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CHAPTER 3 – CELLS AND TISSUES
Cells And Tissues
Objectives:
1. Demonstrate an Understanding of the
basic organization of the cell
2. Categorize the relationship of the cell
and its functions to the more complex
levels of organization within the body
3. know the four major categories of
tissues and their location, structure, and
function
CELL THEORY
Cell Theory:
1. The cell is the unit of
structure of all living things
2. The cell is the unit of
function of all living things
3. All cells come from preexisting cells
Anatomy of a Generalized Cell
Remember -- all cell types are not exactly like
each other, they often have some basic parts
and functions that are common to all cells.
There are three main regions to a cell
•nucleus
•cytoplasm
•plasma membrane
Resources for the cell: for your review:
Cellsalive.com http://cellsalive.com/
Biology4kids
http://www.biology4kids.com/files/cell_main.html
Animal Cell Structure :
http://micro.magnet.fsu.edu/cells/animalcell.html
In this section we will discuss some of the types of cells
built for specific functions:
Cells that connect body parts
Fibroblast- this type of cell secretes cable-like fibers. It
has plenty of rough ER and large Golgi Apparatus.
These structures are necessary to secrete the proteins
that are the building blocks of the cable-like fiber
structures
Cells that cover and line body organs
Epithelial cells - shaped much like the honeycomb of a
beehive. This allows the cells to be stacked into
sheets. It has abundant intermediate filaments that
resist being torn when they are rubbed or pulled
Cells that move organs and body parts
Muscle cells ( skeletal and smooth) - these are
elongated cells with numerous contractile filaments.
These filaments are able to contract to move bones or
change the size of internal organs
Cell that store nutrients
Fat cells- these contain a large lipid droplet in their
cytoplasm. This results in their large sperical shape.
Cells that fight disease
Macrophages- This type of cell extends large
psuedopods to crawl through tissue to reach sites of
infection. The lysosomes within the cell digest the
microorganisms that it engulfs. A macrophage is a
type of phagocytic cell
.
Cells that fight disease
Macrophages- This type of cell extends large
psuedopods to crawl through tissue to reach sites of
infection. The lysosomes within the cell digest the
microorganisms that it engulfs. A macrophage is a
type of phagocytic cell
Cells that gather information and control body functions
(Neurons- Nerve cells)- This type of cell is equipped
with long processes for the reception of messages.
The cell can then transmit these messages to other
structures found in the body. The processes are
covered wit an extensive plasma membrane
swim.
Cells of reproduction
Oocyte (the egg cell)- This is the largest cell in the
human body. It contains many copies of all organelles.
These are ready to be distributed to the daughter cells
that would result from fertilization.
Sperm - This long streamlined cell is built for
swimming. It has a long flagellum that enables it to
swim
Body Tissues
1. Cells are arranged in tissues that
provide specific functions for the
body.
2. Cells of different tissues are
structured differently, which leads to
their differences in function.
3. The tissues of the human body
include four major types.
Body Tissues
1.
2.
3.
4.
Epithelial
Connective
Muscle
Nervous
No you don’t have to copy – but you need to know examples
Epithelial tissue is widespread throughout the
body, it covers organs, and lines body surfaces.
Epithelial tissues are anchored to a basement
membrane, are made up of tightly packed cells
containing very little intercellular material,
generally lack blood vessels, and are replaced
frequently.
They function in protection, secretion,
absorption, excretion, and sensory reception.
EPITHELIAL TISSUE - types
1.Simple Squamous Epithelium
2.Simple Columnar Epithelium
3.Pseudostratified Columnar
Epithelium
4.Stratified Squamous Epithelium
5.Stratified Cuboidal Epithelium
6.Stratified Columnar Epithelium
7.Transitional Epithelium
CONNECTIVE TISSUES - characteristics
A. General Characteristics
Connective tissues bind, support, protect, serve as
frameworks, fill spaces, store fat, produce blood
cells, protect against infection, and repair tissue
damage.
Unlike epithelial tissues, connective tissues have
abundant matrix, or intercellular material,
throughout, and have good blood supplies (except
cartilage).
CONNECTIVE TISSUES – Cell types
B. Major Cell Types
The fibroblast is the most common cell type, and is a
fixed, star-shaped cell that secretes fibers and is
large in size.
Wandering macrophages function as scavenger cells
and defend against infection.
Mast cells are large and are located near blood
vessels where they release heparin (anticoagulant)
and histamine (promotes inflammation).
Fibroblasts
macrophage
Mast Cells
Connective Tissue Fibers
1) Strong collagenous fibers (white fibers),
made of the protein collagen, add strength
for holding body parts together.
2) Elastic fibers (
), made of
the protein elastin, are stretchy and add
flexibility to certain types of connective
tissues.
3) Reticular fibers are thin collagenous
fibers that form supportive networks in a
variety of tissues.
Loose Connective (areolar) Tissue
This type of tissue forms delicate,
thin membranes throughout the
body that bind body parts together
such as skin and underlying organs.
The majority of the cells are
fibroblasts that are separated by a
gel-like ground substance that
contains collagenous and elastic
fibers.
Adipose Tissue
Adipose tissue is loose connective
tissue designed to store fat.
It is found beneath the skin, around
joints, padding the kidneys and other
internal organs, and in certain
abdominal membranes
Dense Connective Tissue - densely packed
collagenous fibers – is very strong but lacks a
good blood supply. - found as part of tendons
and ligaments.
hyaline cartilage, is white with abundant fine
collagen fibers, is found at the ends of bones,
and supports respiratory passages.
Elastic cartilage, with elastic fibers, provides a
framework for the external ears and parts of the
larynx.
Fibrocartilage, with many collagenous fibers, is
a tough tissue that provides a shock-absorbing
function in intervertebral disks and in the knees
.
and pelvic girdle
Bone
Bone is the most rigid connective tissue, with
deposits of mineral salts and collagen within the
matrix.
Bone internally supports the body, protects,
forms muscle attachments and is the site for
blood cell formation.
Bone cells, called osteocytes, lie within lacunae
and are arranged in concentric circles (osteons)
around osteonic canals interconnected by
canaliculi.
Bone has a good blood supply, enabling rapid
recovery after an injury.
Blood
Blood is composed of cells (red and white)
suspended in a liquid matrix called plasma.
It functions to transport substances
throughout the body.
Muscle Tissues: General Characteristics
Muscle cells, or fibers, can contract and
consist of three major types.
Skeletal (striated)
Smooth
Cardiac (heart)
Skeletal Muscle Tissue
Skeletal muscle is attached to bone and can be
controlled by conscious effort (voluntary).
The cells (muscle fibers) are long and cylindrical,
striated, have many nuclei and contract from
nervous impulse.
Smooth Muscle Tissue
Smooth muscle tissue lacks striations, is
uninucleate, and consists of spindle-shaped
cells.
This involuntary muscle is found in the walls of
internal organs, and in the digestive tract,
blood vessels, and urinary bladder.
Cardiac Muscle Tissue
Cardiac muscle tissue is found only in the
heart and consists of branching fibers that are
connected to each other with intercalated
disks.
This involuntary muscle has a single nucleus in
each cell but appears striated.
Nervous Tissues:
Nervous tissues are found in the
brain, spinal cord, and nerves.
Neurons, or nerve cells, conduct
nervous impulses while helper cells,
or neuroglia, insulate, support, and
protect the neurons