Chapter 3 Cells and Tissues

Anatomy of a Cell Plasma Membrane “cell” – Fluid Mosaic Model Phospholipids – cushioning insulation Proteins – growth maintenance and repair Both are double layered Specializations – Microvilli – tiny projections that absorb nutrients – Membrane Junctions

Membrane Transport Semipermeable – Allows only certain substance in and out Passive Processes – Simple diffusion – higher concentration to lower concentration – Osmosis – diffusion of H 2 O – Facilitated diffusion – carrier molecules speed up diffusion rate. – Filtration - kidneys

Membrane Transport Cont.. Active Transport– cell uses energy (lower to higher) – Active processes – move against a concentration gradient – Bulk transport Exocytosis – large particles leave cell Endocytosis – Phagocytosis – engulfs large solids – Pinocytosis – engulfs large liquids

Cellular Organization Cytoplasm – jelly like material in cells – 70% H 2 0, 30% proteins lipids minerals Organelles – Mitochondria “powerhouse” “cellular respiration” makes energy ATP – Ribosomes Makes “protein synthesis” – Endoplasmic Reticulum “canal systems” Rough E.R. – transport proteins Smooth E.R. – make lipids & transport them

More Cellular Organization Golgi Apparatus – Package and store proteins, lipids, carbohydrates Lysosomes – Digestive organelles Vacuoles – Storage organelles Cytoskeletal – Support cell, protein filaments Centrioles – Cell division, cylinders

Nucleus – control center Nuclear Membrane Nucleoli (nucleolus) – makes ribosomes & RNA Chromatin – Thread like – All chromosomes in a strand – DNA – heredity (code of life)

Cell Growth & Reproduction Cell Life Cycle – Interphase – “resting” normal replicate DNA Mitosis – cell division – Prophase Spindle fibers, centrioles migrate Nucleus fades Chromosomes shortened, thickened & doubled – Metaphase Paired chromosomes (chromatids) line up in middle of the cell Centromere- attaches chromatids to spindle fibers

Cell Growth & Reproduction cont… – Anaphase Pairs split apart Single strands migrate to each end – Telophase – cell membrane pinches in Cytokinesis – cell divides Two new cells are formed- daughter cells

Cell Growth & Reproduction Cont.. Protein Synthesis – DNA Deoxyribonucleic acid, codes heredity – RNA Transfer --  translate code Messenger --  read code – Transcription – A-T U A – Translation - C-G G C (Serine) » G-C C G » Ribosomal --  make proteins

Epithelial Tissues – Primary Functions Protection Absorption Filtration Secretion Features of Epithelial Cells – Cell Junctions – close – One cell surface is free Apical – exposed to surface or cavity

Epithelial Cont.. – Basement membrane – lowest surface – Avascular – no blood supply, diffusion – Regeneration – easy fast, mitosis Cell Shapes – Squamous Scale, flattened – Cuboidal Cube shaped – Columnar Taller than wide

Types of Epithelial Tissues Simple – Single layer Stratified – Many layers Pseudostratified – Looks like many layers- is really only one

Epithelial cont Simple Squamous – One layer – Filtration – Diffusion – Locations: Pericardium, Pleura, Alveoli, Capillary walls Simple Cuboidal – One layer – Cube shaped – Locations: Ducts of glands, Salivary & sweat glands, Covering ovary

More Body Tissues Simple Columnar Taller than wide – Line digestive tract – Goblet cells Secrete mucus Pseudostratified Columnar One cell layer(looks like more) – Ciliated w/Goblet cells – Line respiratory tract

Body Tissues Stratified Squamous – Several layers – Located: Rectum, Skin Lining of mouth, top third of esophagus Transitional – Located: – bladder, uterus – Stretched – one layer – Relaxed – many layers

Body Tissues Glandular Epithelial- secretes – Endocrine “in” Ductless Hormones --  blood – Exocrine “out” Ducts – Lined with stratified cuboidal or stratified columnar – Sweat, salivary, oil glands, bile duct, pancreatic duct

Connective Tissues Functions Protects Supports Connects & binds – Vascularized Good blood supply Except for … – Tendons – Ligaments – Cartilage have none – Extracellular matrix Non living – Liquid – Gel solid – Semi solid – solid

Body Tissues – Fibers Collagen - protein – White- strength Elastin – Yellow- stretch – Specialized Cells Fibroblasts- make fibers Osteocytes- bone cells Chondrocytes- cartilage cells Macrophages- engulf bacteria

Types of Connective Tissue – Loose – areolar (most common) Matrix : liquid Fibers: collagen & elastin Cells: fibroblasts, macrophages, fat cells, plasma cells – Dense – “fibrous” poor blood supply Collagen fibers few fibroblasts Tendons – bone to muscle Ligaments- bone to bone

Adipose – “fat” – Large vacuole w/ droplet of oil – Subcutaneous layer around organs – Insulation – Cushion – Store energy

Cartilage – no blood supply Cartilage cells in gel matrix Collagen & elastin fibers Types Hyaline – glassy “blue” Outer nose Larynx Rib Fetus Elastin –mostly elastin fibers Outer ear Epiglottis Fibrocartilage – collagen & found in vertebral discs & knees

Bone – “osseous” Bone cells- osteocytes – Collagen fibers – Solid matrix – Ca & P Blood – “liquid” – Blood cells Red White platelets – Fluid matrix Plasma Fibers

Muscle Tissue – Skeletal – striated Striations Voluntary Attached to bone Gross movements – Cardiac Striations Branching Involuntary Heart

– Smooth Muscle No striations Involuntary Blood vessels Organs of digestion Peristalsis Nervous Tissue – Functions Irritability “react to stimuli” Conductivity – flow of ions Na+ & K+

Tissues Tissue Repair – Regeneration Mitosis Replacement w/ same type of cell – Fibrosis Scar tissue Repair w/ fibrous connective tissue

Tissues Developmental Aspects – Growth mitosis – Aging Collagen fibers loss Muscle-loss Bone-loss Thinning of epithelial

Tissues Neoplasms – Cancerous Abnormal growth rapidly dividing cells – Benign – stopped – Malignant – still undergoing rapid mitosis – Hyperplasia Enlargement of body tissue – Atrophy Decrease in size (muscle) – Hypertrophy-increase