Unit 8: Muscular Tissue & Muscular System Flashcards
Functions part 2
Create motion, stabilize body positions and maintain posture, store substances using sphincters, move substances by peristaltic contractions, generate heat through thermogenesis
Skeletal muscle
Found on skeleton; generate movement, heat, and maintain posture; striated, multinucleated, fibers parallel; voluntary movement
Cardiac muscle
Found in the heart only; pumps blood continuously; striated, branches, one central nucleus; involuntary movement
Visceral (smooth) muscle
Found in the GI tract, uterus, eye, blood vessels; peristalsis, blood pressure, pupil size, erects hair; no striations once central nucleus; involuntary
Connective tissue layers
Epimysium, perimysium, endomysium, muscle fascia
Epimysium
Covers entire muscle
Perimysium
Covers uncle of muscle fibers (cells)
Endomysium
Covers a single muscle fiber (cell)
Muscle fascia
Connects 2 muscles end to end
Tendons
Bands of fibrous connective tissue joining muscles to bones
Fascia
A sheet/band of fibrous connective tissue enveloping, separating, or binding together of muscle
Fascile
A small bundle of muscle
Aponeurosis
A thick fascia that connects to muscle bellies
Sarcolemma
Plasma membrane (muscle tissue)
Sarcoplasm
Cytoplasm (muscle cell)
Myofibril
Thin/thick filaments arranged in a specific order
Sacromere
Contractile unit of muscle - basic functional unit
Actin
Thin filaments
Myosin
Thick filaments p; pulls against thin filament; does the work
Fibromyalgia
Chronic painful nonarticular rheumatic disorder that affects the fibrous CT components of muscles, tendons, ligaments; autoimmune disorder
Muscular hypertrophy
Enlargement of muscle fibers from forceful repetitive muscular activity such as strength training (working out muscles don’t replace themselves)
Muscular hyperplasia
Increase in number of muscle fibers (cancer)
Muscular atrophy
Wasting away of muscles due to disease, disuse, or denovation
Muscular fibrosis
Replacement of muscle fibers by fibrous scar tissue (excessive use/disuse)
Sliding filament mechanism of muscle contraction
1) ATP hydrolysis
2) attachment
3) power stroke
4) detachment
Role of calcium
Muscle contraction
Role of ATP
Energy supply
Neuromuscular junction
Excitation contraction coupling (EC Coupling) involved events at the junction between a motor neuron and skeletal muscle fiber.
The thought process going on in the brain; the AP arriving at the neurotransmitter junction; the regeneration of an AP on the muscle membrane; release of calcium from the sarcoplasmic reticulum; sliding of the thick/thin filmaments; muscle movements
What ions trigger the release of the neurotransmitter
Calcium
What is the biggest neurotransmitter
Ocetylcholine (acCh)
Role of acetylcholinesterase
Breaks down acCh after a period of time
Sources of muscle energy
1) stored ATP
2) creatine phosphate (energy transfer)
3) aerobic ATP production
4) anaerobic glucose
Lactic acid
Causes muscle fatigue “burning”
EPOC excess post exercise oxygen consumption
The amount of oxygen repayment required after exercise to:
Replenish ATP stores
Replenish creatine phosphate/myoglobin stores
Convert lactic acid back into pryuvate to be used again in Krebs cycle (ATP)
High precision motor unit
Fewer muscle fibers/neurons; laryngeal/extra ocular muscles; 1 nerve few cells; gentle movements; eye muscles (1-4 nerves per cell)
Low precision motor unit
Many muscle fibers/neuron; thigh muscles (2,000-3,000); crude movements 1 nerve = 1,000s of cells; quad muscles
Red muscle
(Dark meat) have a high myoglobin count; ,ore mito hundred; more energy stores; greater blood supply
White muscle
(White meat) have less myoglobin, mitochondria and blood supply
Twitch
Recorded when a stimulus that results in a contraction of a single muscle fiber is measured over a very bread millisecond time frame
Tetanus
Result in fusion of contractions
Muscle tone
Small amount- weakness/involuntary contractions of motor units; established by neurons in the brain/spinal cord; excite motor neurons
Hypotonia
Low muscle tone; flaccid paralysis; atrophy
Hypertonia
Increase in muscle tone; spastic stiffness rigid; stiffness without reflexes affected
Isotonic contraction
Results in movement
Eccentric contraction
Contraction in which muscle t sit on and resistance (muscle lengthens)
Concentric contraction
Contraction in which muscle shortens while generating force
Isometric contraction
Result in no movement
Muscle force = resistance
Supporting objects in a fixed position/posture
Muscle spasm
Sudden involuntary contraction of a single muscle within a large group of muscles
Muscle cramp
Involuntary painful sustained muscle contractions
Myasthenia gravis
Autoimmune disease; causes chronic progressive damage of NMJ; muscles become fatigued easily, neck face affected first
Muscular dystroph
Groups of inherited muscle destroying diseases that cause progressive degeneration of muscle fibers (duchennes, boys affected)
Origin
Where tendons attach to stationary usually proximal done (where it’s not moving)
Insertion
The point or mode of attachment of muscle to bone
Prime mover/agonist
Leader muscle; responsible for causing desired movement
Antagonist
Stretches yields relaxes to the effects of the prime movement
Synergist
Muscles used to prevent unwanted movements at intermediate joints; muscles that work together for an action
Occipitofrontalis
Back of school to front; raises eye brows, wrinkles forehead, draws scalp back and forward
Orbicularis oculi
Lower eyelids
Orbicularis oris
Mouth muscles (kissing)
Buccinator
Cheeks (whistling)
Zygomaticus major
Upper/lower checks (smiling)
Levator palpebrae superioris
Upper eyelids
Platysma
Mouth/neck (widens mouth)
Temporalis
Temple-jaw (closes mouth)
Masseter
Mouth (closes mouth)
Sternocleidomastoid
Neck (nodding/turning head flexing head)
Scalenes
Neck nodding flexing head
Extracular muscles
Eyes (moves eyes)
Intercostals
Thoracic cage (inhale/exhale)
Diaphragm
Thoracic cage (chest, breathing)
Abdominal muscles Refute abdominis External oblique Internal oblique Transverse abdominis
Abdomen flexes/compresses abdomen
Prectoralis major
Chest, pulls arm down
Trapezius
Back/shoulder blade/spine, helps strengthen spine
Rotator cuff: Supraspinatus Infraspinatus Teres minor Subscapularis
Shoulder, shoulder movement
Latissimus dorsi
Sides of arm, pulls arm inward/extends shoulder
Deltoid
Upper shoulder, raises arm at shoulder
Biceps brachii
Arm/forearm, flexes forearm at elbow arm at shoulder
Brachiodradialis
Arm/forearm flexes arm at elbow rotates forearm
Brachialis
Forearm flexes arm at elbow joint
Triceps brachii
Arm forearm, extends forearm at elbow joint arm and shoulder joint
Flexor/extensor carpi
Wrist
Flexor/extensor digitorum
Forearm, fingers
Flexor/extensor pollicis
Thumb movement
Abductor/adductor pollicis
Thumb joint
Thenar/hypothenar
Cupping hand motion
Gluteal group
Buttox, thigh and hip
Iliopsoas
Hip, flexes
Tensor fasciae latae
Hip, a ducts thigh at hip joint
Adductor group
Thigh/hip pulls leg in
Hamstring group
Leg/thigh, flexes leg and knee
Quadriceps group
Thigh/knee extends knee
Sartorius
Thigh, rotates thigh
Tibialis anterior
Front of leg, brings up foot
Flexor/extensor hallucis
Foot, extends big toe
Flexor/extensor digitorum
Toes, flexes toes
Gastrocnemius/soleus
Ankle, flexes foot, Achilles’ tendon
Hallux
Big toe
Functions of muscular tissue
Muscles are excitable or irritable; they have the ability to respond to a stimulus; contract able (shorten in length), extensible (extend or stretch), elastic (return to their original shape)