1. 3.2 Organ Systems in Animals

2. Cells Working Together
Single-celled organisms such as bacteria and yeast can live on their own since they do not depend on any other cells.
A single skin or muscle cell, however, would quickly die if it is separated from the larger group of cells as they work as a network of specialized cells.

3. Level of Organization
Hierarchy- levels of organization of increasing or decreasing complexity.

5. Building up Levels
1. Cells
2. Tissue – group of cells with the same structure and function
Ex: muscle, bone, blood, skin, nerve
3. Organ – group of two or more types of tissue that perform a specific task.
Ex: stomach, heart
4. Organ system – group of organs that work together for a vital body function
Ex: Nervous system
5. Organism – a living thing. Ex humans

6. Organ Systems
Anatomy – The structure of living things Physiology- The function of living things

7. Tissue – A group of cells that work. together to perform a
Tissue – A group of cells that work together to perform a specific task.
Organ – A structure composed of different tissues specialized to carry out a specific function.
(i.e. stomach, heart, kidneys)
Organ System- A group of organs that have a related function.

8. ORGAN SYTEMS

9. ORGAN SYTEMS (continued)

10. Organs Breaking down food occurs with tissues acting together.
Stomach tissues include:
Muscle cells
Nerve cells
Blood cells
Outer/inner lining
Cells that excrete enzymes
Acid and mucus

11. Animal Tissues 4 major types: Epithelial Tissues Connective Tissues
Nerve Tissues
Muscle Tissues
Provide: covering,
connections and
support
Sensing and
responding

13. Epithelial tissue
Sheets of tightly packed cells used for lining or protection of body’s internal organs and cavities
Examples:
Skin (made of several layers) –greater protection
Lung air sacs (made of one layer) –less protection

14. Connective Tissue
Connective Tissues- made up of both specialized cells and non-living materials
that supports, protects and connect the body’s organs.
Different types of cells held
together by a liquid or solid matrix
Examples:
bone
ligament
cartilage
tendons

15. A torn ACL (ligament holding the knee joint together)

16. Nerve Tissue
Nerve Tissues- very complex long, thin cells that can conduct electrical impulses.
Examples:
Nerve
Brain
Spinal cord
The signals between the body and the brain happen very fast.

17. 3 Kinds of Nerve Cells Sensory Neurons – 2. Motor Neurons –
carries information from
the body to the brain or spinal cord
(info about the outside world)
2. Motor Neurons –
carries instructions from the brain or
spinal cord to another part of the body,
usually muscles.
3. Interneurons-
connects the sensory and motor neurons
(brain and spinal cord are made of these)

18. If your hand gets close to a hot surface, you pull your hand away
If your hand gets close to a hot surface, you pull your hand away. This is because your body can feel since your skin contains millions of nerve cells.

19. Muscle Tissue
Muscle tissues- bundles of long specialized tissues cells that can shorten or contract.
Allows movement and enables organs to function
3 types of muscle tissues:
Striated (voluntary)
Smooth (involuntary) -lines the walls of organs, veins, arteries
Cardiac (involuntary) – lines the walls of the heart