1. By Theophilus Bhatti BSc (hons) MLT, MS (Micro & Immuno)
Human Tissues By
Theophilus Bhatti
BSc (hons) MLT, MS (Micro & Immuno)

2. Tissue
Biological tissue is a collection of interconnected cells that perform a similar function within an organism.
Cells in a Tissue have common embryonic origin
Morphological features
Arrangement

3. Types of Tissues
Although there are many types of cells in the human body, they are organized into four broad categories of tissues

4. Task: How these Ts. are formed?

5. Epithelial Tissue
Epithelial cells cover or line all body surfaces, cavities and tubes. So, These are called covering epithelia.
Epithelial cells form the functional units of secretory glands. So, These are called glandular epithelia.

6. Functions:
 Protection of underlying tissues from radiation, desiccation, toxins, invasion by pathogens, and physical trauma.
The regulation and exchange of chemicals
Secretion of hormones
Secretion of sweat, mucus, enzymes etc
Sensation
Absorption
Filtration

7. Classification of Epithelia
Based on thickness
simple
stratified
Pseudostratified
Based on shape
squamous
cuboidal
columnar

8. Simple Squamous Epithelium
Description: Single layer of flattened
cells with disc-shaped central nuclei
and sparse cytoplasm; the simplest
of the epithelia.
Function: Passive transport of
gases and fluids.
Location: Alveoli of lungs, lining body cavities (mesothelium), lining blood vessels (endothelium)

9. Simple Cuboidal Epithelia
Description : Single layer of cubelike cells with large, spherical central nuclei.
Function : Secretion and absorption.
Location: Kidney tubules;
ducts and secretory portions
of small glands; ovary surface.

10. Simple Columnar Epithelia
Description: Single layer of tall
cells with round to oval nuclei.
Types:
(i)Ciliated columnar epithelia.
(ii)Non-ciliated columnar epithelia.
Function: Absorption; secretion of mucus, Enzymes and other substances.
Location: Digestive tract, gall bladder etc.

11. Stratified Squamous Epithelia
Description: Multilayered, surface cell are squamous, basal cells are cuboidal and divided constantly.
Function: Protection.
Location: Oral cavity, cervix, anal canal.

12. Stratified Cuboidal Epithelia
Description: Generally two layers of cube-like cells.
Function: Protection.
Location: Large ducts of sweat glands, mammary glands and salivary glands.

13. Stratified Columnar Epithelia
Description: Multilayered, superficial cells elongated and columnar.
Function: Protection; secretion.
Location: Rare in the body; small amount in the male urethra.

14. Pseudo Stratified Columnar Epithelia
Description: Single cell layered, all cell attach to the basement membrane but not all reach the free surface. Nuclei at varying depth.
Function: Secretion of
mucus, propulsion of
mucus by ciliary action.
Location: Lines of trachea.

15. Transitional Epithelia
Description: Characterized by domelike cells that are neither squamous nor columnar. The form of the cells changes.
Function: Stretching and protection.
Location: Bladder and part of urethra.

16. Connective Tissue
As the name implies, connective tissue serves a "connecting" function.
Unlike epithelial tissue which has cells that are closely packed together, connective tissue typically has cells scattered throughout an extracellular matrix of fibrous proteins and glycoproteins attached to a basement membrane.
Most abundant & widely distributed tissue

17. Functions: Connects, binds and supports structures,
Tendons, ligaments, etc.
Protects & cushions organs and tissues,
Insulates (fat) and
Transports substances (blood).
Storing reserve fuel

18. Types:
Loose Connective Tissue
Dense Connective Tissue
Adipose
Blood
Cartilage
Bone

19. Loose Connective Tissue
 Description: Loose, most common type
Function: holds organs in place and attaches epithelial tissue to other underlying tissues.
Location: under skin, most epithelia

20. Loose Connective Tissue
There are three main types:
Collagenous fibers are made of collagen and consist of bundles of fibrils that are coils of collagen molecules.
Elastic Fibers are made of the protein elastin and are stretchable.
Reticular Fibers join connective tissues to other tissues.

21. Dense Connective Tissue
Description: composed of large amounts of closely packed collagenous fibers.
Function: help attach muscles to
bones and link bones together at
joints i.e. support, elasticity
Location: Tendons, ligaments,
skin, kidney capsule

22. Adipose Description: form of loose connective tissue that stores fat.
Function: lines organs and body cavities to protect organs, insulate the body,  produces endocrine hormones.
Location: Under Skin, around kidney, heart

23. Blood
Description: fluid connective tissue, the matrix consists of the plasma and red blood cells, white blood cells & platelets
Function: transport gases, nutrition; removal of waste; immunity

24. Cartilage
Description: a form of fibrous connective tissue composed of closely packed collagenous fibers
Function: flexible support, cushion between the bones of joints
Location: nose, trachea, 
ears, joints

25. Bone
Description:  mineralized connective tissue that contains collagen and calcium phosphate, a mineral crystal
Function: skeleton, support, movement

27. Muscle Tissues
Muscle tissue is made of "excitable" cells that are capable of contraction.
Associated with the bones of the skeleton, the heart and in the walls of the hollow organs of the body.

28. Muscle Tissue Functions:
Movement
Locomotion
Maintains posture
Produces heat
Facial expressions
Pumps blood
Peristalsis
Types
Cardiac Muscles
Skeletal Muscles
Smooth Muscles

29. Cardiac Muscle
Description: branched, striated muscle, Cells are joined to one another by intercalated discs
Location: wall of heart
Function: pumping of heart through electric impulses

30. Skeletal Muscles
Description: not branced, long, striated cells with multiple nuclei, carry Blood vessels and nerves
Location: attached to bones
Function:
Contraction (voluntary movement)
Locomotion
Head and neck movement
Body posture

31. Smooth(Visceral) Muscles
Description: long, spindle shaped single nucleated cells
Location:  blood vessels, the bladder, digestive tract, hollow organs.
Function:
involuntary contraction
Rhythmic  movement
Propulsion

32. Nervous Tissues
Description:  Groups of organized cells in the nervous system
Function: controls the body’s movements, sends and carries signals to and from the different parts of the body, and has a role in controlling bodily functions 
location: Nervous system
(brain, spinal cord, and nerves)

33. Hope you are not nervous!