SLE132 Lecture Notes - Lecture 2: Loose Connective Tissue, Epithelium, Chondroitin Sulfate
11 May 2018
School
Course
Professor
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Melbourne Institute of Business and Technology Pty Ltd trading as Deakin College
CRICOS Provider Codes: Deakin College 01590J, Deakin University 00113B
SLE 132 – Form and Function
Cells, Tissues and Organs
Learning Objectives
•What are the four tissue types possessed by
animals?
•Describe each type of tissue giving examples
of their composition and position in an animal
•How are tissues formed into organs?
Cellular level - muscle cell
Tissue level - muscle tissue
Organ level - heart
Organism level
- many organ systems
Organ system level
- cardiovascular system
The hierarchy of biological organisation
Specialised cells grouped into tissues
•Tissues – groups of cells with a common structure and
function
•Different cells and tissues have different structures
suited to their different functions (form is suited to
function)
–cells are held together by an extra-cellular matrix
•In animals there are 4 major tissue categories:
•Epithelial - Lining
•Connective - Connecting
•Nervous – Sensory/communication
•Muscle - Contractile
Epithelial cells
•Line outsides…
•But think of a body as a doughnut, rather than
only inside and outside.
•E.g. from mouth to anus is technically outside,
and thus lined with epithelial cells.
•Surfaces open to the environment
will have epithelial cells
Epithelial Cells
•Where are the epithelial cells here?
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Epithelium
•covers body surfaces (eg. epidermis of skin)
•lines internal organs (eg. lungs, blood vessels)
•forms a protective layer (barrier)
•in some cases, forms a site of exchange of gases,
liquids or compounds
•movement (via cilia) especially of foreign materials
•secretion of mucus, enzymes
•Epithelial cells sit on a basement membrane (or
Basal Lamina) which attaches epithelium to
underlying tissue.
•Basal Lamina provides support to epithelia and
acts as a filter allowing only water and small
molecules through
•Regenerates itself quite readily, layers are
regularly shed & replaced by new cells
Basal Lamina
Epithelial cells
Epithelial
tissues
are sheets of
tightly packed
cells
classified by:
- shape
- squamous
- cuboidal
- columnar
- number of layers
- simple
- stratified
Fig. 40.5
Epithelial cells
•Think about the shape and structure (form) of
the epithelial cells to understand their
function:
•Single layers of cells tend to be for exchange,
as molecules can easily pass through.
•Layers of cells tend to be for protection of
underlying surfaces
•Have distinct sides, apical side faces the cavity
or lumen, the basal side is attached to the
basement membrane
http://media.pearsoncmg.com/bc/bc_campbell_biology_7/media/interactiv
emedia/activities/load.html?40&B
Quick Question – what are the functions of the
different types of epithelia?
Squamous Columnar Cuboidal
Simple
Stratified
Pseudo
Stratified
Ciliated
N/A N/A
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What the cells look like under the microscope
•Connective tissue mainly binds and supports other
tissues
•It contains sparsely packed cells scattered throughout
an extracellular matrix
•The matrix consists of fibres in a liquid, jellylike, or solid
foundation attached to a basement membrane
•There are 6 major types of connective tissue which
perform various functions:
•loose connective tissue, fibrous connective tissue
adipose tissue, cartilage, bone, and blood.
Connective tissue
6 major types of Connective tissues
Fig. 40.5
Loose connective tissue
•Holds organs in place and attaches epithelial
tissue to underlying tissues
•Collagenous fibres - strength and flexibility
•Elastic fibres – stretchable
•Reticular fibres – joins connective tissue to
other tissue
Fibrous connective tissue
•Large amounts of collagen, relatively few cells
and low extra cellular matrix
•Strong and slightly flexible, found in joints etc
•Tendons (connect muscles to bone)
•Ligaments (connect bones together)
Cartilage
•Cartilage is composed of
specialized cells called
chondrocytes that produce a large
amount of ECM, mostly of
chondroitin sulfate
•Flexible connective tissue found in
ears, nose, ribcage, trachea etc.
•Less dense and rigid than bone
but provides more support than
muscle
Document Summary
Many organ systems: tissues groups of cells with a common structure and function, different cells and tissues have different structures suited to their different functions (form is suited to function) Cells are held together by an extra-cellular matrix: in animals there are 4 major tissue categories, epithelial - lining, connective - connecting, nervous sensory/communication, muscle - contractile. Basal lamina: epithelial cells sit on a basement membrane (or. Epithelial tissues are sheets of tightly packed cells classified by: Quick question what are the functions of the. What the cells look like under the microscope. Loose connective tissue: holds organs in place and attaches epithelial tissue to underlying tissues, collagenous fibres - strength and flexibility, elastic fibres stretchable, reticular fibres joins connective tissue to other tissue. Fibrous connective tissue: large amounts of collagen, relatively few cells and low extra cellular matrix, strong and slightly flexible, found in joints etc, tendons (connect muscles to bone, ligaments (connect bones together)
