1. How do bones, muscles, and nerves work together?
Chapter A1.3

2. Systems working together
Bones and joints
-your bones are living organs made up of connective tissues. The tissues include outer protective membrane, a layer of hard material, and a soft center made up of bone marrow.
Bone marrow- is a connective tissue that produces red blood cells and white blood cells.

3. joints
Bones meet at joints where they are attached to each other and to muscles.
Joints- there are different kinds of joints such as hinge, ball and socket, and non-moveable.
Hinge joints- move like a door hinge, back and forth.
Ball and socket joints- move in a circular motion like a joystick.

4. Hand hinge joint

5. The Skeletal System
Bones are organized into a skeleton which protects your internal organs and supports your body.
Muscles are attached to your bones with tendons on the sides of the bones.
Tendons- are tough bands of connective tissue.
Bones are attached to each other by ligaments.
Ligaments- bands of connective tissue that hold the skeleton together.

7. The Muscular System There are 3 kinds of muscles: 1. voluntary
2. smooth
3. cardiac
Voluntary muscles-move bones and hold your skeleton upright.
Where muscles attach to bones at a joint, they work in pairs to move the joint one way then the other.

8. Smooth muscles- contract slowly and move stuff around the organs they surround. They are found in the walls of blood vessels and the digestive organs.
Cardiac muscles- make the walls of the heart. Their job is to pump blood.

9. The Nervous System-Central and Peripheral
The nervous system consists of two parts- the central nervous system and the peripheral nervous system.
Central nervous system- is made up of the brain and spinal cord.
Spinal cord- is a bundle of nerves that runs from the brain to the hips.

10. The Nervous System- Central and Peripheral
The peripheral nervous system consists of the sensory organs such as the eyes and ears and body nerves.
Nerves- are bundles of nerve cells or neurons.
Neuron- a specialized cell that can receive signals and transmit them to other neurons.
Sensory organs contain neurons called receptors.
Receptors- are nerve cells that detect conditions in the body’s environment.

11. The central nervous system receives signals and determines what response is needed.
The brain also controls the automatic functions like respiration, circulation, and digestion.
Some muscle actions are automatic responses to situations. These are called reflexes.
Reflexes- non-conscious reactions that your body automatically does to respond.

12. Questions 1. What is produced in bone marrow?
A. red and white blood cells
2. What function or job do ligaments perform?
A. they connect bones at joints.
3. What kinds of muscles move food through the digestive system?
A. smooth muscles.

13. 4. What kind of action is a sneeze caused by pepper in the air?
A. a reflex action, it happens automatically.
5. Tendons are connective tissue that-
A. makes blood cells
B.carries signals from receptors
C. connects one bone to another
D. connects a bone to a muscle.