Transcript Tissues & Organs - Cal State LA

Tissues, Organ Systems and
Homeostasis
Dr. A. Russo-Neustadt
Biology 155
Organization of the Animal Body
• Animals’ bodies exhibit hierarchical
organization –
– Biological molecules are organized into
organelles (ex. Phospholipids and proteins are
arranged into the plasma membrane)
– Organelles are organized into a cell (ex.
Nucleus + plasma membrane + cytoplasm
proper + many organelles = cell)
Organization of the Animal Body
(continued)
• Hierarchical organization continued –
– Groups of similar cells are organized into tissues (ex.
Cardiac muscle cells are organized into the tissue,
cardiac muscle); Note that the evolution of multicellular
living forms required development of tissues
– Two or more tissues are organized to form an organ
(ex. Cardiac muscle tissue + connective tissue +
epithelial tissue = the heart; provides force to move
blood)
Organization of the Animal Body
(continued)
• Hierarchical organization continued –
– Organs are organized into organ systems (ex.
Heart + blood vessels + blood = cardiovascular
system; function is transport)
– Organ systems are organized into an organism
(ex. An animal consists of 11 organ systems)
Embryonic Tissues – all adult
tissues are derived from one of
three embryonic tissues
Ectoderm =
“outside skin”
gut
Mesoderm =
“middle skin”
Animal embryo
Endoderm =
“inside skin”
Cross section
through embryo
Fate of Embryonic Tissues
• Ectoderm will become the outer covering
of the body and the nervous system
• Mesoderm will become the muscles and
internal skeletons
• Endoderm will become the lining of the
gastrointestinal tract, lungs, vessels and
ducts
Adult Tissues
• Definition = groups of cells with similar
structure, embryonic origin, and function;
cells are bound together by extracellular
material and function together to perform a
specific task
• There are four main types of adult tissues
in the animal body
Epithelial Tissues
• Source = may be derived from any tissue in
the embryo
• Function = mainly protective, therefore
they cover all free surfaces of the body; can
be specialized for absorption, excretion,
secretion, etc.
Epithelial Tissues (continued)
• Characteristics =
– Closely joined cells with little extracellular
material between the cells
– Presence of a basement membrane secreted by
the epithelial cells; separates the epithelial cells
from underlying tissues
– One free surface not in contact with other cells
Fig. 20.4
Epithelial Tissues (continued)
• Classification = ask and answer two
questions
– How many cell layers above the basement
membrane?
• Simple = one layer of cells; used for exchange (ex.
Diffusion of gases in the alveoli of the lungs,
absorption in the small intestine; see previous slide)
• Stratified = more than one layer of cells; used for
protection (ex. the outer layer of the skin)
Epithelial Tissues (continued)
• Classification continued –
– What shape are the cells? (when viewed from the side)
• Flat and thin = squamous; used to maximize diffusion (nonenergy requiring exchange where things move from an area of
high to an area of low concentration); ex. Alveoli of lungs,
capillaries
• Look like squares = cuboidal; used to maximize energy
requiring exchange such as absorption and excretion (things
can move from an area of low concentration to an area of high
concentration); ex. respiratory system
• Tall and thin = columnar; as cuboidal above; ex. Small
intestine
Fig. 20.4
Connective Tissues
• Source = may be derived from any tissue in
the embryo
• Function = many, but generally holds
things together in the body; can be
specialized to give structure to and protect
body parts
Connective Tissues (continued)
• Characteristics =
– Few cells
– Lots of extracellular material between the cells;
extracellular material is produced by the cells and is
called matrix
– Matrix consists of –
• Protein fibers
• Ground substance = non-fibrous proteins + other molecules
• Fluid
Fig. 20.5
Connective Tissues (continued)
• Classification = ask and answer one
question
– What is the nature of the extracellular matrix?
• Fluid = tissue is blood, functions in gas transport
(Matrix)
Connective Tissues (continued)
• Classification = ask and answer one
question
– What is the nature of the extracellular matrix?
(continued)
• Solid =
– Mainly protein fibers = connective tissue proper (ex.
Loose and dense connective tissues, adipose)
– Protein fibers + ground substance = special connective
tissues (ex. Bone and cartilage)
Fig. 20.5
Muscle Tissues
• Source = derived from the embryonic mesoderm
• Function = allows movement of the body or
movement within the body
• Characteristics =
– Closely joined cells with little extracellular material
– Contain specialized protein fibers capable of
contraction
Fig. 20.6
Muscle Tissue (continued)
• Classification –
– Cardiac Muscle = heart muscle
•
•
•
•
•
One, centrally located nucleus
Presence of striations
Short, branched cells
Presence of intercalated discs
“involuntary”
Fig. 20.6
Muscle Tissue (continued)
• Classification –
– Skeletal Muscle
•
•
•
•
Many, peripherally located nuclei
Presence of striations
long, thin cells
“voluntary”
Fig. 20.6
Muscle Tissue (continued)
• Classification –
– Smooth Muscle – found in “hollow organs”
•
•
•
•
One, centrally located nucleus
no striations
Short, tapered cells
“involuntary”
Fig. 20.6
Nervous Tissue
• Source = derived from the embryonic ectoderm
• Function = communication
• Characteristics –
– Electrically excitable cells (neurons with cell body and
processes), or
– Cells that support, nourish and protect the neurons
(glia)
• Classification = none
Fig. 20.7
Fig. 20.10
Animal Organ Systems
System
Major
Component
Function
Integumentary
Skin
External
Protection
Skeletal
Bones
Support
Muscular
Skeletal
Muscles
Movement
Fig. 20.10
Animal Organ Systems continued
System
Major
Component
Function
Nervous
Brain and
Nerves
Integration
Endocrine
Endocrine
Glands
Integration
Circulatory
Heart and Blood Transport
Vessels
Fig. 20.10
Animal Organ Systems continued
System
Major
Component
Function
Respiratory
Lungs or Gills
Digestive
Gastrointestinal Nutrient
Tract
Acquisition
Urinary
Kidneys
Gas Exchange
Waste
Elimination
Fig. 20.10
Animal Organ Systems continued
System
Major
Component
Function
Reproductive
Ovaries and
Testes
Production of
New Individuals
Immune
White Blood
Cells and
Lymph Glands
Internal
Protection