distal (carpals, phalanges)
What is the anatomical position?
Palms and toes facing forward
What is the coronal/frontal, transverse/axial and sagittal plane?
In limb development, which segments of the spine eventually form the upper and lower limbs?
Upper limbs: C5 - T1
Lower limb: T1 - S3
What is a tetrode?
A vertebrate with 4 digitated limbs
What are the parts of the limb in terms of evolutionary changes?
- The central axis (bone element of the limbs)
- The preaxial border (controlled by ventral muscles)
- The postaxial border (controlled by dorsal muscles)
What movement do dorsal muscles cause?
Lifting/extending
What movement do ventral muscles cause?
Lowering/flexion
How have the limb organisation changed through evolution?
The limbs have been rotated 90° around the central axis.
The lower limbs rotate backwards and the upper lines route forward into the anatomical position.
The forearm pronates to point the digits forward.
Where are the ventral and dorsal muscle groups in the anatomical view of the body?
What are the 3 parts of the upper limb muscle groups?
- Elbow flexors / extensors
- Shoulder flexors / extensors
- Wrist and finger flexors / extensors
What are the upper limb movements?
- Flexion/extension
- Addiction /abduction
- Medial / lateral rotation
- Circumduction
- Pronation/supination
What are the 3 lower limb muscle groups?
- Hip flexors/extensors and abductors/adductors
- Knee extensors/flexors
- Ankle and toe extensors/flexors
What are the lower limb movement’s?
- Extension/flexors
- Abduction/adduction
- Dorsiflexion/plantarflexion
What occurs during weeks 5-8 in the embryology of limb rotation in humans?
What is a myotome?
A group of muscles who receive their motor innervation from a single spinal nerve
Explain the process of segmental innervation during weeks 5-8
Why is there clearer ‘stacking’ of dermatomes on the trunk?
As the ribs in the trunk keep the spinal nerves separated so that these nerves innervate distinct regions.
N.B As a general rule, the lower down the spinal segment, the further distal and inferior the dermatome will be and vice verse
What is a nerve plexus?
The mixing and redistribution of spinal nerves to become peripheral nerves
Why are nerve plexuses useful?
As it allows fibres from one specific spinal (from one spinal nerve) to reach multiple points by contributing to different peripheral nerves
What are the Lexi called in limb innervation?
Brachial in upper limbs and lumbosacial in lower limb
What are 5 clinical relevances for surface anatomy?
- The range of movements around joints
- Identifying pulse sites e.g femoral pulse
- Finding blood vessels for drug administration/ intramuscular injections
- Testing neural lesions
- Testing muscle groups
What are the main lymph nodes that drain the upper and lower limbs?
For the upper limbs, the major lymph nodes are found in the axillary area
For the tower limbs, the major lymph nodes are found in the deep inguinal area
Which arteries supply the upper and lower limbs?
Single subclavian artery from the thoracic aorta supply the upper limbs.
The abdominal aorta splits into two common iliac arteries which branch (external iliac arteries) that supply most of the lower limbs.
N.B the venous system for the limbs mirrors the arterial pattern.
