Chapter 4 Histology

2nd type of epithelial tissue

Stratified Squamous Epithelium - multiple layers of flat cells Areas requiring more protection due to potential for abrasion. a. Epidermis of skin, produces keratin, a waterproofing protein. b. Esophagus c. Rectum d. Vagina

Sixth kind of epithelial tissue.

Transitional Epithelium - cells that stretch and change between Squamous and Cuboidal shapes. a. Urinary Bladder, urinary system- cells change shape as bladder fills with urine.

_______________________, moves; skeletal, cardiac & smooth muscle tissues (hollow organs).

muscle tissue

_______________________, control and communication; carries electrical impulses.

neural tissue

What are the two cell types of neural tissue?

neurons neuroglia

Cardiac muscle tissue is characterized as?

non-striated involuntary muscle

Summary cardiac muscle tissue.

nuclei/cell- 1 mitosis? no striations? yes involuntary striated involuntary muscle

Summary smooth muscle tissue.

nuclei/cell- 1 mitosis? yes striations? no involuntary non-striated involuntary muscle

Summary skeletal muscle tissue.

nuclei/cell- Many mitosis? no striations? yes voluntary striated voluntary muscle

skeletal muscle tissues function?

movement of the body

cardiac muscles function?

movement of the heart, pumps blood.

Neural Tissue : or nervous tissue

-Conduction of electrical impulses in the body. -Most is in the brain and spinal cord, the dorsal cavity. Function: immediate control and communication of the body.

skeletal muscle

-Have long cells called muscle fibers with multiple nuclei. -The cells or fibers have regimented groups of myosin and actin proteins creating a striated appearance. -Muscle cells can't mitose but satellite cells (stem cells) can repair the muscle tissue. -Neurons provide voluntary control of the striated skeletal muscle. -Characterized as striated voluntary muscle.

Cardiac muscle tissue

-The cells have 1 nucleus and a striated appearance, cells do not typically mitose. -The cells are locked together with intercalated discs to ensure coordinated contractions. -The cardiac pacemaker creates a nervous impulse that independently causes a contraction. -Characterized as striated involuntary muscle.* cardiac muscle tissue is characterized as?*striated involuntary muscle.

cardiac muscle tissue

-The cells have 1 nucleus, they are small spindle shaped and have no striations. -It forms the muscular layers of blood vessels and many hollow organs. - Examples of organs include respiratory organs, digestive organs and the reproductive tract. - Smooth muscle cells can mitose and repair themselves unlike the other two muscle tissues. However, there is no voluntary control of the tissue -Characterized as non-striated involuntary muscle.

Five Characteristics of Epithelial Tissue:

1. Epithelial cells have strong cell junctions or interconnections between densely packed cells. 2. Polarity, one cell surface exposed, one surface attached to internal surface basal membrane. (The basal membrane makes up the basement membrane which attaches the cells to the next layer of tissue made up of connective tissue.) 3. Epithelial tissue has no vessels and obtains all nutrients by diffusion. So it is a thin tissue. 4. It is supported by Connective tissue which brings all the nutrients to epithelial tissue. (because it and has the blood vessels.) 5. Tissue has high mitotic ability to repair and replace itself by stem cells. skin = 7 days digestive tract = 5 days

Functions of Epithelial Tissue:

1. Physical protection from abrasion, dehydration, and environmental agents. 2. Control permeability and therefore the movement of substances into the body. 3. Provide sensation with sensory neurons. (Touch, taste, smell, sight, balance, hearing). 4. Provide glandular secretions.

6 types of Epithelial Tissue:

1. Simple Squamous Epithelium - single layer of flat cells 2. Stratified Squamous Epithelium - multiple layers of flat cells 3. Simple Cuboidal Epithelium- single layer of cube-like cells 4. Simple Columnar Epithelium - single layer of column- like cells 5. Pseudostratified Ciliated Columnar Epithelium - single layer of cilia covered column-like cells. (pseudo means false or fake). 6. Transitional Epithelium - cells that stretch and change between Squamous and Cuboidal shapes.

Intercellular Connections

Cell adhesion molecules, CAM -Proteoglycans (protein & sugar) molecules that lace the cell to the basement membrane of epithelial cells.

Make up of neurons (part of the neural tissue)

Dendrites near the nucleus receive impulses from other neurons. Axons (act on) carry the action potential toward other cells. The axon may be very long. Axon Terminal is the region the neurotransmitter is released into the synapse between cells

Glandular Vocabulary: Remember glands are epithelial tissues. Endocrine Glands

Ductless glands, secretes 'inside' body to the interstitial fluid the hormones. Adrenal glands, insulin from pancreas, etc. Note that one of our body systems is the Endocrine or hormone System.

What are the 4 major types of tissues in the body

Epithelial tissues, connective tissue, muscle tissue, neural tissue

muscle tissues function

Function : Movement of the body, the heart and hollow organs.

Epithelial Tissue

Function: covers surfaces, lines passageways, forms glands. These cells line all the outer surfaces and the inner surfaces of the body. Ex: skin, digestive tract, chest cavity, bladder lining, etc.

What is the function of neural tissue?

Function: immediate control and communication of the body.

Glandular Vocabulary: Remember glands are epithelial tissues. Exocrine Glands

Glands with ducts, secrete 'outside' of body onto epithelial surface. Sweat, mucus, milk, hair oil. Goblet cells are one celled glands in the GIT and respiratory tract.

Neuroglia (part of neural tissue)

Glial cells provide support, defense and nutrients to neurons. - the little cells

Fifth kind of epithelial tissue?

Pseudostratified Ciliated Columnar Epithelium - single layer of cilia covered column-like cells. (pseudo means false or fake). Protect and secrete. Large cells with cilia, and tight barriers against microbes. a. Respiratory tract, trachea, bronchi. Cilia move mucus and debris upward to mouth.

Forth kind of epithelial tissue

Simple Columnar Epithelium - single layer of column-like cells Protect, secrete, absorb. Quick diffusion with large cell cytoplasm for processing nutrients. Protection with long walls making tight barriers against micro-organisms, etc. a. GIT, gastro-intestinal tract, absorb with their microvilli.

Third type of epithelial tissue

Simple Cuboidal Epithelium- single layer of cube like cells Larger cell cytoplasm for important work of cell. a. Glands, salivary, pancreas b. Kidney tub

1st type of epithelial tissue

Simple Squamous Epithelium - single layer of flat cells Areas requiring rapid diffusion, no strength or protection needed. a. Lung alveoli- diffusing gases b. Kidney glomeruli - filtering blood c. Blood vessel lining, the endothelium d. Part of the Pleural, Pericardial, Peritoneal membranes called Mesothelium

Intercellular Connections Cell Junctions - three types

a. Tight Junction- seals out water and ions, typically no passage of material. ex. Digestive tract. Seal or band goes all the way around the cell membranes. b. Gap Junction - allows water, small molecules and ions to pass between cells. ex. Cardiac Muscle, smooth muscle Cells can coordinate activity through the interlocking pores between cells. c. Desmosome - strongest attachment, cell membrane is spot welded to the cell's cytoskeleton and attached to neighboring cells for a very strong junction. Anchoring junctions distributes the tension and allows the tissue to resist tearing.

Epithelial cells

are attached or interconnected to adjacent cells and each cell is attached to a basement membrane of connective tissue, also call the basal lamina. These intercellular connections help protect the body from the outside environment.

_________________________- movement of the heart, pumps blood.

cardiac muscle tissue

_______________________, supports, fills spaces, transports materials, stores energy.

connective tissue

What makes up a neuron?

dendrites, axons, axon terminal

_______________________, covers surfaces, lines passageways, forms glands.

epithelial tissue

define tissue

group of cells that have similar structure and that function together as a unit.

Neurons

large cell body and a large nucleus ( in Interphase G0, mature cells can't mitose.)

Exocrine Glands b. Holocrine

material released when cell bursts, example: sebacaceous oil gland of hair.

Muscle Tissue: 3 tissue types.

skeletal, cardiac and smooth muscle

__________________________- movement of hollow organs.

smooth muscle tissue

skeletal muscle tissue is characterized as?

striated voluntary muscle

define histology

study of the microscopic structure of tissues

Glandular Vocabulary: Remember glands are epithelial tissues. Exocrine Glands a. Merocrine

vesicles are released by exocytocis, example: sweat glands, and mucus from goblet cells in GIT, pancreas digestive enzymes Apocrine - material released with portion of the cell cytoplasm, example: milk.