Body Tissues and Membranes
CHAPTER 5
What are tissues?

Cells are organized into groups and layers
called TISSUES

Each tissue is composed of similar cells that
are specialized to carry on a particular
function
◦ Secretion
◦ Absorption
◦ Support
Tissue Types

Epithelial

Muscle

Connective

Nervous
Epithelial Tissue

Covering of all major
body surfaces

Makes up glands

Always has one free
surface and one that’s
attached to connective
tissue
◦ Basement Membrane
Free Surface
Basement Membrane
Connective Tissue
Epithelial Tissue

Lacks blood vessels
◦ Nutrients diffuse from
capillaries of
underlying tissue

Rapid rate of
reproduction
◦ Constantly sloughed
off

Tightly packed
◦ Create good barriers
Epithelial Terms

Shape
◦ Squamous-flat, thin cells
◦ Cuboidal-cube shaped cells
◦ Columnar-tall, elongated cells

Layers
◦ Simple-single layer
◦ Stratified-two/more layers
Types of Epithelial Tissue

Simple Squamous Epithelium
◦ Single layer of “pancake” cells
◦ Easy diffusion
◦ Lung alveoli (air sacs), capillaries
Nucleus
Types of Epithelial Tissues

Simple Cuboidal
◦ Single layer of cube-shaped cells
 Primarily secretory cells
 Ovaries, kidneys, salivary glands
Centrally
located
nucleus
Types of Epithelial Tissue

Simple Columnar
◦ Protection / Absorption
◦ Microvilli
 Increase surface area
◦ Digestive tract
Nuclei located on same level
Types of Epithelial Tissue

Pseudostratified Columnar
◦ Similar to S.C.
◦ Have cilia along edge
 Line respiratory system
Note: how
nuclei are at
two or more
layers

Goblet cell:
secretes
mucus
?
Types of Epithelial Tissue

Stratified Squamous
◦ Many layers thick
◦ New ones push old ones up
 Epidermis

Stratified Cuboidal
◦ 2 or 3 layers of cuboidal cells

Stratified Columnar
◦ 2 or 3 layers of columnar cells
Types of Epithelial Tissue

Transitional Epithelium
◦ Responds to tension - stretches out
◦ Creates protective barriers
◦ Lining of bladder & ureters
Glandular Epithelium
Specialized to produce
and secrete
substances
 Make up glands

◦ Exocrine glands dump secretions into
ducts
◦ Endocrine glands dump secretions into
bloodstream
Epithelial Tissue
-Cells readily divide
-Cells are continually
replaced
-Cells are tightly
packed
-Classified by shape
and number of layers
Connective Tissue

Most abundant type
of tissue by weight

Functions:
◦
◦
◦
◦
Support
Stores fat
Produces blood cells
Protection from
infection
Connective Tissue

Cells spaced
further apart
than epithelia
Types of Fibers

Collagenous fibers - thick,
made of collagen
◦ Strong, slightly elastic, flexible
◦ Ligaments, tendons

Elastic fibers- made of
elastin
◦ Branched, stretch easily
◦ Vocal cords
Loose Connective Tissue
◦ Binds skin to underlying
tissue
◦ Lies beneath most
epithelial tissue
Adipose Tissue (FAT)

Form of loose
connective tissue
◦ Protective cushion
◦ Stores energy
Dense Connective Tissue
◦ Binds body parts
together
◦ Make up tendons,
ligaments
Cartilage

Rigid

Protection, support

Ends of bones, nose,
external ears, larynx,
between vertebrae
Bone

Most rigid

Functions:
◦
◦
◦
◦
Internal structure
Attachment for muscles
Blood formation
Inorganic mineral storage
Other Connective Tissues

Blood
◦ Transports substances
between cells and
external environment
Muscle Tissue

Contractile - tissue can
contract, becoming
shorter and longer
◦ Causes body parts to
move

3 types:
◦ Skeletal muscle-bones
◦ Smooth muscle-organs
◦ Cardiac muscle-heart only
Nervous Tissue

Found in brain, spinal
cord, nerves

Neurons - basic
nerve cells

Respond to changes in
environment and
send messages
Epithelial
tissue
Smo
mu