Chapter 4 Flashcards
Epithelial Tissue
-Covers and lines surfaces
Epithelial Tissue Characteristics
-Highly cellular
-Polar
Has an apical and basal surface
-Basement membrane
-Avascular
No blood vessels
-Regenerative
-Specialized contacts
Simple Squamous Epithelium
- Single layer of flat cells
- Areas of high filtration and diffusion
Simple Squamous location
- Alveolar air sacs of lungs
- Kidney Glomerulus
Special types of simple squamous epithelial
- Endothelium
- Mesothelium
Endothelium
- Lines entire circulatory system (blood vessels and heart)
- Lymphatic vessels
Mesothelium
-Lines serous membranes
Simple cuboidal epithelium
-Secretion and absorption
Simple cuboidal epithelium location
- Kidney tubules
- Glands
Simple columnar epithelium
-Secretion and absorption
Simple columnar epithelium location
- Digestive tract
- Stomach
- Intestines
- Glands
- Uterine tubes
Pseudostratified columnar epithelium
- Single layer of cells, nuclei at various heights
- Secretion
Pseudostratified columnar epithelium location
- Trachea
- Glands
- Sperm carrying ducts
Stratified squamous epithelium
- Protection
- Found in areas exposed to a lot of friction
- Upper layer replaced by rapidly dividing cells in basal layer
Stratified squamous epithelium locations
- Skin
- Mouth
- Esophagus
- Vagina
Stratified cuboidal epithelium
- Rare
- Found in some sweat and mammary glands
- Typically two cell layers thick
Stratified columnar epithelium
- Rare
- Some parts of Pharynx
- Male urethra
- Lining some glandular ducts
- Only apical layer columnar
Transitional Epithelium
- Bladder
- Ureters
- Urethra
Glandular epithelia
- Glands
- Secretions
- Endocrine/Exocrine
Glands
-One or more cells that secrete a product
Secretions
-Water based fluids containing proteins (hormones) and lipids (steroids)
Endocrine glands
-Ductless
-Secrete products into extracellular space by exocytosis
Examples:
-Pituitary Gland
-Thyroid Gland
-Adrenal Gland
Exocrine glands
- Have ducts
- Secrete products onto body surfaces or into body cavities
- Mucus, sweat, oil, saliva, bile (liver), digestive enzymes (pancreas)
Unicellular Exocrine glands
-Single cell
-Ductless
Found in:
-Intestines
-Trachea
Secretion methods
- Merocrine glands
- Holocrine glands
Merocrine glands
-Most common form of secretion
-Cells release contents by exocytosis
Ex:
-Sweat glands
-Goblet cells
Holocrine glands
-Cells release secretions by rupturing
-Cells are killed during secretion process
Ex:
-Sebacious (oil) gland
Connective Tissue Functions
- Connects tissues
- Supports other tissues
- Energy storage
- Transport
Connective tissue characteristics
- Degrees of vascularity
- Lots of extracellular matrix
Connective tissues vascularity
- Cartilage: Avascular
- Adipose: Highly vascular
Connective tissue extracellular matrix
- A lot of extracellular matrix is true for cartilage, bone, tendons, ligaments, areolar tissue, blood, reticular
- Exception: Adipose tissue, not much EM
Extracellular Matrix
- Collagen
- Elastin
- Reticular Fibers
- Ground substance
Collagen
- Tough thick fibers
- Can withstand tension
Elastin
- Thin fibers
- Stretch and recoil
Reticular Fibers
- Very fine collagen fibers
- Form a branched network to support tissue
Ground Substance
- Interstitial fluid
- Proteoglycans
- Proteins
- Polysaccharides
Proteoglycan
-Very negatively charged Attracts water and ions into extracellular space -Keeps tissues hydrated -Helps lubricate fibers -Helps withstand compression
Connective tissue cell types
- “-blast” cells make ECM and ground substance
- Fibroblast
- Chondroblast
- Osteoblast
- Hemotopoetic stem cell (hematocytoblast
Fibroblast
-Makes collagen fibers
Chondroblast
-Makes cartilage
Osteoblast
-Makes bone
Hematopoetic stem cell (hematocytoblast)
-Makes blood cells, not ECM
Blood Borne Cells
- White blood cells
- Macrophages
- Mast cells
- Histamine
White Blood Cells
-Help with tissue response to injury or infection
Macrophages
-“Eat” foreign particles (bacteria, tissue debris) by phagocytosis
Mast Cells
-Release substances from granules
Histamine
-Makes capillaries leaky
Areolar Connective Tissue
- Loose connective
- Loosely packed ECM fibers (all kinds)
- Lots of ground substance
- Blood borne cells
Areolar Connective Tissue Location and Function
- Found under layers of epithelium
- Wraps and cushions tissues
- Vascular
- Defense against infection
Adipose Connective Tissue
- Loose connective
- Highly cellular
- Sparse ECM
- Highly vascular
Adipose Connective Tissue Location
- Subcutaneous
- Around organs
- Behind eyeballs
- Breast
- Abdomen
Adipose Connective Tissue Function
- Shock absorber
- Insulator
- Energy storage
Reticular Connective Tissue
- Loose connective tissue
- Only reticular ECM fibers
- Many white blood cells
Reticular Connective Tissue Locations
- Spleen
- Lymph nodes
- Bone marrow
Reticular Connective Tissue Functions
-Provides a supportive framework for blood cells
Dense Regular Connective Tissue
-Dense connective tissue
-Mostly parallel collagen fiber bundles
Resists tension (pulling)
-Fibroblasts
-Avascular
Dense Regular Connective Tissue Locations
-Tendons Muscle to bone -Ligaments Bone to bone -Aponeuroses Muscle to muscle
Dense Regular Connective Tissue Functions
- Connects bones and muscles
- Resists tension (stretching)
Dense Irregular Connective Tissue
- Dense connective tissue
- Irregularly arranged collagen fiber bundles
- Can withstand tension in multiple directions
- Fibroblasts
Dense Irregular Connective Tissue Location
-Dermis of skin
-Periosteum
Fibrous coverings of bones
Elastic Connective Tissue
-Many elastic fibers
Allows tissue to recoil after stretching
Elastic Connective Tissue Location
- Artery Walls
- Vocal Cords
Cartilage
- Flexible yet tough
- Must withstand tension and compression
- Avascular
- No nervous system innervation
Hyaline Cartilage Locations
- Most abundant type of cartilage
- Embryonic skeleton
- Articular cartilage (ends of bones)
- Costal cartilage
- Nose
- Trachea and Brachial tubes
Hyaline Cartilage
-Dense collagen extracellular matrix
-Chondrocytes
Make matrix
Elastic Cartilage
-ECM contains more elastic fibers
-Chondrocytes
Make matrix
Elastice Cartilage Locations
- More flexible than hyaline
- Ear
- Epiglottis
Fibrocartilage
- Fibrous collagen ECM
- Chondrocytes
- Able to withstand heavy pressure
Fibrocartilage Locations
- Intervertebral discs
- Meniscus (Knee)
- Pubic symphysis
Osseous Tissue
- Hard ECM made of collagen and calcium salts
- Osteoblasts make matrix
- Vascular and nervous innervation
Blood
-Most fluid ECM Plasma Proteins -Red blood cells -White blood cells
Blood function
-Transport
Epithelial Membranes
-Epithelium bound to connective tissue
Cutaneous Membrane
- Dry membranes exposed to air
- Stratified squamous+dense irregular
Mucus Membranes
- Line cavities open to the exterior environment
- Moist
- Respiratory system, GI tract, Urinary system, eyes
Serous Membranes
- Line cavities closed to the exterior environment
- Ventral body cavity
- Dorsal body cavity
- Mesothelium + Areolar tissue
Mesothelium
- A special simple squamous epithelium
- Secretes serous fluid
What are the Serous Membranes?
- Parietal Membrane
- Visceral Membrane
Parietal Membrane
- Lines the entire cavity
- Secrete fluid
Visceral Membrane
- Inner membrane
- Wraps around organ
Special Serous Membranes
- Pleural Membrane
- Pericardium
- Peritoneal Membrane
Pleural Membrane
-Lines the pleural cavity (encasing lungs)
Pericardium
-Lines the pericardial cavity (encasing the heart)
Peritoneal Membrane
-Encases the abdominal cavity
Characteristics of Muscles
- Highly cellular
- Vascular
- Elongated cells (fibers)
- Contracts
Skeletal Muscle
-Attached to bones
-Pull on bones to cause body movements
-Voluntary
Except diaphragm
Skeletal Muscle cells
- Long cylindrical cells
- Multinucleated
- Striated (striped) appearance
Cardiac Muscle
- Heart muscle
- Propels blood through blood vessels to provide oxygen and nutrients to organs
- Involuntary
Cardiac muscle cell
- Striations
- Branched arrangement of myocytes
- Uninuclate
- Intercalated discs
Intercalated discs
-Special junctions between cardiac myocytes that contain gap junctions
Smooth muscle
-Found in hollow organs
GI tract, blood vessels, uterus
-Propels substances through by contracting
-Involuntary
Smooth muscle cells
- No striations
- Cigar shaped myocytes
Nervous Tissue
- Main component of brain, spinal cord, and nerves
- Transmit electrical impulses
Nervous Tissue Cells
- Neurons
- Neuroglia
Neurons
- Generate and conduct nerve impulses
- No mitosis
Neuroglia
- Supporting cells insulate and protect neurons
- Mitosis
How do tissues repair themselves?
- Regeneration
- Fibrosis
Regeneration
- Destroyed tissue is replaced by the same kind of tissue
- Occurs in epidermis
Fibrosis
- Destroyed tissue is replaced by fibrous connective tissue
- Scars
- Occurs in dermis
Step 2 of tissue repair
-Clot is replaced by granulation tissues which contains
Capillaries
Macrophages
Fibroblasts
Step 1 of tissue repair
-Blood vessels are injured
-Local blood vessels become leaky
Allow WBC and clotting proteins to enter site of injury
-A clot is formed
Highly Regenerative Tissues
- Epithelial tissue
- Bone
Poorly Regenerative Tissues
-Skeletal muscle
fibroblasts create scar tissue
satellite cells give rise to new muscle
-Cartilage
No Regenerative Capacity Tissues
- Cardiac Muscle
- Nervous System
What are adhesions?
- Bands of scar tissue that form between organs causing them to stick together
- Usually occur following abdominal surgery
