Nervous System and Excretory System

Nervous System and

Excretory System

What is the Nervous System?

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It enables you to sense your environment and to react to it.

It includes your brain, spinal

cord, and nerves.

2 parts: Central Nervous System and Peripheral Nervous System

Central Nervous System

Brain and Spinal Cord

Peripheral Nervous System

Nerves and sensory organs

Sensory organs

Examples: eyes, ears, touch sensors in your skin

What is a synapse?

a gap between nerve cells that signals travel along

What is a sensory receptor?

They detect changes in your soundings and send signals along nerves to the central nervous system.

Multiple Choice

What is the gap between cells that signals travel along?

• synapse

• dendrite

• axon

• mitochondria

What is a reflex?

An automatic response to a stimuli.

The brain is bypassed in a reflex action!

How do messages travel in a reflex action?

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The nerve signal takes a shortcut.

The spinal cord tells the body to respond to the stimulus before the message even reaches the brain.

Multiple Choice

What is the action that occurs without your brain's help?

• a voluntary action

• a stimulus

• a reflex

What is the Excretory System?

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It is the system that removes waste (ammonia) from the blood.

It includes kidneys and bladder.

Parts of the Excretory System

Kidneys: filter liquid waste from your blood

Ureters: tube urine flows through to get to the bladder.

Parts of the Excretory System

Bladder: muscular organ that hold urine until it is full

Urethra: It is a tube that connects the bladder to the outside of the body. Urine leaves the body through this tube.

Multiple Choice

What do kidneys do?

• make blood

• make bile

• store water

• filter waste out of blood

Multiple Choice

Where is urine stored?

• kidneys

• bladder

• gallbladder

• liver