Flashcards in MUSCULAR SYSTEM PT 1 (UNFINISHED) Deck (58):
Define Electrical Excitability of muscle tissue.
Muscle tissue responds to stimuli by PRODUCING APs
Define Contractility of muscle tissue.
GENERATE TENSION when stimulated by an AP
Define Extensibility of muscle tissue.
STRETCH (LENGTHEN) WTHOUT DAMAGE
Define Elasticity of muscle tissue.
RETURN ORIGINAL SHAPE after contraction or stretch
List the order of the Hierarchy of Skeletal Organization.
Muscle Fibre (Muscle Cell)
What are the characteristics fro Skeletal/Striated Muscle?
- Alternating light and dark bands
- Voluntary/conscious control
A Muscle is subdivided into?
Bundles of fascicles
Describe a Fascicle.
Measured in MM. Made up of many muscle fibres
Describe a Muscle Fibre/Muscle Cell.
Cylindrical in shape and filled with Myofibrils
What is 'Sarcolemma'?
PLASMA MEMBRANE of muscle cell
What are Transverse Tubules (T-tubules)?
Tiny TUNNELS in from the sarcolemma towards the centre of muscle fibre.
What is 'Sarcoplasm'?
The cytoplasm of the muscle fibres, containing glycogen
Describe a Myoglobin.
A protein binding oxygen that diffuses into muscle fibres and delivers it to the mitochondria.
What are Myofibrils?
CONTRACTILE ORGANELLES of the muscle cell
What is the function of Cytoskeletal Proteins in Myofibrils?
Holds Myofibrils in place
What is Sarcoplasmic Reticulum?
SACS/TUBES surrounding each myofibril storing and releasing CALCIUM into cell
Define a Sarcomere.
Functional units of a myofibril (contractions)
What is an Actin?
Makes up THIN filaments
What is an Myosin?
Makes up THICK filaments
What generates force/contractions of a Myofibril?
The overlap and interaction of thick and thin filaments
What are Myofilaments?
2 contractile proteins of the Sarcomere: Actin and Myosin
Explain the PROCESS of the Neurological Control of muscle tissue.
1. Axons reaches muscle using Axon Terminals
2. Axon Terminals form junction with Sarcolemma
3. Axons release Acetylcholine (ACh) over the synaptic cleft
What is a Motor Neuron?
A nerve cell that conducts APs to muscle cells
What is a Motor Unit?
The motor neuron and all the skeletal muscle fibres it innervates
Precise movements require _______ changes in muscle contraction
Imprecise movements require _______ amounts of tension.
Muscles that perform ______ movements are made up of small motor units.
Muscles that perform _______ movements are made up of large motor units.
Explain Motor Unit Recruitment.
AP travels down motor neuron to muscle fibres which will generate force in that motor unit
What are the 3 types of Skeletal Muscle Fibres?
- Slow Oxidative
- Fast Oxidative-Glycolytic
- Fast Glycolytic
Explain the characteristics of Slow Oxidative Fibres/Type l.
- Fatigue resistant
- Endurance-type functions
- Lots of energy substrates
- Generates ATP via aerobic cellular respiration
Explain the characteristics of Fast Oxidative-Glycolytic Fibres/Type lla.
- High resistance to fatigue
- Endurance and shorter-duration functions
- Intermediate amounts of energy substrates
- Generates ATP via aerobic/anaerobic pathways
Explain the characteristics of Fast Glycolytic Fibres/Type llx.
- Low resistance to fatigue
- High intensity,short duration functions
- Low amounts of energy substrates
- Generates ATP via anaerobic pathways
What is the Length-Tension Relationship?
Ability to generate force depends on the length of the sarcomeres within a muscle
Muscle contracts against a resistance that is not changing
Muscle contracts which length of muscle does not visibly change
Define a Variable Resistance.
Muscle contraction that varies the resistance to match the strength curve.
Muscle contraction in a range that keeps movement constant
What is a Twitch Contraction?
A brief contraction to a single AP in its motor neuron
Define Muscle Resting Tone.
A small amount of tension generated in the muscles
Lace of tone from nerve being damaged or cut
What is Hypertrophy?
An INCREASE in muscle size
What is Atrophy?
A DECREASE in muscle size
Which muscle connective tissue surrounds the 'entire muscle'?
Which muscle connective tissue surrounds the 'fascicles'?
Which muscle connective tissue surrounds the 'muscle fibres'?
What is the Musculotendinous Junction?
Connection of muscle to tendon
What is the Tendonperiosteal Junction?
Connection of tendon to periosteum
What is Aponeurosis?
Broad, flat, tendon
What is a Tendon Sheath?
Tube surrounding tendon for protection
What is the function of Satellite Cells?
Muscle repair and regeneration
Heart cells that act as a pacemaker
Describe the characteristics of Smooth Muscle.
- Spindle shape
- Involuntary control
- Found in walls of hollow tubes
- Contractions slow but long
Explain a Single Unit Smooth Muscle Tissue.
One AP supplies several smooth muscle fibres
Explain a Multiunit Smooth Muscle Tissue.
One motor neuron terminal supplies one smooth muscle fibre