Cells & Tissues Chapter 3
Cell Theory Cell is structural and functional unit of life Activity of an organism is dependent upon its cells Principle of Complementarity functions of cells are dependent upon organelles 2
Cellular Components Composed mainly of four elements Carbon Hydrogen Oxygen Nitrogen Three main regions Nucleus Cytoplasm Plasma Membrane 3
Nucleus Nuclear Envelope Nuclear Pores Chromatin Nucleolus 4
Cytoplasm Cytosol Organelles Inclusions 5
Special Role of Golgi and ER Secretory Pathway Non-Secretory Pathway 6
7 Cytoskeletal Elements
Plasma Membrane Barrier for cell contents Phospholipid Bilayer Hydrophobic tails Hydrophilic heads Proteins, cholesterol, glycoproteins, glycolipids Semipermeable 8
Cell Junctions Tight Junctions Desmosomes Gap Junctions 9
Membrane Transport Solution mixture of two or more components Solvent liquid portion Solutes components Intracellular fluid cytosol Interstitial (Extracellular) fluid fluid outside of cell 10
Membrane Transport Semipermeable Membrane Passive Diffusion Simple Diffusion no assistance needed, with gradient Facilitated Diffusion-carrier (protein) is needed, with gradient Active Diffusion Active Transport-pumps, carrier needed, energy (ATP) needed, move molecules against gradient Secondary Active Transport-carrier, need gradient from pump so molecules and ions can move with gradient Endocytosis-moves material inside of cell Exocytosis-moves material outside of cell 11
12 Membrane Transport
13
Life Cycle of Cell Interphase Metabolic phase Cell Division Replication of organelles and genetic material 14
DNA Replication & Protein Synthesis 15
16 BODY TISSUES
Body Tissues Tissues are groups of cells with similar structure and function Four Primary Tissues Epithelial Connective Muscle Nervous 17
Epithelial Tissue Functions Protection body coverings and linings Absorption lungs, kidneys, blood brain barrier Filtration lungs, kidneys, blood brain barrier Secretion glands Cells tend to form sheets Apical side faces free or open surface Basal side rests on basement membrane (laminia propria, basal lamina) formed from connective tissue Avascular no blood supply Regenerative repairs and restores easily and rapidly 18
Epithelial Tissue Classification by shape Classification by number of cell layers Glandular secretion of mucus, hormones, waste Exocrine ducts, secrete to surface Endocrine glands ductless, secrete into blood stream 19
20 Epithelial Tissue
Connective Tissue Found everywhere in body, most abundant tissue Functions binds, supports and protects tissues and organs Characteristics Vascular blood supply Extracellular matrix produced by connective tissue cells Proteins, polysaccharides, fibers Three types of fibers: collagen, elastin, reticular 21
22 Connective Tissue
23 Connective Tissue
Muscle Tissue Function is to produce movement Three Types Skeletal muscle Cardiac muscle Smooth muscle 24
Nervous Tissue Function to send impulses (messages) to other areas of the body Irritable/responsive Most are found in the brain and spinal cord Peripheral nerves found all over body Two Types of cells Supporting cells Neurons 25
26
Tissue Repair (Wound Healing) Regeneration -replacement of destroyed tissue by the same cell types Fibrosis repair by connective tissue, formation of scar tisue Dependent upon type of tissue and severity of injury 27
Tissue Repair Inflammation increased permeability of capillaries, migration of white blood cells Granulation tissue collagen fibers and blood vessels Regeneration of epithelium 28
Tissue Development Three germ layers Mesoderm Ectoderm Endoderm Epithlial tissue arise from all three Connective and muscle tissue arise from ectoderm Nervous tissue arise from ectoderm Age causes decline in tissue mass and viability 29