body tissue types chapter 3. need a tissue or organ? _a_human_kidney

BODY TISSUE TYPES

Chapter 3

Need a tissue or organ?

https://www.ted.com/talks/anthony_atala_printing_a_human_kidney

1. Based on this video, organs and tissues are made of 2 things. What are these?

2. 3D printing is something that is becoming more common, but what do you think about printing using live cells? What are the advantages? Disadvantages?

Organization

Tissue: A collection of cells that are similar in structure & function

4 Main Tissue Types

1. Epithelium (covering)2. Connective (support)3. Muscle (movement)4. Nervous (control)

Epithelial Tissues

Slide 3.42Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Found in different areas· Body coverings· Body linings· Glandular tissue

· Functions· Protection· Absorption· Filtration· Secretion

Epithelium Characteristics

Slide 3.43Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Cells fit closely together· Apical surface—free surface exposed to

the external or internal environment· The lower surface is bound by a

basement membrane· Avascular (have no blood supply)· Regenerate easily if well nourished· Covers all free surfaces in the body

Classification of Epithelium

Slide 3.44aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Number of cell layers· Simple – one layer

· Involved in diffusion & filtration, secretion, and absorption

· Stratified – more than one layer

· Involved in protection (more durable) Figure 3.16a

Classification of Epithelium

Slide 3.44bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Shape of cells· Squamous – flattened

· Cuboidal – cube-shaped

· Columnar – column-like

Figure 3.16b

Simple Epithelium

Slide 3.45Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Simple squamous· Single layer of flat cells· Usually forms

membranes for filtration & rapid diffusion· Lines body cavities

(serous membranes)· Lines lungs and

capillariesFigure 3.17a

Simple Squamous Tissue Slide

Simple Epithelium

Slide 3.46Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Simple cuboidal· Single layer of

cube-like cells· Common in

glands and their ducts

· Forms walls of kidney tubules

· Covers the ovaries

Figure 3.17b

Simple Cuboidal Tissue Slide

Simple Epithelium

Slide 3.47Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Simple columnar· Single layer of tall cells

· Often includes goblet cells, which produce mucus

· Lines digestive tract

· Lines Mucous membranes (mucosa)

Figure 3.17c

Simple Columnar Tissue Slide

Simple Epithelium

Slide 3.48Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Pseudostratified· Single layer, but

some cells are shorter than others

· Often looks like a double cell layer

· Sometimes ciliated, such as in the respiratory tract

· May function in absorption or secretion Figure 3.17d

Stratified Epithelium

Slide 3.49Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Stratified squamous· Cells at the free edge

are flattened· Found as a protective

covering where friction is common

· Locations· Skin· Mouth· Esophagus

Figure 3.17e

Stratified Squamous Tissue Slide

Stratified Epithelium

Slide 3.50Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Stratified cuboidal· Two layers of cuboidal cells

· Stratified columnar· Surface cells are columnar, cells

underneath vary in size and shape· Both are:

· Rare in human body· Found mainly in ducts of large glands

Stratified Columnar Tissue Slide

Stratified Epithelium

Slide 3.51Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Transitional epithelium· Highly modified

· Cells become more flattened during stretching & can slide past each other

· Lines organs of the urinary system Figure 3.17f

Glandular Epithelium

Slide 3.52Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Gland – one or more cells that secretes a particular product

· Two major gland types· Endocrine gland

· Ductless· Secretions are hormones

· Exocrine gland· Empty through ducts to the epithelial surface· Include sweat and oil glands

Connective Tissue

Slide 3.53Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Found everywhere in the body

· Most abundant and widely distributed tissues

· Functions· Binds body tissues together

· Supports the body

· Provides protection

Connective Tissue Characteristics

Slide 3.54Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Variations in blood supply· Some tissue types are well vascularized

· Some have poor blood supply or are avascular

· Extracellular matrix· Non-living material that surrounds living

cells

Extracellular Matrix

Slide 3.55Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Two main elements

1. Ground substance – mostly water along with adhesion proteins and polysaccharide molecules

2. Fibers· Produced by the cells & secreted into ground

substance· Three types

· Collagen fibers· Elastic fibers· Reticular fibers

·The amount of ground substance and fibers depends on the function of the tissue.

Extracellular Matrix

Unique structure allows connective tissue to: Form a soft packing around organs Bear weight Withstand stretching & other abuses

Connective Tissue Types

Slide 3.56Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Bone (osseous tissue)· Cartilage· Dense Connective (tendons

& ligaments)· Areolar· Adipose· Reticular· Blood (will cover in Ch. 10) Figure 3.18a

Will cover in skeletal system notes

Connective Tissue Types

Slide 3.60Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Areolar connective tissue· Most widely distributed

connective tissue· Soft, pliable tissue· Contains all fiber types· Wraps around organs to

cushion & protect· Surrounding tissues receive

nourishment & release waste here

· Can soak up excess fluid during injury(edema) Figure 3.18e

Areolar Tissue Slide

Connective Tissue Types

Slide 3.61Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Adipose tissue· Matrix is an areolar tissue in which fat

globules predominate· Many cells contain

large lipid deposits· Functions

· Insulates the body· Protects some organs· Serves as a site of

fuel storageFigure 3.18f

Adipose Tissue Slide

Connective Tissue Types

Slide 3.62Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Reticular connective tissue· Delicate network of

interwoven fibers· Forms stroma

(internal supporting network) of lymphoid organs· Lymph nodes· Spleen· Bone marrow

Figure 3.18g

Reticular Tissue Slide

Tissue Cinquains

A cinquain is a five line poem that uses the following format: Line 1: 1 word to describe concept (can also

be the title) Line 2: 2 words to describe concept Line 3: 3 words to describe concept (I’m sensing

a pattern here…)

Line 4: 4 words to describe concept Line 5: 1 word to describe concept

Tissue Cinquains

Example cinquain:CinquainShort poemDescribes a conceptFollows a numbering rulePoetry

Tissue Cinquains Assignment1. Choose a partner.2. Choose a tissue type.

1. Make sure that each tissue type is represented in class.

3. Write your cinquain on a piece of paper (include your names!)

4. Share your cinquain with the class.

How are tissues made?

When you were first conceived, you started out as a single cell.

So, how did you get from one general cell to all of these different tissue types?

http://www.youtube.com/watch?v=nB6gFn0_wr8

How are tissues made?

Each cell in the embryo develops into a certain cell type based on its location

These cells then aggregate to form a particular tissue.

http://www.youtube.com/watch?v=k_9MTZgAhv0

Germ Layers

Zygotic cell division & creation of germ layers

Cross section of germ layers

“Tube within a tube” construction

Development & Tissue Differentiation

Slide 3.72Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Endoderm – digestive system

· Mesoderm – muscles, bones, blood, reproductive system (connective tissues in general)

· Ectoderm – skin, nervous tissue

Injury, Injury!

When your tissue gets damaged (let’s say you scrape your knee sliding into first and it starts bleeding), there is a particular process that your body goes through to heal that wound.

Brainstorm with your group and come up with a series of steps for wound healing.

Tissue Repair Video

http://www.youtube.com/watch?v=iXfM13u3mp8

Tissue Repair (Wound Healing) Initiated by inflammatory & immune

responses Inflammation—generalized (nonspecific)

body response that attempts to prevent further injury Ex. Redness & swelling

Immune response—extremely specific that mounts a vigorous attack against recognized invaders (bacteria, viruses, foreign cells)

Tissue Repair Outcomes

Slide 3.69Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

1. Regeneration (most favorable)· Complete return to normal tissue structure

& function

2. Fibrosis/repair· Repair by dense fibrous connective tissue

(scar tissue)· Type of outcome depends on:

1. Type of tissue damaged

2. Severity of the injury

Tissue Repair Outcomes

Regeneration is common with: Minor damage No complications or infections Tissues that are capable of regenerating

Fibrosis/repair is common with: Damage is extensive Infection is present Tissues are not capable of regeneration Fibrin remains in the lesion

Regeneration of Tissues

Slide 3.71Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· Tissues that regenerate easily· Epithelial tissue· Fibrous connective tissue and bone

· Tissues that regenerate poorly· Skeletal muscle

· Tissues that are replaced largely with scar tissue· Cardiac muscle· Nervous tissue within the brain and spinal cord

Scar Tissue

Is very fibrous and less flexible It cannot perform the functions of the

tissue type that it replaces Can be very harmful if too much scar tissue

is formed in the muscular walls of organs such as the heart or bladder

Events in Tissue Repair

Slide 3.70Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

1. Inflammation releases chemicals that makes capillaries very permeable· Introduces clotting proteins that wall off injured area

preventing spread of harmful materials (scab)

2. Formation of granulation tissue

• Delicate pink tissue full of new capillaries from surrounding blood vessels

• Contains phagocytes (WBCs) that get rid of clot and fibroblasts that created collagen fibers to repair wound

3. Regeneration of surface epithelium beneath scab

• Once scab removed, surface epithelium covers fibrous tissue (scar) used to repair injury

New capillaries formed from surrounding blood vessels; phagocytes break down clot & fibroblasts

Creation of scab via fibrin secreted by fibroblasts

Clotting proteins wall off area (scab)

Surface epithelium regenerates to cover fibrous tissue (scar)

Inflammation

Scab & fibrin formation

Granulation tissue formation

Scab removal & epithelial regeneration

Stages of Tissue Repair

Developmental Aspects of Tissue

Tissues are collections of cells, so tissue growth, repair, and maintenance is accomplished by cell division

Growth is rapid in the child and adolescent years and then slows or stops once adulthood is reached

Hyperplasia—enlargement of body tissues due to local irritant or condition that stimulates cells Ex. breast enlargement during pregnancy

Cell division is tightly regulated in the body most cells will stop dividing once they run out of

space or come in contact with surrounding cells

Uncontrolled cell growth

Creates a “neoplasm” or tumor Benign tumors remain in one place Malignant tumors have cells that spread

throughout the body and create new tumors Process of cell spreading is called metastasis These tumors are considered cancerous

Tumor cells are dangerous because they starve healthy cells of nutrients

Carcinogens—external agents that can lead to cancer

Tumor Types

Tissues and Aging

The cause of aging is still a mystery to scientists

But, there are definite signs such as: Overall, mass and viability of tissues

decreases Thinning of epithelial membranes Loss of tissue elasticity Less active exocrine & endocrine glands Weakening of bones & muscles

atrophy—decrease in tissue size due to lack of use/stimulation

Doctor, Doctor, give me the news… You and your group members are a surgical team who

is treating a 12-year-old girl, Kira, who has an ependymoma (brain tumor in the top of her brain). The team has recommended that Kira undergo surgery to have the tumor removed, but you also know that these types of tumors spread quickly to the surrounding healthy tissues. You want to remove as much of the tumor as possible, but you also know that if you remove too much of the healthy tissue, then this may cause movement and memory problems for Kira.

So, doctors, what is your team going to do to remove as much of the tumor as possible while minimizing impacts to the healthy tissue? Come up with a ‘game plan’ and explain your reasoning.

I know, we’ll use tumor paint!! With your group, read the short article about

tumor paint. Answer the following questions:

1. What is an iatrogenic injury?2. Why is tumor paint needed?3. What are the two parts of tumor paint?

1. What does each part do?

4. How does tumor paint help surgeons and patients?

http://vimeo.com/51888804