Presentation is loading. Please wait.

Presentation is loading. Please wait.

INTRODUCTION TO CELLS & TISSUES By Vijay Kapal

Similar presentations


Presentation on theme: "INTRODUCTION TO CELLS & TISSUES By Vijay Kapal"— Presentation transcript:

1 INTRODUCTION TO CELLS & TISSUES By Vijay Kapal
Graduate Studies Course CMM 5001 The Pathological Basis Of Disease

2 Fertilization Fertilization of egg by the sperm Egg + Sperm Sperm
(23 Chromo) (23 Chromo) Fertilized egg (Zygote) (46 Chromosomes) Human body Sperm Ovum (Egg) Sperm Zygote

3 Implantation Zygote Blastocyst Uterus Uterine glands
Maternal blood vessels

4 3-layered Flat Embryo Ectoderm (1) Mesoderm (3) Endoderm (2)
Fertilized egg or Zygote (Single cell) 3-layers of cells All Tissues & Organs of Human body

5 Human Genome Nucleus Cytoplasm Cell membrane Cell
Each cell has 46 chromosomes Form 23 homologous pairs Each parent contributes = 23 Autosomes = 44 Sex chromosomes = 2 (Male = XY, Female = XX) Chromosomes (2N = 46) Each autosome of a homologous pair look alike But each sex chromosome do not look alike

6 Cell Cycle Paclitaxel Vincristine Vinblastine Colchicine
Nondividing cells (Fixed postmitotics) M G0 Resting cells (Reverting postmitotics) G1 G2 Bleomycin Etoposide S Methotrexate

7 Mitosis & Meiosis A Homologous Pair (2 Chromosomes) 1 2 46 1 pair
1st Division 2nd Division Daughter Somatic Cells (2) Gametes (4)

8 Meiosis 2N = 46 chromosomes (2 sets) 1N = 23 chromosomes (1set)
Takes place only in testes and ovaries Is a reductional division Main purpose is to reduce the number of chromosomes from 2N to 1N in sperms & eggs (Chromosomes of each homologous pair will separate from each other) Homologous pair = 1 chromosome from each parent (at fertilization) 2N = 46 chromosomes (2 sets) 1N = 23 chromosomes (1set) So Sperm = 1N chromosomes (23) Egg = 1N chromosomes (23) Fertilization restores chromosome number again to 2N = 46 chromosomes (2 sets)

9 Human Body Cells Tissues Organs Human body Cell Tissue

10 Cell Organelles Nucleus Chomatin, Transcription
Rough ER Protein synthesis & Segregation Smooth ER Fat & Steroid synthesis & Detoxification Golgi Complex Concentrating, Modifying & Packaging of secretory products Lysosomes Intracellular digestion Peroxisomes Contain oxidative enzymes; Use catalase to degrade H2O2 = H2O + O2 Mitochondria Oxydative phosphorylation & ATP production Cell Membrane Lipid bilayer layer with intramembranous proteins Cell cytoskeleton Actin filaments, Microtubules, intermediate filaments

11 Cell Organelles Mitochondria Lysozome Golgi Nucleus Rough ER

12 Cells, Tissues & Various Topics Of Research
Subcellular localisation & trafficking of molecules and oganelles Cell-cell and cell-extracellular matrix interactions Cell cytoskeleton and receptor dynamics and functions Cell and tissue differentiation and remodelling Genetically engineered cells and tissues Three-dimensional reconstructions, particularly of expression patterns over time Cell cycle and cell lineage analysis involving gene expression profiles Apoptosis Gene expression analysis from histological preparations Functional genomics & proteomics Techniques used in molecular histology

13 Epithelial Tissue Outer layer of skin Inner lining of trachea
Inner lining of ducts of sweat glands

14 General Features Diversity Metaplasia Lining and Covering Basal Lamina
Renewal Avascularity Cell Packing Derivation

15 Classifying Principles
1. Number of cell layers: 1. Simple epithelia 2. Stratified epithelia 3. Pseudostratified epithelia 2. Shape of the surface cells: 1. Squamous cells 2. Cuboidal cells 3. Columnar cells 3. Luminal surface modifications: 1. Microvilli (Brush border) 2. Cilia 3. Stereocilia

16 Specific Epithelial Types
Simple squamous epithelium: Simple cuboidal epithelium: Simple columnar epithelium: Pseudostratified epithelium: Stratified Squamous epithelium: a) Keratinized b) Nonkeratinized Stratified cuboidal epithelium: Stratified columnar epithelium: Transitional epithelium:

17 Types of Epithelia Simple squamous Stratified squamous Transitional
Simple cuboidal stratified cuboidal Full Empty Bladder Simple columnar Pseudostratified

18 Kidney (Epithelium) Simple squamous Simple cuboidal Kidney Tubules

19 Small Intestine (Simple Columnar)
Absorptive cells Nucleus Brush border Lamina propria Lumen of gut

20 Esophagus (Stratified Squamous)
Epithelium Lamina propria

21 Skin (Stratified Squamous)
Epidermis (Epithelium) Dermis (Connective tissue)

22 Trachea (Pseudostratified Epithelium)
Cilia Ciliated cells Goblet cells Basal lamina Lamina propria

23 Ureter (Transitional Epithelium)
Lumen Basal lamina Lamina propria

24 Basal Lamina Next to epithelia an acellular sheet like structure is the Basal Lamina. Component Layers & Constinuent Macromolecules: A. Component Layers Lamina lucida Lamina densa B. Constituent Macromolecules Lamina lucida (Laminin that binds to cell surface integrins, collagen IV) Lamina densa (Type IV Collagen) Basement Membrane: Basal lamina accompanied by reticular lamina (Type III Collagen) is called the basement membrane. Functions: Forms sieve-like selective barrier between the epithelia & connective tissue. Aids in cell organization, cell adhesion & maintainence of cell shape. Has a role in maintaining specific cell function. Helps guide migrations of cells during development and regeneration of injured tissue

25 Polarity & Specialization of Epithelial Cells
Specialization of the Apical Surface: 1. Microvilli (Enterocytes & Proximal convoluted tubule cells)) 2. Cilia (Trachea, Bronchus etc.) 3. Stereocilia (Epididymis) 4. Flagella Specialization of the Lateral Surfaces: 1. Zonula occludens (Tight junctions) 2. Zonula adherens (Intermediate junctions) 3. Macula adherens (Desmosomes) 4. Gap junction (Nexus) Specialization of the Basal Surface: 1. Basal lamina 2. Hemidesmosome 3. Sodium-potassium ATPase D. Intracellular Polarity:

26 Cell Junctions Microvilli Zonula occludens Zonula adherens
Terminal web Macula adherens Gap junction Nucleus Hemidesmosome

27 Mucous Membranes Components of Mucous Membrane: 1. Epithelium
2. Basement membrane 3. Lamina propria

28 Mucous Membrane Epithelium Basal lamina Lamina propria

29 Serous Membranes Components of Serous Membrane:
1. Epithelium called mesothelium 2. Basement membrane 3. Submesothelial connective tissue layer

30 Functions of Epithelia
1. Protection from: Mechanical trauma Dehydration Pathogens Secretion of: Hormones, milk, sweat etc. Enzymes, HCl, glycoproteins, Mucous & serous products Lubrication of: Contents of GI tract Fetus in birth canal Joints 4. Filtration of wastes: (Urine) Absorption of food: (Aminoacids, Glucose, Fatty acids) Neuroepithelium: (Taste, Smell, Hearing) Reproduction: (Germ cells)

31 Major Types of Epithelial Cells
Epithelial Cells Specialized for Transport: 1. Ion-transporting cells (Kidney tubules, Gall bladder etc.) 2. Cells that transport by pinocytosis (Endothelial cells of blood capillaries Absorption: (Enterocytes, Proximal convoluted tubule cells) Secretion: 1. Protein-secreting cells (Acinar cells of pancreas, Hepatocytes) 2. Polypeptide-secreting cells (APUD cells) 3. Mucous cells (Goblet cells) 4. Serous cells (Acinar cells of pancreas & secretory cells of parotid salivary glands. 5. Steroid-secreting cells (Adrenal cortex, Leydig cells etc.) D. Contractile Epithelial Cells: (Myoepithelial cells of glands)

32 GLANDS Exocrine & Endocrine Glands: Classification of Exocrine Glands:
1. By structure: a) Number of cells b) Duct system c) Secretory portion 2. By secretory product a) Mucous secretion b) Serous secretion c) Seromucous secretion 3. By mode of secretion a) Merocrine b) Apocrine c) Holocrine

33 Unicellular Multicellular Simple tubular Coiled tubular Branched
Simple branched Simple acinar Compound tubular Compound tubulo-alveolar

34 Salivary Glands Mucous acini Serous acini

35 Mode of Secretion Active transport Merocrine Apocrine Holocrine Endocrine

36 Connective Tissue Fat Fat cells Tanden Fibroblasts Bone Osteocytes

37 Connective Tissue Is one of the 4 basic tissues of the body.
Structurally it is made up of cells and large amount of intercellular space containing extracellular matrix. Matrix is the dominating component of this tissue. It forms framework, connecting, supporting and packing tissue of the body. It also plays a dynamic role in the development, growth and homeostasis of other tissue types.

38 Connective Tissue Loose connective tissue Dense connective tissue
Fibroblasts Extracellular matrix Epithelial tissue Mammary Glands

39 Composition Cells Extracellular matrix

40 Types of Cells in Loose Connective Tissue
Residents: Fibroblasts Macrophages Reticular cells Mesenchymal cells Visitants: Mast cells Plasma cells Leukocytes Fat cells Melanocytes

41 Loose Connective Tissue
Elastic fibers Capillary Neutrophil Plasma cell Fibroblast Collagen fibers Macrophage Adipocyte Mast cell Lymphocyte

42 Fibroblast (Ultrastructure)
Nucleus Rough ER Collagen Extracellular matrix

43 Collagen Producing Cells
Fibroblast-More than one type of collagen Chondroblast- Type II collagen Osteoblast-Type I Reticular cell- Type III Smooth muscle-Type I & III

44 Extracellular Matrix Extracellular matrix (Fibers & Ground substance) is synthesized and secreted mainly by the fibroblasts & the fibers are assembled in the extracellular space. Fibers Prime function is support & plays strengthing role in Ground substance Functions are 1. Acts as a molecular sieve & stops the spread of noxious substances 2. Plays very important role in cellular nutrition & waste removal 3. Plays a vital role in aging. Its amount diminishes with age and wrinkles start appearing.

45 Fiberous Components Connective tissue fibers are long, slender protein polymers that are present in variable proportions in different types of connective tissue. In many cases the predominant fiber type is responsible for conferring specific properties on the tissue. Collagen Fibers: Elastic Fibers: Reticular Fibers:

46 Collagen Fibers Collagen Fibers: Most abundant protein in the body.
Synthesis & assembly: Collagen types- Type I- most abundant & occurs in loose and dense connective tissue & bone. Type II- occurs in cartilage. Type III- occurs in hematopoitic tissues. Type IV- occurs in basal laminae & does not form fibers or fibrils. Type V- in placental basement membranes & blood vessels. Type X- around hypertrophic, degenerating chondrocytes of the growth plate where bone formation is to occur.

47 Synthesis of Collagen Fibroblast Procollagen (Triple-helical units)
Collagen’s main amino acids Glycine (34%) Proline (12%) Hydroxyproline (10%) Fibroblast Procollagen (Triple-helical units) Procollagen peptidase Tropocollagen Collagen fibril Collagen fiber Intracellular Extracellular

48 Ground Substance Proteoglycans: Glycoproteins: Tissue fluids: Salts:
They are made up of a core protein to which glycosoaminoglycans (GAGs) are attached. GAGs are polysacharides that contain aminosugars. GAGs-Chondroitin sulphate, Dermatan sulphate, Keratan sulphate & Heparin sulphate. Hyaluronic acid is a GAG but do not form proteoglycans. Matrix viscosity and rigidity are determined by the amount and types of GAGs, their association with the core protein to form proteoglycans, GAG-fiber association, and GAG-GAG associations. Glycoproteins: Fibronectin-mediates the attachment of cells to the extracellular matrix. Laminin-a component of basal laminae that mediates the attachment of epithelial cells. Tissue fluids: Salts:

49 Connective Tissue Types
A. Connective Tissue Proper: 1. Loose connective tissue 2. Dense connective tissue a) Dense regular connective tissue b) Dense irregular connective tissue Reticular connective tissue: Elastic connective tissue: Mucous connective tissue:

50 Connective Tissue Proper
A. Connective Tissue Proper: 1. Loose connective tissue (lamina propria) 2. Dense connective tissue a) Dense regular connective tissue (Tendon, ligament) b) Dense irregular connective tissue (Dermis, organ capsule) Loose CT Dense CT

51 Elastic Connective tissue
Elastic fibers consist of an amorphous protein called elastin and numerous protein microfibrils embedded in it. Diameter range um. Elastic fibers are collected in thick, wavy, parallel bundles & seperated by loose collagenous tissue with fibroblasts. Ground substance is sparse. Elastic connective tissue provides flexible support. Predominates in the ligamentum flava of the vertebral column & the suspensory ligament of the penis.

52 Reticular Connective Tissue
These fibers look very similar to collagen but are thinner than them ( um). More highly glycosylated. Form delicate silver-staining network instead of thick bundles. Composed mainly of type III collagen and some glycoprotein. These fibers are covered by long processes of the reticular cells. There is very little ground substance. Reticular connective tissue supports motile cells & filters body fluids. It is found mainly in hematopoietic tissue (bone marrow, spleen and lymph nodes).

53 Reticular Connective Tissue
Reticular cell Nu Reticular fibers Lymphocyte Reticular cells Lymph Node

54 Mesenchyme Mesenchyme is embryonic connective tissue.
Its stellate and fusiform cells (mesenchymal cells) are derived from mesoderm. They give rise to all the connective tissue of of the body. These are multipotential cells and persist in adults to give rise to new generations of connective tissue cells especially during wound healing, bone repair and tissue fibrosis.

55 Mesenchymal Tissue (Embryo)
Neural tube Mesenchyme Somite Notochord Neural tube Extracellular matrix Mesenchymal cells

56 Histophysiology A. Functions: 1. Support. 2. Defense. a) Physical
b) Immunologic 3. Repair. 4. Storage. 5. Transport Edema: Hormonal Effects: Nutritional Factors: Collagen Renewal:

57 Special Types of Connective Tissues
Adipose tissue Blood & lymph Cartilage Bone

58 Blood

59 White Blood Cells (Granulocytes)
Neutrophil Eosinophil Basophils Functions:- Neutrophils act as first line of defense in infections. Eosinophils respond to allergic states & parasitic infection Basophils release heparin & histamine

60 Defense System Facilitate ADAPTIVE DEFENSES (Requires immunization)
INNATE DEFENSES (Do not require immunization) Physical barriers Chemical barriers Soluble factors (Skin, mucous membranes) Directly kill infected cells T lymphocytes B lymphocytes (Low pH, Mucous) Cytotoxic (Lysosomes, Interferons, Acute phase proteins, Complements) Help Facilitates CELLS (Macrophages, Granulocytes) ANTIBODIES Facilitate Delayed response Highly flexible Highly specific Memory, lasting immunity Fast response Limited Flexibility Non-specific No memory

61 Mast Cells Mast cells Functions:- Produce heparin, an anticoagulant
Produce histamine to render blood vessels permeable

62 Monocytes Nucleus Cytoplasm Nucleus Cytoplasm Phagocytized RBC Nucleus

63 LYMPHOCYTES B Lymphocytes deliver antibodies-mediated immune response
T lymphocytes deliver cell-mediated immune response Natural killer cells kill tumor & nonself cells

64 Plasma Cells Plasma cells Lymphocyte
Plasma cells produce antibodies to fight the infections Immunoglobulins IgG, IgA, IgM, IgE & IgD

65 Macrophage Macrophage Functions:-
Phagocytose, process & present antigens to lymphocytes Act as scavengers etc.

66 Unilocular Adipose Tissue
Adipocytes Nucleus

67 Multilocular Adipose Tissue

68 Cartilage Perichondrium Chondroblasts Chondrocytes Lacuna
Cartilage matrix Isogenous group of chondrocytes

69 Primary Bone Periosteum Osteoblasts Osteocytes Bone matrix
Bone trabecula

70 Nervous Tissue Cerebellum Spinal cord Spinal ganglion Cortical neurons
Motor neurons Spinal ganglion Sensory neurons

71 Divisions of the Nervous System
Central Nervous System (CNS) Peripheral Nervous System (PNS) Autonomic Nervous System (ANS)

72 Nervous System

73 General Features Two Classes of Cells: 1. Neurons 2. Supporting cells
Impulse Conduction: Synapses: Divisions of the Nervous System: Embryonic Development of Nervous Tissue: Aging and Repair: Meninges: Blood-Brain barrier:

74 Cells of the Nervous Tissue
Two Classes of Cells: 1. Neurons. 2. Supporting, neuroglial or glial cells.

75 Neurons Cell Body Dendrites Axon Classification of Neurons

76 Neuron

77 Neuromuscular Junction
Skeletal muscles Motor end plate Axon

78 Neuron Blood capillary Glial cells Dendrites Nissl bodies Axon hillock
Nucleus Nucleolus Myelinated axons

79 Neuron (Cell body) Cell Body: -It is also called soma or perikaryon
-It is the synthetic & trophic center of cell -It can receive signals from axons of other neurons through synaptic contacts on its cell membrane and relay them to its axon -Nucleus usually large, central, spherical and euchromatic -Nucleus with prominent nucleolus -Cytoplasm contains many organelles like mitochondia, lysosomes etc. -Cytoplasm has abundant free polyribosomes & rough endoplasmic reticulum, appears as basophilic purplish-blue clumps called Nissl bodies -Well developed Golgi to pack & often glycosylates neurotransmitters in neurosecretory, or synaptic vesicles -Abundant neurotubules (microtubules) & neurofilaments (intermediate filaments) in soma, dendrites & axon

80 Neuron (Dendrites) Dendrites: -Extensions of cell body, specialized to
increase the surface area for incoming signals -Synaptic contacts are made on them -Some synaptic sites on them look like sharp projections called dendritic spines gemmules -Proximal ends has some Nissl bodies

81 Neuron (Axon) Axon: -One axon per neuron, its cytoplasm called axoplasm & its plasma membrane, the axolemma. -A complex cell process (uniform diameter) carries impulses away from the soma. -The part of the cell body where axon exits the soma is called the axon hillock and it lacks Nissl bodies. -Axon can be myelinated or unmyelinated. -Myelin sheath in CNS is provided by the oligodendrocyte , while in PNS by the Schwann cell -Axon diameter & myelin thickness determines the speed of nerve impulse. Internode (Myelin –covered) & Node (without myelin) Some axons have branches called collaterals. -Terminal branching of axon is called terminal arborization. -Each branch ends as a bulb-like sac called terminal bouton, each bouton contains many mitochondria & neurosecretory vesicles. Specialized region of plasma membrane of bouton that take part in the formation of synapse is called as presynaptic membrane.

82 Nerve (Myelinated axons)
Perineurium Endoneurium Nodes of Ranvier Axon Myelin

83 Myelinated Axon (E.M.) Neurilemma Myelin Axoplasm Node of Ranvier

84 Synapses (Chemical) Synapses are specialized junctions by which a stimulus is transmitted from a neuron to its target cell. 1. Presynaptic Membrane: This is part of plasma membrane of terminal bouton. 2. Synaptic Cleft: Fluid-filled space between pre and post synaptic membranes. 3. Postsynaptic Membrane: This is part of plasma membrane of the target cell. It is thicker than presynaptic membrane due to the presence of receptors for neurotransmitters. When enough receptors are occupied, hydrophilic channels open, resulting in depolarization of the postsynaptic membrane. Neurontransmitter like acetylcholine that remains in the synaptic cleft is degraded by acetylcholinesterase. This removal of extra acetylcholine allows postsynaptic mambrane to reestablish its resting potential and prevents continuous firing of the postsynaptic neuron in response to a single stimulus.

85 Types of Synapses Axodendritic (Between an axon & a dendrite)
Axosomatic (Between an axon & a cell body) Dendrodendritic (Between dendrites) Axoaxonic (Between axons)

86 Neuron (Types) Based upon Configuration of cell processeses:
Multipolar (Motor neurons of spinal cord) Bipolar (Retina, olfactry mucosa) Unipolar (Photoreceptors, rods & cones of retina) Pseudounipolar (Sensory neurons of dorsal root ganglia) Based upon Cell size: Golgi type I (Motor neurons of spinal cord) Golgi type II (Interneurons of spinal cord) Based upon Function Motor neurons (Multipolar neurons of ventral horn etc.) Sensory neurons (Pseudounipolar neurons of dorsal root ganglia) Interneurons (Golgi type II neurons) Based upon Neurotransmitter released Cholinergic neurons (Most somatic motor neurons) Adrenergic & noradrenergic neurons (Postganglionic sympathatic neurons) Dopaminergic (Some neurons of hypothalamus) GABAergic (Some neurons of the brain)

87 Types of Neurons Unipolar Bipolar Pseudounipolar Multipolar

88 Supporting Cells Provide structural and functional support to neurons.
Take part in the formation of blood-brain barrier, thus monitoring the passage of materials from blood to neurons.

89 Supporting cells of CNS
1. Astrocytes:- (Blood-Brain Barrier) a) Protoplasmic astrocytes b) Fibrous astrocytes Oligodendrocytes:- (Myelin to axons in CNS) Ependymal cells:- (Produce the CSF) Microglial cells:- (Macrophages of the nervous system)

90 Supporting Cells of PNS
Schwann cells: A Schwann cell may envelop segments of several unmyelinated axons or provide a segment of a single myelinated axon with its myelin sheath. Each mylinated axon segment (internode) is wrapped around by layers of a Schwann cell process with most of its cytoplasm squeezed out. This multilayered Schwann cell plasma membrane (mainly of phospholipids) is called myelin. The gaps between myelin sheath segments are the nodes of Ranvier. Satellite cells: Each neuron outside the CNS is surrounded by a single layer of cells, called satellite cells.

91 Aging and Repair A neuron is a terminally differentiated cell.
And is incapable of undergoing mitosis. Aging neurons accumulate more of lipofuscin pigment. Neurons lost through injury or surgery cannot be replaced. If the cell body remains intact, the injured axon can regenerate itself. If stimulated by injury, supporting cells, unlike neurons, can divide.

92 Blood-Brain Barrier Components of the barrier:
1. Endothelial cells of continuous type capillaries (Tight junctions) 2. Basal lamina 3. Cytoplasmic processes of astrocytes.

93 Blood-brain Barrier

94 Peripheral nerve

95 Peripheral Nerve (Fascicle)
Perineurium Endoneurium Myelinated axons

96 Response of Nerve Tissue to Injury
Damage to the Cell Body: A neuron is a terminally differentiated cell & is unable to divide. So damaged or dead neurons can’t be replaced. B. Damage to the Axon: 1. Degenaration:- Distal to the site of injury, axon & myelin degenerate. Within 2-3 days, they are removed & these clear endoneurial channels are occupied by Schwann cells. Proximal to the site of injury, retrograde degeneration of axon goes up to 2 internodes, then injured axon is sealed. Cell body also undergoes changes in response to the injury. The Nissl bodies disappear (chromatolysis) & nucleus moves to the periphery. (2 Weeks) 2. Regeneration:- Begins at 3rd week, Nissl bodies reappear, protein synthesis starts. Axon’s proximal stump gives off a number of small processes called neurites. One of these enters and grows in an endoneurial channel and synaptic contacts are remade with the target cell. The target cell or organ deprived of innervation often atrophy.

97 Nerve Injury & Recovery
A B C D E Cell body Nissl bodies Axon Schwann cells Motor end plate Muscle Before injury weeks weeks months No healing

98 Muscle Tissue Cardiac muscle Skeletal muscle Visceral muscle

99 Basic Properties of Muscle Tissue
Excitability- ability to respond to a stimulus Conductivity- ability to propagate a limited response Contractility- ability to shorten Relaxability- ability to relax (return to original shape after contraction)

100

101

102 IC Disc Nucleus Cardiomyocyte in Longitudinal Section Endomysium Capillary Nucleus Myofibrils Cardiomyocyte Purkinje Cell In Cross Section

103 Smooth Muscle

104 Skeletal Muscle

105 Cardiomyocyte (Long. Section)
Endomysium Cardiomyocytes Nucleus

106 Cardiomyocytes (Cross section)
Nucleus Myofibrils Endomysium Capillaries

107 Comparison Of Types Of Muscles
Property Skeletal Muscle Cardiac Muscle Smooth Muscle Location Cell size/shape Nuclei Striations Z lines T tubules & Sarcoplasmic reticulum Cell junctions Muscles of skeleton Long; cylindrical Many; peripherally located Yes Yes Triads at A-I junctions None Heart Short, branched Single; centrally located Yes Yes Diads at Z line Intercalated disks (Adherens, occludens & nexi) Visceral organs Variable, fusiform Single: central No Dense bodies Caveolae replace T tubules; sparse Nexi (Gapjunctions)

108 EM of Cardiac muscle (IC disc)
Macula adherens Gap junction Fascia adherens

109 EM of Skeletal muscle

110

111


Download ppt "INTRODUCTION TO CELLS & TISSUES By Vijay Kapal"

Similar presentations


Ads by Google