Human Anatomy and Physiology Tissue PDF

University of Northern Philippines College of Arts and Sciences Bachelor of Science in Biology major in Medical Biology HUMAN ANATOMY AND PHYSIOLOGY Tissue Level of Organization...

University of Northern Philippines College of Arts and Sciences Bachelor of Science in Biology major in Medical Biology HUMAN ANATOMY AND PHYSIOLOGY Tissue Level of Organization Chris Paul P. Pagaoa, MSBiol, LPT Instructor, Human Anatomy & Physiology Lecture  OUTLINE OF DISCUSSION II. Tissue Level of Organization 1. Introduction to Histology 2. Cell Junctions 3. Epithelial Tissue 4. Connective Tissue 5. Nervous Tissue 6. Muscular Tissue TISSUE LEVEL OF ORGANIZATION TISSUE LEVEL OF ORGANIZATION  CELL JUNCTIONS  Surfaces of Cells and their Specializations  Cell Junctions  contact points between the plasma membranes of tissue cells.  Types of Cell junctions: 1. Tight junctions 2. Adhesion junctions 3. Desmosomes 4. Hemidesmosomes 5. Gap junctions  CELL JUNCTIONS  Surfaces of Cells and their Specializations 1. Tight junctions  Formed from rows of transmembrane proteins that bind tightly between adjacent cells.  It functions as seals to prevent the passage of molecules between the plasma membranes of adjacent cells.  e.g. tight junctions between intestinal cells  CELL JUNCTIONS  Surfaces of Cells and their Specializations 2. Adhesion junctions  Anchoring junctions that occur just beneath tight junctions.  The transmembrane proteins link together across a small intercellular space.  e.g. cardiac muscle cells  CELL JUNCTIONS  Surfaces of Cells and their Specializations 3. Desmosomes  Small ellipsoidal discs, spot- welds  Intermediate filaments extends into cytoplasm, and transmembrane linker proteins extend through the plasma membrane into the cellular space to bind the discs of adjacent cells.  It increase the strength of tissue.  e.g. skin cells in vertebrates  CELL JUNCTIONS  Surfaces of Cells and their Specializations 4. Hemidesmosomes  Found at the base of cells and anchor them to underlying connective tissue cells.  the transmembrane glycoproteins in hemidesmosomes are integrins rather than cadherins.  CELL JUNCTIONS  Surfaces of Cells and their Specializations 5. Gap junctions  Intercellular communications  Transmembrane proteins, connexins form tiny canals between cells allowing small molecules and ions to pass from one cell to other.  EPITHELIAL TISSUE  Epithelial tissue  Epithelium consists of cells arranged in continuous sheets, in either single or multiple layers. EPITHELIAL TISSUE  EPITHELIAL TISSUE  Major Functions of the Epithelium 1. Selective barriers that limit or aid the transfer of substances into and out of the body. 2. Secretory surfaces that release products produced by the cells onto their free surfaces. 3. Protective surfaces that resist the abrasive influences of the environment.  EPITHELIAL TISSUE  Epithelial tissue  EPITHELIAL TISSUE  Classifications of Epithelial tissue  EPITHELIAL TISSUE  Major Classification of Epithelium EPITHELIAL TISSUE EPITHELIAL TISSUE EPITHELIAL TISSUE EPITHELIAL TISSUE EPITHELIAL TISSUE EPITHELIAL TISSUE EPITHELIAL TISSUE EPITHELIAL TISSUE EPITHELIAL TISSUE EPITHELIAL TISSUE EPITHELIAL TISSUE EPITHELIAL TISSUE EPITHELIAL TISSUE  EPITHELIAL TISSUE  Special Modifications of Epithelial tissue CILIA MICROVILLI STEREOCILIA Motile structures; Uterine Small, non-motile, cover Long, non-motile, branched tubes, Uterus, Conducting absorptive cells in the microvilli in the epididymis and tubes if Respiratory Sys. small intestine vas deferens; absorption  CONNECTIVE TISSUE  Connective tissue  One of the most abundant and widely distributed tissues in the body.  FUNCTIONS: a. It binds together, supports, and strengthens other body tissues; b. Protects and insulates internal organs; c. Compartmentalizes structures; d. Major transport system within the body; e. Stored energy reserves; f. Main source of immune responses.  CONNECTIVE TISSUE General Features: 1. Extracellular matrix  It is secreted by the connective tissue cells and located between its widely spaced cells.  Components: a. Protein fibers b. Ground substances 2. Connective Tissue Cells  Mesodermal embryonic cells called mesenchyme cells give rise to the CTC.  CONNECTIVE TISSUE General Features: 1. CT Extracellular Matrix 1. Ground Substance  It supports cells, bind them together, stores water, and provides medium through which substances are exchanged between the blood and cells.  Components: 1. Glycosaminoglycans (GAGs) a. Hyaluronic acid (WBC, sperm cells, and bacteria - hyaluronidase) b. Chondroitin sulfate (cartilage, bone, skin, blood vessels) c. Dermatan sulfate (skin, tendons, BV, and heart valves) d. Keratan sulfate (cartilage, bone, and cornea) 2. Adhesion proteins  Fibronectin attaches cells to the ground substance.  CONNECTIVE TISSUE General Features: 1. CT Extracellular Matrix 2. Protein Fibers  Strengthen and support CT.  Types: 1. Collagen fibers (bones, cartilage, tendons and ligaments)  Very strong, not stiff which allows tissue flexibility. 2. Elastic fiber (skin, blood vessels, and lung tissue)  Strong and can be stretched up to 150% of their relaxed length, elasticty. 3. Reticular fibers  Provide support (stroma of spleen and lymph nodes) and strength in the walls of blood vessels and form a network around cells.  CONNECTIVE TISSUE General Features: 1. CT Extracellular Matrix 2. Protein Fibers  CONNECTIVE TISSUE General Features: 2. Connective Tissue Cells  Classes of Cells: 1. Immature cells (-blast)  They retain the capacity for cell division and secrete extracellular matrix  e.g fibroblasts – loose and connective tissue chondroblasts – cartilage osteoblast - bones 2. Mature cells (-cyte)  The have reduced capacities for cell division and extracellular matrix formation.  e.g. chondrocytes and osteocytes  CONNECTIVE TISSUE General Features: 2. Connective Tissue Cells  Types of Connective Tissue Cells: 1. Fibroblasts  Large flat cells with branching processes, numerous, capable of migration, and secretes fibers and certain components of ECM. 2. Adipocytes  Found deep to the skin and around organs, store triglycerides. 3. Mast cells  Abundant alongside the blood vessels and produces histamine.  CONNECTIVE TISSUE General Features: 2. Connective Tissue Cells  Types of Connective Tissue Cells: 4. White Blood Cells  They migrate from blood into CT in response to certain conditions.  e.g. Neutrophils and Eosinophils 5. Macrophages  Irregular shape with short branching projections, phagocyting bacteria and cellular debris.  Types: a. Fixed macrophages b. Wandering macrophages  CONNECTIVE TISSUE General Features: 2. Connective Tissue Cells  Types of Connective Tissue Cells: 6. Plasma Cells  Small cells that develop from B lymphocyte.  Important in immune response, secrete antibodies.  Gastrointestinal and respiratory tracts, salivary glands, lymph nodes, spleen, and red bone marrow.  CONNECTIVE TISSUE Types of Connective Tissue 1. Loose Connective Tissue a. Areolar connective tissue b. Adipose connective tissue c. Reticular connective tissue 2. Dense Connective Tissue a. Dense regular connective tissue b. Dense irregular connective tissue c. Elastic connective tissue  CONNECTIVE TISSUE Types of Connective Tissue 1. Loose Connective Tissue  CONNECTIVE TISSUE Types of Connective Tissue 1. Loose Connective Tissue  CONNECTIVE TISSUE Types of Connective Tissue 1. Loose Connective Tissue  CONNECTIVE TISSUE Types of Connective Tissue 2. Dense Connective Tissue  CONNECTIVE TISSUE Types of Connective Tissue 2. Dense Connective Tissue  CONNECTIVE TISSUE Types of Connective Tissue 2. Dense Connective Tissue  SUPPORTIVE TISSUE  Cartilage  It exhibits tensile strength, provides structural support for soft tissue, allows flexibility without distortion, and resilient to compression.  Avascular: antiangiogenesis factor  Components: a. Extracellular matrix (fibers and ground substance) b. Cells (Chrondrocytes and chondroblasts)  SUPPORTIVE TISSUE  Cartilage  SUPPORTIVE TISSUE  Cartilage Perichondrium  a covering of dense irregular connective tissue that surrounds the surface of most cartilage.  It contain blood vessels.  2 Layers: A. Outer fibrous layer – collagen fibers, blood vessels, and fibroblasts B. Inner cellular layer – cells involved in growth of cartilage.  SUPPORTIVE TISSUE  Three Types of Cartilage  SUPPORTIVE TISSUE  Three Types of Cartilage  SUPPORTIVE TISSUE  Three Types of Cartilage SUPPORTIVE TISSUE  SUPPORTIVE TISSUE  Skeletal System  It supports soft tissues, protects delicate structures, and works with skeletal muscles to generate movements. Bones  Components: a. Connective tissue (osseous tissue) b. Periosteum – envelope bones c. Red bone marrow – blood cells production d. Yellow bone marrow – triglyceride storage e. Endosteum – a membrane lining spaces w/n bones storing YBM.  SUPPORTIVE TISSUE Bone Tissue Classification 1. COMPACT BONE  It is an osteon or haversian system.  Parts of the Osteon: 1. Lamellae 2. Lacunae 3. Canaliculi 4. Central (haversian) canal  SUPPORTIVE TISSUE Compact Bone  SUPPORTIVE TISSUE Compact Bone  SUPPORTIVE TISSUE PARTS OF THE OSTEON: 1. Lamellae  Resposible for the compact nature of compact bone  Components: a. Mineral salts b. Collagen fibers 2. Lacunae  Small spaces between lamella containing osteocytes. 3. Canaliculi  Networks of minute canals providing routes for nutrients and wastes. 4. Central (haversian) canal  Contain blood vessels and nerves  SUPPORTIVE TISSUE Bone Tissue Classification 2. SPONGY BONE  It consists of columns of bone called trabeculae.  Composition of the Trabeculae: 1. Lamellae 2. Lacunae 3. Canaliculi 4. Osteocytes  SUPPORTIVE TISSUE Spongy Bone  VASCULAR TISSUE  Blood Tissue  A connective tissue with a liquid extracellular matrix and formed elements.  Functions: 1. Transports oxygen, carbon dioxide, nutrients, hormones, heat, and wastes. 2. Regulates pH, body temperature, and water content of cells. 3. Protect against blood loss through clotting, and against disease through phagocytic white blood cells and antibodies.  VASCULAR TISSUE  Blood Tissue  Components: a. Blood plasma  a pale yellow fluid that consists mostly of water and dissolved substances. b. Formed elements 1. Erythrocytes (RBC) 2. Leucocytes (WBC) 3. Thrombocytes (Platelets) VASCULAR TISSUE VASCULAR TISSUE VASCULAR TISSUE NERVOUS TISSUE  NERVOUS TISSUE  Nervous Tissue Cells: 1. Neuron  A highly specialized cells (sensing, thinking, remembering, controlling muscle activity, and regulating glandular secretions.) 2. Neuroglia  It outnumbered neurons and functions for support, nourishment, protection and maintaining interstitial fluid.  NERVOUS TISSUE  Nervous Tissue Cells:  NERVOUS TISSUE  Nervous Tissue Cells: 1. Neuron  Electrical excitability is the ability to respond to a stimulus and convert it into an action potential.  Action potential is an electric signal that travels along the surface of the neuron membrane.  Parts of a Neuron: 1. Cell body 2. Dendrites 3. Axon  NERVOUS TISSUE  Parts of a Neuron: 1. Cell body  Contains the nucleus surrounded by cytoplasm that includes organelles.  Cytoskeleton includes: a. Neurofibrils for cell shape and support. b. Microtubules which assists in moving materials between the cell body and axon.  Lipofuscin is a pigment of yellowish brown granules.  NERVOUS TISSUE  Parts of a Neuron: 2. Dendrites  Short, tapering, and highly branched.  The receiving or input portions of a neuron.  Their cytoplasm contains Nissl bodies, mitochondria and other organelles  The plasma membrane contain numerous receptor sites for binding chemical messengers form other cells.  NERVOUS TISSUE  Parts of a Neuron: 3. Axon  Single, propagates nerve impulses toward another neuron, a muscle fiber, or a gland cell.  Axon hillock is the cone shaped elevation where the axon is joined to the cell body.  Initial segment is the part of the axon closest to the axon hillock.  Trigger zone is the junction of the axon hillock and initial segment where nerve impulses arise.  NERVOUS TISSUE  Parts of a Neuron: 3. Axon  Cytoplasm: axoplasm, plasma membrane: axolemma.  Axon collaterals are the side branches of axon at right angle.  Axon terminals are the fine processes ends of an axon and collaterals  NERVOUS TISSUE  Structural Classification of Neuron:  NERVOUS TISSUE  Nervous Tissue Cells: 2. Neuroglia  Smaller than neurons, do not generate action potential but can multiply and divide.  NERVOUS TISSUE  Nervous Tissue Cells: 2. Neuroglia A. CNS 1. Astrocytes 2. Oligodendrocytes 3. Microglial cells 4. Ependymal cells B. PNS 1. Schwann cells 2. Satellite cells  NERVOUS TISSUE A. Neuroglia of the CNS 1. Astrocytes  Star-shaped cells have many processes and are the largest and most numerous.  Two types a. Protoplasmic astrocytes  gray matter, short branching b. Fibrous astrocytes  white matter, unbranched  NERVOUS TISSUE  Functions: A. Microfilaments for strength to support neurons. B. Protects neuron from harmful substances from the blood by secreting chemicals that main selective permeability of the endothelial cells. C. Secrete chemicals in the embryo to regulate growth migration and interconnection among neurons. D. Maintain chemical environment for the generation of nerve impulses. E. Learning and memory.  NERVOUS TISSUE A. Neuroglia of the CNS 2. Oligodendrocytes  Oligodendrocytes processes are responsible for forming and maintaing the myelin sheath around CNS axons.  Myelin sheath is a multilayered lipid and protein covering around axons that insulates and increases the speed of nerve impulse conduction. 3. Microglial cells  Function as phagocytes like macrophages removing cellular debris, microbes and damaged nervous tissue.  NERVOUS TISSUE A. Neuroglia of the CNS 4. Ependymal cell  Cuboidal to columnar cells arranged in a single layer that posses microvilli and cilia.  It produces, possibly monitor, and assist in the circulation of cerebrospinal fluid forming the blood-cerebrospinal fluid barrier.  NERVOUS TISSUE B. Neuroglia of the PNS 1.Schwann cells  Schwann cells encircle the PNS axons and forms the myelin sheath around axons..  It participates in axon regeneration. 2. Satellite cells  Flat cells that surround the cell bodies of neuron of PNS ganglia  It provides structural support, regulates the exchanges of materials between neuronal cell bodies and interstitial fluid. NERVOUS TISSUE  MUSCULAR TISSUE  Functions of Muscular Tissue: 1. Producing body movements 2. Stabilizing body positions 3. Storing and moving substances within the body  e.g. Sphincters and cardiac muscle 4. Generating heat MUSCULAR TISSUE MUSCULAR TISSUE  MUSCULAR TISSUE  Properties of Muscular Tissue: 1. Electrical Excitability  The muscle ability to respond to certain stimuli by producing muscle action potentials.  2 types of stimuli trigger action potential: 1. Electrical signals  arising in the muscular tissue itself  e.g. heart 2. Chemical stimuli  e.g. Neurotransmitters and hormones 2. Contractility  The ability of muscular tissue to contract forcefully when stimulated by an action potential.  MUSCULAR TISSUE  Properties of Muscular Tissue: 3. Extensibility  The ability of muscular tissue to stretch, within limits, without being damaged.  e.g. stomach and cardiac muscle 4. Elasticity  The ability of muscular tissue to return to its original length and shape after contraction or extension.  MUSCULAR TISSUE  Components of Muscular Tissue: 1. Muscle fibers (muscle cell)  elongated cells of skeletal muscles.  arises from the fusion of hundred of mesodermal cells called myoblasts. 2. Connective tissue  MUSCULAR TISSUE  Anatomy of Skeletal Muscle Fiber: 1. Sarcolemma, Transverse tubules, and Sarcoplasm  Sarcolemma is the plasma membrane where multiple nuclei are located.  Transverse (T) tubules are tiny invaginations of the sarcolemma.  Sarcoplasm is the cytoplasm of a muscle fiber within the sarcolemma.  Components: a. Glycogen b. Myoglobin  red colored protein; exclusive only in muscle , binds oxygen molecules  MUSCULAR TISSUE  Anatomy of Skeletal Muscle Fiber: 2. Myofibrils and Sarcoplasmic Reticulum  Myofibrils are the contractile organelles of skeletal muscles.  Sarcoplasmic reticulum is a fluid filled system of membranous sacs storing calcium ions..  Terminal cisterns are the dilated end sacs of SR that triggers muscle contractions when calcium are released.  Triad the formed structure of a transverse tubule and the two terminal cisterns.  MUSCULAR TISSUE  Anatomy of Skeletal Muscle Fiber: 3. Filaments and Sarcomere  Myofilaments are smaller protein structures within the myofibrils.  Thin filaments (actin)  Thick filaments (myosin)  Sarcomeres are the basic functional units of myofibrils where thick and thin filaments are compacted.  MUSCULAR TISSUE  Anatomy of Skeletal Muscle Fiber: 3. Filaments and Sarcomere  Zone of overlap is where the thick and thin filaments life side by side. MUSCULAR TISSUE MUSCULAR TISSUE