Review: Epithelial Tissue

• “There are 2 basic kinds of epithelial tissues.” What could that mean?

• You are looking at epithelial cells from the intestine. What do you expect to see?

• You are looking at epithelial cells from the trachea. What do you expect to see?

1 4-1 Four Types of Tissue

Tissue Type Role(s)

- Covers surfaces/passages - Forms glands - Structural support - Fills internal spaces - Transports materials

- Contraction!

- Transmits information (electrically) 2 Classification of connective tissue 1. Connective tissue proper 1a. Loose: areolar, adipose, reticular 1b. Dense: dense regular, dense irregular, elastic

2. Fluid connective tissue 2a. Blood: red blood cells, white blood cells, platelets 2b. Lymph

3. Supporting connective tissue 3a. Cartilage: hyaline, elastic, fibrocartilage 3b. Bone

3 Defining connective tissue by the process of elimination

4 LAB MANUAL Figure 6.4 Areolar connective tissue: A prototype (model) connective tissue.

Cell types Extracellular matrix Ground substance Macrophage Fibers • Collagen fiber • Elastic fiber • Reticular fiber Fibroblast

Lymphocyte

Adipocyte Capillary Mast cell

5 The Cells of Connective Tissue Proper Melanocytes and macrophages, mesenchymal, mast; Adipo- / lympho- / fibrocytes and also fibroblasts. These are the cells of connective tissue proper; Sing this song the whole day long until you know them all!

Melody playback: http://www.noteflight.com/scores/view/172efe927723615fe7c94fc62ff05ab7bc5ce26a

6 4-4 Connective Tissue: importance of extracellular matrix!

Tissue Type Extracellular stuff?

7 Extracellular matrix = ground substance + extracellular protein fibers

© 2015 Pearson Education, Inc. 8 Proteins’ structures suggest their functional properties

Which is elastin, and which is collagen? 9 Tie-in with Chapter 3: Where are extracellular proteins made? How do they reach their final destination?

© 2015 Pearson Education, Inc. 10 LAB MANUAL Figure 6.5a Connective tissues.

Embryonic connective tissue: Mesenchyme

Description: * gel-like ground substance * sparse, fine fibers * star-shaped mesenchymal cells Fibers

Location: Ground Primarily in embryo substance

Mesenchymal cell

Function: 11 LAB MANUAL Figure 6.5b Connective tissues.

Connective tissue proper: loose connective tissue, areolar

Description: * gel-like matrix with all 3 fiber types Collagen * cells: many types! fibers

Fibroblast nuclei Location: Widely distributed under epithelia

Elastic fibers

Epithelium

Lamina propria

Function: 12 LAB MANUAL Figure 6.5c Connective tissues.

Connective tissue proper: loose connective tissue, adipose

Description: * sparse matrix * closely packed adipocytes * nucleus pushed to the side

Location: * under skin Vacuole * around kidneys & eyes containing * abdomen fat droplet * breasts Nuclei of fat cells

Function: 13 LAB MANUAL Figure 6.5d Connective tissues.

Connective tissue proper: loose connective tissue, reticular

Description: * network of reticular fibers * loose ground substance * reticular cells

Location: Lymphoid organs (lymph White nodes, bone marrow, spleen) blood cell (lymphocyte)

Reticular fibers

Spleen

Function: 14 LAB MANUAL Figure 6.5e Connective tissues.

Connective tissue proper: dense connective tissue, dense regular

Description: * primarily parallel collagen fibers * major cell type: fibroblast

Collagen Location: fibers * Tendons * Ligaments

Nuclei of fibroblasts Shoulder joint

Ligament

Tendon

Function: 15 Figure 6.5f Connective tissues.

Connective tissue proper: dense connective tissue, elastic

Description: * Mostly elastic fibers

Location: * Walls of large arteries Elastic * Between vertebrae fibers

Aorta

Heart Photomicrograph: Elastic connective tissue in the wall of the aorta (250).

Function: 16 LAB MANUAL Figure 6.5g Connective tissues.

Connective tissue proper: dense connective tissue, dense irregular

Description: * primarily irregularly arranged collagen fibers * major cell type: fibroblast Nuclei of fibroblasts

Location: * capsules of organs & joints * dermis of skin

Collagen fibers Fibrous joint capsule

Function: 17 LAB MANUAL Figure 6.5h Connective tissues.

Cartilage: hyaline

Description: * amorphous but firm matrix * collagen fibers form an imperceptible network Chondrocyte in lacuna

Location: * ends of long bones * ribs * nose, trachea, larynx Matrix

Costal cartilages

Function: 18 LAB MANUAL Figure 6.5i Connective tissues.

Cartilage: elastic Description: * Similar to hyaline cartilage, but more elastic fibers

Chondrocyte in lacuna Location: * external ear (auricle) * epiglottis Matrix

Function: 19 LAB MANUAL Figure 6.5j Connective tissues.

Cartilage: fibrocartilage

Description: * Matrix similar to but less firm than hyaline cartilage’s * Mostly thick collagen fibers

Location: * intervertebral discs * pubic bones * knee joint Chondrocytes in lacunae Intervertebral discs Collagen fiber

Photomicrograph: Fibrocartilage of an intervertebral disc (160). Special staining produced the blue color seen.

Function: 20 LAB MANUAL Figure 6.5k Connective tissues.

Bones (osseous tissue)

Description: * hard, calcified matrix with many collagen fibers Central * osteocytes in lacunae * abundant blood supply canal

Lacunae Location:

Lamella

Function: 21 LAB MANUAL Figure 6.5l Connective tissues.

Blood Description: * fluid matrix (plasma) Plasma

Neutrophil

Location: Red blood cells

Lymphocyte

Photomicrograph: Smear of human blood (1000); two white blood cells (neutrophil and lymphocyte) are seen surrounded by red blood cells.

Function: 22 4-4 Connective Tissue

• Functions of Connective Tissues? (summary of previous slides…)

1. Connective tissue proper

2. Fluid connective tissues

3. Supporting connective tissues

23 Review: Connective Tissue

• Which is stiffer?

24 Review: Connective Tissue

• Which is stiffest, based on location in body?

• Hyaline cartilage

• Elastic cartilage

• Fibrocartilage

25