10: The Muscular System and Homeostasis Flashcards
(34 cards)
What is the primary function of all muscles?
Contracting (shortening)
Muscles do their work by contracting to facilitate movement.
What is the passive state of a muscle called?
Relaxation
Relaxation is when a muscle is not actively contracting.
Name the three types of muscle cells.
- Skeletal
- Smooth
- Cardiac
Each type of muscle cell has distinct characteristics and functions.
What are the characteristics of skeletal muscle cells?
- Attached to bones
- Many nuclei
- Striated
- Tubular
- Voluntary contraction
Skeletal muscles facilitate voluntary movement of the skeleton.
What are the characteristics of smooth muscle cells?
- Found in internal organs
- One nucleus
- Not striated
- Involuntary contraction
Smooth muscles are responsible for involuntary movements in organs.
What are the characteristics of cardiac muscle cells?
- Form walls of the heart
- One nucleus
- Striated
- Tubular
- Branched
- Involuntary contraction
Cardiac muscle cells are specialized for the heart’s rhythmic contractions.
Why must skeletal muscles work in pairs?
Because they can only pull, not push
A relaxed muscle is lengthened when the opposing muscle contracts.
What model explains skeletal muscle contractions?
Sliding filament model
This model describes how muscle fibers contract through the sliding of myofilaments.
What additional functions does skeletal muscle provide besides movement?
- Produces heat
- Supports the body
- Pads the body
Skeletal muscles play a critical role in thermoregulation and body structure.
What are muscle fibers made up of?
Clusters of bundles of muscle fibers containing myofibrils
Myofibrils consist of thin (actin) and thick (myosin) myofilaments.
What role do blood vessels play in muscle function?
- Supply nutrients
- Supply oxygen
- Remove wastes
Blood vessels are essential for sustaining muscle activity and metabolism.
What fuels cellular respiration in muscles?
Oxygen
Cellular respiration provides the energy required for muscle contractions.
What triggers and controls muscle contractions?
Nerves
Nerve signals initiate the contraction process in muscle fibers.
How long do muscle contractions last in each muscle fiber?
Only a fraction of a second
Muscle contractions occur in rapid succession to create a sustained contraction.
What is the difference between slow-twitch and fast-twitch fibers?
- Slow-twitch: good for endurance
- Fast-twitch: good for intense activities
Different muscle fiber types are suited for various physical demands.
What is necessary to maintain and build the function of skeletal muscles?
Using the skeletal muscles
Regular use is essential for muscle health and strength.
What keeps blood moving in the circulatory system?
Muscle contraction
This includes contraction in the heart, blood vessels, and lymphatic vessels.
What do blood vessels deliver to muscles?
Nutrients and oxygen
Blood vessels also carry away waste products.
What role does the immune system play in the body?
Protects against infection
What accounts for peristalsis in the digestive system?
Smooth muscle contraction
How do skeletal muscles function in the digestive system?
Support and help protect abdominal organs
What does the digestive tract provide for muscle activity?
Glucose
What does the liver metabolize following anaerobic muscle activity?
Lactate
What types of muscle tissue comprise the muscular system?
Cardiac, smooth, and skeletal muscle tissue
