Science 11 Flashcards
Order the following things from superficial to deep: skeleton, skin, skeletal muscles.
Skin, skeletal muscles, skeleton.
A skeletal muscle is contracting. What is happening to its antagonist?
Its antagonist is being stretched.
A person’s biceps brachii muscle is currently at its maximum normal length. Is the person’s arm being held straight or is it bent at the elbow?
It is being held straight.
Order the following from superficial to deep: perimysium, endomysium, epimysium.
Epimysium, perimysium, endomysium.
What structure in the muscle cell actually does the contracting? What is it made of?
The myofibril does the contracting. It is made of two proteins that slide relative to each other.
If you work out a muscle and make it stronger, what has changed in the muscle cells? What does that do to the mass of the muscle?
The number of myofibrils has increased. It increases.
If you lay in bed for a week and don’t move, what will happen to your muscles?
The muscles will lose myofibrils. It is called atrophy.
What is the position of the effort, load, and fulcrum in a first-class lever?
The fulcrum is between the load and effort.
What is the position of the effort, load, and fulcrum in a second-class lever?
The load is between the fulcrum and the effort.
What is the position of the effort, load, and fulcrum in a third-class lever?
The effort is between the fulcrum and the load.
What is the most common class of lever in the skeletal muscle system?
The third-class lever.
Which types of muscles have striations when they are viewed with a microscope?
Skeletal muscles and cardiac muscles.
Which types of muscles are involuntary?
Smooth muscles and cardiac muscles.
Which type of muscle is made of branched cells?
Cardiac muscles.
What type of muscle has one nucleus per muscle cell?
Smooth muscles.
What color are your veins? Why do they appear blue through the skin?
Veins are red. They appear blue through the skin because the skin distorts their color.
Which is superficial: arteries or veins?
Veins.
In what kind of blood vessel does the blood actually give its oxygen to the tissues?
The blood gives oxygen to the tissues in a capillary.
Blood is coming into the heart after giving oxygen to the tissues. List the chambers of the heart that the blood flows through in order. Also, indicate when the blood goes to and comes back from the lungs.
The blood goes into the right atrium, to the right ventricle, to the lungs, back from the lungs, into the left atrium, and into the left ventricle.
Which is thicker, an artery or a similarly-sized vein? Which has one-way valves? Why?
Arteries are thicker because they have more pressure to withstand. Veins have one-way valves because there is less pressure so the blood can flow backwards.
What is the part of the blood that carries the macronutrients and other important chemicals called?
Plasma.
What are the three categories of things found in the cellular elements of the blood? What are their functions?
Red blood cells carry oxygen to the tissues and pick up carbon dioxide. White blood cells fight foreign agents in the body. Blood platelets help the blood clotting process.
A blood cell has a nucleus. What kind of blood cell is it?
White blood cells.
A blood cell is biconcave. What kind of blood cell is it?
Red blood cells.
