7th grade · Science · Unit 4 of 10
Body Systems
Nerves, hormones, kidneys and more
What your child practices
How the nervous and endocrine (hormone) systems send messages, how the excretory system removes waste, and the basic organs of the reproductive system, all at a simple organ-and-job level.
Minnesota K-12 Academic Standards benchmark: 7L.4.1.1.1 · how the body is a system of interacting subsystems made of groups of cells
How we explain it
Children can open this short lesson before they practice.
- The nervous system sends fast signals along nerves. A reflex is fast and automatic.
- The endocrine system sends slower messages with hormones in the blood.
- The excretory system removes waste: kidneys filter blood and the bladder stores urine.
Example: You pull your hand away from a hot pan before you think. What is this? It happens automatically. It is very fast. Answer: a reflex
Body Systems in Minnesota
In the Minnesota K-12 Academic Standards, this is unit 4 of 10 in 7th grade Science, after Cells & Life Processes and before How Plants Work.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
Which body system does each part belong to? Tap an item, then tap its basket.
Sort into: ⚡ nervous system · 🚰 excretory system · 🧪 endocrine (hormone) system
- 🎛️pituitary gland
- 🧠brain
- 🦋thyroid gland
- 💧kidneys
- 🎈bladder
- 🔗spinal cord
⚡ nervous system: brain, spinal cord · 🚰 excretory system: kidneys, bladder · 🧪 endocrine (hormone) system: pituitary gland, thyroid gland
Hint: The nervous system carries fast electrical messages. The excretory system removes wastes. Endocrine glands release hormones into the blood.
Question 2
What happens during fertilization?
- a nerve sends a message
- a sperm cell and an egg cell join
- a baby is born
- the kidneys make urine
a sperm cell and an egg cell join
Hint: Fertilization is the very first step in making a new living thing. Two reproductive cells join into one.
Question 3
Put the path of liquid waste (urine) through the excretory system in order.
- Ureters carry urine down from the kidneys
- The bladder stores urine
- Kidneys filter wastes out of the blood
- Urine leaves the body through the urethra
Kidneys filter wastes out of the blood → Ureters carry urine down from the kidneys → The bladder stores urine → Urine leaves the body through the urethra
Hint: The kidneys clean the blood first. Tubes called ureters lead to the bladder, which stores urine until it leaves through the urethra.
Question 4
What does the reproductive system make possible?
- keeping your balance
- digesting food
- removing waste from the blood
- producing offspring (babies)
producing offspring (babies)
Hint: To reproduce means to make new living things of the same kind.
Question 5
Which organs filter wastes out of your blood to make urine?
- heart
- bladder
- stomach
- kidneys
kidneys
Hint: You have two bean-shaped kidneys near your lower back. They clean your blood all day long.
Question 6
Using the table, which kind of message pulls your hand off a hot pan?
Two ways the body sends messages Feature Nerve signals Hormones Travel through nerves the blood Speed a fraction of a second seconds to hours Effect lasts a short time minutes to years - nerve signals
- hormones
- both, at exactly the same speed
nerve signals
Hint: You need to move in a fraction of a second. Check the Speed row.