Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
70 Cards in this Set
- Front
- Back
|
Muscles with large ratio motor units (1 neuron: many muscle fiber) can provide what?
|
powerful muscle contractions but not for delicate, fine, precise movements (legs/arms)
|
|
|
What is a motor unit?
|
the functional unit of a skeletal muscle (organ) composed of a voluntary motor neuron and the one or more skeletal muscle fibers which it innervates.
|
|
|
Muscles with small ratio motor units (1 neuron: 1 muscle fiber) proves what?
|
Cannot give powerful contractions but proves delicate fine movements for precise movements (fingers)
|
|
|
What is a muscle twitch?
|
the response of a skeletal muscle to a single stimulation (or action potential).
|
|
|
Why don't some muscles fatigue, such as when holding a pencil or standing up?
|
It is not used at max potential and some motor units innervating the same muscles take turn in stimulating it.
|
|
|
Define summation
|
The degree of contraction of a skeletal muscle is influenced by the number of motor units being stimulated (with a motor unit being a motor neuron plus all of the muscle fibers it innervates.
|
|
|
With rapid stimulation there isn't enough time between successive stimulations to remove all the calcium from the sarcoplasm, which does what?
|
So, with several stimulations in rapid succession, Ca2+ levels in the sarcoplasm increase. More calcium means more active cross-bridges and, therefore, a stronger contraction.
|
|
|
What is a tetanus
|
Max. sustained contraction of a skeletal muscle.
|
|
|
What are the two types of muscle contraction?
|
Isotonic and Isometric
|
|
|
Explain Isotonic muscle contractions.
|
Tension or force generated by the muscle is greater than the load and the muscle shortens (lifting a book)
|
|
|
Explain an Isometric muscle contraction.
|
load is greater than the tension or force generated by the muscle and the muscle does not shorten the max. contraction cannot lift the load therefore muscles is prevented from shortening (trying to lift a whale)
|
|
|
For cardiac muscles why is there no need for NTs?
|
Because signaling is spread through gap juctions
|
|
|
Why are heart transplants possible?
|
Because the heart has cells that generate its own depolarization, called pacemaker cells.
|
|
|
Cardiac muscles have long action potentials (200-259 ms) which means what?
|
This means that it has very long refractory periods. So, if one stimulates the heart with high frequency, it will not summate and, therefore, cannot get tetanus.
|
|
|
In smooth muscles cells are made up of thick and thin myofilaments. Thin filaments in smooth muscle do not contain troponin so what does calcium bind to?
|
Calcium binds to a protein called calmodulin. This complex 'activates' myosin which then binds to actin and contraction begins
|
|
|
What cells do not have t-tubules and have very little sarcoplasmic reticulum?
|
smooth muscle cells
|
|
|
What is the circulatory system of an insect?
|
They have open circulatory systems. To move the fluid in the body, the insect need a pressure gradient. hemolymph is passed throughout the whole body.
|
|
|
What is the circulatory system of a worm?
|
closed circulatory system: blood is entirely within vessels
|
|
|
What is the circulatory system of a fish?
|
Fish have a single circulation. Blood is oxygenated through the gills not the lungs.
|
|
|
What is the circulatory system of a reptile?
|
Reptiles have a shunt that connects their right ventricle to the systemic system and this is important for when they submerge under water.
|
|
|
What is the circulatory system of a frog?
|
Pulmocutaneous circuit which consists of two atria but one ventricle. The blood is sent to the lungs and skin to get oxygenated. Frogs can exhange gases and ions thorugh their skin
|
|
|
What is the circulatory system of mammals?
|
double circulation
-Systemic circulation -Pulmonary circulation |
|
|
What is pulmonary adema?
|
When the left ventricle fails, blood will be backed up in the lungs, congestion of blood in the lungs causing the person drown in their own fluid
|
|
|
What happens when the right ventricle fails?
|
The blood will be backed up in the veins and will cause swelling in the veins and throughout the body
|
|
|
How is the heart selfish?
|
The first arteries that the heart feeds oxygenated blood to are the coronary arteries, which bring blood to the heart muscles
|
|
|
What are the two main veins of the heart?
|
-Superior vena cava: brings venomous blood from the upper parts of the body (head/arms)
-Inferior vena cava: brings venous blood from lower parts of the body (legs/extremities/toes etc...) |
|
|
Arteries carry blood away from the heart and veins carry blood...
|
towards the heart.
|
|
|
Pulmanary arteriers do what?
|
carry deoxygenated blood away from the heart and to the lungs.
|
|
|
Pulmanary veins do what
|
carries oxygenated blood towards the heart from the lungs.
|
|
|
What is diastole?
|
relaxtion of the heart.
|
|
|
What is systole?
|
contraction of the heart.
|
|
|
What are the four valves that prevent backflow and keep blood moving in the right direction?
|
Semi Lunar valves, AV valves, aortic valves, and pulmonary valve
|
|
|
In order to push the aortic valve open to fill the arteries (pulse), do the ventricles need to generate a higher or lower pressure than that of the arteries?
|
Higher
|
|
|
How is the first heart sound (LUB) created?
|
By the recoil of blood against the closed AV valve.
|
|
|
How is the second heart sound (DUB) created?
|
By the recoil of blood against the closed semilunar valves
|
|
|
The atria and ventrical are diastole, blood returing from large veins flow into the atria and ventricles during what phase?
|
relaxation phase
|
|
|
Cardiac muscle fibers must contract in synchrony. True or False?
|
True
|
|
|
What fixes the condition when your heart is not in synchrony (contracting at different times)?
|
electric shock, which depolarize all the cells.
|
|
|
AV valve separate the atria from the what?
|
the ventricles
|
|
|
Semilunar separate the ventricles from the what?
|
the arteries
|
|
|
Arteries carry oxygenated blood, away from or toward the heart?
|
away from the heart
|
|
|
Veins carry deoxygenated blood toward or away from the heart?
|
toward the heart
|
|
|
In the cardiac cycle the relaxed period is known as the what?
|
Diastole
|
|
|
In the cardiac cycle the contracted period is known as the what?
|
Systole
|
|
|
Pressure is equal to what?
|
The volume of the contents/volume of the container
|
|
|
When referring to circulation, the content is what? and the container is what?
|
The content is blood and the container is vessels, atria, and ventricles
|
|
|
The amount of blood pushed out by the ventricles with each contraction is known as what?
|
Stroke volume (pulse)
|
|
|
The amount of blood being pumped out by the heart each minute is known as what?
|
Cardiac output
|
|
|
Why do trained athletes have a higher cardiac output?
|
Cardiac muscles are stronger, a large volume of blood is pumped out by the ventricles, so higher stroke volume.
|
|
|
Synchrony of the cardiac cycle is maintained by two nodes called the SA node and the AV node which do what?
|
SA node depolarizes the atria, and the AV node depolarizes the ventricles.
|
|
|
Capillaries have the highest cross-sectional area in the body, and thus have the highest or lowest velocity of blood flow?
|
the lowest
|
|
|
Blood pressure is highest in arteries and lowest in what?
|
veins
|
|
|
Where is the primary site of gas exchange in the body?
|
capillaries
|
|
|
Where does the right atrium collect blood from?
|
inferior (lower) and superior (upper) venae cavae
|
|
|
Where does the left atrium collect its blood from?
|
the lungs
|
|
|
Left ventricle pumps blood to the what?
|
the body
|
|
|
Where does the right ventricle pump blood to?
|
the lungs
|
|
|
Pulmonary artery has low oxygen while the pulmonary vein has?
|
high oxygen
|
|
|
Which ventricle works harder and why?
|
The left because it has to pump blood through out the body whereas the right ventricle has to pump blood to the lungs which is a short distance away.
|
|
|
When ventricles contract, do AV valves open or close?
|
close, to prevent back flow into the atria.
|
|
|
Semilunar valves open or close to prevent back flow of blood into ventricles?
|
close
|
|
|
During diastole what happens?
|
-filling period of the heart
-No contraction -AV valves are open and arterial valves are closed |
|
|
When atria is systole and ventricles are diastole what happens?
|
-atria contract and top off ventricles
|
|
|
When ventricles are systole and atria is diastole what happens?
|
-atria is relaxed and ventricles are contracted
-AV valves are closed and arterial valves are open. |
|
|
What are the functions of dissolved ions in Plasma?
|
Functions for osmotic pressure, pH buffering, and regulation of membrane permeability
|
|
|
What are the blood plasma proteins?
|
-Immunoglobulin: antibodies that function in body defense
-Fibrinogen: proteins function in blood clotting -Albumin: main contributor to osmotic pressure of plasma |
|
|
How do erythrocytes generate ATP when it contains no nucleus and no mitochondria?
|
Through glycolysis, which is anaerobic metabolism.
|
|
|
What are platelets?
|
cell fragments from bone marrow involved in clotting.
|
|
|
What do blood clots do?
|
Plug leaks when blood vessels are injured.
|
|
|
What is thrombosis?
|
Clot that forms within a vessel and blocks blood flow in the vessel.
|
