Conference: Basic Anatomical Concepts 1 (8/13/13) Flashcards
Anatomical Definition of Muscle Origin
more proximal attachment
Anatomical Definition of Muscle Insertion
more distal attachment
Functions of synergistic muscles
act to stabilize other joints and neutralize undesirable motions
What is a motor unit
Basic function units that make up each muscle. Consists of a single motor neuron and the muscle fibers that it supplies.
Three types of muscle contraction
1) Shortening Contraction (concentric or isotonic)
2) Static or Isometric Contraction
3) Lengthening Contraction (eccentric or isotonic)
Two major division of the nervous system
CNS: Central Nervous System (brain and spinal cord)
PNS: Peripheral Nervous System
Peripheral nerve
a group or bundle of nerve fibers (axons and supporting cells) located outside the CNS
Cranial nerve
a peripheral nerve arising from the brain
May have only one functional fiber of as many as five. Further classified into: motor, sensory, or mixed.
Spinal nerve
a peripheral nerve arise from the spinal cord
How is the gross spinal nerve formed?
dorsal and ventral roots emerging from each segment of the spinal cord combined to form a spinal nerve (1cm long) before terminating into dorsal and ventral ramus
What are the 2 general kinds of terminal branches of peripheral nerve that are derived from the rami?
muscular branches and cutaneous branches
What is meant by Afferent and Efferent nerve fibers?
afferent= sensory (towards CNS, cell body outside CNS) efferent= motor (away from CNS, cell body inside CNS)
Major function kinds of nerve fibers in:
Dorsal Roots
Sensory (afferent)
Major function kinds of nerve fibers in:
Ventral Roots
Motor (efferent)
Major function kinds of nerve fibers in:
Spinal Nerves
sensory (afferent) and motor (efferent)
Major functional kinds of nerve fibers in:
Dorsal Rami
sensory (afferent) and motor (efferent)
Major functional kinds of nerve fibers in:
Ventral Rami
sensory (afferent) and motor (efferent)
Where are nerve cell bodies found for afferent and efferent fibers?
afferent: (dual pathway) dorsal ganglion
efferent: (motor pathway) spinal cord gray matter (ventral horn)
What is meant by “somatic” and “visceral”?
Somatic= body wall and extremities (bones, muscles, joints, skin) Visceral= internal organs, glands, vessels
SE, VE, SA, VA are abbreviations for what functional fiber types?
Somatic efferent, visceral efferent, somatic afferent, visceral afferent
Define dermatome
the area of skin supplied by a single spinal nerve (each dermatome supplied by both dorsal and ventral rami of corresponding spinal nerve)
Define the Radiography Term “PA”
posterior-anterior (the path of the x-ray beam)
Factors determining image appearance on x-ray
1) tissue density
2) tissue thickness
3) superimposition
Radiolucent vs Radiopaque
radiolucent= black, x-rays able to pass thru
radiopaque= white, x-rays blocked or absorbed
*Can use contract material to enhance soft tissue structures
5 major categories of radiodense materials in order of increasing density
Air/Gas < Fat < Soft Tissue (muscle, organs) < Bone < Metal
CT Scan
Computer Temography, scans many x-rays (360 per level) and compiles into 2D image
(+) Enhanced discrimination
(+) Sectional images overcome superimposition
Myotome
Specific mass of muscle innervated by a single spinal nerve.
Which of following nerve fiber types is LEAST likely to be found in a cutaneous branch of a dorsal ramus?
SE since skeletal muscle isn’t usually found in the skin areas innervated by spinal nerves.
*SA from exteroceptors, VA and VE to innervate blood vessels and sweat glands.
