Chapter 3b Compartmentation: Cells and Tissues

Golgi Complex Membranes surrounded by vesicles Protein modification Protein packaging into secretory vesicles

Golgi Complex Figure 3-18a Vesicle Lumen (a)

Golgi Complex Figure 3-18b

Cytoplasmic Vesicles Secretory vesicles Released from cell Lysosomes Digestive enzymes Peroxisomes Hydrogen peroxide Detoxification Fatty acid degradation

Cytoplasmic Vesicles Lysosomes and peroxisomes Figure 3-19 Peroxisomes Lysosomes Mitochondrion

Nucleus Nuclear envelope Nuclear pore complex Chromatin Nucleoli Control RNA synthesis

Nucleus Figure 3-20 Nucleolus contains DNA that controls synthesis of ribosomal RNA. Chromatin is DNA and protein. Nuclear envelope is a double membrane that separates the nucleus from the cytoplasm. Nuclear pores regulate movement of material into and out of the nucleus.

Primary Tissue Types Epithelial Lining and glands Connective Protection, support and storage Muscle movements Nervous Communication, sense internal and external environment

Histology Four types of tissues: 1)Epithelial 1)Lining 2)glands 2)Connective 1)Protection 2)Storage 3)connections 3)Muscle 1)movement 4)Nervous 1)Sense 2)communication

Epithelial Tissues: Cell Junctions and CAMs Cell to cell Gap junction Tight junction Anchoring junction

Cell Junctions and CAMs Table 3-3

Types of Cell-Cell Junctions Figure 3-21a Tight junctions prevent movement between cells. Adherens junction Desmosomes anchor cells to each other. (a) Tight junction Claudin and occludin proteins Intercellular space Cell membrane Cytosol Cell 1 Cell 2

Types of Cell-Cell Junctions Figure 3-21b Tight junctions prevent movement between cells. Adherens junction Desmosomes anchor cells to each other. (b) Desmosome, an anchoring junction Cadherin proteins Intercellular space Cell membrane Cytosol Plaque glycoproteins Intermediate filament

Types of Cell-Cell Junctions Figure 3-21c Clusters of gap junctions create cytoplasmic bridges between adjacent cells. Heart muscle has gap junctions. (c) Gap junction Connexin proteins Intercellular space Cell membrane Cytosol

Cell Junctions and CAMs A map of cell junctions Figure 3-22 Function Location Type Membrane protein Cytoskeleton fiber Matrix protein Actin Intermediate filaments Actin Keratin (intermediate filaments) Fibronectin and other proteins Laminin Communicating Occluding Anchoring Cell-cell junctionsCell-matrix junctions Gap junction Tight junction Adherens junctionDesmosome Focal adhesion Hemidesmosome Connexin Claudin, occludin CadherinIntegrin CELL JUNCTIONS

Epithelial Tissue: Structure Basal lamina Basement membrane Cells in contact junctions

Epithelial Tissue: Structure Figure 3-23 Basal lamina is an acellular matrix layer that is secreted by the epithelial cells. Epithelial cells attach to the basal lamina using cell adhesion molecules. Underlying tissue

Epithelial Tissue: Functions based on Layers, Shape and Features Table 3-4

KEY Integumentary System Musculoskeletal system Respiratory system Digestive system Circulatory system Reproductive system Urinary system Cells exchange epithelium exchange secretion secretory epithelium protective epithelium ciliated epithelium transporting epithelium Distribution of Epithelia in the Body Figure 3-24

Exchange Epithelia Figure 3-25a Pore Extracellular fluid Blood (a) Leaky exchange epithelium allows movement through gaps between the cells. Capillary epithelium

Transporting Epithelia Figure 3-25b Lumen of intestine or kidney (b) Tight junctions in a transporting epithelium prevent movement between adjacent cells. Substances must instead pass through the epithelial cell, crossing two phospholipid cell membranes as they do so. Extracellular fluid Apical membrane Basolateral membrane Tight junction Transporting epithelial cell

Ciliated and Protective Epithelia Figure 3-26a Cilia Microvilli Basement membrane Golgi apparatus Nucleus Mitochondria (a) Ciliated epithelium lining the airways

Ciliated and Protective Epithelia Figure 3-26b Cilia Microvilli (b) Scanning electron micrograph showing ciliated cells mixed with cells covered with shorter microvilli

Cilia and smoking The following series of slides illustrate microscopic changes that happen when a person smokes. The first slide is showing an illustrated blow-up of the normal lining of the bronchus. On the top we see the cilia, labeled (H). They are attached to columnar cells, labeled (I). The cilia sweep the mucous produced in the goblet cells, labeled (J) as well as mucous coming from deeper glands within the lungs and the particulate matter trapped in the mucous. The bottom layer of cells, labeled (L) are the basal cells.

Cilia and smoking Below we start to see the changes that occur as people begin to smoke. You will see that the columnar cells are starting to be crowded out and displaced by additional layers of basal cells. Not only are fewer cilia present but the ones that are still functioning are doing so at a much lower level of efficiency. Many chemicals in tobacco smoke are toxic to cilia, first slowing them down, soon paralyzing them all together and then destroying them.

Cilia and smoking As you see with the cilia actions being diminished, mucous starts to build up in the small airways making it harder for the smoker to breathe and causing the characteristic smokers cough in order to clear out the airways. Eventually though, the ciliated columnar cells are totally displaced. As can be seen below ominous changes have taken place. Not only is the smoker more prone to infection from the loss of the cleansing mechanism of the cilia, but these abnormal cells (O) are cancerous squamous cells. These cells will eventually break through the basement membrane wall and invade into underlying lung tissue and often spread throughout the body long before the person even knows they have the disease.

Smoker’s lungs

Secretory Epithelia Goblet cells Figure 3-27 Mucus Basal lamina Golgi apparatus Nucleus Goblet cells secrete mucus into the lumen of hollow organs such as the intestine.

Secretory Epithelia Development of endocrine and exocrine glands from epithelium Figure 3-28 Epithelium Connective tissue Duct Connecting cells disappear Blood vessel Endocrine secretory cells Exocrine secretory cells Exocrine Endocrine