This is the perfect slideshare for 6th grades who are not ready for a test! Use this slideshare to stude and get ready to get a 10 and A star!

1. MID1A – Science
This unit

2. MID1A – Science
BRAIN – Our computer: receives, processes and
sends out data.
Brain is the control centre of the Nervous
System, and it controls our body
Brain + Spinal cord + Nerves = nervous system
Organ: description (overview)
BRAIN and the NERVOUS system

3. MID1A – Science
Brain
Spinal cord
Nerves
BRAIN – Our computer: receives, processes and sends out data.
SPINAL CORD -- pathway for messages
sent by:
brain  body and
body  brain
NERVES – throughout
the body (e.g. TO MUSCLES or
FROM SENSORY CELLS)

4. Neurons (also called nerve cells): VERY peculiar cells
Neurons are specialized to receive and transmit signals (synapse)
axon
dendrites
myelin sheath
MID1A – Science
Nerves are enclosed, cable-like bundles of nerve fibres (axons) in the peripheral nervous system
Like cables, they transport signals (electro-chemically). For example, to muscles.
axon end branches

5. MID1A – Science
NERVE cells (= Neuron ): receive and transmit signals
axon
dendrites
myelin sheath

6. MID1A – Science
BRAIN is our computer.
Brain
Receives and Decode,
Process and Transmit,
Organize and Store
information
NERVES are our cables
Transmit the signals
to brain: stimulus > brain
from brain: brain > effectors)

7. MID1A – Science
NERVE  MUSCLE: the Neuromuscular junction
Muscle and nerves

8. MID1A – Science
The super-simple scheme: the mechanics of the Musculoskeletal system
Muscle
Bone 1
Bone 2
Tendon
Ligament
Motor nerve
Muscle and nerves and bones

9. MID1A – Science
The super-simple scheme: the mechanics of the Musculoskeletal system
Muscle
Bone 1
Motor nerve
axon
Impulse from brain
(move!)
Bone 1
BEFORE
Impulse from brain
AFTER
(muscle contraction)
No impulse
Yes impulse

10. MID1A – Science
The super-simple scheme: the basic concept of how muscle contraction allows movement
Length of muscle, L1
If relaxed (longer)
L1
Length of muscle, L2
If contracted (shorter)
L2
A B
When muscle is relaxed (A) its length is L1. When muscle is engaged (B), it become shorter: its length is L2.
Since it is attached to bones (1 and 2), the shortening pulls bone 2. The movement is shown in GREEN
Bone 1
Bone 2

11. MID1A – Science
The super-simple scheme
L1
L2
Bone 1
Bone 2
Impulse from brain
L2 < L1, therefore ---> Bone 2 is PULLED (green arrow)
Bone 2
Muscle contraction and movement

12. MID1A – Science
A more realistic depiction of the contraction movement (in the example, the arm)
Note that more than one muscle is involved: in this case, the two shown are biceps and triceps
(also called an “antagonist” pair, as they sort of do opposing jobs: if one is contracted, the other
is relaxed)

13. 1) Skeleton is the scaffold  2) on which MUSCLES operate, and are reached by 3) NERVES and
4) Blood VESSELS (arteries and veins) --- muscles need a lot of Oxygen! And produce a lot of CO2!
MID1A – Science
They all concur to the movement (bone+muscle+nerve+blood)
Musculoskeletal system blood
nerves

14. Muscle
Nerve
Artery
Nerve
Artery
Muscle
MID1A – Science
Musculoskeletal system + Nerves + Blood Vessels: the .. “functional task force”
Musculoskeletal system
An example: the Shoulder

15. MID1A – Science Musculoskeletal system
Musculoskeletal system provides shape, support, stability, and movement to the
body. Made up of the bones of the skeleton, muscles, cartilage, tendons, ligaments,
joints, and other connective tissue that supports and binds tissues and organs together.

16. MID1A – Science
Joint
The point at which two (or more) bones meet
(bone to bone)
Cartilage
Soft connective tissue found at the end of the
bones (e.g. in joints, see picture on the right and
on next slide)
Ligaments
Connective tissue that attaches bone to bone at a
joint
Tendons Connective tissue that attaches muscle to bone
It provides support, stability, shape, and movement
Musculoskeletal system
Let’s see some key terms
Musculoskeletal system

17. MID1A – Science
Bone, Muscles, Joints, Ligaments
and Tendons
Ligament (b--b): bone – to – bone
Tendon (b--m): bone – to – muscle

18. Ball and socket joint
A joint in which the rounded surface
of a bone moves within a depression
on another bone, allowing greater
freedom of movement than any
other kind of joint.
Hinge joint
A joint in which the articular surfaces are molded to each
other to permit motion only in one plane.
MID1B – Science joints
There are other types of joints (e.g. fibrous joints – in the skull; facet joints – backbone), which we will not
cover in this unit (although we saw some pictures in class)

19. MID1B – Science Human Skeleton
SKELETON
The human skeleton is the
internal framework of the
human body
(made of more than 200 bones (as adult,
206; more at birth).

20. Sternum
Tibia
Fibula
ulna
Vertebra
Skull
Femur
Rib
Pelvis
humerus
radius
MID1A – Science
CAN YOU ASSIGN THE RIGHT NAME TO THE EACH BONE?

21. MID1B – Science Human Bone
Bone are not only Structure
and protection!
Bone marrow (found in spongy part
of the bone) contains hematopoietic
cells (particularly in red marrow) and
fat cells (yellow marrow).
Hematopoietic cells in bone marrow
are progenitor cells which are
destined to mature into blood and
lymphoid cells (red blood cells, white
blood cells, platelets)

22. Skeleton (easy) -- video 1 (simpler images, but rather exahustive)
https://www.youtube.com/watch?v=2k6H2Vnn3o4
Skeleton (easy) -- video 2 (simple content, more realistic images)
https://www.youtube.com/watch?v=ywDOiNEdJVc
Musculoskeletal system (easy) – video 1
https://www.youtube.com/watch?v=ynVRDsDC-84
Locomotor system (easy) -- video 2
https://www.youtube.com/watch?v=ghpmVXSUfWs
MID1A – Science Muscles and bones

23. BRAIN – SNC (both easy, the first more cartoonish, but well outlined)
https://www.youtube.com/watch?v=KZVeFTDszTs
https://www.youtube.com/watch?v=6O-0CVAgaEM
BRAIN – SNC (medium; it contains some info on neurons, their synapses and nerves)
https://www.youtube.com/watch?v=L6w0_j6mWbo
OPTIONAL
Motor units (advanced, not super – but some simple images – 1.30 min to 4.00 min)
https://www.youtube.com/watch?v=qTt_2oPI2kk
Neuro junctions (too advanced, but good – useful at the beginning 0.00 - 1.10 )
https://www.youtube.com/watch?v=zbo0i1r1pXA
MID1A – Science Muscles and nerves

24. MID1A – Science Digestive system

25. Major stages of the digestive system:
1. Chewing - Chewing is the first stage of the digestive system. When you chew your food it breaks
up big pieces into little pieces that are easier to digest and swallow. Also, your saliva is more than just
water. It has special enzymes that start to break down starchy food (potatoes, bread) while you chew.
2. Swallowing - Food doesn't just fall down our throats into our stomach. First, our tongue helps to
push food into the back of our throat. Then there are special throat muscles that force the food down
into a long tube that leads to our stomach, called the esophagus.
MID1A – Science Digestive system

26. 3. Stomach:
The next stage is the stomach. Food hangs out in the stomach for around four hours. While the food sits
there, more enzymes go to work on it, breaking down things like proteins that our bodies can use. The
stomach kills a lot of bad bacteria as well, so we don't get sick.
4. Small Intestine:
4a: The first part of the small intestine works with juices from the liver, gallbladder and pancreas
to continue to break down our food.
4b: In the second part the food gets absorbed from the intestine and into our blood.
5. Large Intestine:
The last stage is the large intestine. Any food that the body doesn't need or can't use is sent to the large
intestine and later leaves the body as waste.
MID1A – Science Digestive system

27. https://www.youtube.com/watch?v=v3E1txcKPe8
https://www.youtube.com/watch?v=ZBZWgrfZFbU
MID1A – Science Digestive system
Simple videos, for a general overview of the Digestive System
https://www.youtube.com/watch?v=5ufESc1bK78 (pill 2)

28. KIDNEYS – filtering blood
Where are your kidneys?
Kidneys are shaped like beans. Each kidney is about 10-12 centimeters long.
Kidneys are in your lower back.
What do kidneys do?
They are like washing machines for the blood in the body. The kidneys filter the
blood and take out all the waste in the blood (while not wasting important
components). The kidneys send the waste on to the bladder in the form of urine.

29. What Do Kidneys Do?
One of the main jobs of the kidneys is to filter the waste out of the blood. How does the waste get in your blood?
Well, your blood delivers nutrients to your body. Chemical reactions in the cells of your body break down the
nutrients. Some of the waste is the result of these chemical reactions. Some is just stuff your body doesn't need
because it already has enough. The waste has to go somewhere; this is where the kidneys come in.
MID1 – Science KIDNEYS
https://kidshealth.org/en/kids/kidneys.html
https://www.youtube.com/watch?v=dZREDWD_5bA

30. Blood flows through the kidneys into tiny capillaries. The capillaries lead then to tiny tubes
called nephrons (there are more than one million of these nephrons in each kidney). In these
tubes, water in excess is removed and substances (e.g. salts, vitamins, etc) are checked: if a
substance is not useful, or simply we have too much of it, then it will be exctreted with the
excess water. This exctretion is urine
Urine will then pass from the kidney to bladder, which stores it until it leaves the body..
A claryfing note:
Kidneys, while filtering, take actually back most of the useful nutrients and most of the water
(and send it back into the blood). Only water in excess, and non-useful substances are instead
excreted as urine.
KIDNEYS – filtering blood