Body Organization
What is the basic unit of structure and function in living things?
A Cell
Which body system brings oxygen into the lungs and removes carbon dioxide?
The respiratory system
What is a stimulus?
A change or signal in the environment that can make an organism react
What is digestion?
Breaking food into smaller substances the body can absorb
What do nutrients provide to the body?
Energy or materials for growth, repair, and body functions
What is a tissue?
A group of similar cells working together to perform a function.
Which system transports blood, oxygen, nutrients, and wastes around the body?
The circulatory system
What is a response?
An action or behavior change that occurs because of a stimulus
Which nutrient group is a major source of energy?
Carbohydrates
What is mechanical digestion?
Physical breakdown of food into smaller pieces, such as chewing or stomach churning
What is an organ?
A structure made of different types of tissues working together.
Name the three systems that work together to produce body movement
The nervous, muscular, and skeletal systems
What is homeostasis?
Maintaining relatively stable internal conditions even when the environment changes
What is peristalsis?
Wave-like muscle contractions that push food through the digestive tract
What is chemical digestion?
Enzymes and other chemicals break large food molecules into smaller molecules
Put these levels in order from smallest to largest: organ, cell, organ system, tissue
Cell → tissue → organ → organ system
During a race, which system supplies nutrients that cells can use for energy?
The digestive system
When you get too hot, what two responses help your body lose heat?
Sweating and widening of skin blood vessels
Where does most nutrient absorption happen?
In the small intestine
What are villi, and why are they important?
Tiny fingerlike projections in the small intestine that increase surface area for nutrient absorption
Heart muscle cells form muscle tissue. Muscle tissue combines with other tissues to form the heart. What level of organization includes the heart working with blood vessels and blood?
The circulatory system (an organ system)
A runner's lungs bring in oxygen and the blood carries it to working muscles. Explain how the two systems cooperate.
The respiratory system brings oxygen into the body; the circulatory system transports it in the blood to muscle cells
How are nervous-system signals and hormonal signals different?
Nervous signals are often fast and brief; hormonal signals often act more slowly and last longer.
Nervous controls muscles/movement; hormones control growth, muscle gain, etc.
What do the liver and pancreas contribute to digestion?
The liver makes bile/the pancreas sends digestive enzymes and bicarbonate into the small intestine
Trace how a bite of food helps a muscle cell get usable energy. Include digestion, absorption, and the circulatory system.
Food is broken down into nutrients such as glucose; nutrients are absorbed mostly in the small intestine into blood; the circulatory system carries them to cells, where glucose can be used in cellular respiration to release usable energy.