DEN: Ch 7&8 Cells & Basic Tissues

Endocytosis

Engulf extracellular material

Exocytosis

Expel material into extracellular space

Macrophages perform __________

Phagocytosis

Phagocytosis

Eating bacteria, germs, virus

Pseudopods

The “hands” of macrophages that “hug” bacteria

What does a lysosome contain

Digestive enzymes

Phagosome

Area of macrophage where bacteria is encapsulated

Phagolysosome

Enzymes destroy bacteria

Cell membrane function

• Outer cell layer

• Controls what goes in and out

• Phospholipid bilayer

Cytoskeleton

• Framework of cell

• Gives cell its shape

• Structural stability

Golgi complex

• Packages proteins, fats, hormones

• “Post office”

Rough endoplasmic reticulum

Aids in making proteins, lipids, steroids

Nucleus

Control center holding DNA

Mitochondria

• POWERHOUSE

• Makes energy

• Aerobic respiration

Smooth endoplasmic reticulum

Aids in making fats removes harmful substances

Cell division for tissue cells

Reproduce themselves and replaces the dead tissue cells

End result of cellular division

Two identical daughter cells

Phases of cell division

1. Interphase

2. Prophase

3. Prometaphase

4. Metaphase

5. Anaphase

6. Telophase

First phase of cell division

Interphase

Interphase

• Chromatin is duplicating

• Cell is growing

Second phase of cell division

Prophase

Prophase

• Chromatin condenses into chromosomes

• Replicated centrioles migrate to opposite poles

• Nuclear membrane and nucleolus start to disintegrate

Third phase of cellular division

Prometaphase

Prometaphase

Nuclear membrane breaks down and chromosomes attach to spindle fibers

Fourth phase of cell division

Metaphase

Metaphase

• Cell’s chromosomes move together, align in the center of cell

• Nucleus has dissolved

• “Lined up at the 50-50 line”

Fifth phase of cell division

Anaphase

Anaphase

• Chromosomes separate and move together opposite ends

• Daughter chromosomes being pulled apart

Sixth stage of cell division

Telophase

Telophase

• Two nuclear membranes form

• Separate the cell into two nuclei

What is the result of cell division

2 daughter cells with 46 chromosomes each

How do cells stick together to form an organ, and further, a system?

Intracellular Junctions

Intracellular Junctions

Helps cells stick together to form an organ and/or system

What are the 2 Intracellular Junctions

1. Desmosomes

2. Hemidesmosomes

Hemidesmosome

Attachment of a cell to an adjacent noncellular surface like a basement membrane

How are hemidesmosomes involved in the oral cavity

Allows gingival tissue to be secured to the tooth surface by the epithelium attachment

Desmosome

• Strong connective junctions between cells

• “Glue” to hold cells together

How are desmosomes involved in the oral cavity

In areas exposed to significant stress like the gum line and inner cheek lining where cell turnover is high

Where are desmosomes located in the oral cavity

• Gum line

• inner cheek lining

• Areas where cell turnover is high

Occluding or Tight Junctions

Holds cells tightly together so that space between is impermeable and large molecules cannot enter

What are the 4 basic tissue types

1. Epithelial Tissue

2. Nervous tissue

3. Muscle tissue

4. Connective tissue

Types of animal/human tissue

• Blood

• Bone tissue

• Epithelial tissue

• Cartilage tissue

• Adipose tissue

• Nervous tissue

• Muscle tissue

• Connective tissue

Does enamel have regenerative properties

NO

Cell Regeneration

Individual cells die and new ones takes their place

In what age group does cell regeneration occur in more?

Children opposed to older people

How many phases of cell regeneration is there?

4

What are the 4 phases of cell regeneration?

1. Hemostasis phase

2. Inflammatory phase

3. Proliferation phase (blood clot)

4. Remodeling phase (scab)

What is the first phase of cell regeneration

Hemostasis phase

Hemostasis phase

1. Vasoconstriction; blood vessels constrict to help clotting

2. Platelets arrive

3. Leukocytes (WBCs) arrive to fight off infection

What first happens during the hemostasis phase

Vasoconstriction for clotting

What happens secondly during the hemostasis phase

Platelets arrive

What happens thirdly during the hemostasis phase

Leukocytes (WBCs) arrive to fight off infection

What leukocytes are present during the hemostasis phase

Neutrophils and macrophages

What do neutrophils and macrophages do during the hemostasis phase

Cleans the wound site from dead cells, bacteria, and other pathogens or debris

Hemostasis phase basic rundown

Vasoconstriction → Platelets → WBC (leukocytes)

What is the second phase of cell regeneration

Inflammatory phase

Inflammatory phase

1. Neutrophils arrive first to phagocytose/engulf damaged cells

2. Clear oozing substance due to damaged blood vessels

3. Macrophages arrive and phagocytose damaged cells, debris, foreign invaders including the neutrophils

What arrives FIRST during the inflammatory phase

Neutrophils

What do neutrophils do during the inflammatory phase

They release antimicrobial substances

What causes the oozing clear substance mean during the inflammatory phase

Due to damaged blood vessels

What do macrophages do during the inflammatory phase

Phagocytose damaged cells, debris, foreign invaders

Do neutrophils have a short or long lifespan

Short lifespan

How long do neutrophils live

Only a few days

Do macrophages have a short or long lifespan

Long lifespan

How long do macrophages live

Months or even years

Is the first line of defense neutrophils or macrophages

Neutrophils

Is the second line of defense neutrophils or macrophages

Macrophages

What is the third phase of cell regeneration?

Proliferation phase

Proliferation Phase

1. Granulation tissue is forming and replaces damaged tissue

2. Rebuilding via growth of blood vessels and the migration of fibroblasts which produce collagen

3. Macrophages are still cleaning up debris

4. The wound is typically pink at this point

What is the fourth phase of cell regeneration

Remodeling phase

Remodeling phase

1. Collagen becomes more organized

2. Vascular regression

3. Fibroblasts transform into myoflibroblasts which contribute to scar tissue formation

What is granulation tissue

Newly forming connective tissue through proliferation of fibroblasts and capillaries to wound site

What is common in areas with granulation tissue

Commonly sore and bleeds easily

What does the epithelium tissue cover/line

Both the external and internal body surfaces (vessels and small cavities)

What is the epithelium tissue also involved in BESIDES being a protective covering or lining

Involved in tissue absorption, secretion, sensory, other specialized functions

What are three epithelial cell types?

1. Squamous cells

2. Cuboidal cells

3. Columnar cells

What are 4 types of simple epithelial tissue (non-keratinized)

1. Simple squamous epithelium

2. Simple cuboidal epithelium

3. Simple columnar epithelium

4. Pseudostratified epithelium

What is the structural foundation of simple squamous epithelium

Single layer of flat cells

What is the structural foundation of simple cuboidal epithelium

Single layer of cube-shaped cells

What is the structural foundation of simple columnar epithelium

Single layer of tall rectangular cells

What is the structural foundation of Pseudostratified epithelium

Single layer that appear stratified due to nuclei at different levels - ciliated or non ciliated

Function of simple squamous epithelium

Allows easy movement of substances (like oxygen and nutrients)

Function of simple cuboidal epithelium

Secretion and absorption

Function of simple columnar epithelium

Secretion and adsorption

Function of Pseudostratified epithelium

Secretion and if ciliated, movement of mucus

Oral cavity location of simple squamous epithelium

Lining of blood vessels under the gums and tongue

Oral cavity location of Simple cuboidal epithelium

Ducts of salivary gland, parotid, submandibular, sublingual

Oral cavity location of Simple columnar epithelium

Lining of some ducts of salivary glands. Epithelium of the soft palate and oropharynx

Oral cavity location of Pseudostratified epithelium

Lining of nasal cavity, paranasal sinuses and nasopharynx

What are 4 types of stratified epithelial tissue

1. Stratified squamous

2. Stratified cuboidal

3. Stratified columnar epithelium

4. Transitional

What is the structural function of ALL stratified epithelial tissue

All multiple layers of cells

Function of stratified squamous

Provides protection against friction, bacteria, and damage

Function of stratified cuboidal

Provides protection against friction, bacteria, and damage

Function of stratified columnar epithelium

Provides protection against friction, bacteria, and damage

Function of transitional epithelial tissue

Protective barrier/normally in urinary tract

Oral cavity location of stratified squamous

Mucosa buccaneers, labial, floor of mouth, soft palate. Keratinized and non-keratinized

Oral cavity location of stratified cuboidal

Salivary ducts; parotid, submandibular, sublingual

Oral cavity location of stratified columnar epithelium

Covers the tongue, cheeks, gums, roof of mouth to protect against chewing and food abrasion

What is going to heal faster? A laceration in the oral cavity, or an abrasion on the knee?

A laceration in the oral cavity

Is cell turnover time high or low in the oral cavity?

High cell turnover time