2. Organization of Organisms
Tissue is composed of similar cells
working together to perform a similar
function
Organs are tissues organized to work
together to accomplish a specific task
Organ systems are groups of organs that
carry out functions for the organism
3. Tissues
4 Main types, but are subdivided as we will see
later
Epithelial tissue covers body surfaces and
lines body cavities
Connective tissue supports and binds body
parts
Muscular tissue provides movement
Nervous tissue provides communication
4. Epithelial Tissue
Primary function:
Protection- it lines all body surfaces
and cavities, and the inner and outer
linings of organs
Substances have to pass through it
to get into the body
Generally only one cell thick
5. Epithelial Tissue
3 types of cells, differ in shape
Squamous epithelium - flattened cells
line the air spaces in lungs, blood
vessels, and skin
Skin is layered, reinforced by keratin
Skin protects body from desiccation,
injury , and pathogens
6. Epithelial Tissue
Columnar epithelium - rectangular cells
lines the digestive tract, absorbs
nutrients
Cuboidal epithelium - cube shaped
lines the kidney tubules, absorbs
molecules
lines the bladder, can stretch
7. Epithelial Tissue
Also forms glands, can produce products
and secrete them
Goblet Cells in trachea, digestive tract also
secrete mucus and other products to aid
digestion
This type of tissue constantly replaces its
cells- useful in skin, digestive tract
Liver is also derived from epithelial tissue
8. Connective Tissue
Binds organs, body together and
provides support
The cells of connective tissue are usually
separated by matrix, which is
noncellular and comes in many forms
Collagen is one common matrix fiber
9. Connective Tissue
Loose fibrous - Connects epithelial tissue to the other
tissues in an organ,
Also can form a protective layer around some
organs
Cells are called fibroblasts - they produce a
matrix that contains fibers
This tissue enables blood vessels and lungs to
expand and then return to original shape
Adipose tissue is this type- the cells in it store fat
10. Connective Tissue
Dense fibrous - contains lots of collagen,
packed tightly together
Specific functions: tendons,
ligaments
Cartilage- solid yet flexible matrix
Bone - rigid, Ca salts around
collagen fibers provide rigidity
11. Connective Tissue
Blood is a type of connective tissue- the matrix is
the plasma (liquid)
Transports nutrients and oxygen to cells and
removes their waste products
Red blood cells - small disk shaped, no nucleus,
carry oxygen
White blood cells - fight infection by either
engulfing pathogens or producing antibodies
Platelets - fragments of cells that cause clots
12. Muscular Tissue
3 types:
Skeletal - voluntary muscle attached through tendons
to bones, causes movement of the parts of skeleton
Have long cells formed by several fused together,
this allows for fast reaction
Cardiac - found only in the heart- involuntary
because it’s contractions are automatic
Separate cells, but bound together at the ends to
allow the contraction impulse to spread from one to
the next
13. Muscle Tissue
Smooth - has a smooth appearance,
involuntary
Inside the digestive tract, blood vessels
Contracts slowly but can hold the
contraction for a long time
14. Nervous Tissue
Provides communication between parts of the
body
Nerve cells are called neurons
Each cell conducts a nerve impulse through
itself to either another neuron or a muscle
cell or gland
Neuroglia are cells that surround neurons
and provide support to them
15. Nervous Tissue
Each neuron has 3 parts:
Dendrite - extension that conducts incoming
impulses
Cell body - contains nucleus and most
cytoplasm
Axon - long extension that conducts outgoing
impulses - actual nerves contain only axons,
the rest is in the spinal cord or brain
16. Organs
Organs are composed of different types
of tissues working together
The structure and function of an organ
is dependent on the tissues it is made of
Organs work together in Organ systems
17. Organ Systems
5 groups of organ systems that we will
discuss:
1. Transport
2. Maintenance
3. Control
4. Sensory and Motor
5. Reproduction
18. Transport Systems
Cardiovascular - Blood, heart, blood vessels
Transports nutrients and O2 to the tissue fluid,
which surrounds all cells; removes waste
Lymphatic - Lymphatic vessels, lymph, lymph
nodes
Absorb fat and tissue fluid for redistribution,
involved in defense
Immune - Spleen, thymus, cells in blood and lymph
Protects the body from disease
19. Maintenance Systems
Respiratory - Lungs, trachea and associated tubes for gas
transport
Brings in O2 and expells CO2, exchanges these gases
with air/ blood
Urinary - kidneys, bladder, transport tubes for urine
Removes waste, regulates fluid levels and chemicals in
blood
Digestive - Teeth, tongue, esophagus, stomach, intestines,
saliva glands, liver, pancreas, etc.
Receives food, processes it into usable nutrients
20. Control Systems
Nervous - Brain, spinal cord, nerves
conduct nerve impulses both from
sensory organs to brain and from brain
to rest of the body
Endocrine - hormonal glands
Secretes hormones that are signals to
other parts of the body, involved in
reproduction as well
21. Sensory and Motor Systems
Integumentary - Skin and accessory structures,
sensory organs
Respond to external stimuli
Protects body from outer environment
Skeletal - bones
Anchor for muscles, provides protection for vital
organs
Muscular - Muscles
Enables the body to move
22. Reproductive System
Obviously, different for males and
females
Male: Testes, several ducts and
associated glands, penis
Female: Ovaries, oviducts, uterus,
vagina, also associated glands
23. Homeostasis
Homeostasis - the maintenance of the internal
environment at near constant conditions
The internal environment consists
primarily of the blood and tissue fluid
Ex: Endothermic control of body T
Ex: pH stays the same inside the body
Ex: blood pressure stays steady despite
dehydration
24. Homeostasis
All systems contribute to homeostasis
It is constant work to just maintain the
constant environment needed to live
Regulators of blood composition: liver and
kidneys
kidneys- regulate salt, blood volume, and
pH
liver- regulates glucose concentrations,
removes toxic chemicals
25. Homeostasis
Control systems involved as well
Nervous system can create a fast
response
Ex: Escape from icy water!
Endocrine system can create a slower
but lasting response
Ex: Store more fat
26. Negative Feedback
This is the primary way in which the body
maintains homeostasis
‘Negative’ refers to the result of the cycle
removing the original stimulus
Sensor: Detects change (stimulus) in
environment
Control center: Initiates actions that bring
conditions back to normal
