Unit 6 - Muscular System Flashcards
(19 cards)
Describe a sarcolemma and its function
the plasma membrane in skeletal muscle cells that conducts electrical signals to trigger muscle contractions.
Describe a sarcomere and its function
the smallest functional unit of a skeletal muscle fiber, leads to muscle contractions, a muscle cell
Describe the sarcoplasmic reticulum and its function
a network of tubules, similar to the of the ER in a cell, but it stores calcium
Describe T-tubules and their functions
indentations in the sarcolemma that conduct action potential (electrical impulses) inside of the cells to trigger muscle contractions
Describe a tendon and its function
bundles of collagen fibers that connect muscles, stabilize joints, and attach muscles to bones.
Describe a ligament and its function
help tendons to stabilize joints
Describe aponeurosis and its function
a broad, flat sheet of connective tissue that helps skeletal muscle connections
Describe the process of a muscle contraction
• Within sarcomeres are the proteins Actin and Myosin. They bundle together by the hundreds to create muscle filaments (strands). Within these filaments are also the proteins Troponin and Tropomyosin, they act as regulators to allow muscle contractions when high amounts of calcium are present.
Describe a neuromuscular junction
The free space between the end of a motor neuron and the muscle cell membrane (sarcolemma) where stimulation occurs. First the motor neurons release a neurotransmitter called acetylcholine, into the neuromuscular junction, that then binds to receptors located on the sarcolemma. The action potential then travels down the sarcolemma and then down to the T-tubule, and then reaches the sarcoplasmic reticulum causing it to release calcium. This excess calcium causes actin and myosin to bind together and shorten the sarcomeres which results in a muscle contraction.
Pectoralis Major / Deltoid
Shoulder Flex / Shoulder Extension
Biceps / Triceps
Elbow Flex / Elbow Extension
Flexor Carpi / Extensor Carpi
Wrist Flex / Wrist Extension
Flexor Digitorum / Extensor Digitorum (profundus)
Finger Flex / Finger Extension
Iliopsoas / Gluteus Maxiumus
Hip Flex / Hip Extension
Hamstrings / Quadriceps
Knee Flex / Knee Extension
Tibialis / Gastrocnemius & Soleus
Ankle Flex / Ankle Extension
Flexor Digitorum / Extensor Digitorum (longus)
Toe Flex / Toe extension
Describe skeletal muscle
Voluntary, enables movement, cylindrical, multinucleated, striated (bands), traditional muscles
Describe cardiac muscle
Involuntary, spindle-shaped, striated (bands), mononuclear, contraction/relaxation of heart
