Ch.10-11 muscular system Flashcards
(87 cards)
What are the 3 types of muscle tissue
- Skeletal muscles
- associated with bones
- Smooth Muscle
- visceral organs (liver, stomach ect)
- Cardiac muscle
- heart muscle
Describe the characteristics of skeletal muscle tissue
- undergoes voluntary contractions due to concious control by CNS
- somatic nervous system
- muscle cells called muscle fibers
- striated muscles (under microscope)
- light and dark bands alternate
- multinucleated, large cylindrical cells
What are the functions of skeletal muscles?
- Motion
- gross and fine movements involving most of the body or localized function
- relies on integration between bones, joints, and skeletal muscles
- Stabilize Body positions
- postural skeletal muscles
- provide sustained contraction while awake to stabilize joints and maintian body position
- Movement of Substances
- moves blood in veins and lymph back to heart
- swallowing initially involves a contraction of skeletal muscles
- Thermogensis
- muscles generate heat when glucose is oxidized by mitochondria in muscle fibres to produce atp
- shivering is a form of thermogensis
How are skeletal muscles fibers stimulated?
by neurotransmitters from motor neurons to contraction
Describe the gross anatomy of muscle fibers
- Skeletal muscles
- Fascia
- Tendons

What do skeletal muscles consist of
- muscle cells
- neurons and sensory receptors
- connective tissue coverings
- blood vessels
- lymphatic vessels
Describe Fascia
- covers muscles
- sheets of dense irregular connective tissue
- 2 types of fascia
- Superficial
- Deep
Describe superficial fascia
seperates the muscle from skin
Describe deep fascia
surrounds muscle to hold it in place
Describe tendons
- cords of connective tissue attach muscle to bone
Describe ligaments
Cords of Connective tissue connect bone to bone
Describe the microscopic anatomy of muscle cells
- Muscle fibers
- Facicles
- Sarcolemma
- Mitochondria and nucleus
- pushed to edge of cell
- Sarcoplasmic reticulum
- Myofibrils
- filaments
- Sarcomeres

Describe muscle fibers
Individual muscle cells
Describe fascicles
bundles of mucle cells/fibers that are grouped together
Describe Sarcolemma
plasma membrane covering for the muscles
Describe sacrcoplasmic reticulum
key organelle in muscle cells that store calcium ions needed for contraction
Describe microfibrils
- cytoplasm of muscle cells
- full of proteins arranged in threadlike cylinders
Describe Filaments
- provide a striated appearance of muscle cells
- Thick filaments
- composed of protein myosin
- thin protein
- composed of the protein actin
Describe sacromeres
basic functional units of striated muscle fibers in a repeated arrangement of filaments
What is the neuromuscular junction
- synapses between a motor neuron and a skeletal muscle fiber
- typically at the midpoint of a cell
- site of an action potential

What is an action potential
nerve impulse from neuron, transmits an electrical impulse indirectly to a cell without touching it
What are neurotransmitters
- chemicals that are released from synaptic vessels of the synapic end bulb and are diffused across the synaptic cleft
What is the name for the neurotransmitter that is released by muscle?
Acetylcholine
What is the specialized region of the muscle cell membrane associated with the neuromuscular junction
- motor end plate
- possesses receptors for acetylcholine