Introduction to Human
Body Systems
The Tissues
Levels of Organization
Molecules (like DNA and proteins)
Organelles
Cells
Tissues
Organs
Organ Systems
Organism
Populations
Communities
Levels of Organization
A bunch of cells make up tissues (like
muscular tissue)
Tissues come together to form organs (like
a heart)
Organs work together in organ systems (like
the circulatory system)
Organ systems work together to make
organisms (like humans)
Guess the Organ Systems…
What are some organ systems that you can
think of?
Tissues
All of the organ
systems are made up
of just four TYPES of
tissues
Epithelial tissue
Connective tissue
Muscle tissue
Nervous tissue
Each tissue type
contains many
different tissues
Epithelial Tissue
Function: cover, protect, secrete and absorb
makes up various surfaces.
Cuboidal: Single layer of cube like cells.
Columnar: Single layer of tall slender cells;
may have microvilli at free surface.
Connective Tissue
Properties: living cells are separated by a nonliving
matrix, which is usually secreted by the cells
themselves. The MATRIX gives the tissue its
properties.
White fibrous tissue: collagen fibrils secreted by fibroblasts.
Makes up the tendons and ligaments.
Bone: Extremely hard with calcium salts in matrix. Cells are
called osteocytes arranged is Haversian system.
Adipose: Fat storage. Large storage structure with nucleus
moved to side.
Blood: Matrix is liquid (plasma) and is NOT formed by the
blood cells themselves. Various cells: erythrocytes, various
types of leucocytes, and platelets or thrombocytes.
White Fibrous Tissue
Bone
Bone Tissue
Blood
(Plasma is on top)
Adipose Tissue
Muscle Tissue
Function: specialized for contraction. Have
elongated shape containing proteins that undergo
changes in shape to cause shortening.
Smooth muscle: controlled by autonomic nervous
system, involuntary control.
Skeletal muscle: striated muscle moved under
voluntary control. Cells are multinucleated.
Cardiac muscle: Found only in the heart.
Striated, branched, with one nucleus. Under
autonomic nervous control.
Nervous Tissue
Function: Receives stimulus from internal
and external environment which is
converted into action potentials which
evoke appropriate responses.
Picture
Organs
Multiple tissue or tissue
layers form organs…
What type of tissue do
you think make up the
following
organs/structuresIntestines
Heart
Skin
Bones
Organ Systems
Organs that work together make up organ
systems…
Do you think all organs belong to only one
organ system?
Do you think that all organ systems operate
independently of one another?
Guess that Organ System
What organ system do you think the
following organs belong to?
Heart
Skin
Liver
Lung
Kidney
Intestine
Blood cells
What is/are the function(s) of the various
organ systems…how do they fit together?
Integunmunintary
Skeletal System
Muscular System
Circulatory System
Respiratory System
Digestive System
Excretory System
Immune System
Nervous System
Endocrine System
Reproductive System
A few relationships…
Circulatory and respiratory systems – the blood carries
oxygen to the cells…
Circulatory and digestive systems – the blood carries
nutrients to the cells…
Endocrine and reproductive systems – hormones in the
endocrine system help the reproductive system function
Integunmunintary and immune system – our skin is our
first line of defense against germs
Nervous and all systems – the brain and nervous
system help control them all!