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Questions and Flashcards based on Human Skeletal & Muscle System Notes
What’s the primary function of the muscle?
Responsible for all movement of the body.
How do muscles create movement
Through flexing and extending
What are muscles called as they transform chemical energy into mechanical energy? (from food to movement) and what do they contain and why?
body energy converters and they contain many mitochondria since they have energy demand
How much percent of the body weight is muscle?
50% of body weight is muscle
What is muscle made up of?
water and proteins
Tendons. what are they capable of
A tough band of fibrous connective tissues that connect bone to muscle or other body structures
capable of withstanding tension
Ligaments
The fibrous connective tissues that connect bones to another
keeps structure stable
Skeletal and smooth muscle are… (shape/size)
elongated
Muscle Cell =
Muscle Fiber
What causes muscle contraction?
The movement of microfilaments (protein fibers) cause muscle contraction
myo and mys refer to..
muscles
sarco refers to..
flesh
Multinucleated
have more than one nucleus
Why are Skeletal Muscles multinucleated?
they’re formed from the fusion of multiple cells
→ ensure muscle fibre produces enough proteins to meet high energy demands
What do the skeletal muscles contain? What do they do?
Many kinds of mitochondria
produce energy in the form of ATP
Skeletal Muscle are… which means..
Striated = striped/banding
What type of muscle is consciously controlled?
Skeletal Muscle
What are the four functions of skeletal muscle?
Produce movement
Maintain posture
Generate heat
Stabilize joints
What is the shape of a cell (fibre) of a skeletal muscle?
long and cylindrical
What are Myofibrils?
units in the skeletal muscle cells that can contract and shorten
What do Myofibrils contain?
They contain two protein filaments
Actin
Myosin
What do the things that Myofibrils contain do?
The two filaments (Actin and Myosin):
overlap and use energy from mitochondria, ATP
ATP powers the filaments to slide over each other to shorten the myofibril
causes muscle contraction
What is sliding filament theory?
The explanation of how muscles contract
What type of muscle tissue lacks striations?
Smooth muscle
Describe the shape of smooth muscle cells.
Spindle shaped with Actin and myosin filaments present (protein fibres)
How many nuclei does a smooth muscle typically have?
one
Are smooth muscle contractions voluntary or involuntary?
Involuntary
Where are smooth muscle cells primarily found in the body?
the walls of hollow organs
How are smooth muscle cells arranged in the walls of hollow organs?
they line the wall of the digestive tract
What is peristalsis, and how is it achieved in the digestive tract?
involuntary tightening or relaxation of the muscles of the intestine
from alternate contraction of circular and longitudinal muscle in the intestine
What type of muscle tissue is found only in the heart?
Cardiac
What are the characteristics of cardiac muscle cells?
short, branched, and interconnected
striated
usually one nucleus
How does the shape of cardiac muscle cells differ from skeletal muscle cells?
skeletal is spindle shaped
branching cells
What type of muscle is cardiac?
involuntary with rhythmic contractions
How do heart muscle cells behave as a unit?
behave as one unit
all contract and relax together
What is the unique characteristic of heart muscle contractions?
it always contracts to its fullest extent
What is the only type of muscle can carry a nerve impulse?
Cardiac
Note
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