Chapter 5 - Muscular System Flashcards
What is the muscular system?
This system links the nervous and nervous system and is responsible for generating the forces that MOVE the human body.
Note: Bones help us stand up straight, where as the muscles help us move and attach to the bones via tendons.
What are the 3 types of muscles in the body?
skeletal, cardiac (heart), and smooth (tissues and internal organs)
What is skeletal muscle? What are the primary functions?
The type of muscle tissue that connects to bones and generates the forces that create movement.
Primary functions: Produce movement, support the skeletal system (bones), help with homeostasis by producing heat.
What is the fascia?
The first layer of connective tissue. It surrounds the skeletal muscles and bones.
What is epimysium?
The inner layer of the fascia that directly surrounds the muscle. Also known as “deep fascia”.
What are fascicles?
The largest bundle of fibers that within a muscle. Fascicles are surrounded by perimysium.
What is perimysium?
Connective tissue surrounding a muscle fascicle.
What is endomysium?
Connective tissue that wraps around individual muscle fibers within a fascicle.
What is glycogen?
Glucose (sugar), that is deposited and stored in bodily tissues (like liver and muscle cells). The storage form of carbohydrates.
What is myoglobin?
Protein-based molecule, that carries oxygen into the muscles.
What is myofibrils?
Where contraction of a muscle occurs. They are the contractile components of a muscle cell.
*These are the circles within the muscle fiber.
The myofilaments (actin and myosin) are contained within a myofibril.
What is myofilaments?
The filaments of a myofibril; include actin and myosin.
What is Actin?
A thin myofilament that helps produce muscular contraction.
What is Myosin?
A thick myofilament that helps product muscular contraction.
What is Sarcomere?
The structural unit of a myofibril composed of actin and myosin filaments between two Z-lines. This is the functional unit of the muscular system, this is where muscular contraction occurs.
What is the Z-line?
The meeting point of each sarcomere.
What is neural activation?
The nervous system’s signal that tells a muscle to contract.
The communication link between the nervous system and the muscular system.
What is the neuromuscular junction?
The specialized site where the nervous system communicates directly with muscle fibers.
What is synapse?
A junction or small gap between the motor neuron and muscle cells.
What is a motor unit?
A motor neuron and all of the muscle fibers that it innervates.
What is action potential?
Nerve impulse that is relayed from the central nervous system, through the peripheral nervous system, and into the muscle across the neuromuscular junction.
What are neurotransmitters?
Chemical messengers that cross the synapse between neuron and muscle and assist with nerve transmission.
Essentially, neurotransmitters represent the translation of the nervous system’s electrical message into a form the muscle cells can understand and act on.
What is Acetylcholine (ACh)?
A neurotransmitter used by the neuromuscular system
It helps the action potential cross the synapse into the muscle, which initiates the steps in a muscle contraction.
What is Sliding Filament Theory?
The series of steps in muscle contraction involving how myosin (thick) and actin (thin) filaments slide past one another to produce a muscle contraction, shortening the entire length of the sarcomere.
