WEEK 1 Flashcards
(74 cards)
What is a (i) Dermatome (ii) Myotome?
(i) strip of skin supplied by one spinal nerve
(ii) muscles/group of muscles supplied by one spinal nerve
What is the tip for remembering the lower limb dermatome sequence?
Stand on S1
Squat on S2
Sit on S3
What is the role of deep fascia?
Forms a continuous sleeve (UL) or stocking (LL) around the muscles, but also sends septae between the muscles to separate them into compartments and often provide extra muscle attachment
What is the importance of the space between superficial and deep fascia?
the intervening potential space allows movement
What 2 things can deep fascia form?
Interosseous membranes (IO) - between bones Retinaculae - hold tendons in place
Describe the deep fascia of the LL.
Forms a continuous stocking enclosing the thigh - Fascia Lata, and extends to the leg - Crural Fascia.
The fascia Lata thickens laterally as the Iliotibial Tract, and sends septae to divide the thigh into anterior, medial and posterior compartments.
Where does the LL lumbo sacral plexus form? What ventral rami is it derived from?
Within psoas major on the posterior abdominal wall, and on the lateral wall of the pelvis.
L1 to L5 and S1 to S3
What are the branches of the Lumbo-Sacral Plexus?
Femoral
Obturator
Sciatic
Tibial -> medial & lateral plantar
Common Fibular -> deep & superficial fibular
Describe the passage of venous flow.
From superficial -> deep via perforators and then the muscle pump, arterial pulsation and negative intrathoracic pressure all help venous return to the heart, against gravity.
Understand the lymph of the UL.
Axillary lymph nodes receive all lymph from UL and drain to subclavian trunk
Cubital lymph nodes are palpable
List the lymph nodes of the LL.
Inguinal nodes - superficial (palpable) and deep Popliteal nodes (palpable)
Explain some important features of the clavicle.
Lateral end - flat, articulates with acromion
Rounded, medial 1/3 - convex anteriorly
Medial end - quadrangular, articulates with manubrium of sternum
On inferior surface there is sites for ligament attachment
Space posterior to clavicle for NVB
Describe the Sternoclavicular Joint and the Acromioclavicular Joint.
Sternoclavicular - synovial, bone-ends covered by fibrocartilage. Divided by a disc that attaches to the clavicle and manubrium, and the capsule, adding great strength => dislocation rare.
Acromioclavicular - less strong, allows small range gliding movement. Synovial with fibrocartilage over articular surfaces and a small disc => may become arthritic & cause shoulder pain.
What are the ligaments which support the Sternoclavicular joint and the Acromioclavicular joint, respectively ?
SC - ligaments anteriorly & posteriorly, plus interclavicular & costoclavicular ligaments
AC- Conoid & Trapezoid parts of caracoclavicular ligament
Describe the “space” within the shoulder, what surrounds it and what it is home to.
narrow “space” between the upper aspect of the shoulder joint and the overlying acromion, acromioclavicular joint and coraco-acromial ligament
home to the subacromial bursa and the tendon of supraspinatus muscle
What does the pelvic girdle consist of?
Ilium, Ischium and Pubic bones, fused to form the Hip Bone, which attaches the Lower Limb to the Sacrum via the Sacro-iliac Joint
The Hip Bones attach to each other at the Pubic Symphysis
Describe the Sacro-Iliac joint
Extremely limited movement, essentially for weight transference
Synovial anteriorly, supported by Anterior Sacro-iliac ligament
Fibrous posteriorly, linked by Interosseous Ligament
What “safe” area of the buttock is used for intramuscular injections?
upper, outer quadrant
Know the attachments for Serratus Anterior, what nerve supplies it, and what actions it accounts for.
thick, flat, very strong muscle, wraps around thorax from ribs 1 to 8, all the way to the MEDIAL border of the scapula
Long Thoracic Nerve
Protracts scapula and holds it against thoracic wall; laterally rotates scapula
Know the attachments for Trapezius, what nerve supplies it, and what actions it accounts for.
skull, ligamentum nuchae and thoracic spines, passing to the lateral clavicle, acromion and spine of the scapula
Spinal Accessory Nerve (Cranial Nerve XI)
elevates the scapula as in shrugging the shoulders and retracts the scapula or braces the shoulders backwards
upper fibres, pull the glenoid upwards, while the lower fibres pull the medial spine downwards
Know the key concepts of the LL.
- In standing upright, the hip is already extended
Think of hip extension as standing up from sitting, or climbing stairs, or walking and running - The muscles that abduct the hip are crucial in keeping the pelvis level when walking i.e. when body weight is supported on one leg
The neck of the femur is essential to the efficient function of these muscles - The femur rotates at the hip during walking
What 3 things are cardiac muscle’s activity dependant upon?
Intrinsic properties
Hormones
Autonomic NS
What are (i) intercalated discs (ii) gap junctions?
(i) Mechanical connection between adjacent cardiac muscle cells (structural). Electrical connection between adjacent cardiac muscle cells (functional).
(ii)Constructed from a hexagonal array of protein subunits – CONNEXINS
Sites of low electrical resistance between cells
Act as communicating channels – CONNEXON
Give a summary of the events that occur at the motor end plate.
- Action potentials arriving at the axon terminal open voltage gated Ca2+ channels
- Inward diffusion of Ca2+
- Fusion of acetylcholine-containing vesicles (Ach) with the pre-synaptic membrane
- ACh diffusion across the 20nm synaptic cleft
- Nicotinic Ach receptors (nAChR) are chemically gated ion channels which permit monovalent cations to flow through
- Net entry of Na+ into end plate region causes depolarisation – end plate potential (epp)
- Action potential triggered in muscle fibres membrane