Tissues (click for research

on cells

(Histology)Chapter 5

Learning Targets• By the end of today, you should be able

to:• Name the 4 different types of tissues in

the body.• Give examples of the 4 different types

of tissues and where they may be found.

• Contrast the 4 different types of tissues.

Teamwork

• The human body contains~50-100 trillion cells.

• No one cell can carry out all bodily functions by itself.

• Cells specialize (take on special structures to perform unique functions).

• Tissue = Group of cells with a similar structure and function.

• The study of tissues is known as histology.

TissuesThere are 210 different types of cells in the human body, each classified as one of 4 types of tissue:

1. Epithelial (covering/lining)2. Connective (support)3. Muscle (movement)4. Nervous (control)

Epithelial Tissue

• Covers and forms internal lining of organs (stomach, trachea, blood vessels, etc.)

• Always has an exposed surface with the other surface anchored to connective tissue

One epithelial cell

Epithelial Tissue• Cells readily divide, continually replaced• Tightly packed – form a good protective barrier against injury, microbes• May contain sensory receptors • May secrete hormones, enzymes, mucous• Absorbs nutrients in intestines• Filters air in lining of lungs (cilia)

Epithelial Tissue – Skin

side view top view

Connective Tissue• Wide variety of form and function: blood, bone,

cartilage, fat, tendons, ligaments, etc.

• Connects body tissues and organs together, offers support, nutrients, transport, protection, storage

• Cells are spaced far apart within an extracellular matrix (non-living material outside cells)

adipose tissue (fat) blood

Connective Tissue

bone

cartilage

fibrocartilage

Fibrous connective tissue

Muscle TissueOnly cells able to contract

(shorten), and thus move.

Functions:• Movement of skeleton• Posture• Facial expressions• Producing body heat• Movement of food through

intestines• Pumping of blood

3 types:1. Skeletal2. Smooth3. Cardiac

skeletal muscle

smooth muscle

cardiac muscle

Nervous Tissue

Found in brain, spinal cord, and nerves throughout body

Transmits impulses (messages) through long wire-like cellular extensions

Functions:• Sensory perception

• Integration (processing/interpretation)

• Response (both voluntary and involuntary)

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