Introduction to Anatomy of Muscles and Nerves Lecture Flashcards
Understand the organisation of muscle fibres within skeletal muscles.
Skeletal muscle is a highly organized tissue composed of bundles of muscle fibers called myofibers which contain several myofibrils. Each myofiber represents a muscle cell with its basic cellular unit, the sarcomere. Bundles of myofibers form fascicles, and bundles of fascicles form muscle tissue.
Understand the role of connective tissue in binding muscle fibres together,forming tendons and influencing the line of pull of muscles.
When muscle fibres contract they pull on these sheaths of connective tissue which transmit this pulling force on the bone. Direct muscle attachments occur when the outermost layer of connective tissue (epimysium) connect with the periosteum or the perichondrium (outermost layer of bone or cartilage).
Appreciate that muscle fibres within a named muscle may have different???
orientations and the effects of this on lines of pull of muscles.
Skeletal muscles are often grouped together in?? What do the individual muscles within these groups commonly have??
Fascial compartment (e.g., as flexors, or extensors) and that the individual muscles within these groups commonly have the same nerve supply.
Describe the basic anatomy of a motor unit.
A motor unit consists of 1 anterior horn cell, its axon, and all the muscle fibers innervated by that motor neuron. The type I motor units refer to those firing first when a person starts to contract a muscle. Those fibers are the smallest.
Describe the basic anatomy of spinal nerves.
Spinal nerves are mixed nerves that interact directly with the spinal cord to modulate motor and sensory information from the body’s periphery. Each nerve forms from nerve fibers, known as fila radicularia, extending from the posterior (dorsal) and anterior (ventral) roots of the spinal cord. The roots connect via interneurons. Grossly, the root fibers join together within the intervertebral foramina to form a spinal nerve.
Describe the anatomical differences between the main subdivisions of the nervous
system.
The nervous system is divided into the central nervous system (CNS) and the peripheral nervous system. The CNS includes the brain and spinal cord, while the peripheral nervous system consists of everything else. The CNS’s responsibilities include receiving, processing, and responding to sensory information
Define the terms ‘dermatome’ and ‘myotome’
Dermatomes are areas of skin that are supplied by a single sensory nerve root. The main difference between a dermatome and a myotome is that dermatomes control sensation while myotomes control movement. A group of muscles innervated by the motor fibres of a single nerve root is known as a myotome.
