Hole’s Human Anatomy and Physiology Twelfth Edition Shier w Butler w Lewis Chapter 3 Cells Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

3.1: Introduction The basic organizational structure of the human body is the cell. There are 50-100 trillion cells in the human body. Differentiation is when cells specialize. As a result of differentiation, cells vary in size and shape due to their unique function.

3.2: A Composite Cell Also called a ‘typical’ cell Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Also called a ‘typical’ cell Major parts include: Nucleus Cytoplasm Cell membrane Phospholipid bilayer Flagellum Nucleus Nuclear envelope Chromatin Nucleolus Ribosomes Microtubules Basal body Cell membrane Centrioles Rough Endoplasmic reticulum Mitochondrion Smooth Endoplasmic reticulum Microvilli Secretory vesicles Cilia Golgi apparatus Microtubule Microtubules L ysosomes

Cell Membrane (aka Plasma Membrane) Outer limit of the cell Controls what moves in and out of the cell Selectively permeable Phospholipid bilayer Water-soluble “heads” form surfaces (hydrophilic) Water-insoluble “tails” form interior (hydrophobic) Permeable to lipid-soluble substances Cholesterol stabilizes the membrane Proteins: Receptors Pores, channels and carriers Enzymes CAMS Self-markers

a: © Biophoto Associates/Photo Researchers, Inc. Cell Membrane Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Extracellular side of membrane Glycolipid Carbohydrate Fibrous protein Glycoprotein Cell membrane (b) “Heads” of phospholipid Double layer of Phospholipid molecules “Tails” of phospholipid Cholesterol molecules Globular protein Hydrophobic fatty acid “tail” (a) a: © Biophoto Associates/Photo Researchers, Inc. Cytoplasmic side of membrane Hydrophilic Phosphate “head”

Cell Adhesion Molecules (CAMs) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Guide cells on the move Selectin – allows white blood cells to “anchor” White blood cell Attachment (rolling) Selectin Integrin – guides white blood cells through capillary walls Carbohydrates on capillary wall Adhesion Adhesion receptor proteins Integrin Important for growth of embryonic tissue Blood vessel lining cell Exit Splinter Important for growth of nerve cells

Cytoplasm Cytosol = water Organelles = solids Cytoplasm is really like a Jello fruit salad where the Jello is the cytosol and the fruits (oranges, grapes, bananas, maybe walnuts, etc.) are the organelles.

Organelles Endoplasmic Reticulum (ER) Connected, membrane-bound sacs, canals, and vesicles Transport system Rough ER Studded with ribosomes Smooth ER Lipid synthesis Added to proteins arriving from rough ER Break down of drugs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Membranes Membranes Ribosomes (b) (c) Ribosomes Free floating or connected to ER Provide structural support and enzyme activity to amino acids to form protein

a: © Bill Longcore/Photo Researchers, Inc. Organelles Golgi apparatus Stack of flattened, membranous sacs Modifies, packages and delivers proteins Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Vesicles Membranous sacs Store substances Inner membrane Cristae Mitochondria Membranous sacs with inner partitions Generate energy Outer membrane (a) (b) a: © Bill Longcore/Photo Researchers, Inc.

a: © Don W. Fawcett/Visuals Unlimited Organelles Lysosomes Enzyme-containing sacs Digest worn out cell parts or unwanted substances Centrosome Two rod-like centrioles Used to produce cilia and flagella Distributes chromosomes during cell division Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Peroxisomes Enzyme-containing sacs Break down organic molecules Centriole (cross-section) Centriole (longitudinal section) (a) a: © Don W. Fawcett/Visuals Unlimited (b)

Organelles Cilia Short hair-like projections Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cilia Short hair-like projections Propel substances on cell surface Flagellum Long tail-like projection Provides motility to sperm a: © Oliver Meckes/Photo Researchers, Inc. © Colin Anderson/Brand X/CORBIS

© M. Schliwa/Visuals Unlimited Organelles Microfilaments and microtubules Thin rods and tubules Support cytoplasm Allows for movement of organelles Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Microtubules Inclusions Temporary nutrients and pigments Microfilaments © M. Schliwa/Visuals Unlimited