3.1 and 3.2 The skeleton

• Biologie
• Middelbare school
• vwo
• Leerjaar 1

Welcome to this lesson!

Today, we will discuss paragraph 3.1 and a little part of 3.2.

That is the only part of Chapter 3 that we will be discussing, so let's keep it short!

Planning

• Introduction 
• Explanation
• Homework & what about next week?
• Work on exercises

Zoom

• At the end of this lesson (09.30) I will be available for questions via Zoom
• You do not have to be there, unless you have questions!
• Find the link in SomToday (click on the homework)

Introduction

• This paragraph is about the different types of skeletons animals can have
• We will discuss the human skeleton a bit
• At the end we will also discuss page 53 and page 54 of the textbook, which is a part of paragraph 5.2.
• This is about the different types of bone in your body

Why do we have a skeleton?

• It helps you move
• It protects your organs
• It gives you shape and strength
• It produces blood cells

Skeletons

We have different types of skeletons:

• Endoskeleton
• Exoskeleton
• Hydrostatic skeleton

We will discuss them all!

Endoskeleton

• Skeleton is inside the body
• Not very heavy
• Able to repair itself
• Example: humans, dogs, ...

Exoskeleton

• Skeleton is outside the body
• Often made of chitin 
• Very heavy
• Animal has to moult (shed the skin and grow a new one)
• Examples: insects, spiders, snails, crabs

Hydroskeleton

• Not really even a skeleton
• Shape and support comes from water
• Only animals that live in water
• Out of the water: no shape and strength
• Exampless: jellyfish

Link to the correct skeleton type!

Exoskeleton

Endoskeleton

Hydrostatic skeleton

Starfish

Wasp

Snake

Only in water

Moults

Has bones

And humans?

We have an endoskeleton, that contains 4 parts:

• Skull protects the brain
• Backbone (or spine) carries the weight and protects the spinal cord 
• Rib cage protects lungs and heart
• Limbs for locomotion (walking)

Spinal cord: consists of nerve tissue, so has to be protected. If the nerve tissue damages, you can't walk anymore

Paragraph 3.2

Humans have two types of bones:

• Cartilage
• Bone

Cartilage

• Flexible
• Prevents the bones from breaking
• Protects the bones
• Babies have a lot of it (need to be flexible), most of it will be replaced by bone later on
• Adults: ears, nose, in the joints

Joint = gewricht

Bone

• Less flexible, but very tough
• Grows and repairs itself
• Blood vessels go through it

That was it!

• That's all you need to know for the skeleton
• Paragraph 3.1
• Paragraph 3.2 (page 53 and 54)
• Now, I'll explain what the homework is and what we're going to do next week

Homework (weektaak)

• Make exercise 1-7 of paragraph 3.1
• Read both paragraphs again and take notes if you need to
• Build your own human skeleton with things you can find at home (paper, sticks, leaves, pens, pasta, ...). Lay it out on a table or floor, and take a picture of it. Do this before next Friday! (example on the next page). I will upload a document on SomToday that explains how you do it.

Zoom

• At the end of this lesson (09.30) I will be available for questions via Zoom
• You do not have to be there, unless you have questions!
• Find the link in SomToday (click on the homework)