1. Cells & Tissues
Chapter 3 & 5

2. Cells & Tissues
Tissues are groups of similar cells that perform a common function
Human tissue can be categorized into 4 major groups:
Epithelial Tissue
Connective Tissue
Muscle Tissue
Nervous Tissue

3. Epithelial Tissue
Epithelial tissues are found throughout the body, including:
Covering the body surface and organs
Inner lining of body cavities
Lining of hollow organs
Composes glands

4. Epithelial Tissue
Lack blood vessels
Epithelial tissues readily divide—injuries heal quickly as new cells replace the damaged ones
Skin cells and cells that line the stomach and intestine
Tightly packed—form protective barriers for the outer layer of the skin and the lining of the mouth
There are 7 categories of epithelial cells

5. Simple squamous
Simple squamous epithelial cells consist of a single layer of thin, flattened cells fitting tightly together
Substances pass easily through simple squamous
Easily damaged because it is so thin and delicate

7. Simple Cuboidal
Simple cuboidal epithelial cells consist of a single layer of cube-shaped cells
Simple cuboidal covers the ovaries and lines most of the kidney tubules

9. Simple Columnar Simple columnar cells are taller than they are wide
Enables protection of whatever is underneath
Simple columnar is a single layer of cells with elongated nuclei located near the bottom of the cell
Can have cilia—help to move the egg cell down the uterine tube toward the uterus
Nonciliated simple columnar lines the uterus and part of the digestive tract

11. Pseudostratified Columnar
The cells in pseudostratified appear to be layered but they are not
Nuclei sit at 2 or more levels in the row of cells
May have cilia
Line the passages of the respiratory system

13. Stratified Squamous
Because of many cell layers, stratified squamous is relatively thick
Cell divide in the deeper layers and the newer cells push the older cells to the outside
Form the superficial layer of the skin, line the oral cavity and esophagus

15. Stratified Cuboidal
Stratified cuboidal consists of two or three layers of cuboidal cells
The layers provides more protection than a single layer
Lines the ducts of mammary, sweat, salivary glands and the pancreas

17. Stratified Columnar
Stratified columnar consists of several layers of skin
The superficial cells are columnar
The base layers are cuboidal
Found in the male urethra and the larger ducts of glands

19. Connective Tissue
Connective tissues bind structures, provide support and protections, serve as frameworks, fill spaces, store fat, produce blood cells, protect against infections, and help repair tissue damage
Connective tissue cells can divide and typically have good blood supplies, but the density of blood vessels varies with the type of connective tissue

20. Connective Tissue Connective tissue can be categorized into 5 groups:
Loose Connective Tissue
Dense Connective Tissue
Cartilage
Bone
Blood

21. Loose Connective Tissue
Includes areolar tissue, adipose tissue, and reticular connective tissue
Areolar tissue forms delicate, thin membranes
Binds the skin to the organs underneath and fills the space between muscles

22. Loose Connective Tissue
Adipose tissue (fat) develops when certain cells store fat as droplets in their cytoplasm and enlarge
Lies beneath the skin, in spaces between muscles, around the kidneys, behind the eyeballs, surface of the heart, & around certain joints
Reticular connective tissue is composed of thin fibers in a 3D network
Helps provide the framework of certain internal organs

23. Dense Connective Tissue
Many closely packed, thick, collagen fibers
These fibers are very strong, which allows the tissue to withstand pulling forces
Binds body structures as part of tendons and ligaments
In the protective white layer of the eyeball and the deep skin layer

24. Cartilage Rigid connective tissue
Provides support, frameworks, and attachments
Protects underlying tissues
Forms the structural models for many developing bones
3 forms:
Hyaline cartilage—ends of bones in many joints, soft part of the nose, and in respiratory system
Elastic cartilage—provides the framework for the external ears and parts of the larynx
Fibrocartilage—intervertebral discs, cushions bones in the knees and in the pelvic girdle

25. Bone Most rigid connective tissue
Hardness due to mineral salts, such as calcium phosphate and calcium carbonate
Internally supports body structures
Protects vital parts in the cranial and thoracic cavities
Contains red marrow—makes blood cells

26. Blood
Blood transports a variety of materials between interior body cells and those that exchange substances with the external environment
4 parts
Red Blood Cells
White Blood Cells
Platelets
Plasma

27. Muscle Tissue Muscle tissues are made up of cells called muscle fibers
Able to contract and relax
3 kinds of muscle:
Skeletal Muscle—forms muscles that typically attach to bone and can be controlled by conscious effort
Smooth Muscle—composes the walls of hollow internal organs (stomach, intestines, bladder)
Cardiac Muscle—only found in the heart

28. Nervous Tissue Nervous tissues are made of cells called neurons
Found in the brain, spinal cord, and peripheral nerves
Neurons sense changes in their surroundings and respond by conducting electrical impulses