PLTW BIOMEDICAL SCIENCE EXAM 1 2025/2026 Q&A
Why do we need so many muscles in our hands, wrists, and arms? - hands are the most frequently
used body part that also has the most variety of uses; because we can/need to do so many things
with our hands, they have many more joints and muscles than other parts of our bodies
What organ systems work together to move your arm, your wrist, and your fingers? - cardiovascular,
respiratory, circulatory, nervous, digestive, skeletal, etc
What are some factors that make design of a prosthetic limb for human use a difficult task? - there
are so many joints, bones, and muscles in our limbs that have very specific movements and therefore
very varying functions; reproducing that is very hard without a central nervous control system
How have prosthetic limbs changed throughout history? - before they used to be made out of wood,
metal, leather, etc; now they are much more mechanical, with high-tech metal, even plastic parts
that work together to create movements that can be more helpful; there are even prosthetics
(prototypes) that can receive signals from the brain of the patient
How have myoelectric control and targeted muscle reinnervation revolutionized prosthetic limb
technology? - now, the patient can obtain a prosthetic that acts like an actual limb that moves the
way that the brain would tell a normal limb to move
Explain how myoelectric arms are controlled by the patient. - an electrically-powered prosthesis uses
rechargeable battery to power small electric motors that move the prosthetic; when a muscle is
contracted a small electrical signal (EMG) is created by a chemical interaction in the body; an
electrode is attached to the surface of the skin to record the EMG signal; once recorded, the signal is
amplified, then processed by a controller that switches the motors on or off to produce movement
Describe soft tissue - Soft tissues are the tissues that connect, support,
and surround other structures and organs of the
body, not being bone.
What are some examples of soft tissue in the body? - tendons, ligaments, fascia, skin, fibrous tissues,
fat, synovial membranes (connective tissues), muscles, nerves, and blood vessels.
Which soft tissue connects bone to bone? - ligament
, What is muscle?
(a characteristic that makes muscle muscle) - tissue that when stimulated contracts
and produces movement
Which soft tissue connects muscle to bone? - tendon
What is a soft tissue injury? - damage of skin, muscles, ligaments, and tendons throughout the body
What are the most common causes of a soft tissue injury? - sprain, strain, blow resulting in
contusion, overuse of particular body part
What are the 5 signs of inflammation? - R-redness
H-heat
S-swelling
P-pain
L-loss of function
What is vasodilation? - dilation or narrowing of blood vessels
Why does redness occur after a soft tissue injury? - due to vasodilation and increase in blood flow
Why does an injured person experience heat after a soft tissue injury? - due to vasodilation and
increase in blood flow
Why does swelling occur after a soft tissue injury? - due to increase in blood flow to the injured area
and possibly from blood that leaks into the injured tissue
What is a bruise/how does bruising occur? - injury causes capillaries to burst and blood gets trapped
under the surface of the skin
Why does an injured person experience pain after a soft tissue injury? - due to the pressure of fluids
or swelling through the nerve endings
Why do we need so many muscles in our hands, wrists, and arms? - hands are the most frequently
used body part that also has the most variety of uses; because we can/need to do so many things
with our hands, they have many more joints and muscles than other parts of our bodies
What organ systems work together to move your arm, your wrist, and your fingers? - cardiovascular,
respiratory, circulatory, nervous, digestive, skeletal, etc
What are some factors that make design of a prosthetic limb for human use a difficult task? - there
are so many joints, bones, and muscles in our limbs that have very specific movements and therefore
very varying functions; reproducing that is very hard without a central nervous control system
How have prosthetic limbs changed throughout history? - before they used to be made out of wood,
metal, leather, etc; now they are much more mechanical, with high-tech metal, even plastic parts
that work together to create movements that can be more helpful; there are even prosthetics
(prototypes) that can receive signals from the brain of the patient
How have myoelectric control and targeted muscle reinnervation revolutionized prosthetic limb
technology? - now, the patient can obtain a prosthetic that acts like an actual limb that moves the
way that the brain would tell a normal limb to move
Explain how myoelectric arms are controlled by the patient. - an electrically-powered prosthesis uses
rechargeable battery to power small electric motors that move the prosthetic; when a muscle is
contracted a small electrical signal (EMG) is created by a chemical interaction in the body; an
electrode is attached to the surface of the skin to record the EMG signal; once recorded, the signal is
amplified, then processed by a controller that switches the motors on or off to produce movement
Describe soft tissue - Soft tissues are the tissues that connect, support,
and surround other structures and organs of the
body, not being bone.
What are some examples of soft tissue in the body? - tendons, ligaments, fascia, skin, fibrous tissues,
fat, synovial membranes (connective tissues), muscles, nerves, and blood vessels.
Which soft tissue connects bone to bone? - ligament
, What is muscle?
(a characteristic that makes muscle muscle) - tissue that when stimulated contracts
and produces movement
Which soft tissue connects muscle to bone? - tendon
What is a soft tissue injury? - damage of skin, muscles, ligaments, and tendons throughout the body
What are the most common causes of a soft tissue injury? - sprain, strain, blow resulting in
contusion, overuse of particular body part
What are the 5 signs of inflammation? - R-redness
H-heat
S-swelling
P-pain
L-loss of function
What is vasodilation? - dilation or narrowing of blood vessels
Why does redness occur after a soft tissue injury? - due to vasodilation and increase in blood flow
Why does an injured person experience heat after a soft tissue injury? - due to vasodilation and
increase in blood flow
Why does swelling occur after a soft tissue injury? - due to increase in blood flow to the injured area
and possibly from blood that leaks into the injured tissue
What is a bruise/how does bruising occur? - injury causes capillaries to burst and blood gets trapped
under the surface of the skin
Why does an injured person experience pain after a soft tissue injury? - due to the pressure of fluids
or swelling through the nerve endings
