Part 1.1, Skeletal and muscular systems Flashcards
What is a motor unit?
A motor neuron and the muscle fibres stimulated by its axon
What is a motor neuron?
A nerve cell which conducts a nerve impulse to a group of muscle fibres
What is an action potential?
Positive electrical charge inside the nerve and muscle cells which conducts the nerve impulse down the neuron and into the muscle fibre
What is a neurotransmitter?
A chemical (acetylcholine) produced and secreted by a neuron which transmits the nerve impulse across the synaptic cleft to the muscle fibre
What is the all-or-none law?
Depending on whether the stimulus is above a threshold, all the muscle fibres will give a complete contraction or no contraction at all
Articulating surfaces at the knee
Femur and tibia
Articulating surfaces at the elbow
Radius, ulna and humerus
Articulating surfaces at the shoulder
Humerus and scapula
Articulating surfaces at the hip
Pelvis and femur
Articulating surfaces at the wrist
Radius, ulna, carpals
Articulating surfaces at the ankle
Tibia, fibula and talus
Four quadriceps
Vastus medialis
Vastus intermedius
Vastus lateralis
Rectus femoris
Three hamstrings
Semimembranosus
Semitendinosus
Bicep femoris
Agonist during plantar flexion
Gastrocnemius and soleus
Agonist during dorsi-flexion
Tibialis anterior
What are the 5 joint types, with examples
Hinge joint - elbow
Ball and socket joint - shoulder
Condyloid joint - wrist
Pivot joint - radio-ulna
Gliding joint - spine
Sagittal plane
Lies vertically and divides the body into left and right parts from the medial to the lateral
Frontal plane
Lies vertically and divides the body into anterior and posterior parts
Transverse plane
Lies horizontally and divides the body into anterior superior (upper) and inferior (lower) parts
Horizontal flexion
Movement of the limbs towards the midline of the body parallel to the ground
Horizontal extension
Movement of the limbs away from the midline of the body parallel to the ground
Rotation
Movement whereby articulating bones turn about their longitudinal axis in a screwdriver action
Fixator
A muscle that stabilises the body whilst another moves
Agonist and antagonist of flexion at the hip
Agonist - iliopsoas
Antagonist - gluteus maximus