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White Blood Cells
True or False: Reflexes happen without you thinking about them.
True
Muscles work in ___________ to move bones
Pairs
Which part of the skin contains nerve endings, sweat glands, and blood vessels?
Dermis Layer. Also our thickest layer of skin.
What is the main function of the skeletal system?
Support and protect the body
What do platelets do?
When you get a cut, platelets rush to the injury. They stick together and form a plug to close the wound. They release chemicals that help form a blood clot, sealing the cut so you don’t lose too much blood.
Which part of a neuron receives messages?
Dendrite
What does an X-RAY show? What does an MRI show?
X-Ray
Best for showing hard structures like bones and teeth.
Can reveal fractures, breaks, and bone alignment.
Doesn’t show soft tissues (like muscles or organs) very well.
MRI (Magnetic Resonance Imaging)
Best for showing soft tissues like muscles, ligaments, tendons, brain, and organs.
Helps doctors see injuries to muscles, brain activity, or problems in organs.
Takes longer than an X-ray and requires lying still inside a machine.
How does the skin help protect the body from germs?
The skin acts as a barrier that blocks bacteria, viruses, and other harmful substances from entering.
True or False: Skeletal muscles are controlled voluntarily.
True
What are the four main parts of blood, and what does each part do?
Which body system coordinates voluntary and involuntary movements?
Nervous system – It controls both voluntary actions (like walking) and involuntary actions (like breathing).
What is the primary function of ligaments?
Connect bone to bone – Ligaments connect bones to each other at joints, helping with stability.
What are the main layers of the skin, and what does each layer do?
Epidermis (outer layer, protection, prevents water loss), Dermis (middle layer, contains nerves, blood vessels, sweat and oil glands), Hypodermis (fat layer for cushioning and insulation).
Bones are made of living tissue. What does bone marrow do?
Makes blood cells
How does blood work with the muscular system?
Blood delivers oxygen and nutrients to muscles so they can move, and removes waste like carbon dioxide.
Why do we need reflexes to be so fast?
Reflexes protect us from danger or injury by making the body respond quickly without waiting for the brain to think first.
Explain why muscles work in pairs.
Muscles can only pull, not push. One muscle contracts to move the bone in one direction, while the partner muscle contracts to move it back.
How does sweat help maintain homeostasis?
What are the three different muscles and where are they found?
The three types of muscles are skeletal muscles (on bones for movement), smooth muscles (in organs like the stomach and blood vessels), and cardiac muscle (in the heart to pump blood).
How does blood help keep your body in balance (homeostasis)?
It regulates temperature, delivers what cells need, and removes waste to keep conditions stable.
A reflex arc involves three main parts. Name them and explain how they work together.
A reflex arc involves a sensory neuron, the spinal cord, and a motor neuron. The sensory neuron detects a stimulus, the spinal cord processes it, and the motor neuron sends a signal to the muscle to react quickly.
How do the skeletal, muscular, and nervous systems work together to allow you to catch a ball?
The skeletal system provides the bones, the muscular system moves those bones, and the nervous system sends signals to coordinate the movement. Together, they allow you to catch a ball.
How do muscles help maintain homeostasis?
By producing heat during movement, shivering to warm the body, and working with other systems to keep balance in the body.
Describe the role of tendons and ligaments. How are they different?
Tendons connect muscles to bones, allowing movement.
Ligaments connect bones to other bones, providing stability at joints.