Download 3.1 How the Animal Body is Organized

3.2
Organ Systems in
Animals
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.
Level of Organization
Hierarchylevels of organization
of increasing or
decreasing complexity.
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
Organ Systems
Anatomy – The structure of living things
Physiology- The function of living things
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
ORGAN SYTEMS
ORGAN SYTEMS (continued)
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
Animal Tissues
 4 major types:
1. Epithelial Tissues
2. Connective Tissues
3. Nerve Tissues
4. Muscle Tissues
Provide: covering,
connections and
support
Sensing and
responding
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
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
A torn ACL (ligament holding the knee joint together)
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.
3 Kinds of Nerve Cells
1. Sensory 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. Interneuronsconnects the sensory and motor neurons
(brain and spinal cord are made of these)
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.
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