Exploring Human Biology and Science Lecture Notes PDF

Exploring Human Biology and Science Nermin Eissa, Ph.D. College of Health Sciences Abu Dhabi University Fall-2023 Learning Outcomes: Comprehend the basic characteristics common to all living organisms. Describe the levels of organizat...

Exploring Human Biology and Science Nermin Eissa, Ph.D. College of Health Sciences Abu Dhabi University Fall-2023 Learning Outcomes: Comprehend the basic characteristics common to all living organisms. Describe the levels of organization of life. Classification of living organisms. Determine the general process of the scientific method. Activity: https://edpuzzle.com/media/5f4cef8267b9f93f724ffb1e ©2020 McGraw-Hill Education 2  LIFE IS ORGANIZED Levels of biological organization: Atoms join together to form molecules. Cell—smallest structural and functional unit of an organism. Some organisms are single-celled; some, like humans, are multicellular (composed of many cells). Tissue—group of similar cells that perform a particular function. ©2020 McGraw-Hill Education 3  LEVELS OF BIOLOGICAL ORGANIZATION ©2020 McGraw-Hill Education Access the text alternative for these images 4  LIFE IS ORGANIZED 2 Organ—composed of several tissue types. Organ system—group of organs that work together for a common purpose. Organism—collection of organ systems. Species—a group of interbreeding organisms. Population—the members of one species in a particular area. Community—interacting populations. ©2020 McGraw-Hill Education 5  LIFE IS ORGANIZED 3 Ecosystem—community of populations interacting with the physical environment. Biosphere—all of the Earth’s ecosystems. ©2020 McGraw-Hill Education 6  LIFE REQUIRES MATERIALS AND ENERGY 1 Energy—the capacity to do work. Humans acquire materials and energy by eating. Food provides nutrients, which are used for building blocks and energy. Maintain the body's essential functions and physical tasks. ©2020 McGraw-Hill Education 7  LIFE REQUIRES MATERIALS AND ENERGY 2 Metabolism—all of the chemical reactions that occur within cells. The ultimate source of energy for life on Earth is the sun. Photosynthesis—used by plants, algae, and some bacteria. Harvests energy from the sun and converts it to chemical energy. Produces sugars, which serve as the basis for the food chain for other organisms. ©2020 McGraw-Hill Education 8  LIVING ORGANISMS MAINTAIN AN INTERNAL ENVIRONMENT Homeostasis—a constant internal environment. Most organ systems strive to maintain homeostasis. Homeostasis would be impossible to maintain without the ability to respond to stimuli. That is, external stimuli: remove one’s hand from a hot stove. That is, internal stimuli: adjustments to blood pressure in response to values outside of normal. ©2020 McGraw-Hill Education 9 LIVING ORGANISMS REPRODUCE AND DEVELOP 1 When organisms reproduce, they pass on their genetic information to the next generation. Growth—increase in size and in the number of cells. Development—all changes that occur from fertilization until death. Includes changes occurring in childhood, adolescence, and adulthood; also repair after injury. ©2020 McGraw-Hill Education 10 LIVING ORGANISMS REPRODUCE AND DEVELOP 2 DNA (deoxyribonucleic acid)—the genetic information of all life. Contains hereditary information that directs the structure and function of all cells. Contains genes—short segments that specify traits Mutations—variations in genes. Can be beneficial and make organism better suited for its environment (this is the basis for evolution). ©2020 McGraw-Hill Education 11 ORGANISMS HAVE AN EVOLUTIONARY HISTORY ▪ Evolution—how a population changes over time. ▪ Natural selection—the process by which evolution occurs. When a new variation occurs that allows organisms to capture more resources, those individuals have more offspring. ▪ Adaptation—over time, population has more individuals with this advantageous variation. ©2020 McGraw-Hill Education 12  CHECK YOUR PROGRESS Summarize the levels of biological organization. Explain the relationship between adaptations and evolutionary change. ©2020 McGraw-Hill Education 13  HUMANS ARE RELATED TO OTHER ANIMALS 2 All life is classified into one of three domains: Bacteria, Archaea, Eukarya. Bacteria and Archaea contain prokaryotes—single- celled organisms that lack a nucleus. Eukaryotic cells contain a nucleus. Some eukaryotes are single-celled, some are multicellular (like humans). ©2020 McGraw-Hill Education 14  THE EVOLUTIONARY RELATIONSHIPS OF THE THREE DOMAINS OF LIFE 15 ©2020 McGraw-Hill Education Access the text alternative for these images HUMANS ARE RELATED TO OTHER ANIMALS 3 The domain Eukarya is divided into four kingdoms: Plants (Plantae). Fungi (Fungi). Animals (Animalia). Protists (Protista). ©2020 McGraw-Hill Education 16  THE CLASSIFICATION OF LIFE (ARCHAEA AND BACTERIA) Access the text alternative for these images 19 ©2020 McGraw-Hill Education (Left image): ©Eye of Science/Science Source; (Right image): ©Science Photo Library/Getty Images  THE CLASSIFICATION OF LIFE (PROTISTA AND PLANTAE) Access the text alternative for these images 20 ©2020 McGraw-Hill Education (Left image): ©M. I. Walker/Science Source; (Right image): ©Pixtal/age fotostock  THE CLASSIFICATION OF LIFE (FUNGI AND ANIMALIA) Access the text alternative for these images 21 ©2020 McGraw-Hill Education (Left image): ©Ingram Publishing; (Right image): ©Fuse/Getty Images  KINGDOM ANIMALIA Most organisms in kingdom Animalia are invertebrates. That is, earthworms, insects, mollusks. Vertebrates. Have a nerve cord protected by a vertebral column. That is, fish, reptiles, amphibians and birds. Vertebrates with hair or fur and mammary glands are called mammals. That is, humans, raccoons, seals. ©2020 McGraw-Hill Education 20  HUMANS Humans are most closely related to apes, but are distinguished from apes by: Highly developed brains. Completely upright stance. Creative language skills. Ability to use a wide variety of tools. Humans and apes have a common ancestor. Humans are members of the biosphere. ©2020 McGraw-Hill Education 21  CHECK YOUR PROGRESS Define the term biosphere. Explain why humans belong to the domain Eukarya and kingdom Animalia. ©2020 McGraw-Hill Education 22  SCIENCE AS A PROCESS 2 Science—a way of knowing about the natural world. The scientific process uses the scientific method. It is a problem-solving method. A standard series of steps: making observations of the world, proposing ideas about how something works, testing those ideas and discarding (or modifying) our ideas in response to the test results—is the essence of the scientific method. ©2020 McGraw-Hill Education 23 STEPS OF THE SCIENTIFIC METHOD Those important Question (testable) (Observation) steps are: Perform background research Formulate a hypothesis Conduct experiment Analyze data/result False hypothesis True hypothesis Report conclusion  START WITH AN OBSERVATION Observation is a formal way of watching the natural world. Made with. the senses (sight, smell). the help of instruments like microscopes. through research. Background Research Make a research about the topic ©2020 McGraw-Hill Education 25  DEVELOP A HYPOTHESIS ▪ A hypothesis is a possible explanation for the observation of a natural event. ▪ Inductive reasoning—when someone uses creative thinking to combine facts into a cohesive whole. ▪ Scientists make a testable prediction based on a hypothesis. ©2020 McGraw-Hill Education 26  TEST A HYPOTHESIS Develop and follow a procedure. Include a detailed materials list. Choose the independent (manipulated) variable, there must be just ONE independent/experience. Choose the dependable (responding) variable to measure. Test groups and a control groups are also used. ©2020 McGraw-Hill Education 27  COLLECTING AND ANALYZING THE DATA 1 Results are derived from experiments. Results, in the form of data, may be presented in a variety of formats. Graphs are useful tools to summarize data. Line graphs, bar graphs. Statistics are used to interpret data. ©2020 McGraw-Hill Education 28  DEVELOP A CONCLUSION Scientists analyze the data in order to reach a conclusion about whether a hypothesis is supported or not. The conclusion of one experiment can lead to the hypothesis for another experiment. Studies can be published in Scientific publications. ©2020 McGraw-Hill Education 29  AN EXAMPLE OF A CONTROLLED STUDY Hypothesis: antibiotic B is better than the currently used antibiotic A. Control group: subjects with ulcers receive a placebo (a pill that contains no medication). The two test groups each receive one of the antibiotics Double-blind study—neither the doctors nor the patients know which group they are in. Conclusion—antibiotic B had better results. ©2020 McGraw-Hill Education 30  CHECK YOUR PROGRESS Describe each step of the scientific method. Explain why a controlled study is an important part of the experimental design.. ©2020 McGraw-Hill Education 31 Cell structure and Function (Part II) Nermin Eissa, Ph.D. College of Health Sciences Abu Dhabi University Fall -2023 Learning Outcomes: Describe the structure of the nucleus and explain its role as the storage place of genetic information. Summarize the functions of the organelles of the endomembrane system. Explain the role of the cytoskeleton in the cell and the major protein fibers. Describe the role of flagella and cilia in human cells. Identify the role of an enzyme in a metabolic reaction. Summarize the roles of the anaerobic and aerobic pathways in energy generation. 2 ©2020 McGraw-Hill Education  Endomembrane System 2 The endomembrane system is a series of membranous organelles that function to process materials for the cell. Consists of the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, and vesicles. Functions to compartmentalize the cell and transport substances throughout the cell. endomembrane system 3 ©2020 McGraw-Hill Education  The Nucleus 1 The nucleus: Contains DNA in the form of chromatin most of the time, and chromosomes when the cell is dividing. DNA is made up of genes, which contain instructions for the production of proteins. Nucleoplasm—the fluid inside the nucleus. Nucleolus—dark region inside the nucleus. Produces ribosomes. Cell parts and function-Nucleus-Nucleur membrane- nucleolus-nuclear pores: https://youtu.be/HxdajtjxRvg 4 ©2020 McGraw-Hill Education  The Nucleus and Endoplasmic Reticulum The nucleus: Nuclear envelope—a double membrane around the nucleus. Nuclear pores—holes in the nuclear envelope; allow passage of substances in and out of the nucleus. 5 ©2020 McGraw-Hill Education  Ribosomes Ribosomes. Made of rRNA and protein. Sites of protein synthesis. Found attached to the endoplasmic reticulum or free-floating in the cytoplasm. When free-floating, occur singly or in groups called polyribosomes. What are Ribosomes?: https://youtu.be/WjnUJusSYAo The Endomembrane System: https://youtu.be/Fcxc8Gv7NiU 6 ©2020 McGraw-Hill Education  The Endomembrane System 2 Endoplasmic reticulum (ER): a continuous membrane system that forms a series of flattened sacs within the cytoplasm of eukaryotic cells. Rough endoplasmic reticulum (RER)—studded with ribosomes used to make proteins. Smooth endoplasmic reticulum (SER)—lacks ribosomes; synthesizes lipids. Has different functions in various cell types. Golgi apparatus—flattened sacs; modify proteins and lipids. Involved in processing, packaging, and secretion of vesicles. 7 ©2020 McGraw-Hill Education  The Endomembrane System 3 Vesicles—small membranous sacs used for transport. Lysosomes—vesicles made by the Golgi that contain hydrolytic enzymes, which break down molecules into smaller parts. Prevalent in white blood cells that engulf disease- causing microbes. 8 ©2020 McGraw-Hill Education  Check Your Progress Describe the functions of the following organelles: endoplasmic reticulum, Golgi apparatus, and lysosomes. Describe the organelles of the endomembrane system involved in the export of a protein from the cell. 9 ©2020 McGraw-Hill Education  The Cytoskeleton, Cell Movement, and Cell Junctions The cytoskeleton. Protein fibers that maintain cell shape, anchor and/or move organelles in the cell. Made of 3 types of fibers: 1. microtubules, which are the largest; 2. middle-sized intermediate filaments; 3. thin actin filaments. Cytoskeleton Microtubules: https://youtu.be/5rqbmLiSkpk 10 ©2020 McGraw-Hill Education  The Cytoskeleton 2 The cytoskeleton: 1. Microtubules (Tubulin) 2. Intermediate filaments. Microtubule assembly is Sized in-between actin controlled by the centrosome. filaments and microtubules. Help maintain cell shape. Function is purely structural Act as tracks along which 3. Actin filaments. organelles move. Made of the protein actin. During cell division, form the Long and very thin. spindle apparatus, which helps move chromosomes. Involved in movement and many cellular processes. 11 ©2020 McGraw-Hill Education  Cilia and Flagella Cilia (singular, cilium) and flagella (singular, flagellum). Both are made of microtubules. Both are used in movement. Cilia: in the respiratory tract move mucus toward the throat. Flagella: on sperm propel them toward the egg. 13 ©2020 McGraw-Hill Education  Extracellular Matrix Extracellular matrix. A protective mesh of proteins and polysaccharides. Surrounds the cell that produces it. Contains collagen, which resists stretching, and elastin, which provides resilience. Fibronectin—an adhesive protein that binds to integrin, an integral membrane protein that is connected to the cytoskeleton. Plays a role in cell signaling. 57 ©2020 McGraw-Hill Education  Extracellular Matrix Access the text alternative for these images 58 ©2020 McGraw-Hill Education  Check Your Progress List the three types of fibers in the cytoskeleton. Describe the structure of cilia and flagella, and state the function of each. 16 ©2020 McGraw-Hill Education  Metabolic Pathways Metabolism—all chemical reactions that occur in the body. Enzymes: Speed up the rate of a chemical reaction. Often named for the molecules that they work on (called substrates). eg, lipids are broken down by lipase. Active site—area of the enzyme where the substrate binds. Impart specificity to the enzyme. Are not used up in a reaction; are reused. 17 ©2020 McGraw-Hill Education  Action of an Enzyme Enzymes and Activation Energy: https://youtu.be/ueup2PTkFW8 Function of Enzymes: Substrate, Active Site & Activation Energy: https://youtu.be/wp_yyDEEC3k Access the text alternative for these images 18 ©2020 McGraw-Hill Education  Enzymes 2 Enzymes, continued. Lower the energy of activation—the energy needed to start a chemical reaction. Some enzymes are aided by nonprotein molecules called coenzymes. Vitamins are often components of coenzymes. 19 ©2020 McGraw-Hill Education  Mitochondria and Cellular Respiration Mitochondria (singular, mitochondrion). Convert the chemical energy stored in glucose into chemical energy stored in adenosine triphosphate (ATP). Called cellular respiration—uses up O2, gives off CO2 Has an inner and outer membrane. Inner membrane is folded into cristae that contain enzymes for cellular respiration reactions. 20 ©2020 McGraw-Hill Education  ATP-ADP Cycle Production of ATP in a cell. When energy is needed, ATP is broken down into ADP (adenosine diphosphate) and a phosphate. When energy is obtained from food, it is used to add a phosphate back onto ADP to make ATP. This cycles repeatedly. 70 ©2020 McGraw-Hill Education  Cellular Respiration Cellular respiration breaks glucose down into carbon dioxide and water. Three pathways are involved: Glycolysis. Citric acid cycle (Krebs cycle). Electron transport chain. These pathways allow the energy to be released slowly; a tremendous amount of heat would be lost if glucose breakdown occurred all at once. Cellular Respiration: https://youtu.be/eBl3U-T5Nvk Electron Transport Chain (Music Video): https://youtu.be/VER6xW_r1vc 23 ©2020 McGraw-Hill Education  Glycolysis Glycolysis. Breaks glucose, a 6-carbon sugar, into two 3-carbon pyruvates. Occurs in the cytoplasm of almost every cell type. Is anaerobic—does not require oxygen. Produces NADH and 2 ATP molecules. NADH: Nicotinamide adenine dinucleotide 24 ©2020 McGraw-Hill Education  Production of ATP When oxygen is available, pyruvate then enters the preparatory (prep) reaction. Prepares the pyruvates for use in the citric acid cycle. When oxygen is not available, fermentation occurs. Access the text alternative for these images 25 ©2020 McGraw-Hill Education  Citric Acid Cycle 1 Citric acid cycle (Krebs cycle). A cyclical series of enzymatic reactions. Occurs in the matrix of mitochondria. Completes the breakdown of glucose by breaking the bonds between carbons. Each pyruvate enters the citric acid cycle as acetyl CoA. Produces NADH and 2 ATP. Releases carbon dioxide. 26 ©2020 McGraw-Hill Education  Citric Acid Cycle 2 Citric acid cycle, continued. The remaining hydrogen and electrons are carried away by NADH and a similar molecule called FADH2. Fats and proteins may be converted to compounds that can enter the citric acid cycle. FADH2: the reduced form of flavin adenine dinucleotide (FAD) 27 ©2020 McGraw-Hill Education  Electron Transport Chain 1 Electron transport chain. NADH from glycolysis and the citric acid cycle deliver electrons to the electron transport chain. The members of the electron transport chain are carrier proteins embedded in the mitochondria cristae. Each carrier accepts two electrons and passes them on to the next carrier. Electron Transport Chain ETC Made Easy: https://youtu.be/C8VHyezOJD4 29 ©2020 McGraw-Hill Education  Electron Transport Chain 2 Electron transport chain, continued. Oxygen is the final acceptor of the electrons at the end of the chain (so the chain is aerobic). After oxygen receives the electrons, it combines with hydrogens and becomes water. The reason why we breathe in oxygen is so it can receive electrons at the end of the electron transport chain. The energy released during cellular respiration is used to make 32 to 34 ATP. 30 ©2020 McGraw-Hill Education Electron Transport Chain 2  Check Your Progress Summarize the roles of enzymes in chemical reactions. Describe the basic steps required to break down glucose by cellular respiration. Explain why the ATP cycle resembles that of a rechargeable battery. 32 ©2020 McGraw-Hill Education Cell structure and Function (Part I) Nermin Eissa, Ph.D. College of Health Sciences Abu Dhabi University Fall-2023 Cell Structure and Function Learning Outcomes: Explain how the surface-area-to-volume ratio limits cell size. Summarize the role of microscopy in the study of cells. Distinguish between the structure of a prokaryotic cell and that of a eukaryotic cell. Identify the roles of the plasma membrane and the organelles of a cell. Distinguish between the processes of diffusion, osmosis, facilitated transport, active-transport mechanisms, endo- and exo–cytosis. 2 ©2020 McGraw-Hill Education  The Cell Theory Cell—the basic unit of life. All living things are made up of cells. New cells arise only from preexisting cells. Cells Vary in Structure and Function 3 ©2020 McGraw-Hill Education  Cell Size Cells are small because of their surface-area-to- volume ratio. Smaller cells have a larger amount of surface area compared to the volume. An increase in surface area allows for more nutrients to pass into the cell and more wastes to exit the cell. There is a limit to how large a cell can be while remaining efficient and metabolically active. 4 ©2020 McGraw-Hill Education  Surface-Area-to-Volume Ratio Limits Cell Total surface area 96 cm2 192 cm2 384 cm2 (height × width × number of sides × number of cubes) Total volume 64 cm3 64 cm3 64 cm3 (height × width × length × number of cubes) Surface area: 1.5:1 3:1 6:1 Volume per cube (surface area ÷ volume) 5 ©2020 McGraw-Hill Education  Microscopy 1 Resolution of the image varies among different types of microscopes. 1.Compound light microscope. Lower magnification than other microscopes. Uses glass lenses and light beams to view images. Can view live specimens. 6 ©2020 McGraw-Hill Education  Micrographs of Human Red Blood Cells Access the text alternative for these images 9 ©2020 McGraw-Hill Education (a): ©Ed Reschke/Getty Images; (b): ©Steve Gschmeissner/Science Photo Library/Getty Images; (c): ©Science Photo Library/Getty Images  Microscopy 2 2. Transmission electron microscope. 2-D image. Uses a stream of electrons to view magnified images. The human eye cannot see the image; it must be projected onto a screen. High magnification, no live specimens. 8 ©2020 McGraw-Hill Education  Microscopy 3 3. Scanning electron microscope. 3-D image. Uses a beam of electrons to view surface structures of specimens. High magnification, no live specimens. 9 ©2020 McGraw-Hill Education  Microscopy 3 4.  How Cells Are Organized 2 Cells are classified into two categories: prokaryotes and eukaryotes. Prokaryotic cells (prokaryotes). Lack a nucleus. Include two groups of bacteria: eubacteria and archaebacterial. Eukaryotic cells (eukaryotes). Have a nucleus. Include animals, plants, fungi, protists. 11 ©2020 McGraw-Hill Education  The Structure of a Typical Eukaryotic Cell 12 ©2020 McGraw-Hill Education ©Alfred Pasieka/Science Source  The Structure of a Typical Eukaryotic Cell Access the text alternative for these images 16 ©2020 McGraw-Hill Education  How Cells are Organized 3 Both types of cells have: A plasma membrane. Surrounds the cell. Made of a phospholipid bilayer that is selectively permeable (regulates what enters and leaves the cell). A cytoplasm: the semifluid substance inside the cell. Includes organelles (internal compartments with specialized functions). 14 ©2020 McGraw-Hill Education  Check Your Progress Summarize the role of the plasma membrane in a cell. Describe the main differences between a eukaryotic and a prokaryotic cell. 15 ©2020 McGraw-Hill Education  The Plasma Membrane 1 Plasma membrane. Phospholipid bilayer with proteins that are attached and embedded. Hydrophilic heads face the cytoplasm and extracellular fluid. Hydrophobic tails face inward. 16 ©2020 McGraw-Hill Education  The Plasma Membrane 2 Plasma membrane Contains cholesterol for support. Glycoproteins and glycolipids—carbohydrate chains attached to proteins and lipids. Identify the cell as “self” or “foreign” and act as receptors. 17 ©2020 McGraw-Hill Education  The Plasma Membrane 3 Plasma membrane Some membrane proteins act as channels. Allow some things in while keeping other substances out. Small, hydrophobic substances pass freely through the phospholipid bilayer. Eg: gases like oxygen and carbon dioxide. Ions and large molecules need help passing through. Water can cross the membrane by passing through channels called aquaporins. 18 ©2020 McGraw-Hill Education  Selective Permeability of the Plasma Membrane 19 ©2020 McGraw-Hill Education  Ways Substances Cross the Plasma Membrane 1 Diffusion. Osmosis. Facilitated diffusion. Active transport. Endocytosis and exocytosis. Diffusion, Facilitated Diffusion & Active Transport: Movement across the Cell Membrane: https://youtu.be/UgN76naeA1Q What is Osmosis? - Part 1: https://youtu.be/SD1AKWUazPU Osmosis Process - Part 2: https://youtu.be/MCvbfqz7ASs Endocytosis and Exocytosis: https://youtu.be/_dlbw8ubjgc 20 ©2020 McGraw-Hill Education  Ways Substances Cross the Plasma Membrane 2 Diffusion—the random movement of molecules from a higher concentration to a lower concentration. Until they are equally distributed. Passive movement; no energy is required. Molecules move in both directions, but the net movement is from high to low concentration. At equilibrium, the same number of molecules move in and out of the cell. 21 ©2020 McGraw-Hill Education  Diffusion Across the Plasma Membrane Access the text alternative for these images 22 ©2020 McGraw-Hill Education  Osmosis Osmosis—the diffusion of water molecules; from high to low water concentration. Normally body fluids are isotonic to cells. The same concentration of impermeable solutes. Cells do not change in size. Hypotonic solutions have fewer solutes. Cells swell and can burst (lysis). Hypertonic solutions have more solutes. Cells shrink (crenation). Osmotic pressure drives osmosis. 23 ©2020 McGraw-Hill Education  Effects of Changes in Tonicity on Red Blood Cells Access the text alternative for these images 31 ©2020 McGraw-Hill Education (a–b): ©Power and Syred/Science Photo Library/Getty Images; (c): ©Steve Gschmeissner/Science Photo Library/Getty Images  Facilitated Transport Facilitated transport. The transport of molecules across the plasma membrane from higher concentration to lower concentration via a protein carrier. Passive transport (no energy required). Protein transporters are very specific and only move certain molecules. 32 ©2020 McGraw-Hill Education  Facilitated Transport Across a Plasma Membrane Access the text alternative for these images 33 ©2020 McGraw-Hill Education  Active Transport Active transport—the movement of molecules from a lower to higher concentration. Uses ATP as energy. Requires a protein carrier, which is often called a pump. 34 ©2020 McGraw-Hill Education  Active Transport and the Sodium- Potassium Pump Access the text alternative for these images 35 ©2020 McGraw-Hill Education  Bulk Transport 1 Cells use bulk transport to move large molecules across the membrane. Endocytosis transports molecules or cells into the cell via invagination of the plasma membrane to form a vesicle. Phagocytosis—endocytosis of pathogens (that is, bacteria) by white blood cells. Pinocytosis—endocytosis of fluid with small particles. Receptor-mediated endocytosis—particles first bind to receptors in the plasma membrane; this initiates endocytosis. 36 ©2020 McGraw-Hill Education  Examples of Bulk Transport Access the text alternative for these images 30 ©2020 McGraw-Hill Education  Bulk Transport 2 Exocytosis transports molecules outside the cell via the fusion of a vesicle with the plasma membrane. Sort of like reverse endocytosis. 31 ©2020 McGraw-Hill Education  Check Your Progress Describes the structure of the plasma membrane. Compare and contrast diffusion, osmosis, facilitated transport, and active transport. Discuss the various ways cells can move materials in bulk into and out of the cell. 32 ©2020 McGraw-Hill Education Types of Tissues-Organ systems Part I Nermin Eissa, Ph.D. College of Health Sciences Abu Dhabi University Fall-2023  Learning Outcomes: Describe the four major classes of tissues and provide a general function for each. Compare the structure and function of bone and cartilage. Differentiate between blood and lymph. Distinguish among the three types of muscles with regard to location and function in the body. Describe the structure of a neuron. State the role of epithelial cells in the body with regard to location and function. 2 ©2020 McGraw-Hill Education  Types of Tissues Tissue—a collection of cells of the same type that perform a common function. There are 4 major tissue types in the body: Connective tissue—binds and supports body parts. Muscular tissue—moves the body and its parts. Nervous tissue—conducts nerve impulses. Epithelial tissue—covers body surfaces; lines body cavities. 3 ©2020 McGraw-Hill Education  Connective Tissue 1 Connective tissue. Has three main components: specialized cells, ground substance, and protein fibers. Ground substance—noncellular material between the cells. Varies in consistency from solid (bone) to fluid (blood). 4 ©2020 McGraw-Hill Education  Connective Tissue 2 There are three types of protein fibers: Collagen fibers—flexible and strong. Reticular fibers—thin, highly branched collagen fibers. Elastic fibers—contain elastin, a protein that stretches and recoils. There are three main types of connective tissue: fibrous, supportive, and fluid. 5 ©2020 McGraw-Hill Education  Components of Connective Tissues Access the text alternative for these images 6 ©2020 McGraw-Hill Education  Types of Connective Tissue Access the text alternative for these images 7 ©2020 McGraw-Hill Education  Fibrous Connective Tissue 1 Fibrous connective tissue. Comes in two main forms: loose and dense. Both contain fibroblasts separated by matrix (ground substance and fibers). Loose fibrous connective tissue. Includes areolar connective tissue, reticular connective tissue and adipose tissue. Dense fibrous connective tissue. Found in tendons (connect muscles to bones) and ligaments (connect bones to bones). 8 ©2020 McGraw-Hill Education  Fibrous Connective Tissue 2 Loose fibrous connective tissue supports epithelium and many internal organs. Adipose tissue stores fat. Has very little extracellular matrix. Adipocytes—cells filled with liquid fat. Functions in energy storage, insulation and cushioning. Found primarily under the skin and around some organs. Dense fibrous connective tissue contains densely packed collagen fibers. 9 ©2020 McGraw-Hill Education  Connective Tissues Found in the Knee 10 ©2020 McGraw-Hill Education (photos, all): ©Ed Reschke  Supportive connective tissue Supportive connective tissue. Two major types: cartilage and bone. Functions in structure, shape, and protection. Cartilage. Chondrocytes—cells that lie in small spaces called lacunae. Matrix is solid but flexible. Lacks a direct blood supply, so heals slowly. 11 ©2020 McGraw-Hill Education  Cartilage 3 types, distinguished by the type of fibers found in the matrix: Hyaline cartilage—fine collagen fibers. Found in the tip of the nose, ends of long bones and the fetal skeleton. Elastic cartilage—lots of elastic fibers. Found in the outer ear. Fibrocartilage—strong collagen fibers. Found in the disks between vertebrae. 12 ©2020 McGraw-Hill Education  Bone The most rigid connective tissue. Matrix is made of collagen and calcium salts. There are two types of bone tissue: compact and spongy. Compact bone makes up the shafts of long bones. Consists of cylindrical structural units called osteons. The central canal contains blood vessels and nerves. Bone cells are located in lacunae. Spongy bone is inside the ends of long bones. Lighter than compact bone, but strong. 13 ©2020 McGraw-Hill Education  Fluid Connective Tissue There are two types of fluid connective tissue: blood and lymph. Blood. Made of a fluid matrix called plasma and cellular components called formed elements. 3 formed elements: Red blood cells (erythrocytes)—cells that carry oxygen. White blood cells (leukocytes) —cells that fight infection. Platelets (thrombocytes)—pieces of cells that clot blood. 15 ©2020 McGraw-Hill Education  Fluid Connective Tissue 2 Lymph. the fluid that flows through the lymphatic system Contains white blood cells. Lymphatic vessels absorb excess interstitial fluid and return lymph to the cardiovascular system. 16 ©2020 McGraw-Hill Education  Check Your Progress Describe the three general categories of connective tissue, and provide some examples of each type. 17 ©2020 McGraw-Hill Education  Muscular Tissue Moves the Body 2 Muscular tissue. Specialized to contract. Cells are called muscle fibers. Three types: skeletal, smooth, and cardiac. 18 ©2020 McGraw-Hill Education  Skeletal Muscle Skeletal muscle. Attached to the skeleton by tendons. Contraction moves the skeleton. Voluntarily controlled. Muscle fibers are very long; can run the entire length of the muscle. Have multiple nuclei. Striated, or striped, in appearance. 19 ©2020 McGraw-Hill Education  Smooth Muscle Smooth muscle. No striations. Spindle-shaped cells with one nucleus. Involuntarily controlled. Found in the walls of viscera. 20 ©2020 McGraw-Hill Education  Cardiac Muscle Cardiac muscle. Found only in the walls of the heart. Striated. Involuntary. Single nucleus. Cells are connected by intercalated disks. 27 ©2020 McGraw-Hill Education  Check Your Progress Explain the difference in the structure and function of skeletal, smooth, and cardiac muscle. Describe where each type of muscle fiber is found in the body. 22 ©2020 McGraw-Hill Education  Nervous Tissue Nervous tissue Consists of neurons and neuroglia. Three primary functions: sensory input, integration, and motor output. 23 ©2020 McGraw-Hill Education  Neurons 1 Neuron. Has three parts: dendrites, a cell body, and an axon. Dendrites carry information toward the cell body. The cell body contains the nucleus and other organelles. Axon conducts nerve impulses away from the cell body. 24 ©2020 McGraw-Hill Education  Some axons are covered in myelin, a fatty substance. Nerves—bundles of axons traveling to and from the brain and spinal cord. Neuroglia. Take up more than half the volume of the brain. Main function is to support and nourish neurons. Access the text alternative for these images 33 ©2020 McGraw-Hill Education ©Xia Yuan/Moment Open/Getty Images  Check Your Progress Describe the structure and function of a neuron. Explain the general function of the neuroglia. 26 ©2020 McGraw-Hill Education  Epithelial Tissue Protects 2 Epithelial tissue (epithelium, or plural, epithelia). Made of tightly packed cells. Lines body cavities, covers body surfaces, and is found in glands. Anchored by a basement membrane on one side and is free on the other side. Named for the number of cell layers and the shape of the cells. 27 ©2020 McGraw-Hill Education  Epithelial Tissue Protects 3 Epithelial tissue: Is either simple or stratified. Simple epithelium. Single layer of cells. Stratified epithelium. Multiple layers of cells. 28 ©2020 McGraw-Hill Education  Epithelial Tissue 29 ©2020 McGraw-Hill Education  Simple Epithelia 1 Simple epithelia. Simple squamous epithelium. Single layer of flattened cells. That is, found in the lungs, where it functions in gas exchange. Simple cuboidal epithelium. Single layer of cube-shaped cells. 30 ©2020 McGraw-Hill Education  Simple Epithelia 2 Simple columnar epithelium. Single layer of column-shaped cells. Pseudostratified columnar epithelium. Because of the location of the nuclei, appears stratified but every cell touches the basement membrane. Often has cilia, which move mucus across its surface. 31 ©2020 McGraw-Hill Education  Stratified Epithelia Stratified epithelia. Several layers of cells. Stratified squamous epithelia forms the outer layer of the skin and lines the mouth, esophagus. Transitional epithelia. Cells change shape in response to tension (from cuboidal to squamous). That is, found lining the urinary bladder. 32 ©2020 McGraw-Hill Education  Check Your Progress List the functions of epithelial tissue. Describe the structure of each major type of epithelial tissue. 33 ©2020 McGraw-Hill Education Types of Tissues- Organ systems- Part II Nermin Eissa, Ph.D. College of Health Sciences Abu Dhabi University Fall-2023 Learning Outcomes: Explain the function of human skin. Describe the structure of the epidermis and dermis. Summarize the function of each organ system in the human body. Identify the major cavities of the human body. Name the body membranes and provide a function for each. Define homeostasis and provide an example. Distinguish between positive and negative feedback mechanisms. 2 ©2020 McGraw-Hill Education  The Integumentary System 1 Integumentary system. Includes the skin and accessory organs such as hair, nails, and glands. Functions: Protects underlying tissues from trauma, pathogen invasion, and water loss. Helps regulate body temperature. Contains sensory receptors, such as touch and temperature receptors. 3 ©2020 McGraw-Hill Education  The Integumentary System 2 Skin Skin has 2 main regions: the epidermis and the dermis. Under the skin there is a subcutaneous layer (hypodermis). 4 ©2020 McGraw-Hill Education  The Epidermis 1 Epidermis Thin, outermost layer of the skin. Made of stratified squamous epithelium. Stem cells that produce new epidermal cells are in the deepest layer. If an injury destroys the stem cells, skin needs to be replaced. Autograft—from another area of the body. Allograft—from another person. Can also grow skin in the lab. 5 ©2020 McGraw-Hill Education  The Epidermis 2 Cells of the epidermis. Keratinocytes—in the upper layers of epidermis. Dead and filled with keratin. Forms a waterproof barrier. Langerhans cells—a type of white blood cell. Melanocytes—produce melanin. Produces skin color and protects from UV light. People have the same number of melanocytes but the amount of melanin produced varies. 6 ©2020 McGraw-Hill Education  The Epidermis 3 Epidermal cells produce vitamin D when exposed to UV rays. Vitamin D is important in the regulation of calcium and phosphorus levels in the body. 7 ©2020 McGraw-Hill Education  Skin Cancer Skin cancer. Caused by ultraviolet rays from the sun. Basal cell carcinoma—cancer of the epidermal stem cells. Most common type of skin cancer; easily curable. Melanoma—cancer of melanocytes. Extremely serious. 8 ©2020 McGraw-Hill Education  The Dermis The dermis. Thick, inner layer of the skin. Made of dense fibrous connective tissue. Contains collagen and elastic fibers for strength and elasticity. Contains blood vessels, sensory receptors, and glands. Sensory receptors are specialized for touch, pressure, pain, hot, and cold. 9 ©2020 McGraw-Hill Education  The Subcutaneous Layer The subcutaneous layer. Technically not part of the skin. Composed of loose connective tissue and adipose tissue. Stores energy, insulates and protects. 10 ©2020 McGraw-Hill Education  Organ Systems, Body Cavities, and Body Membranes 2 Organ—a group of tissues performing a common function. Groups of organs with a similar function form an organ system. Some of these organ systems (for example, the respiratory system) occupy specific cavities; others, (for example, the muscular system) are found throughout the body. Organs and cavities are lined with membranes, many of which secrete fluid. 11 ©2020 McGraw-Hill Education  Organ Systems of the Body Access the text alternative for these images 12 ©2020 McGraw-Hill Education  Organ Systems of the Body Access the text alternative for these images 13 ©2020 McGraw-Hill Education  Body Cavities Body cavities. Two main cavities: ventral and dorsal. Ventral cavity. Contains the thoracic, abdominal, and pelvic cavities. Thoracic and abdominal cavities are separated by the diaphragm. Dorsal cavity. Contains the cranial cavity and vertebral canal. 14 ©2020 McGraw-Hill Education  Body Membranes Body membranes line cavities and the internal spaces of organs and tubes that open to the outside. Four types: mucous, serous, and synovial membranes and the meninges. 15 ©2020 McGraw-Hill Education  Mucous Membranes Mucous membranes Line the tubes of the digestive, respiratory, urinary, and reproductive systems. Composed of epithelium overlying loose fibrous connective tissue. Contains goblet cells that secrete mucus. 16 ©2020 McGraw-Hill Education  Serous Membranes Serous membranes. Line closed cavities (not open to the environment) and cover the surface of the organs contained within. That is, pleurae line the thoracic cavity and cover the lungs. That is, pericardium forms the pericardial sac and covers the heart. That is, peritoneum lines the abdominal cavity and covers its organs. ©2020 McGraw-Hill Education 17  Synovial Membranes and Meninges Synovial membranes. Composed only of loose connective tissue. Line freely moveable joints. Secrete synovial fluid for lubrication. Meninges. Composed only of connective tissue. In the dorsal cavity (around the brain and spinal cord). Meningitis—inflammation of the meninges. 18 ©2020 McGraw-Hill Education  Check Your Progress Describe the location of the major body cavities. List the four types of body membranes, and describe the structure and function of each. 19 ©2020 McGraw-Hill Education  Homeostasis 2 Homeostasis. A relatively constant internal environment. There are various conditions in the body that are maintained within a relatively narrow range of normal values. blood glucose, pH, body temperature. If conditions vary too much, illness results. 20 ©2020 McGraw-Hill Education  The Internal Environment The internal environment has two parts: blood and interstitial fluid. Blood delivers oxygen and nutrients to the tissues and carries away carbon dioxide and wastes. Interstitial fluid surrounds body cells; substances are exchanged through it. Body systems work together to keep these substances within the range of normalcy. 21 ©2020 McGraw-Hill Education  The Body Systems and Homeostasis The nervous and endocrine systems coordinate the other organ systems. The nervous system is faster, but the effects of the endocrine system last longer. The endocrine system secretes hormones— chemical messengers that travel in blood. 22 ©2020 McGraw-Hill Education  Mechanisms for Maintaining Homeostasis 1 Mechanisms for maintaining homeostasis: negative and positive feedback. Negative feedback. The primary mechanism used in the body. Has two components: a sensor and a control center. The output of the system turns down, or off, the production. That is, how a furnace works. That is, temperature regulation. 23 ©2020 McGraw-Hill Education  Negative Feedback Mechanisms 24 ©2020 McGraw-Hill Education  Action of a Complex Negative Feedback Mechanism Access the text alternative for these images 25 ©2020 McGraw-Hill Education  Body Temperature Homeostasis Access the text alternative for these images 26 ©2020 McGraw-Hill Education  Mechanisms for Maintaining Homeostasis 2 Positive feedback. Brings about a change in the same direction as the original stimulus. For example, childbirth: the fetus’ head pushes against the cervix, which stimulates signals that are sent to the brain. The brain then secretes the hormone oxytocin, which causes stronger contractions. This causes more oxytocin to be released. Childbirth stops the positive feedback. 27 ©2020 McGraw-Hill Education  Check Your Progress Define homeostasis, and explain why it is important to body function. Summarize how the body systems contribute to homeostasis. 28 ©2020 McGraw-Hill Education