Cells and Tissues Lecture Presentation PDF

Essentials of Human Anatomy & Physiology i eenth Edition Global Edition Chapter 3 Cells and Tissues Lecture Presentation by Patty Bostwick-Taylor...

Essentials of Human Anatomy & Physiology i eenth Edition Global Edition Chapter 3 Cells and Tissues Lecture Presentation by Patty Bostwick-Taylor Florence-Darlington Technical College Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Pa I: Cells One Cells are the structural units of all living things e human body has 50 to 100 trillion cells ey car out the metabolism activities needed to sustain life, and they divide to form or repair tissues Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Ove iew of the Cellular Basis of Life Most cells are composed of four elements: 1. Carbon 2. Hydrogen 3. Oxygen 4. Nitrogen Cells are about 60% water Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Anatomy of a Generalized Cell In general, a cell has three main regions or pa s: 1. Plasma membrane 2. Nucleus 3. Cytoplasm Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Plasma Membrane (1 of 9) Transparent barrier for cell contents Contains cell contents Separates cell contents from surrounding environment Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Plasma Membrane (2 of 9) Fluid mosaic model is constructed of: – Two layers of phospholipids arranged “tail to tail” – Cholesterol and proteins scattered among the phospholipids – Sugar groups may be attached to the phospholipids, forming glycolipids Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.1 Structure of the Plasma Membrane Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Plasma Membrane (3 of 9) Phospholipid arrangement in the plasma membrane – Hydrophilic (“water loving”) polar “heads” are oriented on the inner and outer su aces of the membrane – Hydrophobic (“water fearing”) nonpolar “tails” form the center (interior) of the membrane ▪ is interior makes the plasma membrane relatively impermeable to most water-soluble molecules Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Plasma Membrane (4 of 9) Role of proteins – Responsible for specialized membrane functions: ▪ Enzymes ▪ Receptors for hormones or other chemical messengers ▪ Transpo as channels or carriers Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Plasma Membrane (5 of 9) Role of sugars – Glycoproteins are branched sugars attached to proteins that abut the extracellular space – Glycocalyx is the fuzzy, sticky, sugar-rich area on the cell’s su ace Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Plasma Membrane (6 of 9) Cell membrane junctions – Cells are bound together in three ways: 1. Glycoproteins in the glycocalyx act as an adhesive or cellular glue 2. Wavy contours of the membranes of adjacent cells t together in a tongue-and-groove fashion 3. Special cell membrane junctions are formed, which va structurally depending on their roles Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Plasma Membrane (7 of 9) Main types of cell junctions – Tight junctions ▪ Impermeable junctions ▪ Bind cells together into leakproof sheets ▪ Plasma membranes fuse like a zipper to prevent substances from passing through extracellular space between cells Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Plasma Membrane (8 of 9) Main types of cell junctions – Desmosomes ▪ Anchoring junctions, like rivets, that prevent cells from being pulled apa as a result of mechanical stress ▪ Created by buttonlike thickenings of adjacent plasma membranes Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Plasma Membrane (9 of 9) Main types of cell junctions – Gap junctions (communicating junctions) ▪ Allow communication between cells ▪ Hollow cylinders of proteins (connexons) span the width of the abutting membranes ▪ Molecules can travel directly from one cell to the next through these channels Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.2 Cell Junctions Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Nucleus (1 of 4) Control center of the cell Contains genetic material known as deoxyribonucleic acid, or DNA – DNA is needed for building proteins – DNA is necessa for cell reproduction ree regions: 1. Nuclear envelope (membrane) 2. Nucleolus 3. Chromatin Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.3a Anatomy of the Generalized Animal Cell Nucleus Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.3b Anatomy of the Generalized Animal Cell Nucleus Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Nucleus (2 of 4) Nuclear envelope (membrane) – Consists of a double membrane that bounds the nucleus – Contains nuclear pores that allow for exchange of material with the rest of the cell – Encloses the jellylike uid called the nucleoplasm Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Nucleus (3 of 4) Nucleolus – Nucleus contains one or more dark-staining nucleoli – Sites of ribosome assembly – Ribosomes migrate into the cytoplasm through nuclear pores to se e as the site of protein synthesis Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Nucleus (4 of 4) Chromatin – Composed of DNA wound around histones (proteins) – Scattered throughout the nucleus and present when the cell is not dividing – Condenses to form dense, rodlike bodies called chromosomes when the cell divides Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Cytoplasm (1 of 12) e cellular material outside the nucleus and inside the plasma membrane Site of most cellular activities Includes cytosol, inclusions, and organelles Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.3a Anatomy of the Generalized Animal Cell Nucleus Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Cytoplasm (2 of 12) ree major component of the cytoplasm 1. Cytosol: Fluid that suspends other elements and contains nutrients and electrolytes 2. Inclusions: Chemical substances, such as stored nutrients or cell products, that oat in the cytosol 3. Organelles: Metabolic machine of the cell that pe orm functions for the cell ▪ Many are membrane-bound, allowing for compa mentalization of their functions Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.4 Structure of the Generalized Cell Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Cytoplasm (3 of 12) Mitochondria – “Powerhouses” of the cell – Mitochondrial wall consists of a double membrane with cristae on the inner membrane – Car out reactions in which oxygen is used to break down food into ATP molecules Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Cytoplasm (4 of 12) Ribosomes – Made of protein and ribosomal RNA – Sites of protein synthesis in the cell – Found at two locations: ▪ Free in the cytoplasm ▪ Attached to the rough endoplasmic reticulum Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Cytoplasm (5 of 12) Endoplasmic reticulum (ER) – Fluid- lled tunnels (or canals) that car substances within the cell – Continuous with the nuclear membrane – Two types: ▪ Rough ER ▪ Smooth ER Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Cytoplasm (6 of 12) Endoplasmic reticulum (ER) – Rough endoplasmic reticulum ▪ Studded with ribosomes ▪ Synthesizes proteins ▪ Transpo vesicles move proteins within cell ▪ Abundant in cells that make and expo proteins Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.5 Synthesis and Expo of a Protein by the Rough ER (1 of 5) Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.5 Synthesis and Expo of a Protein by the Rough ER (2 of 5) Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.5 Synthesis and Expo of a Protein by the Rough ER (3 of 5) Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.5 Synthesis and Expo of a Protein by the Rough ER (4 of 5) Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.5 Synthesis and Expo of a Protein by the Rough ER (5 of 5) Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Cytoplasm (7 of 12) Endoplasmic reticulum (ER) – Smooth endoplasmic reticulum ▪ Lacks ribosomes ▪ Functions in lipid metabolism ▪ Detoxi cation of drugs and pesticides Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Cytoplasm (8 of 12) Golgi apparatus – Appears as a stack of attened membranes associated with tiny vesicles – Modi es and packages proteins arriving from the rough ER via transpo vesicles – Produces di erent types of packages ▪ Secreto vesicles (pathway 1) ▪ In-house proteins and lipids (pathway 2) ▪ Lysosomes (pathway 3) Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.6 Role of the Golgi Apparatus in Packaging the Products of the Rough ER (1 of 2) Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Cytoplasm (9 of 12) Lysosomes – Membranous “bags” that contain digestive enzymes – Enzymes can digest worn-out or nonusable cell structures – House phagocytes that dispose of bacteria and cell debris Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Cytoplasm (10 of 12) Peroxisomes – Membranous sacs of oxidase enzymes ▪ Detoxify harmful substances such as alcohol and formaldehyde ▪ Break down free radicals (highly reactive chemicals) ▪ Free radicals are conve ed to hydrogen peroxide and then to water – Replicate by pinching in half or budding from the ER Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Cytoplasm (11 of 12) Cytoskeleton – Network of protein structures that extend throughout the cytoplasm – Provides the cell with an internal framework that determines cell shape, suppo s organelles, and provides the machine for intracellular transpo – ree di erent types of elements form the cytoskeleton: 1. Micro laments (largest) 2. Intermediate laments 3. Microtubules (smallest) Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.7 Cytoskeletal Elements Suppo the Cell and Help to Generate Movement Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.  e Cytoplasm (12 of 12) Centrioles – Rod-shaped bodies made of nine triplets of microtubules – Generate microtubules – Direct the formation of mitotic spindle during cell division Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Table 3.1 Pa s of the Cell: Structure and Function (1 of 5) Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Table 3.1 Pa s of the Cell: Structure and Function (2 of 5) Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Table 3.1 Pa s of the Cell: Structure and Function (3 of 5) Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Table 3.1 Pa s of the Cell: Structure and Function (4 of 5) Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Table 3.1 Pa s of the Cell: Structure and Function (5 of 5) Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Cell Extensions Su ace extensions found in some cells – Cilia move materials across the cell su ace ▪ Located in the respirato system to move mucus – Flagella propel the cell ▪ e only agellated cell in the human body is sperm – Microvilli are tiny, ngerlike extensions of the plasma membrane ▪ Increase su ace area for absorption Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.8g Cell Diversity (1 of 2) Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Cell Diversity (1 of 8) e human body houses over 200 di erent cell types Cells va in size, shape, and function – Cells va in length from 1 /12,000 of an inch to over 1 yard (ne e cells) – Cell shape re ects its specialized function Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Cell Diversity (2 of 8) Cells that connect body pa s – Fibroblast ▪ Secretes cable-like bers – E throcyte (red blood cell) ▪ Carries oxygen in the bloodstream Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.8a Cell Diversity Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Cell Diversity (3 of 8) Cells that cover and line body organs – Epithelial cell ▪ Packs together in sheets ▪ Intermediate bers resist tearing during rubbing or pulling Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.8b Cell Diversity Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Cell Diversity (4 of 8) Cells that move organs and body pa s – Skeletal muscle and smooth muscle cells ▪ Contractile laments allow cells to sho en forcefully Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.8c Cell Diversity Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Cell Diversity (5 of 8) Cell that stores nutrients – Fat cells ▪ Lipid droplets stored in cytoplasm Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.8d Cell Diversity Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Cell Diversity (6 of 8) Cell that ghts disease – White blood cells, such as the macrophage (a phagocytic cell) ▪ Digests infectious microorganisms Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.8e Cell Diversity Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Cell Diversity (7 of 8) Cell that gathers information and controls body functions – Ne e cell (neuron) ▪ Receives and transmits messages to other body structures Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.8f Cell Diversity Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Cell Diversity (8 of 8) Cells of reproduction – Oocyte (female) ▪ Largest cell in the body ▪ Divides to become an emb o upon fe ilization – Sperm (male) ▪ Built for swimming to the egg for fe ilization ▪ Flagellum acts as a motile whip Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Figure 3.8g Cell Diversity (2 of 2) Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed. Cell Physiology Cells have the ability to: – Metabolize – Digest food – Dispose of wastes – Reproduce – Grow – Move – Respond to a stimulus Copyright © 2022 Pearson Education, Ltd. All Rights Rese ed.