Tissues – Epithelial Tissue

Tissues 

Tissues – group of similar cell types that perform a common function



The human body has four basic types of tissue: 

Epithelial



Connective



Muscle



Nervous

Tissues – Epithelial Tissue 

Epithelium is tightly packed sheets of cells that line organs and outer surfaces, as well as the insides of hollow organs, vessels, and body cavities.

Epithelial Tissue 

Epithelia are typically anchored on one face, but free on another 

The free side is typically exposed to the environment of body fluids



Can be single layer or many layers thick



Function in protection, secretion, and absorption



Epithelial cells are continuously sloughing off and are replaced by cell division

Tissues – Epithelial Tissue 

Many organs are lined with epithelial tissue

Tissues – Epithelial Tissue 

Many organs are lined with epithelial tissue

Simple Squamous Epithelial Tissue – inside your cheek, skin cells

Tissues – Epithelial Tissue 

Many organs are lined with epithelial tissue

Simple Cuboidal Epithelial Tissue – kidney tubule cells

Fourth Edition

BIOLOGY Science for Life | with Physiology Colleen Belk • Virginia Borden Maier

© 2013 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc.

PowerPoint Lecture prepared by Jill Feinstein Richland Community College

Tissues – Epithelial Tissue 

Many organs are lined with epithelial tissue

Simple Columnar Epithelial Tissue – large intestine

Tissues – Epithelial Tissue 

Many organs are lined with epithelial tissue

Ciliated Pseudostratified Columar Epithelial Tissue - trachea

Tissues– Connective Tissue  Loosely

organized and composed of cells embedded in a matrix

 Matrix

is composed of

protein fibers and  ground substance 

 Usually

binds organs or tissues to one another

Tissues – Connective Tissue  Six

different types:

Loose connective tissue  Adipose tissue  Blood  Fibrous connective tissue  Cartilage  Bone 

Tissues – Connective Tissue 

Loose connective tissue 

Most widespread tissue in animal body



Matrix composed of collagen and elastin fibers



It is called “loose” because of the fibers that are loosely woven together



Binds epithelia to tissues, pads the skin, and holds organs in place

Loose connective tissue

Tissues – Connective Tissue 

Adipose tissue 

Also called fat



Connects skin to underlying structures, pads organs



Used for storage of energy (fat)



Primarily cells; small amount of matrix

Adipose tissue

Tissues – Connective Tissue 

Blood 

Cellular component, red blood cells, white blood cells and platelets



Matrix is the plasma



Functions include carrying oxygen and nutrients; fighting infection

Blood

Blood

Blood

Tissues – Connective Tissue 

Fibrous connective tissue 

Forms tendons and ligaments



Matrix is densely packed collagen fibers running in parallel.

Fibrous connective tissue

Nuclei of fibroblasts

Tissues – Connective Tissue 

Cartilage 

Cellular component  chondrocytes



Chondrocytes secrete own matrix



Cartilage cushions joints, forms

support for ears and nose 

Not vascularized, so takes a long time to heal if injured

Cartilage

Damaged Cartilage

Tissues – Connective Tissue 

Bone 

Rigid connective tissue



Osteoblasts secrete matrix that is composed of collagen fibers and calcium salts



Osteocytes maintain the hardened bone matrix



Body can make use of calcium from bones if dietary levels are too low

Bone

Tissues – Muscle Tissue 

Skeletal Muscle 

Usually attached to bone



Produces all voluntary movements



Striated



Long, thin, cylindrical shape

Striated (Skeletal) Muscle Tissue

Smooth Muscle 

Smooth muscle 

Not striated and involuntary



Musculature of organs, blood vessels, digestive tract



Contracts more slowly and for longer than skeletal muscle

Cardiac Muscle

Tissues – Nervous Tissue 

Neurons conduct electrical signals and compose the cells of the brain and spinal cord



Main functions of neurons are to:





Sense stimuli



Process stimuli



Transmit signals

Most cells of nervous system do not undergo cell division

Tissues – Nervous Tissue

Nervous Tissue

Tissues – Tissue Donation 

One person’s tissues can improve the lives of as many as 50 people. 

Injuries from motor vehicle accidents, burst blood vessels, and drowning are common causes of brain death.  Once

dead, brain cells cannot recover.



Brain dead is different than being in a coma or vegetative state.



Tissues can be treated to remove any proteins that a person’s immune system may react to so there is no need for donor matching.

Tissues – Tissue Donation 

Types of tissues 

Corneas



Eye tissue



Skin



Bones



Tendons



Veins



Heart valves