CHAPTER-3-CELL-AND-TISSUE.pptx-COMPLETE.pptx

Cell and Tissues Here is where your life begins Cell Biology Overview of the Cellular Basic of Life Part 1 Anatomy of Generalized Cell Cell Physiology Part 2 Body Tissues Part 01 Overview of 01...

Cell and Tissues Here is where your life begins Cell Biology Overview of the Cellular Basic of Life Part 1 Anatomy of Generalized Cell Cell Physiology Part 2 Body Tissues Part 01 Overview of 01 the Cellular Basis of Life  It is basic living, structural, Cells and functional unit of the body Cytology It is a branch of science concerned with the study of cells.  Cell Theory Cells 1. A cell is the basic structural and functional unit of living organism. 2. The activity of an organism depends on the collective activities of its cells 3. The activites of cells are dictated by their structure (anatomy), which determines function (Physiology) 4. Continuity of life has a cellular basis 02 Anatomy of a Generalized Cell Parts of the cell Parts of the cell Anatomy of Cells Nuclear Envelope Nucleolus NUCLEUS Chromatin The Headquarters 4 1 nucle = kernel 2 contains the DNA DNA has genes 3 Anatomy of Cells NUCLEUS It is spherical or oval in shape and largest structure in the cell. Has a double membrane that it called the nuclear membrane. NUCLEUS NUCLEAR ENVELOPE Is a double membrane and between the membrane is a fuid - filled called “moat” or space. Allow some substances to pass through it. It encloses a jellylike fluid called the nucleoplasm. NUCLEUS NUCLEOLUS Are sites where cell structures called ribosomes are assembled. Ribosomes eventually migrates into the cytoplasm, where they serve as the actual sites of protein synthesis. NUCLEUS CHROMATIN Is a genetic material comprising of DNA, RNA, and Proteins which result in the formation of chromosomes within the nucleus Scattered around the nucleus Anatomy of Cells PLASMA MEMBRANE The Fluid Mosaic Model Cell Membrane Junctions  Tight Junctions  Desmosomes  Gap Junctions Anatomy of Cells PLASMA MEMBRANE The thin barrier that separates the internal components of the cell from the external environment It is the gate keeper that regulates the passage of substances into and out of the cell. Anatomy of Cells PLASMA MEMBRANE It is made up of lipids and proteins The main lipids are 1. phospolipids 2. cholesterol 3. glycolipids PLASMA MEMBRANE THE FLUID MOSAIC MODEL This phospholipids contains 75% phosphorus These are arranged in lipid bilayer These are AMPHIPATHIC in nature, divided into 2 parts 1. Polar head (hydrophilic) 2. Hydrocarbon Tails (hydrophobic) PLASMA MEMBRANE THE FLUID MOSAIC MODEL PLASMA MEMBRANE Cell Membrane Junction Are the connections between cells and allowing them to communicate with each other. These complexes help anchor cells to each other, as well as the environment called the extracellular matrix. PLASMA MEMBRANE Cell Membrane Junction 3 ways that are cells are bound together: 1. Glycoproteins in the glycocalyx act as adhesive or cellular glue 3. A special cell membrane 2. Wavy contours of the junction are formed. vary membrane of adjacent cells structurally depending on fit together in a tongue like - their roles and - groove fashion PLASMA MEMBRANE Cell Membrane Junction PLASMA MEMBRANE Tight Junctions Impermeable junctions made of the plasma membrane Bind cells together into leakproof sheets Prevent substances from passing through extracellular space between cells PLASMA MEMBRANE Desmosomes Anchoring junctions that prevent cells from being pulled as a result of mechanical stress Created by “buttonlike” thickening of adjacent plasnma membranes PLASMA MEMBRANE Gap Junctions Allow direct diffusion of ions and small molecules between adjacent cells Hollow cylinders of proteins (connexons) function like tunnels to send messages Anatomy of Cells CYTOPLASM Cellular Regions between the nuclear and plasma membranes. Consist of: 1. Cytosol 2. Organelles 3. Inclusions Cytoplasm ORGANELLES Cytoplasm ORGANELLES Mitochondria - Site of aerobic respiration and ATP synthesis; Powerhouse of the Cell Ribosomes - The sites of protein synthesis Cytoplasm ORGANELLES Rough Endoplasmic Reticulum - Sugars groups are attached to proteins within the tunnels. - Proteins are bound in Smooth Endoplasmic vesicle for transport to the Reticulum Golgi apparatus and other - Site of lipid and steroid sites. synthesis, lipid metabolism, and drug detoxification Cytoplasm ORGANELLES Golgi Apparatus - Packages, modifies, and segregates proteins for secretion from the cell, inclusion in lysosomes, or incorporated into the plasma membrane. Cytoplasm ORGANELLES Peroxisomes - Detoxifies the cells such as free radicals - Breaks done hydrogen peroxide into O2 and H2O Lysosomes - The stomach of the cells Cytoplasm ORGANELLES Cytoskeleton - structural organelle - 3 types: 1. Microfilament 2. Intermediate Filament 3. Microtubule Centrioles - Direct cell division via mitotic spindle Cell Extensions Are whiplike cellular extensions that moves Cilia substances along the cell surface. Flagella Are whiplike cellular extensions that moves substances along the cell surface. Cell Extensions Microvilli Are tiny, fiingerlike extensions of the plasma membrane that projects from an exposed cell surface. Anatomy of Cells CELL DIVERSITY Cells that connect body parts Cells that cover and line body organs Cells that move organs and body parts Cell that stores nutrients Cell that fights disease Cell that gathers information and controls body function Cells of reproduction Cell Diversity Cells That Connect Body Parts Fibroblast - is a type of cell that contributes to the formation of connective tissue Cell Diversity Cells that Move Cells that Cover and Organs and Body Line Body Organ Parts Epithelial Cells Muscle Cells -are among the most - is a cell that has abundant cells covering differentiated for the the skin, body cavities, specialized function of and blood vessels. contraction. Cell Diversity Cell that Fights Cell that Stores Disease Nutrients White Blood Cells - The many Fat Cells lysosomes within the - They provide energy cells digest the storage, insulation from infectious extreme temperatures microorganism and cushioning around soft organs Cell Diversity Nerve Cells Cell that Gather - receiving messages Information and and transmitting then to other structures in Controls Body Funtion the body. Gamate Cells of Reproduction - For reproduction 03 Cell Physiolog y Cell Physiology Cells have the ability to: Reproduce Metabolize Grow Digest food Move Dispose of Respond to a wastes stimulus Cell Physiology MEMBRANE TRANSPORT Solution - Homogenous mixture of two or more components Solvent - Dissolving medium: typically water in the body. Solutes - components in smaller quantities within a solution Cell Physiology MEMBRANE TRANSPORT Intracellular Fluid Interstitial Fluid - Nucleosplasm and - Fkuid on the exterior of the cytosol cell - solutions containing - Contains thousands of gases, nutrients, and ingredients, such as salts dissolved in water nutrients, hormones, neurotransmitters, salts, and waste products Cell Physiology MEMBRANE TRANSPORT The plasma membrane is Passive Processes a selectively permeable - No energy is required barrier Active Processes - some materials can - Cell must provide pass through while others metabolic energy are excluded Membrane Transport Passive Processes Diffusion Driving force is the kinetic energy Particles tend to distribute themselves evenly within a solution Molecules Size of molecule and movement: temperature affects the speed of diffusion from high to low concentration Membrane Transport Passive Processes Diffusion Example: - Pour a cup of coffee and drop in a cube of sugar - Do not stir the sugar into the coffee; leave the cup of coffee sitting all day, and it will taste sweet at the end of the day - Molecules move by diffusion and sweeten the entire cup Membrane Transport Passive Processes Diffusion Molecules will move by diffusion if any of the following applies: 1. The molecules are small enough to pass through the membrane’s pores 2. The molecules are lipid - soluble 3. The molecules are assisted by a membrane carrier Passive Proceeses Diffusion Types of 1. Simple Diffusion 2. Osmosis Diffusion 3. Facilitated Diffusion Simple Diffusion - An unassisted process - Solutes are lipid - soluble or small enough to pass though membrane pores Passive Proceeses Diffusion Osmosis Simple diffusion of water Highly polar water molecules easily cross the plasma Water moves down its concentration gradient Solutions: 1. Isotonic 2. Hypertonic 3. Hypotonic Passive Proceeses Diffusion Facilitated Assisted with membrane proteins - channels and carriers Diffusion Transports lipid - insoluble and large substances Glucose is transported via facilitated diffusion Protein membrane channels or protein molecules that act as carriers are used Membrane Transport Passive Processes Filtration Pressure gradient must exist Water and solutes are forced through a membrane by fluid or hydrostatic pressure Movement: Filtration is critical for the From high pressure area to kidneys to work properly lower pressure area Membrane Transport Active Processes Types of Active 1. Active Transport Processes 2. Vesicular Transport Sometimes called the solute pumping ATP is used for transport Require protein carriers to trasnport subtances that: 1. large to travel through membrane channels 2. May not be lipid - soluble 3. May have to move against a concentration gradient Active Processes Active Transport Called solute pumping ATP energizes solute pump Amino acid, some sugars, and ions are transported by protein carriers known as solute pimps In most cases, substances are moved against concentration (or electrical) gradients Active Processes Vesicular Transport Substances are moved without actually crossing the plasma membrane Types: 1. Exocytosis 2. Endocytosis Active Processes Vesicular Transport Exocytosis Moves materials out of the cell Material is carried in a membranous sac called a vesicle Vesicle migrates to plasma membrane Vesicle combines with plasma membrane Material is empties to the outside Active Processes Vesicular Transport Endocytosis 1. Phagocytosis Types: 2. Pinocytosis 3. Receptor - Mediated Endocytosis Extracellular substances are engulfed by being enclosed in membranous vescicle Vesicle typically fuses with a lysosome Active Processes Vesicular Transport Phagocyctosi s “cell eating” Cell engulfs large particles such as bacteria or dead body cells Active Processes Vesicular Transport Pinocytosis “cell drinking” Cell “gulps” droplets of extracellular fluid containing dissolved proteins or fats Active Processes Vesicular Transport Receptor - Mediated Endocytosis Method for taking up specific target molecules Cell Physiology CELL DIVISION Cell life cycle is a series of changes the cell experiences from the time it is formed until it divides Cycle has two major periods 1. Interphase 2. Cell Division Cell grows Cell replicates itself Cell carries on metabolic processes Cell Division Preparation: DNA Replication Genetic material is duplicated and readies a cell for a division into two cells Occurs toward the end of interphase DNA Replication Preparation: DNA Replication DNA uncoils into two nucleotid chains, and each side nerves has a template Nucleotides are complementary Adenine (A) always bonds with thymine (T) Guanine (G) always bonds with cytosine (C) For example, TACTGC bonds with new nucleotides in the order ATGACG DNA Replication Events of Cell Division Mitosis-division of the nucleus Results in the formation of two daughter nuclei Cytokinesis-division of the cytoplasm Begins when mitosis is near completion Results in the formation of two daughter cells Events of Cell Division Stages of Mitosis Prophase First part of the cell division Chromatin coils into chromosomes Chromosomes are held together by a centromere A chromosome has two strands Each strand is called a chromatid Events of Cell Division Stages of Mitosis Events of Cell Division Stages of Mitosis Prophase Centrioles migrate to the poles to direct assembly of mitotic spindle fibers Mitotic spindles are made of microtubules Spindle provides scaffolding for the attachment and movement of the chromosomes during the later mitotic stages Nuclear envelope breaks down and disappears Events of Cell Division Stages of Mitosis Events of Cell Division Stages of Mitosis Metaphase Chromosomes are aligned in the center of the cell on the metaphase plate Metaphase plate is the center of the spindle midway between the centrioles Straight line of chromosomes is now seen Events of Cell Division Stages of Mitosis Events of Cell Division Stages of Mitosis Anaphase Centromere splits Chromatids move slowly apart and toward the opposite ends of the cell Anaphase is over when the chromosomes stop moving Events of Cell Division Stages of Mitosis Events of Cell Division Stages of Mitosis Telophase Reverse of prophase Chromosomes uncoil to become chromatin Spindles break down and disappear Nuclear envelope reform around chromatin Nucleoli appear in each of the daughter nuclei Events of Cell Division Stages of Mitosis Events of Cell Division Stages of Mitosis Cytokinesis Division of the cytoplasm Begins during the late anaphase and completes during telophase A cleavage furrow forms to pinch the cells into two parts Cleavage furrow is a contractile ring made of microfilaments Events of Cell Division Stages of Mitosis Two daughter cells exist at the end of cell division In most cases, mitosis and cytokinesis occur together In some cases, the cytoplasm is not divided Binucleate or multinucleate cells result Common in the liver Mitosis gone wild is the basis for tumors and cancers Events of Cell Division Stages of Mitosis Cell Physiology PROTEIN SYNTHESIS DNA serves as a blueprint for making proteins Gene: DNA segment that carries a blueprint for building one protein or polypeptide chain Proteins have many functions Fibrous (structural) proteins are the building materials for cells Globular (functional) proteins act as enzymes (biological catalysts Cell Physiology PROTEIN SYNTHESIS DNA information is coded into triplets Triplets Contain three bases Call for a particular amino acid For example, a DNA sequence of AAA specifies the amino acid phenylalanine Cell Physiology Role of RNA Most ribosomes, the manufacturing sites of proteins, are located in the cytoplasm DNA never leaves the nucleus in interphase cells DNA requires a decoder and a messenger to build proteins, both are functions carried out by RNA (ribonucleic acid) Cell Physiology Role of RNA How does RNA differ from DNA? RNA: Is a single-stranded Contains ribose sugar instead of deoxyribose Contains uracil (U) base instead of thymine (T) Protein Synthesis Role of RNA Transfer RNA (tRNA) Transfer appropriate amino acids to the ribosome for building the protein Ribosomal RNA (rRNA) Helps form the ribosomes where proteins are built Messenger RNA (mRNA) Carries the instructions for building a protein from the nucleus to the ribosome Protein Synthesis Role of RNA Protein synthesis involves two major phase Transcription Translation We will detail these two phases next Protein Synthesis Transcription Transfer of information from DNA’s base sequence to the complementary base sequence of mRNA Only DNA and mRNA are involved Triplets are the three-base sequence specifying a particular amino acid on the DNA gene Codons are the corresponding three-bases sequences of mRNA Protein Synthesis Transcription Example of transcription: DNA triplets AAT-CGT-TCG mRNA codons UUA-GCA-AGC Protein Synthesis Translation Base sequence of nucleic acid is translated to an amino acid sequence Amino acids are the building blocks of proteins The Role of RNA Protein Synthesis Translation mRNA leaves nucleus and attaches to ribosome, and translation begins Incoming tRNA recognizes a complementary mRNA codon calling for its amino acis by binding via its anticodon to the codon. The Role of RNA Protein Synthesis Translation As the ribosome moves along the mRNA, a new amino acid is added to the growing protein chain. Released tRNA reenters the cytoplasmic pool, ready to be charged with new amino acid. The Role of RNA  Part 02 Body Tissues  Body Tissues Four primary types: Epithelial tissue (epithelium) Connective tissue Muscle tissue Nervous tissue EPITHELIAL TISSUE Locations: Body Coverings Body linings Functions: Gladular tissue Protection Absorption Filtration Secretion Epithelium Characteristics Cells fits closely together and often form sheets The apical surface is the Avascular (no blood free surface of the tissue supply) The lower surface of the Regenerate easily if epithelium rests on a well rounded basement membrane Classification of Epithelia 2 Indicators Simple CELL LAYERS Stratified Squamous SHAPE Cuboidal Columnar Simple Epithelia Simple squamous Single layer of flat cells Location-usually forms membranes Lines air sacs of the lungs Forms walls of capillaries Forms serous membranes (serosae) that line and cover organs in vetral cavity Functions in diffusion, filtration, or secretion in membranes Simple Epithelia Simple Epithelia Simple cuboidal Single layer of cube-like cells Locations: Common in glands and their ducts Forms walls of kidney tubules Covers the surface of ovaries Function in secretion and absorption; ciliated types propel mucus or reproductive cells Simple Epithelia Simple Epithelia Simple columnar Single layer of tall cells Goblet cells secrete mucus Location: Line digestive tract from stomach to anus Mucous membranes (mucosae) line body cavities opening to the exterior Functions in secretion and absorption; ciliated types propel mucus or reproductive cells Simple Epithelia Simple Epithelia Pseudotratified columnar All cells rest on a basement membrane Single layer, but some cells are shorter than others giving a false (pseudo) impression of stratification Location: Respiratory tarct, where it is ciliated and known as pseudotratified ciliated columnar epithelium Functions in absorption or secretion Simple Epithelia Stratified Epithelia Stratified squamous Named for cells present at the free (apical) surface, which are flattened Functions as a protective covering where frictions is common Locations-lining of the: Skin(outer portion) Mouth Esophagus Stratified Epithelia Stratified Epithelia Stratified cuboidal two layers of cuboidal cells; functions in protection Stratified columnar surface cells are columnar, and cells underneath vary in size and shape; functions in protection Stratified cuboidal and columnar Rare in human body Found mainly in ducts of large glands Stratified Epithelia Transitional epithelium Composed of modified stratified squamous epithelium Shape of cells depends upon the amount of stretching Functions in stretching and the ability to return to normal shape Locations: urinary system organs Stratified Epithelia Glandular Epithelium Gland One or more cells responsible for secreting a particular product Secretions contain protein molecules in an aqueous (water-based) fluid Secretion is an active process  Glandular Epithelium Two major gland types Endocrine gland Ductless; secretions diffuse into blood vessels All secretions are hormones Examples include thyroid, adrenals, and pituitary Glandular Epithelium Two major gland types Exocrine gland Secretions empty through ducts to the epithelial surface Include sweat and oil glands, liver, and pancreas Includes both internal and external glands CONNECTIVE TISSUE Found everywhere in the body Includes the most abundant and widely distributed tissues Functions: Provides protection Binds body tissues together Supports the body CONNECTIVE TISSUE Characteristics Variations in blood supply Some tissue type are well vascularized Some have a poor blood supply or are avascular Extracellular matrix Nonliving material that surrounds living cells CONNECTIVE TISSUE Extracellular matrix Two main elements Ground substance-mostly water along with adhesion proteins and polysaccharide molecules Fibers Produced by the cells Three types Collagen (white) fibers Elastic (Yellow) fibers Reticular fibers (a type of collagen) CONNECTIVE TISSUE TYPES From most rigid to softest, or most fluid: Bones Cartilage Dense connective tissue Loose connective tissue Blood CONNECTIVE TISSUE TYPES Bone (osseous tissue) Composed of: Osteocytes (bone cells) sitting in lacunae (cavities) Hard matrix of calcium salts Large numbers of collagen fibers Functions to protect and support the body CONNECTIVE TISSUE TYPES CONNECTIVE TISSUE TYPES Cartilage Less hard and more flexible than bone Found in only a few places in the body Chondrocyte (cartilage cell) is the major cell type CONNECTIVE TISSUE TYPES Hyaline Cartilage Most widespread type of cartilage Composed of abundant collagen fibers and a rubbery matrix Locations: Larynx Entire fetal skeleton prior to birth Epiphyseal plates Functions as a more flexible skeletal element than bone CONNECTIVE TISSUE TYPES CONNECTIVE TISSUE TYPES Elastic Cartilage Provides elasticity Location: Supports the external ear Fibrocartilage Highly compressible Location Forms cushionlike discs between vertebrae of the spinal column CONNECTIVE TISSUE TYPES CONNECTIVE TISSUE TYPES Dense connective tissue (dense fibrous tissue) Main matrix element is collagen fiber Fibroblasts are cells that make fibers Locations: Tendons-attach skeletal muscle to bone Ligaments-attach bone to bone at joints and are more elastic than tendons Dermis- lower layers of the skin CONNECTIVE TISSUE TYPES  CONNECTIVE TISSUE TYPES Loose connective tissue types Areolar tissue Most widely distributed connective tissue Soft, pilable tissue like “cobwebs” Functions as a universal packing tissue and “glue” to hold organs in place Layer of areolar tissue called lamina propria underlies all membrane All fiber types form a loose network Can soak up excess fluid (causes edema) CONNECTIVE TISSUE TYPES CONNECTIVE TISSUE TYPES Loose connective tissue types Adipose tissue Matrix is an areolar tissue in which fat globules predominate Many cells contain large lipid deposits with nucleus to one side (signet ring cells) Functions Insulates the body Protects some organs Serves as a site of fuel storage CONNECTIVE TISSUE TYPES CONNECTIVE TISSUE TYPES Loose connective tissue types Reticular connective tissue Delicate network of interwoven fibers with reticular cells (like fibroblasts) Locations: Forms stroma (internal framework) of organs, such as these lymphoid organs: Lymph nodes Spleen Bone marrow CONNECTIVE TISSUE TYPES CONNECTIVE TISSUE TYPES Blood (vascular tissue) Blood cells surrounded by fluid matrix as blood plasma Soluble fibers are visible only during clotting Functions as the transport vehicle for the cardiovascular system, carrying: Nutrients Wastes Respiratory gases CONNECTIVE TISSUE TYPES MUSCLE TISSUE Function is to contract, or shorten, to produce movements Three types: Skeletal muscle Cardiac muscle Smooth muscle MUSCLE TISSUE Skeletal muscle Voluntarily (consciously) controlled Attached to the skeleton and pull on bones or skin Produces gross body movements or facial expressions Characteristics of skeletal muscle cells Striations (stripes) Multinucleate (more than one nucleus) Long, cylindrical shape MUSCLE TISSUE MUSCLE TISSUE Cardiac muscle Involuntarily controlled Found only in the heart Pumps blood through blood vessels Characteristics of cardiac muscle cells Striations Uninucleate, short, branching cells Intercalated discs contain gap junctions to connect cells together MUSCLE TISSUE MUSCLE TISSUE Smooth (visceral) muscle Involuntarily controlled Found in walls of hollow organs such as stomach, uterus, and blood vessels Peristalsis, a wavelike activity, is a typical activity Characteristics of Smooth muscle cells No visible striations Uninucleate Spindle-shaped cells MUSCLE TISSUE NERVOUS TISSUE Composed of neurons and nerve support cells Function is to receive and conduct electrochemical impulses to and from body parts Irritability Conductivity Support cells called neuroglia insulate, protect, and support neurons NERVOUS TISSUE TISSUE REPAIR (WOUND HEALING) Occurs in two ways Regeneration Replacement of destroyed tissue by the same kind of cells Fibrosis Repair by dense (fibrous) connective tissue (scar tissue) TISSUE REPAIR (WOUND HEALING) Whether regeneration or fibrosis occurs depends on: Type of tissue damaged Severity of the injury Clean cuts (incisions) heals more successfully than ragged tears of the tissue EVENTS IN TISSUE REPAIR Inflammation Capillaries become very permeable Clotting proteins migrate into the area from the bloodstream A clot walls oof the injured area Granulation tissue forms Growth of new capillaries Phagocytes dispose of blood clot and fibroblasts Rebuild collagen fibers EVENTS IN TISSUE REPAIR Regeneration of surface epithelium Scab detaches Whether scar is visible or invisible depends on severity of wound Regeneration of Tissues Tissues that regenerate easily Epithelial tissue (skin and mucous membranes) Fibrous connective tissues and bone Tissue that regenerate poorly Skeletal muscle Tissue that are replaced largely with scar tissue Cardiac muscle Nervous tissue within the brain and spinal cord Developement Aspect of Cells and Tissues Growth through call division continues through puberty Cell populations exposed to friction (such as epithelium) replace lost cells throughout life Connective tissue remains mitotic and forms repair (scar) tissue With some exceptions, muscle tissue becomes amitotic by the end of puberty Nervous tissues becomes amitotic shortly after birth. Developement Aspect of Cells and Tissues Injury can severly handicap amitotic tissues The cause of aging is unknown, but chemical and physical insults, as well as genetic programming, have been proposed as possible causes Developement Aspect of Cells and Tissues Neoplasms, both benign and cancerous, represent abnormal cell masses in which normal controls on cell division are not working Hyperplasia (increase in size) of a tissue or organ may occur when tissue is strongly stimulated or irritated Atrophy (decrease in size) of a tissue or organ occur when the organ is no longer stimulated normally THANK YOU ^_^