1. Histology
W.U. : Using your medical dictionary, what do you think Histology is the study of?

2. Histology The study of different types of tissues
Tissue: Cells working together in functionally related groups

3. Histology
Separated into four major categories based on their function and the embryonic tissue of origin
Tissue
Function
Embryonic Tissue
Epithelial
Cover & Protection
Ectoderm, endoderm, and mesoderm
Connective
Support
Mesoderm
Muscle
Movement & contraction
Nervous
Signaling & communication
Ectoderm

4. Epithelial Tissue Location: Function:
Lines nearly every cavity and surface of the human body
Form glands
Function:
Protect the tissues they cover
Regulate gas and nutrient exchange
Secrete substances such as sweat, hormones, mucus, and enzymes
Provide sensation with the environment

5. Epithelial Classification:
First name of tissue indicates the number of layers
Simple: One layer of cells
Stratified: More than one layer
of cells

6. Epithelial Classification
Last name of tissue describes the SHAPE of cells
Squamous: cells wider than tall
Cubodial: cells are as wide as tall, as in “cubes”
Columnar: cells are taller than they are wide, like columns

7. Epilthelial Put it all together… Special epithelial tissues
Simple squamous
Simple columnar
Stratified cubodial
Special epithelial tissues
Pseudostratified
Transitional

8. Epithelial Special characteristics:
Cells are packed tightly together, forming a protective layer around organs
High capacity for regeneration
Produce fluids for lubricating tissues and organs
Avascular: No capillaries that directly nourish the cells
Cells get what they need through diffusion of nutrients through the basement membrane

9. Simple Squamous Epithelium
Single layer of flat cells with disc-shaped nuclei
Function:
Passage of materials by passive diffusion and filtration
Secrete lubricating substances in serosae

10. Simple Squamous Epithelium
Location
Renal corpuscles
Alveoli of lungs
Lining of heart, blood, and lymphatic vessels
Lining of ventral body cavity

11. Simple Cuboidal Epithelium
Single layer of cube-like cells with large, spherical nuclei
Function:
Secretion and absorption

12. Simple Cuboidal Epithelium
Location:
Kidney tubules
Secretory portions of small glands
Ovary and Thyroid follicles

13. Simple Columnar Epithelium
Single layer of column-shaped cells with oval nuclei
Some may have cilia
Function:
Absorption
Secretion of mucus, enzymes, and other substances
Ciliated type propels mucus or reproductive cells by ciliary action

14. Simple Columnar Location:
Non-ciliated: lines digestive tract, gallbladder, ducts of some glands
Ciliated form: lines small bronchi, uterine tubes, uterus

15. Connective Tissues Most abundant tissue type in the body
Ex: blood, bone, cartilage, tendons, ligaments…
Made up of fibers and extracellular components in the embedded in fluid
Types of Connective Tissues
Loose Connective Tissue
Dense Connective Tissue
Cartilage
Other Tissues

16. Connective Tissue Function: Protect Store energy Transport Insulate
Connect all body tissues

17. Loose Connective Tissue
Areolar:
Binds cells and fibers together, allows movement
Found under skin, surrounds capillaries
Adipose:
Fat, stores nutrients, insulates, protects organs
Found under skin, around kidneys, within abdomen
Reticular:
Allows for structure and flow of substances
Found in lymph nodes, bone marrow, spleen
Loose arrangement of collagen fibers

18. Dense Connective Tissue
Regular:
Make up tendon and ligaments, tightly organized bundles of collagen
Found in tendons, ligaments, fascia around muscles
Irregular:
Make up the dermis, tight bundles of collagen that are unorganized
Found in the dermis of skin, submucosa of digestive tract

19. Cartilage Hyaline: Elastic
Provides support while still being pliable, most abundant form
Found in the ends of long bones, nose, trachea, and larnyx
Elastic
Provides support while still able to stretch
Supports external ear, epiglottis

20. Cartilage Fibrocartilage:
Provides strong support and handles heavy pressure
Found in intervertebral discs, pubic symphysis, discs of knee joints

21. Other Tissues… Bone Blood
Support, hard tissue of collagen fibers and calcium surrounding osteocytes
Blood
Tissue that contains red blood cells, proteins, and plasma

22. Muscle Tissue
Cells are extremely long and contain protein fibers capable of contracting
Separated into 3 main types:
Skeletal muscle tissue
Smooth muscle tissue
Cardiac muscle tissue

23. Skeletal Muscle Tissue
Voluntary muscle
Can be contracted voluntarily
Function in movement and maintenance of posture
Visible striations
Makes up the muscles that are attached to our skeleton

24. Smooth Muscle Tissue Involuntary muscle Found in:
Muscle does not contract voluntarily
Lines most of the organs of the body
No visible striations
Found in:
GI Tract
Respiratory Tract
Blood vessels
Bladder
Uterus

25. Cardiac Muscle Heart, extremely dense, strong tissue Involuntary
Large number of mitochondria to provide energy for the continuous contracting of the heart
Striated like muscle tissue

26. Nervous Tissue Found in the brain, spinal cord, and nerves
Consists of 2 main cells
Neurons
Neuroglia cells
Responsible for communication

27. TED Talks Could tissue engineering mean personalized medicine?
Anthony Atala: Growing new organs