Purpose: To Test for the presence of shoulder instability. Test position: Sitting or standing. Performing the Test: The examiner grasps the wrist of the patient's elbow and pulls the arm distally. Observation is made of the amount of sulcus (space between the acromion process and humeral head) that is present with the distal arm pull. A positive test is considered for multidirectional instability if 1-2 cm of sulcus is noted. Diagnostic Accuracy: Unknown.
> Synapsis (also called syndesis) is the pairing of two homologous chromosomes that occurs during meiosis. It allows matching-up of homologous pairs prior to their segregation, and possible chromosomal crossover between them. Synapsis takes place during prophase I of meiosis.
The synapse is a small gap separating neurons. The synapse consists of: a presynaptic ending that contains neurotransmitters, mitochondria and other cell organelles, a postsynaptic ending that contains receptor sites for neurotransmitters and, a synaptic cleft or space between the presynaptic and postsynaptic endings. It is about 20nm wide. An action potential cannot cross the synaptic cleft between neurones. Instead the nerve impulse is carried by chemicals called neurotransmitters. These chemicals are made by the cell that is sending the impulse (the pre-synaptic neurone) and stored in synaptic vesicles at the end of the axon.