Chapter 5: The nervous, muscular and skeletal system Flashcards
Human movement system (HMS)
Collective components and structures that work together to move the body: muscular, skeletal and nervous systm
Kinetic chain
Concept that describes the human body as a cain of interdependent links that work together to perform movement
Nervous system
Network of specialized cells called neurons that transmit and coordinate signals, providing a communication network within the human body
Neuron
Specialized cell that is the functional unit of the nervous system
Nucleus
Cellular structure or organelle that contains the majority of the cell’s genetic material in the from of chromosoms
Organelles
Cellular structures that perform specific functions within the cell. Eg. nuclei, mitochondria, lysosomes, ribosomes, ER
Mitochondria
Powerhouse of the cell
Effector sites
A part of the body, such as a muscle or organ, that receives a signal from a neuron to produce a physiological response
Electrolytes
Minerals that have an electrical charge to help transmit nerve impulses through the body such as sodium, potassium and magnesium
Central nervous system (CNS)
Brain and spinal cord
Peripheral nervous system (PNS)
Nerves that connect the rest of the body to the CNS
Afferent pathway
Sensory pathway that relays information to the CNS
Efferent pathway
Motor pathway that relays information from the CNS to the rest of the body
Interneurons
Neurons located in the spinal cord and brain that transmit impulses between afferent and efferent neurons
Mechanoreceptors
Specialized structures that respond to mechanical force within tissues and then transmit signals through sensory nerves
Somatic nervous system
Nerves that serve the outer areas of the body and skeletal muscle and are largely responsible fir the voluntary control of movement
Autonomic nervous system
Division of the peripheral nervous system that supplies neural input to organs that run the involuntary processes of the body eg blood circulation, digestion
Sympathetic nervous system
Subdivision of the autonomic nervous system that works to increase neural activity and put the body in a heightened state (fight or flight)
Parasympathetic nervous system
Subdivision of the autonomic nervous system that works to decrease neural activity and put the body in a more relaxed state (rest and digest)
Sensory function
Ability of the nervous system to sense changes in either the internal or external environment
Proprioception
The body’s ability to naturally sense its general orientation and relative position of its parts
Integrative function
The ability of the NS to analyze and interpret the sensory information to allow for proper decision-making, which produces an appropriate response
Motor function
The neuromuscular response to the integrated sensory information
Golgi tendon organ (GTO)
Specialized sensory receptor located at the point where skeletal muscle fibers insert into the tendons of skeletal muscle; sensitive to changes in muscular tension and rate of tension change
Joint receptors
Receptors located in and around the joint capsule that respond to pressure, acceleration and deceleration of the joint
Neuroplasticity
Concept that the braun will continually change or grow, reforming neural pathways throughout an individual’s entire life span
Neurocircuitry
Interconnection of neurons in the brain and spinal cord
Motor skills
Specific movements through the coordinated effort of the sensory and motors subsystem
Skeletal system
Bones of the body
Osteoporosis
Condition of reduced bone mineral density, which increases risk of bon fracture
Joints
The site where two bones meet and movement occurs as a result of muscle contraction
Axial skeleton
Division of the skeletal system consisting of the skull, rib cage, and the ventrebal column
Appendicular skeleton
Division of the skeletal system consisting of the arms, legs, and pelvis girdle
Levers
Rigid rods where muscles attach
Remodeling
Process by which bone is constantly renewed by the resorption and formation of bone structure
Osteoclasts
Cells that break down and remove old bone tissue
Osteoblasts
Cells that form and lay down new bone tissue
Wolff’s law
Scientific explanation of how remodeling occurs along the lines of stress placed on the bone
Depressions
Flattened or indented portions of the bone
Processes
Projections protruding from the bone where tendons and ligaments can attach
Vertebral column
Bones that house the spinal cord; consists of cervical, thoracic and lumbosacral regions
Spinal cord
Bundle of nerves housed within the vertrebrae
Intervertebral discs
Fibrous cartilage structures between vertebrae that act as shock absorbers and assist with movement
Neutral spine
Represents the position in which the vertebrae and associated structures are under the least amount of load and can most optimally support functional movement
Osteokinematics
Movement of a limb that is visible
Arthrokinematics
Description of joint surface movement; consistent of three major types: roll, slide or glide and spin
Synovial joints
A joint with a liquid-filled joint capsule
Nonaxial
A gliding joint that moves in only one plane, either back and forth or side to side
Nonsynovial joints
Joints that have no joint capsule, fibrous connective tissue or cartilage in the uniting structure
Ligament
Fibrous connective tissue that connects bone to bone
Collagen
Protein found in connective tissue, muscle, and skin that provides strength and structure. It is the most abundant protein in the human body
Elastin
Protein that provides elasticity to skin, tendons, ligaments and other structures
Growth plate
Specialized cartilage disc located in the epiphysis that is responsible for longitudinal bone growth
Fascia
Connective tissue that surrounds muscles and bones
Epimysium
Inner layer of fascia that directly surrounds an entire muscle, commonly referred to as the deep fascia
Fascicles
Largest bundles of fibers within a muscle. Fascicles are surrounded by perimysium
Perimysium
Connective tissue surrounding a muscle fascicle
Endomysium
Connective tissue that wraps around individual muscle fibers with a fascicle
Glycogen
Glucose that is deposited and stored in bodily tissue, such as the liver and muscle cells; storage form of carbohydrates
Myoglobin
Protein-based molecule that carries oxygen molecules into the muscle
Myifibrils
Contractile components of the muscle cell; the myofilaments (actin and myosin) are contained within a myofibril
Myofilaments
Filaments of a myofibril, including actin and myosin
Actin
Thin, stringlike myofilament that acts along with myosin to produce muscular contraction
Myosin
Thick myofilament that acts along with actin to produce muscular contraction
Sarcomere
Structural unit of a myofibril composed of actin and myosin filaments between two Z-lines
Z-line
Meeting point of each sarcomere
Neural activation
NS signal that tells a muscle to contract
Neuromuscular junction
Site where the NS communicates directly with muscle fibers
Synapse
Junction between motor neuron and muscle cell
Motor unit
Motor neuron and all the muscle fibers that it innervates
Action potential
Nerve impulse that is relayed from the CNS, though the PNS and into the muscle across the neuromuscular junction
Neurotransmitter
Chemical messenger that cross the synapse between neuron and muscle and assist with nerve transmission
Acetylcholine (ACh)
Neurotransmitter that helps the action potential to cross the synapse into the muscle, which initiates the steps in a muscle contraction
Sliding filament theory
Series of steps in muscle contraction involving how myosin and action filaments slide past one another to produce a muscle contraction, shortening the entire length of the sarcomere
Excitation-contraction coupling
Physiological process of converting an electrical stimulus to a muscle contraction
Power stroke
The myosin heads bin to actin and pull them toward the sarcomere center, which slides the filaments past each other, shortening the muscle
Adenosine triphosphate
high-energy molecule that serves as the main form of energy in the human body, known as the energy currency of the body
Resting length
Length of a muscle when it is not actively contracting or being stretched
Typen I (slow twitch) muscle fibers
Fibers that are small in size, generate lower amounts of force, and are more resistant to fatigue
Type II muscle fibers
Fibers that are larger ins size, generate higher amounts of force, and are faster to fatigue
All-or-nothing principle
Motor units cannot vary the amount of force they generate; they either contract maximally or not at all
Capillaries
Smallest blood vessels and the site of exchange of elements between the blood and the tissue
