1. 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

3. 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.

4. 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

5. Tissues – Epithelial Tissue
Many organs are lined with epithelial tissue

7. Tissues – Epithelial Tissue
Many organs are lined with epithelial tissue
Simple Squamous Epithelial Tissue – inside your cheek, skin cells

8. Tissues – Epithelial Tissue
Many organs are lined with epithelial tissue
Simple Cuboidal Epithelial Tissue – kidney tubule cells

10. Tissues – Epithelial Tissue
Many organs are lined with epithelial tissue
Simple Columnar Epithelial Tissue – large intestine

11. Tissues – Epithelial Tissue
Many organs are lined with epithelial tissue
Ciliated Pseudostratified Columar Epithelial Tissue - trachea

12. 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

13. Tissues – Connective Tissue
Six different types:
Loose connective tissue
Adipose tissue
Blood
Fibrous connective tissue
Cartilage
Bone

14. 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

15. Loose connective tissue

16. 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

17. Adipose tissue

18. 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

19. Blood

20. Blood

21. Blood

22. Tissues – Connective Tissue
Fibrous connective tissue
Forms tendons and ligaments
Matrix is densely packed collagen fibers running in parallel.

23. Fibrous connective tissue
Nuclei of fibroblasts

24. 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

25. Cartilage

26. Damaged Cartilage

27. 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

28. Bone

29. Tissues – Muscle Tissue
Skeletal Muscle
Usually attached to bone
Produces all voluntary movements
Striated
Long, thin, cylindrical shape

30. Striated (Skeletal) Muscle Tissue

31. Smooth Muscle Smooth muscle Not striated and involuntary
Musculature of organs, blood vessels, digestive tract
Contracts more slowly and for longer than skeletal muscle 31

32. Cardiac Muscle

33. 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

34. Tissues – Nervous Tissue

35. Nervous Tissue

36. 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.

37. Tissues – Tissue Donation
Types of tissues
Corneas
Eye tissue
Skin
Bones
Tendons
Veins
Heart valves