Download Overview of Systems, tissues Notes

Chapter 28
Overview of Tissues
A. The Hierarchy of Structural
Organization
• Anatomy – structure
• Physiology – function
• Structure and function are related in
Biology.
• Molecules  cells  tissues  organs 
systems  organism
• For example:
– Protein  muscle cell  muscle tissue 
heart  cardiovascular system  animal
• Tissue: similar cells that perform a common
function
• Organ: structure made of two or more types of
tissue that together perform a specific task
• Organ system: multiple organs that together
perform a vital body function
B. Stem Cells
• Specialized cells that start off as generic
cells and become specialized.
C. There are four main types of
animal tissues:
Epithelial
Connective
Muscle
Nervous
1. Epithelial tissue: sheets of tightly
packed cells that cover body surfaces
and line internal organs & cavities
- Cover both inner and outer surfaces of internal
organs
Layer
Cell Shape
Squamous
(floor tiles)
Location & function
capilary and air sac lining
Great for diffusion
Simple
(single layer)
Stratified
(more than one)
Pseudostratified
(one layer but
looks like more)
Cuboidal
(like dice)
kidney tubules and thyroid gland
secretes
Columnar
(like bricks on end)
intestinal lining
Secretes
Squamous
Skin
Takes a beating/ regenerates fast
Cuboidal
sweat and mammary glands
secretes
Columnar
pharynx and anus
secretes
Columnar
upper respiratory
secretes
2. Connective tissue
binds and supports other tissues
• Contains fewer cells, scattered throughout
an matrix
– Matrix:
• Secreted by the cells
• Contains a web of fibers embedded in a liquid,
jelly, or solid
• Non- living
• Made from collagen, and elastin
– CFLABB
• Loose connective Types
• Fibrous connective
tissue: binding and
tissue: tendons and
packing material to
ligaments
hold organs in place
– Fibers are mainly
loosely woven
collagen and elastic
– Fibers are densely
packed bundles of
collagen
• Adipose tissue: pads • Cartilage: shock
and insulates the
absorber in joints,
body and stores
nose, and ears
energy
– Many collagen fibers
– Stores fat within cells
– Little matrix
embedded in a
rubbery matrix
• Bone: support
structure
– Collagen fibers
embedded in a hard
mineral matrix of
calcium, magnesium,
and phosphate
• Blood: functions in
transport and immunity
– Consists of cells suspended
in a liquid matrix (plasma)
• red blood cells (RBCs or
erythrocytes)
• white blood cells (WBCs or
leukocytes)
• platelets
3. Muscle tissue
functions in movement
• Muscle tissue bundles of muscle cells
– Most abundant tissue in most animals
– In cytoplasm of muscle, large amounts of
contractile proteins. (uses ATP from Mito to
fuel proteins.)
Types
• Skeletal muscle
– Attached to bones by
tendons
– voluntary body
movements
– Striped or striated
appearance
• Cardiac muscle
– Forms the heart
– Cells are striated and
branched
– Cells connect at
specialized junctions
for coordinated
contraction
– Involuntary
• Smooth muscle
– Lacks striations
– Responsible for
involuntary organ
motions
– Ex: intestinal
movements
(peristalsis)
4. Nervous tissue
forms a communication network
• Nervous tissue: senses stimuli and
quickly transmits information from one part
of the animal to another
Structure
• Neuron:
• Specialized to conduct electrical impulses
• Dendrites convey information toward the
neuron cell body
• Axons convey information away from the
neuron cell body
• Nervous tissue also includes supporting
cells
D. Organs
made up of tissues
• DERNCRIMUILS
Organ systems work together to
perform life’s functions
• Endocrine : secretes • Skeletal: supports
hormones to regulate the body allows
movement
body functions
• Circulatory:
exchanges nutrients,
gases, and wastes
• Respiratory :
exchanges gases with
the environment
• Muscular : produces
movement and heat
• Integumentary :
protects against
injury, infection, and
dehydration
• Lymphatic :
provides fluid balance
and immunity
• Immune : defends
against infection and
cancer
• Urinary : excretory;
removes wastes from
the blood
• Digestive : ingests,
breaks down, and
absorbs nutrients
• Reproductive :
initiates and supports
developing embryos
• Nervous : detects,
interprets, and directs
response to stimuli
E. Animals regulate their internal
environment
• Regulating both internal & external
• An animals internal environment is the
interstitial fluid that surrounds the cells.
– Internal salt and water balance and blood
temperature must be kept stable
• Homeostasis: maintaining a “steady
state” internal environment
– There are always slight fluctuations
• Homeostasis depends on negative
feedback
• Negative feedback: a change in a variable
triggers mechanisms that reverse that
change
– Analogous to a thermostat that controls a
furnace
– Many animal control centers are located in the
hypothalamus of the brain
– Shivering and sweating are ways of
controlling human body temperature