Week 1 Lecture Chapter 4 Student Copy Human Anatomy and Physiology PDF

Human Anatomy and Physiology BIOL3306 Fall 2024 Week 1: Introduction to the course Histology The Integumentary System Professor: Nour Nissan  Your Professor Nour Nissan, PhD Plant (Soybean) molecular biology at AAFC -omics studies Contra...

Human Anatomy and Physiology BIOL3306 Fall 2024 Week 1: Introduction to the course Histology The Integumentary System Professor: Nour Nissan  Your Professor Nour Nissan, PhD Plant (Soybean) molecular biology at AAFC -omics studies Contract Professor Scientist Email: [email protected] send an email anytime and I will try to answer within 24-48 hours. (weekends not included) Include course code in the title Course Expectations Expectations Respect to your peers, the professor, TAs, and yourself. Value diverse perspectives Refrain from discrimination of any kind Harassment or disruptive behavior will not be tolerated Participation and Attendance Participation is encouraged ! Remember, this is how I get to know you Attendance will not be taken. You are university students! Plagiarism Policies All submitted work must be your own. Any text that is not yours must be referenced. Plagiarized work will immediately go to the Dean Communication Email communication (24-48 hours (weekdays only)) Course Expectations Materials and Resources Human Anatomy & Physiology, 3rd edition by Erin C. Amerman. Office hours By appointment Accommodations LOA’s should be sent to me ASAP  Course Expectations Assessments and Grading 3 TAs grading your work (possibly 4) Aj Deneka (Full TA) (Assignment and exam grading, proctoring & emails) Myra Thapar (Full TA) (Assignment and exam grading, proctoring & emails) Acacia Frempong-Manso (1/2 TA) (Midterms & exam grading) Course syllabus Questions? Let’s Begin 4.1 Introduction to Tissues Tissue— A group of structurally and functionally related cells and their external environment that together perform common functions. Histology—The study of the normal structure of tissues All tissues share 2 basic components: – A discrete population of cells that are related in structure and function – The surrounding material, called Extracellular Matrix (EC M), which does differ in composition in each tissue type 4.1 Types of Tissues There are 4 Primary Tissue Types 1. Epithelial Tissues—Sheets of tightly packed cells with little EC M; Covers and lines body surfaces and cavities and form parts of glands 2. Connective Tissues—Connect all other tissues together; Cells are scattered through the EC M; Bind, support, protect, and allow transport of substances 3. Muscle Tissues—Cells contract and generate force; Little EC M 4. Nervous Tissues—Cells (Neurons) generate, send, and receive messages; Includes cells that support the neurons with some EC M Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.1 Extracellular Matrix (1 of 4) Extracellular Matrix —Composed of substances surrounding the cells in a tissue that function to: Provide the tissue with strength to resist tensile (stretching) and compressive forces Direct cells to their proper places within a tissue Regulate the development, mitotic activity, and survival of cells Hold cells in their proper positions EC M has 2 main components: Ground Substance and Protein Fibers Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.1 Extracellular Matrix (2 of 4) Ground Substance—Gel-like substance that contains extracellular fluid (EC F) with water, ions, nutrients, and other solutes, and 3 families of macromolecules: Glycosaminoglycans (G AG s) —are carbohydrate polymers that attract water and form a gel-like substance in the ECM, providing hydration and cushioning (ex. Hyaluronic Acid). Proteoglycans—large molecules with GAG chains attached to a core protein, contributing to tissue structure, cell signaling, and ECM organization. Act as a barrier to diffusion of substances through the EC M (ex. Aggrecan). Glycoproteins—are proteins with carbohydrate chains that play roles in cell adhesion, matrix formation, and signaling (ex. Fibronectin). Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.1 Extracellular Matrix (3 of 4) Protein Fibers—Entwined fibrous protein subunits that provide tensile strength; Three types are found in the EC M: Collagen Fibers—At least 20 different types of collagen fibers are made in the body; Make up 20-25% of all protein in the body; Resemble entwined pieces of a steel cable; Very resistant to tension and pressure Elastic Fibers—Made of elastin protein surrounded by glycoproteins; May stretch to ½ times their resting length without breaking (distensibility) and then return to their original length (elasticity) Reticular Fibers—Type of collagen fiber that is thinner and shorter than regular collagen; Interweaves to form a scaffold that supports the cells and ground substance of tissues; Form “webs” in some organs to trap foreign cells Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.1 Extracellular Matrix (4 of 4) Figure 4.1 Extracellular matrix. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.1 Marfan Syndrome Marfan Syndrome results from defects in the gene that codes for the glycoprotein fibrillin-1 With defective fibrillin-1, elastic fibers cannot function properly because they are incorrectly anchored in the EC M Signs and symptoms include tall stature, long limbs and fingers, multiple skeletal abnormalities, joint dislocations, abnormalities of heart valves and lens of the eyes Most lethal complication is dilation of the largest artery in the body, the aorta, which may lead to aortic rupture and fatal blood loss if not treated immediately Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.1 Cell Junctions Cell Junctions—Connections of neighboring cells in a tissue linked to one another by integral proteins Tight (Occluding) Junctions—Junctions composed of integral “locking” proteins in adjacent plasma membranes; Prevents passage of macromolecules, although some are leaky and don’t provide a complete seal Desmosomes—Junctions composed of integral “linker” proteins in adjacent plasma membranes; Distribute mechanical stress Gap Junctions—Small pores made of protein channels in adjacent plasma membranes; Allow small substances to pass freely Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.2 Let’s Talk Tissues: Epithelial Tissues Epithelial Tissue—Found on every external and internal body surface, so acts as a barrier between the body and the environment Functions of Epithelial Tissue: Protection—Continuous surface that shields underlying tissue from mechanical and thermal injury; Produce hard protein keratin; Undergoes mitosis rapidly and frequently Immune Defenses—Cells of the immune system are scattered throughout epithelial tissues Secretion—Form glands that produce substances such as sweat, oil and hormones Transport into other Tissues—Selectively permeable barriers that allow certain substances to pass by passive or active transport Sensation—Most epithelia are supplied with nerves that detect changes in the internal and external environments; Specialized epithelial cells are responsible for some sensations Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved  4.2 Components and Classification of Epithelia (2 of 4) Components of Epithelia: Basement Membrane: anchors the Figure 4.3 Structure epithelial tissue to the underlying connective of epithelial tissue. tissue and has 2 components: Basal Lamina—This is the EC M of the epithelial tissue; Consists of collagen fibers and ground substance Reticular Lamina—Manufactured by the connective tissue deep to the epithelial tissue; Consists of reticular fibers and ground substance Epithelial cells have 1 side in contact with the extracellular space (Apical Surface), and 1 in contact with deeper cells or the basal lamina (Basal Surface) Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved  4.2 Components and Classification of Epithelia (3 of 4) Classification of Epithelia: Number of Cell Layers – Simple Epithelia—Single layer of cells – Stratified Epithelia—More than one layer of cells – Pseudostratified Epithelia—Single layer of cells that appears to be multilayered Shape of the Cells – Squamous Cells—Flattened cells – Cuboidal Cells—Short cells – Columnar Cells—Tall and elongated cells Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.2 Covering and Lining Epithelia (1 of 15) Simple Epithelia—One cell layer thick, Does not work for protection; Lines hollow organs and surfaces where diffusion or transport occurs; Includes: – Simple Squamous – Simple Cuboidal – Simple Columnar – Pseudostratified Columnar Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.2 Covering and Lining Epithelia (2 of 15) Simple Squamous Epithelia—Single layer of flat cells; Resemble fried eggs that fit together like floor tiles; Diffusion occurs quickly across cells; Found in air sacs of lungs, serous membranes, and lining of blood vessels Figure 4.5a Structure of simple epithelia. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.2 Covering and Lining Epithelia (3 of 15) Simple Cuboidal Epithelia—Single layer of roughly cube- shaped cells; Appear square with a large, central nucleus; Diffusion occurs and some secrete substances; Found in kidney tubules and glands Figure 4.5b Structure of simple epithelia. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved  4.2 Covering and Lining Epithelia (4 of 15) Simple Columnar Epithelia—Single layer of tall cells; Appear rectangular in a section; Some have folds of the apical surface (microvilli); Some have cilia, which move something along the apical surface; Some produce secretions; Found in small intestine, uterine tube, kidney tubules and glands Figure 4.5c Structure of simple epithelia. Why is cilia helpful in the uterine tube? Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.2 Covering and Lining Epithelia (5 of 15) Pseudostratified Columnar Epithelia—Single layer of cells that appears to be stratified; Looks this way because nuclei are at different heights and some cells are shorter; Most are ciliated; Include goblet cells that secrete mucus; Found in respiratory passages and nasal cavities for protection Figure 4.5d Structure of simple epithelia. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved  4.2 Covering and Lining Epithelia (8 of 15) Stratified Epithelia—Thicker than simple epithelia; Effective protective barriers, so common in areas of high stress; Cell shape changes throughout the thickness of the tissue, so named according to the shape in their apical layers; Includes: – Stratified Squamous Epithelia (keratinized and nonkeratinized); Keratinized – Stratified Cuboidal Epithelia – Stratified Columnar Epithelia – Transitional Epithelia What is Keratin? atin is a protein that helps form hair, nails and your skin's outer layer (epidermis) Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.2 Covering and Lining Epithelia (9 of 15) Stratified Squamous Epithelia—Nonkeratinized stratified squamous epithelia has distinct nucleated cells on the apical surface; Found in epithelium of mouth, pharynx, esophagus, anus, and vagina Figure 4.7a Structure of stratified epithelia. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.2 Covering and Lining Epithelia (10 of 15) Stratified Cuboidal Epithelia—Rare in the human body; Two layers of cuboidal cells; Lines the ducts of sweat glands Figure 4.7b Structure of stratified epithelia. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.2 Covering and Lining Epithelia (11 of 15) Stratified Columnar Epithelia—Rare in the human body; Few layers of cells that are columnar in apical layers and cuboidal in basal layers; Found in ducts of salivary glands; parts of male urethra, and the conjunctiva (membrane lining the surface of the eye) Figure 4.7c Structure of stratified epithelia. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.2 Covering and Lining Epithelia (12 of 15) Transitional Epithelia—Cells in the basal layer are cuboidal and apical cells are dome-shaped when the tissue is relaxed; When stretched, apical cells appear squamous; Found in lining of kidneys, ureters, urinary bladder, and urethra. Found in organs that a lot of stretching happens. Figure 4.7d Structure of stratified epithelia. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.2 Covering and Lining Epithelia (14 of 15) Figure 4.8 Summary of epithelial tissues. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.2 Covering and Lining Epithelia (15 of 15) Figure 4.8 Summary of epithelial tissues. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.3 Connective Tissues (1 of 2) Connective Tissue Functions: Connecting and Binding —Bind tissue layers together in organs and anchor organs in place and to one another Support—Certain connective tissues, such as bone and cartilage, support the weight of the body Protection—Bone protects internal organs; Cartilage and fat tissue provide shock absorption; Elements of the immune system are found within connective tissues Transport—Blood, which is the main transport medium in the body, is a type of connective tissue Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.3 Connective Tissues (2 of 2) Classification of Connective Tissue: General Connective Tissue also known as Connective Tissue Proper— Widely distributed in the body, where it connects tissues and organs to one another and forms part of the internal architecture; Includes: – loose – dense – reticular – adipose tissues Specialized Connective Tissues—Class that includes – cartilage – bone – blood Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.3 Cells that form Connective Tissue Proper (1 of 3) Fibroblasts—Produce protein fibers, ground substance, and other EC M elements; Usually lie close to collagen fibers that they produce Adipocytes—Fat cells with single large inclusion that contains lipids with organelles pushed to the perimeter Figure 4.12ab Cells of connective tissue proper. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.3 Cells of Connective Tissue Proper (2 of 3) Mast Cells—Cells of the immune system with cytosolic inclusions (or granules) containing inflammatory mediators such as histamine Phagocytes—Immune cells that phagocytize foreign substances, microorganisms, and dead and damaged cells; Includes macrophages and neutrophils Other Immune Cells—Other cells of the immune system can move in and out of connective tissues depending on the needs of the body Figure 4.12cd Cells of connective tissue proper. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.3 Types of Connective Tissue Proper (1 of 7) Loose (Areolar) Connective Tissue—Ground substance with all 3 types of protein fibers, fibroblasts, and other cells including immune cells; Jelly-like consistency; Found deep to the epithelium of the skin and in membranes; Supports and houses blood vessels Figure 4.13 Structure of loose connective tissue. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.3 Types of Connective Tissue Proper (2 of 7) Dense Irregular Connective Tissue—Composed of protein fibers with mostly collagen fibers that are arranged haphazardly; Strong tissue that resists tension in all 3 planes; Found in dermis and around organs and joints Figure 4.14a Structure of dense connective tissue. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.3 Types of Connective Tissue Proper (3 of 7) Dense Regular Collagenous Connective Tissue— Contains thick collagen fibers arranged in parallel bundles; Resist tension in one direction; Found in tendons (which join muscle to bone) and ligaments (which join bone to bone) Figure 4.14b Structure of dense connective tissue. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.3 Types of Connective Tissue Proper (4 of 7) Dense Regular Elastic Connective Tissue—Also known as “elastic tissue;” Consists of mostly parallel elastic fibers with randomly oriented collagen fibers; Allow organs to stretch; Found in the lining of the large blood vessels and some ligaments Figure 4.14c Structure of dense connective tissue. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.3 Types of Connective Tissue Proper (5 of 7) Reticular Tissue—Includes numerous reticular fibers(typically collagenous fibers) produced by surrounding fibroblasts; Form fine, meshlike networks for support and weblike nets that trap foreign cells; Forms part of basement membrane Figure 4.15 Structure of reticular tissue. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.3 Types of Connective Tissue Proper (6 of 7) Adipose Tissue—Fat tissue consisting of adipocytes and surrounding fibroblasts and ECM; Adipocytes can increase in size; Functions in insulation, warmth, shock absorption, protection, and energy reserve Figure 4.16 Structure of adipose tissue. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.3 Special Connective Tissues Cartilage Tough, flexible tissue that absorbs shock and is resistant to tension, compression, and shearing forces EC M is solid and gel-like with glycosaminoglycans, proteoglycans, collagen fibers, and elastic fibers Chondroblasts—Immature cartilage cells Chondrocytes—Mature cartilage cells, which live in small cavities called Lacunae Surrounded by an outer sheath of dense irregular connective tissue called the Perichondrium, which supplies blood to the cartilage Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.3 Special Connective Tissues Bone Supports the body, protects vital organs, provides attachment sites for muscles, stores calcium salts, and houses bone marrow, which produces our red blood cells and stores fat Bone Cells – Osteoblasts—Carry out bone deposition – Osteocytes—Mature osteoblasts that are surrounded by EC M; Produce substances for bone maintenance – Osteoclasts—Multinucleated cells that carry out bone resorption (break down) Bone Remodeling—Bone deposition and bone resorption are constantly occurring in healthy bone Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.3 Special Connective Tissues Blood EC M is fluid and is called Plasma, with water, dissolved solutes, and globular proteins Cells are Erythrocytes (red blood cells), which carry oxygen, leukocyte (white blood cells), which function in immunity, and cell fragments called platelets, which function in blood clotting Figure 4.19 Components of blood. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.4 Muscle Tissues Muscle Cells (Myocytes)—Excitable cells that respond to electrical or chemical stimulation; Cytoplasm is filled with bundles of proteins called Myofilaments; Surrounded by a small amount of EC M called Endomysium Striated Muscle Cells—Myofilaments are organized into regions that produce dark and light areas called “bands;” Alternating light-dark bands are called Striations Smooth Muscle Cells—Myofilaments are in irregular bundles scattered in the cytoplasm so no striations are visible Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.4 Types of Muscle Tissue (1 of 4) Skeletal Muscle—Found attached to the skeleton to produce body movement; Controlled by the nervous system; Typically voluntary movements; Formed by the fusion of embryonic myoblasts resulting in large, multinucleate cells (also called Muscle Fibers) Figure 4.21a Structure of muscle tissues. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.4 Types of Muscle Tissue (2 of 4) Cardiac Muscle—Found only in the heart; Involuntary contractions; Shorter than skeletal muscle cells with branches and a single nucleus; Intercalated discs, which contain gap junctions and tight junctions, are found between cells and permit heart muscle to contract as a unit Figure 4.21b Structure of muscle tissues. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.4 Types of Muscle Tissue (3 of 4) Smooth Muscle—Found in the walls of hollow organs, walls of blood vessels, the eyes, the skin, and the ducts of some glands; Involuntary contractions; Cells are flattened, with a single nucleus; Gap junctions in the plasma membrane connect cells to other smooth muscle cells Figure 4.21c Structure of muscle tissues. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.5 Nervous Tissue (1 of 2) Nervous Tissue—Makes up majority of the brain, spinal cord, and nerves; EC M is different from other tissues and contains few protein fibers but is mostly ground substance with unique proteoglycans Cells include Neurons and Neuroglial Cells Neuroglial Cells—Supportive cells that anchor neurons and blood vessels in place, speed up the rate of nerve impulse transmission, and circulate fluid around the brain and spinal cord Neuroglial cells can divide by mitosis Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.5 Nervous Tissue (2 of 2) Neurons—Generate, Figure 4.22 Structure of conduct, and receive nerve nervous tissue. impulses (electrical signals); Include 3 main parts: – Cell Body—Large center with the nucleus and organelles – Axon—Moves impulse to the target cell – Dendrites—Arms that receive messages – Neurons are amitotic Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.8 Tissue Repair (1 of 2) Tissue Repair—Process of wound healing; Occurs differently in different tissues and is dependent on the tissues ability to regenerate Regeneration—Damaged or dead cells are replaced with cells of the same type Fibrosis—Fibroblasts divide by mitosis and produce collagen to fill in the defect left by the injury; Results in Scar Tissue, which is dense irregular connective tissue Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved  Conditions Favoring Regeneration: Conditions Leading to Fibrosis: Cell Type: Tissues with high regenerative Severe Injury: Extensive damage to capacity, such as epithelial tissues (skin, tissue structure and the ECM can gastrointestinal lining) and some make regeneration difficult, leading to connective tissues (liver, bone), are more fibrosis. likely to regenerate. Chronic Inflammation: Prolonged or Extent of Damage: Regeneration is more chronic inflammation can lead to likely when the damage is not extensive, excessive deposition of collagen and and the tissue architecture is minimally other ECM components, resulting in disrupted. fibrosis. Presence of Stem Cells: Tissues with Lack of Regenerative abundant stem cells or progenitor cells can Capacity: Some tissues, such as regenerate effectively. For example, skin cardiac muscle or nervous tissue, have and liver tissues have significant limited regenerative capacity and are regenerative potential due to their stem cell more prone to fibrosis following injury. populations. Disruption of ECM: Significant Minimal Scarring: When the underlying damage to the ECM can interfere with extracellular matrix (ECM) is intact and not the ability of tissues to regenerate excessively damaged, regeneration can normally, favoring scar formation occur with less fibrosis. instead. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved 4.8 Tissue Repair (2 of 2) Figure 4.26 Tissue repair by regeneration or fibrosis. Copyright © 2025, 2019, 2016 Pearson Education, Inc. All Rights Reserved