Physiology and Anatomy Essentials: CELLS & TISSUES.

Physiology and Anatomy Essentials: CELLS & TISSUES. Form fits function.

1. BIOL 111- CELLS & TISSUES Dr. Khaled Ouanes E-mail: [email protected] Twitter: @ khaled_ouanes

2. FORM FITS FUNCTION

3. CELLS AND TISSUES Cells are the building blocks of all living beings Tissues are group of similar cells from the same origin that carry out a specific function

4. CELLS

5. Anatomy of the Cell Cells are not all the same (Form fits function here too) All cells share general structures Cells are organized into 3 main regions Nucleus Cytoplasm Plasma membrane

6. MAIN REGIONS OF A HUMAN CELL

7. The Nucleus Control center of the cell Contains genetic material (DNA) 3 regions Nuclear membrane Nucleolus Chromatin

8. NUCLEUS

9. Nuclear Membrane Barrier of nucleus Consists of a double phospholipid (bi-layer) membrane Contain nuclear pores allowing material exchange with the rest of the cell

10. Nucleoli Nucleus contains one or more nucleoli It is a non-membrane bound organelle taking part in synthesis of ribosomes, including processing of rRNA and the assembly of them into ribosome subunits.

11. Nucleoli The Nucleus is also involved in several other cellular processes, such as mitosis, stress response and cell cycle regulation. After the synthesis step, ribosomes will then migrate to cytoplasm through nuclear pores

12. Staining of nucleoli in human cell line A-431

13. Chromatin Composed of DNA & proteins Scattered throughout the nucleus Chromatin condenses to form chromosomes when the cell division starts

14. Chromatin Chromatin and condensed chromosome structure

15. Plasma Membrane Barrier for cell contents Double phospholipid layer Hydrophilic heads + Hydrophobic tails Other materials in plasma membrane Protein Cholesterol Glycoproteins

16. Plasma Membrane

17. Plasma Membrane: Specializations Microvilli Finger-like projections that increase surface area for absorption

18. Membrane junctions Tight junctions Desmosomes & hemi-desmosomes Gap junctions Plasma Membrane: Specializations

19. Cytoplasm Material outside the nucleus and inside the plasma membrane Cytosol: Fluid that contains other elements Organelles: Metabolic machinery of the cell Inclusions: Non-functioning units (Lipids …)

20. Ribosomes Made of protein and RNA Sites of protein synthesis Found at two locations Free in the cytoplasm Attached to rough endoplasmic reticulum Cytoplasmic Organelles

21. Cytoplasmic Organelles A ribosome “at work”

22. Endoplasmic reticulum ( ER): Fluid-filled tubules for carrying substances – 2 types of ER - Rough Endoplasmic Reticulum: is studded with ribosomes and where building materials of cellular membrane are formed. - Smooth Endoplasmic Reticulum: Functions in cholesterol synthesis and breakdown, fat metabolism, and detoxification of drugs Cytoplasmic Organelles

23. Cytoplasmic Organelles Schema of the 2 types of ER

24. Cytoplasmic Organelles 3D of the 2 types of ER

25. Golgi apparatus Modifies & packages proteins Produces several types of packages Secretory vesicles Cell membrane components Lysosomes Cytoplasmic Organelles

26. Cytoplasmic Organelles Golgi Apparatus

27. Cytoplasmic Organelles Golgi Apparatus “at work”

28. Mitochondria “ Power-houses ” of the cell Provide ATP for cellular energy Change shape constantly Carry out reactions using oxygen break down food Cytoplasmic Organelles

29. Cytoplasmic Organelles A mitochondrion

30. Lysosomes: Contain enzymes that digest non-usable materials within the cell Peroxisomes Membranous sacs of oxidase enzymes Detoxify harmful substances Break down free radicals Replicate by pinching in halves Cytoplasmic Organelles

31. Cytoskeleton Network of protein structures that extend throughout the cytoplasm Provides the cell with an internal framework Cytoplasmic Organelles

32. Cytoplasmic Organelles The cytoskeleton. The actin is stained red and the microtubules, which are composed of the protein tubulin, are stained green.

33. Cytoskeleton 3 different types Microfilaments Intermediate filaments Microtubules Cytoplasmic Organelles

34. Cytoplasmic Organelles The cytoskeleton. This organelle is the ‘skeleton’ of our cells. It maintains cell shape. We couldn’t move without the cytoskeleton’s contractions of microtubules, microfilaments, and intermediate fibers.

35. Centrioles Rod-shaped bodies made of microtubules Direct formation of mitotic spindle during cell division Probably involved in other cell functions that are still not very well known Cytoplasmic Organelles

36. Cytoplasmic Organelles Centriole Centrosome Microtubule Centrioles

37. The Cell. The basic  unit  of structure and function.

38. Cellular Projections Not found in all types of cells Used for movement: Cilia move materials across the cell surface Flagellum propels the whole cell (e.g. sperm cell)

39. Cellular Projections Flagella and cilia differ in the way they move. Flagella use an undulating, propeller-like motion to propel a cell. Cilia beat back and forth, perpendicular to the cilium, bending & sweeping sideways.

40. Cellular Projections Flagella and cilia. Movement and structure.

41. Cell Diversity

42. Cell Diversity

43. Cell Diversity

44. Cell Diversity

45. Cellular Physiology: Membrane Transport Membrane Transport – movement of substance in and out of the cells Transport is by 2 basic methods: Passive transport: No energy is required Active transport: Metabolic energy required

46. Solutions and Transport Solution: homogeneous mixture of 2 or more components Solvent: dissolving medium (e.g. Water) Solutes: components in smaller quantities within a solution Intracellular fluid: nucleoplasm & cytosol Interstitial fluid: fluid on the exterior of the cell (Extracellular fluid)

47. Selective Permeability The plasma membrane allows some materials to pass while excluding others This permeability includes movement in and out of the cells

48. Passive Transport Processes Diffusion Particles tend to distribute themselves evenly within a solution Movement is from high concentration to low concentration, or down a concentration gradient

49. Passive Transport Processes Diffusion.

50. Types of diffusion Simple diffusion: Unassisted process. Solutes are lipid-soluble materials or small enough to pass through membrane pores. Osmosis – simple diffusion of water: Highly polar water easily crosses the plasma membrane. Facilitated diffusion: Substances require a protein carrier for passive transport. Passive Transport Processes

51. Diffusion through Plasma Membrane

52. Filtration: Water and solutes are forced through a membrane by fluid, or hydrostatic pressure. A pressure gradient must exist Solute-containing fluid is pushed from high pressure area to lower pressure one Passive Transport Processes

53. Transport of substances that are not able to pass by diffusion because they: M ay be too large May be unable to dissolve in the fat of membranes May have to move against a concentration gradient 2 common forms of active transport: Solute pumping & Bulk transport Active Transport Processes

54. Solute pumping Amino acids, some sugars and ions are transported by solute pumping ATP energizes protein carriers, & in most cases, moves substances against concentration gradients Active Transport Processes

55. Solute Pumping

56. Bulk transport Exocytosis: Moves materials out of the cell. Material is carried in a membranous vesicle. STEPS: Vesicle migrates to plasma membrane Vesicle combines with plasma membrane Material is emptied to the outside Active Transport Processes

57. Exocytosis

58. Bulk transport Endocytosis: Extracellular substances are engulfed by being enclosed in a membrane vesicle. TYPES OF ENDOCYTOSIS: Phagocytosis: cell eating Pinocytosis: cell drinking Active Transport Processes

59. Endocytosis

60. Cell Life Cycle Cells have 2 major periods Interphase: Cell grows and carries on metabolic processes Cell division: Cell replicates itself to produce more cells for growth and repair processes

61. DNA Replication Genetic material duplicated and readies a cell for division into two cells Occurs toward the end of interphase DNA uncoils and each side serves as a template

62. Cell Division Steps Mitosis: Division of the nucleus. Results in the formation of 2 nuclei. Cytokinesis: Division of the cytoplasm. Begins when mitosis is near completion. Results in the formation of 2 new cells.

63. Stages of Mitosis Interphase: No cell division occurs. The cell carries out normal metabolic activity & growth. Prophase: First part of cell division. Centromeres migrate to the poles

64. Metaphase: Spindle from centromeres are attached to chromosomes that are aligned in the center of the cell Stages of Mitosis

65. Anaphase: Daughter chromosomes are pulled toward the poles. The cell begins to elongate. Telophase : Daughter nuclei begin forming. A cleavage furrow (for cell division) begins to form Stages of Mitosis

66. Stages of Mitosis

67. Stages of Mitosis

68. Protein Synthesis Gene: DNA segment that carries a ‘blueprint‘ for building one protein Proteins have many functions Building materials for cells Act as enzymes (biological catalysts) RNA is essential for protein synthesis

69. Role of RNA Transfer RNA ( tRNA ): Transfers appropriate amino acids to the ribosome for building the protein Ribosomal RNA ( rRNA ): Helps form the ribosomes where proteins are built Messanger RNA (mRNA): Carries the instructions for building a protein from the nucleus to the ribosome

70. Transcription and Translation Transcription: Transfer of information from DNA’s base sequence to the complimentary base sequence of mRNA. Translation: Base sequence of nucleic acid is translated to an amino acid sequence. Remember? Amino acids are the building blocks of proteins

71. Proteins Synthesis

72. TISSUES

73. Body Tissues Cells are specialized for particular functions Tissues: Groups of cells with similar origin, structure and function

74. Body Tissues 4 primary types of tissues: Epithelium Connective tissue Nervous tissue Muscle

75. Epithelial Tissues Found in different areas Body coverings Body linings Glandular tissue Functions Protection Absorption Filtration Secretion

76. Cells fit closely together Tissue layer always has one free surface The lower surface is bound by a basement membrane Avascular (have no blood supply) Regenerate easily if well nourished Epithelium Characteristics

77. 1-Number of cell layers: Simple: one layer Stratified: more than one layer Classification of Epithelium

78. 2- Shape of cells: Squamous: flattened Cuboidal: cube-shaped Columnar : column-like

79. Simple Epithelium Single layer of flat cells Usually forms membranes (Lines body cavities, Lines lungs and capillaries) Simple squamous

80. Simple cuboidal Single layer of cube-like cells Common in glands and their ducts Forms walls of kidney tubules Covers the ovaries Simple Epithelium

81. Simple columnar Single layer of tall cells Often includes goblet cells, which produce mucus Lines digestive tract Simple Epithelium

82. Pseudostratified Single layer, but some cells are shorter than others Often looks like a double cell layer Sometimes ciliated, such as in the respiratory tract May function in absorption or secretion Simple Epithelium

83. Stratified squamous Cells at the free edge are flattened Found as a protective covering where friction is common Locations : Skin , Mouth , Esophagus. Stratified Epithelium

84. Stratified cuboidal: Two layers of cuboidal cells. Stratified columnar: Surface cells are columnar, cells underneath vary in size and shape. Stratified cuboidal and columnar: Rare in human body. Found mainly in ducts of large glands. Stratified Epithelium

85. Transitional epithelium Shape of cells depends upon the amount of stretching Lines organs of the urinary system Stratified Epithelium

86. Gland: one or more cells that secretes a particular product 2 major gland types: Endocrine gland: Ductless , Secretions are hormones. Exocrine gland: Empty through ducts to the epithelial surface. Include sweat & oil glands. Glandular Epithelium

87. Found everywhere in the body Includes the most abundant and widely distributed tissues Functions: Binds body tissues together Supports the body Provides protection Connective Tissue

88. Variations in blood supply Some tissue types are well vascularized Some have poor blood supply or are avascular Extracellular matrix: Non-living material that surrounds living cells Connective Tissue Characteristics

89. 2 main elements: Ground substance: mostly water along with adhesion proteins and polysaccharide molecules Fibers: Produced by the cells 3 types Collagen fibers Elastic fibers Reticular fibers Extracellular Matrix

90. Composed of: Bone cells in lacunae (cavities) Hard matrix of calcium salts Large numbers of collagen fibers Connective Tissue Types Bone (osseous tissue): Used to protect and support the body.

91. Hyaline cartilage: Most common cartilage. The entire fetal skeleton is hyaline cartilage. Composed of: Abundant collagen fibers Rubbery matrix Connective Tissue Types

92. Elastic cartilage Provides elasticity Example: supports the external ear Connective Tissue Types

93. Fibrocartilage Highly compressible Example: forms cushion-like discs between vertebrae Connective Tissue Types

94. Main matrix element is collagen fibers Cells are fibroblasts Examples: Tendon – attach muscle to bone Ligaments – attach bone to bone Connective Tissue Types Dense connective tissue

95. Most widely distributed connective tissue Soft, pliable tissue Contains all fiber types Can soak up excess fluid Connective Tissue Types Areolar connective tissue

96. Adipose tissue (Fat) Matrix is an areolar tissue in which fat globules predominate. Many cells contain large lipid deposits. Functions: Insulates the body Protects some organs Serves as a site of fuel storage Connective Tissue Types

97. Delicate network of interwoven fibers Forms stroma (internal supporting network) of lymphoid organs Lymph nodes Spleen Bone marrow Connective Tissue Types Reticular connective tissue

98. Blood Blood cells surrounded by fluid matrix Fibers are visible during clotting Functions as the transport vehicle for materials Connective Tissue Types

99. Function is to produce movement 3 types Skeletal muscle Cardiac muscle Smooth muscle Muscle Tissue

100. Skeletal muscle Can be controlled voluntarily Cells attach to connective tissue Cells are striated Cells have more than one nucleus Muscle Tissue Types

101. Cardiac muscle Found only in the heart Function is to pump blood (involuntary) Cells attached to other cardiac muscle cells at intercalated disks Cells are striated One nucleus per cell Muscle Tissue Types

102. Smooth muscle Involuntary muscle Surrounds hollow organs Attached to other smooth muscle cells No visible striations One nucleus per cell Muscle Tissue Types

103. Neurons and nerve support cells Function is to send impulses to other areas of the body Irritability Conductivity Nervous Tissue

104. Regeneration: Replacement of destroyed tissue by the same kind of cells Fibrosis: Repair by dense fibrous connective tissue (scar tissue) Determination of method Type of tissue damaged Severity of the injury Tissue Repair

105. Capillaries become very permeable Introduce clotting proteins & Wall off injured area Formation of granulation tissue Regeneration of surface epithelium Events in Tissue Repair

106. Tissues that regenerate easily: Epithelial tissue Fibrous connective tissue and bone Tissues that regenerate poorly: Skeletal muscle Tissues that are replaced largely with scar tissue: Cardiac muscle Nervous tissue within the brain and spinal cord Regeneration of Tissues

107. Epithelial tissue arises from all 3 primary germ layers Muscle & connective tissue arise from the mesoderm Nervous tissue arises from the ectoderm With old age there is a decrease in mass and viability in most tissues Development aspects of Tissues

108. BIOL 111- CELLS & TISSUES Dr. Khaled Ouanes E-mail: [email protected] Twitter: @ khaled_ouanes