-
In the knee joint shown in the figure, what would the result be if the quadriceps failed to function?
- The leg wouldn’t straighten.
- The leg wouldn’t bend.
- The hip wouldn’t bend.
- The hip wouldn’t straighten.
-
What is the difference between the three types of muscle?
- They are all striated, but have different functions.
- The heart muscle is unique in appearance and function compared to the other types of muscle.
- They all contract and relax under voluntary control, but appear different.
- They have different characteristics, functions, and mechanisms of control.
-
Which part of the muscle cell is responsible for the storage of calcium ions to aid in muscle contraction?
- Myofilbril
- Sarcoplasmic reticulum
- T tubule
- Plasma membrane
-
What is needed to stimulate muscle contraction?
- As one muscle cell contracts, it stimulates the next one to contract.
- Muscle cells release neurotransmitters from one cell to the next through gap junctions.
- An action potential from a motor neuron stimulates a group of muscle fibers to contract at the same time.
- The firing of a sensory neuron causes the muscle cells in a group of muscles fibers to contract at the same time.
-
When a person dies, their muscles become stiff and experience rigor mortis. Why do the muscles stiffen?
- Without ATP, calcium remains in the cytoplasm, causing myosin to continuously bind to actin.
- Without calcium, ATP remains in the cytoplasm, causing myosin to permanently bind to actin.
- The sarcoplasmic reticulum can no longer release calcium ions, keeping the myosin from binding to the actin.
- Without ATP, the myosin heads cannot bind to the actin.
-
Why are some people destined to be world class marathoners while most are not?
- Successful marathoners build increased amounts of muscle cells early in life that remain later in life.
- At anytime, a person can train and build muscle to become a world class athlete.
- World class marathoners are genetically predisposed to possess a higher proportion of slow twitch muscle fibers.
- World class marathoners have more fast twitch muscle, whereas most people have more slow twitch muscle.
-
Why do all of the cells of the heart beat simultaneously?
- Numerous motor neurons are connected to each muscle cell and simultaneously send action potentials.
- The sarcoplasmic reticulum of heart muscles are always open to allow for myosin heads to bend and move over actin.
- Gap junctions between the muscle cells allow action potentials to spread rapidly across the cells of the heart.
- An action potential is generated simultaneously in each muscle cell of the heart.
-
What characteristic links the three types of skeletons?
- All are composed of bone or cartilage.
- All have connections to blood flow.
- All have muscles attached for movement of the body.
- All are the main support system of the body.
-
Which of the following is NOT a function of the vertebrate skeleton?
- Framework of support
- Movement
- Encloses the body
- Produces blood cells
-
What is one reason that joints ache as people get older?
- The bone wears down and grinds against itself.
- Years of overuse causes all the blood vessels to break down and lose their function of delivering oxygen and taking away waste products, causing pain.
- Bone grinds on bone due to a lack of cushioning cartilage because the repair process of cartilage is slow or nonexistent.
- As you get older, active bone cells that replace joint tissue are broken down faster than they can be replaced.
-
A baby’s head molds into a cone shape when it is coming out of the birth canal, but hardens later in life because:
- Soft cartilage is broken down by osteocytes and replaced with bone by osteoblasts.
- Soft cartilage is broken down by osteoclasts and replaced with bone by osteoblasts.
- Soft cartilage is broken down by osteoblasts and replaced with bone by osteoclasts.
- Soft cartilage is broken down by osteocytes and replaced with bone by osteoclasts.
-
How are smooth muscles like cardiac muscle?
- Their cells have multiple nuclei.
- Their cells are striated in appearance.
- The appearance of the cells is not striated.
- The cells contract in unison.
-
Why might the hand you generally use to control your video games have denser bone than the other hand?
- One hand is genetically programmed to have more bone.
- Increased muscle use causes an increased use of calcium and builds up the bone.
- Osteoclasts build up bone where there is increased muscle use.
- Bone mass builds up with increased use and weight bearing activities.
-
What would be the first event that occurs when a bone breaks?
- Osteoblasts secrete a callus.
- Nonspecific external barriers take charge.
- Osteoclasts devour cartilage while osteoblasts form new bone.
- Nonspecific internal defense mechanisms target the damaged tissue.
-
In the knee joint shown in the figure, what would the result be if the quadriceps failed to function?
- The leg wouldn’t straighten.
- The leg wouldn’t bend.
- The hip wouldn’t bend.
- The hip wouldn’t straighten.
|
|
