Nervous System ðŸ§
What type of cell carries messages through the nervous system?
Neuron
Which part of the eye detects light?
Retina
What connects bone to bone?
Ligament
What waste gas do we breathe out?
Carbon dioxide
Which is faster: light or sound?
Light
What is the difference between the CNS and PNS?
CNS = brain and spinal cord
PNS = all nerves outside them
Which structure in the inner ear helps us hear sounds?
Cochlea
What is the soft material inside many bones that makes blood cells?
Bone marrow
What tiny air sacs in the lungs exchange gases?
Alveoli
Which is faster: a nerve signal or a Formula 1 race car?
A nerve signal (430 km/h)
Which part of the nervous system controls most reflex actions?
Spinal cord
Which part of the ear helps maintain balance?
Semicircular canals
Name three functions of the skeletal system.
Support, protection, movement, production, or storage
Which muscle is mainly responsible for breathing?
Diaphragm
How many bones does an adult human have?
206
Which part of a neuron carries signals away from the cell body?
Axon
Why is the pupil larger in a dark room?
To allow more light into the eye
Which mineral is especially important for helping prevent osteoporosis?
Calcium
What tube carries air from the throat to the lungs?
Trachea
Why do people often lose their balance after spinning in circles?
The fluid in the semicircular canals keeps moving even after you stop, confusing the brain
What part of the nervous system controls involuntary actions like heartbeat?
Autonomic nervous system
What happens to the tiny hair cells in the cochlea when sound enters the ear?
They bend and convert vibrations into nerve signals
Why are bones both hard and lightweight?
Compact bone = strength
Spongy bone = spaces to reduce weight
Describe the path air takes from the nose to the lungs.
Nose → Pharynx → Trachea → Bronchi → Lungs
Why does one nostril often feel more open than the other?
Your nose naturally switches airflow between nostrils every few hours in a process called the nasal cycle.