Chapter 4 Flashcards
Four types of tissue
Epithelial
Connective
Muscular
Nervous
Epithelial tissue
Covers body’s surface, lines hollow organs/cavities, forms glands
Connective tissue
Protects/supports body/organs, stores energy (fats), immunity to disease
Muscular tissue
Cells specialized for contraction/force, generates heat
Nervous
Detects changes, generates electrical signals, activates muscular contractions/secretions
Five types of cell junctions
Right
Adherents
Desosomes
Hemidesosomes
Gap
Tight junctions
Fuse outer surface of membranes together to seal of passageway between cells=prevents leakage (stomach, intestines, urinary bladder)
Adheren junctions
Plaque on inside of planes membrane attaching to members proteins and microfilaments, helps epithelial resist separation during contraction
Cadherens: transmembrane proteins joining cells
Adhesion belts: extensive zones of adherens
Desosomes
Contains plaque, cadherens extend into ICF, attach cells, don’t attach to microfilaments but instead intermediate filaments
Hemidesosomes
Like Desosomes but integrity’s instead of cadherins, attach to laminin (proteins) present in basement membrane
Gap junctions
Connexins (tiny tube tunnels) for rapid diffusion
Epithelial vs connective
Tightly packed cells, little matrix, no BV, almost always surface layer (except BV where blood passes over)
Cells widely scattered lots of matrix, has BV
General features of epithelial tissue
Cells in continuous sheets single or multiple layer
Various surfaces have different structures/functions
Own nerve supply
Avascular
High rate of cell division
Function: protects secretes absorbs excretes
Simple squamous (two types)
Flat single layer of cells
Found:
Endothelium: lines cardiovascular/lymphatic system
Mesothelium: epithelial layer of serous membranes
Function: filtrations/diffusion or secretion of serous membranes, not subject to wear and tear
Simple cuboidal
Cube single layer
Found: surface of ovary, anterior lens of eye, pigment of retina, lines kidney tubules/smaller ducts of glands, secreting portion of glands
Function: secretion/absorption
Nonciliated simple columnar
Single layer columnar cells, microvilli, goblet cells
Found: lines GI, ducts of glands, gallbladder
higher secretion/absorption, secreted mucus lines respiratory/reproductive/digestive tract, prevents destruction of stomach lining
Ciliates simple columnar
Single layer columnar, cilia, goblet cells
Found: bronchiales, fallopian tubes, sinuses, central spinal cord
Function: move mucus to be coughed up, move oocytes from ovaries
Nonciliated pseudostratified columnar
Different levels of nuclei, not all cells reach surface, no goblet/cilia
Found: lines epididymis, larger ducts of glands, make urethra
Function: absorption/secretion
Ciliated pseudostratified columnar
Goblet cells and cilia
Found: lines airways of most upper respiratory tract
Function: secreted mucus, traps foreign particles cilia swell away
Stratified squamous
Many layers of cells top is flat
Found:
Keratinized: superficial layer of skin
Non keratinized: lines wet surface/tongue
Function: protection against abrasion, UV, water loss, foreign invasion
Stratified cuboidal
Fairly rare
Found: ducts of adult sweat/esophageal glands, male urethra
Function: protection, limited secretion/absorption
Stratified columnar
Uncommon
Found: urethra, large ducts of glands, anus mucous membrane, parts of eye
Function: protection/secretion
Transitional
Relaxed=stratified cuboidal stretched=stratified squamous
Found: lines urinary bladder, ureter/urethra
Function: stretch without rupturing, maintain protective lining
Endocrine glands
Secretions enter interstitial fluid then bloodstream, no duct
Found: pituitary, pineal, thyroid, parathyroid, adrenal, pancreas, ovaries, tested, thymus
Function: hormones regulate metabolic/physiological a activities
Exocrine glands
Release into ducts onto surface epithelium
Found: sweat, oil, ear was glands of skin, digestive glands, pancreas
Function: produce substances, sweat oil earwax saliva digestive enzymes
Exocrine glands shapes
Simple: doesn’t branch
Compound: branches
Tubular: tubular
Acinar: rounded
Tubuloacinar: both
Exocrine gland types of secretion
Merocrine: released from cell in secretory vesicles via Exocytosis
Apocrine: portion of cell lunches off via Exocytosis
Holocrine: whole cell ruptures
General feature of connective tissue
Most abundant
Lots of extra cellular matrix
Vascular (except catilage=none, tendons=little)
Not usually on body surfaces
Nerves (except cartilage)
Cells in connective tissue
Fibroblasts
Macrophages
Plasma cells
Mast cells
Adipocytes
Leukocytes
Fibroblasts
Large, flat, branching cells
In general connective tissue
Macrophages
Phagocytes
Fixed reside in particular tissue
Wandering move through tissue to gather at sites of inflammation/infection
Plasma cells
All over body, mostly connective tissue, especially GI/respiratory tracts
Mast cells
Involved in inflammatory response, bind/ingest/kill bacteria
Adipocytes
Fat cells store triglycerides
Deep to skin/around organs
Leukocytes
WBC
Migrate from blood to connective tissue for different responses
Ground substance structure/function
Can be fluid, semi fluid, gelatinous, calcified
Supports/binds cells, stores water, medium for exchange between blood/cells
Hyaluronic acid
Viscous slippery substance
Bind cells, lubricates joints, maintains shape of eyeballs
Fibers in connective tissue
Collagen: strong, rests pulling/stretching, not stiff, found in most connective tissues (esp. bone cartilage ligaments tendons(
Elastic: strong, stretch 150%, return to normal shape (esp. skin, BV walls, lung tissue)
Reticular: support/strength/form basement membrane, helps form stroma
Stroma
Supporting framework of organs
Embryonic tissue types
Mesenchyme
Mucous connective tissue
Mesenchyme
Irregular shaped cells in semi fluid ground substance, reticular divers
Found: under skin/along bones of embryo, some adult esp. BV
Function: form almost all other types of connective tissue
Mucous connective tissue
Widely scattered fibroblasts, jelly-like ground substance, collagen fibres
Found: umbilical cord
Function: support
Proper loose connective tissue types
Fibers loosely arranged
Areolar connective tissue
Adispose tissue
Reticular connective tissue
Areolar connective tissue
Widely distributed, 3 fibers, many cells, semi fluid
Found: in/around every body structure, subcutaneous layer, superficial dermis, lamina propria, BV, nerves, organs
Function: strength, elasticity, support
Adipose tissue
Cels fill with droplet of tryglyceride, BAT found mostly in fetus/infant
Found: Areolar tissue, heart/kidneys, yellow bone marrow, joints, eye
Function: reduced heat loss, energy reserve, supports/protects organs, stem cells
Reticular connective tissue
Interlacing network of reticular fibers/cells
Found: stroma of liver spleen lymph nodes, red bone marrow, reticular lamina, around BV/muscles
Function: forms stroma, binds cells, filters/removes worn out blood cells in spleen/microbes in lymph nodes
Proper dense connective tissue types
More fibers densely packed
Dense regular connective tissue
Dense irregular connective tissue
Elastic connective tissue
Dense regular connective tissue
Shiny white extracellular mix, collagen rows with fibroblasts between
Found: tendons, ligaments, aponeuroses
Function: strong attachment between structures, withstands pulling
Dense irregular connective tissue
Collagen fibers irregularly arranged with fibroblasts
Found: in sheets fascia, reticular dermis, pericardium, perichondrium, cartilage, joint/membrane capsules, heart valves
Function: provides tensile (pulling) strength
Elastic connective tissue
Elastic fibers with fibroblasts, yellowish
Found: lung tissue, walls of elastic arteries, teachea, bronchial tubes, vocal cords, suspensory ligaments of penis, some ligament of vertebrae
Function: stretching of organs, strong can recoil to og shape (lung tissue, elastic arteries)
Cartilage types
Hyaline
Fibrocartilage
Elastic cartilage
Hyaline cartilage
Bluish white, shiny chondrocytes found in lacunae surrounded by perichondrium
Found: most abundant in body, long bones, ribs, nose, larynx, trachea, bronchi, bronchial tubes, embryonic/fetal skeleton
Function: smooth surfaces for movement at joint, flexibility/support, weak (can be fractured)
Fibrocartilage
Chondrocytes collagen fibers no perichondrium
Found: pubic symphysis, cerebral discs, knee, tendons
Function. Support/joining structures, strength/rigidity=strongest
Elastic cartilage
Chondrocytes elastic fibers perichondrium
Found: epiglottis, external ear, auditory tubes
Function: strength/elasticity, maintain shape
Bone tissue
Compact: osteons containing lamellae, lacunae, oesteocytes, central canal
Spongy: trabeculae, red bone marrow
Function: support protection storage house blood forming tissues enables movement
Blood
Blood plasma formed elements (RBC,WBC, platelets)
Found: BV heart
Function: RBC (transport o2/co2) WBC (phagocytosis, allergic response, immune) platelets (blood clotting)
Types of membranes
Epithelial membrane
-mucous membrane:lines body cavity open to exterior, tight junctions
-serous membrane: body cavity not open to exterior, Areolar tissue, simple squamous (mesothelium), secretes serous fluid
-cutaneous membrane: skin, keratinized stratified squamous, Areolar/irregular connective tissue
Synovial membrane: joining cavities, no epithelium, synoviocytes, secrets synovial fluid
Define membrane
Flat sheets of pliable tissue that cover/line a part of the body
Classification of membranes
Opens to exterior or not
Epithelial or not
General features of muscular tissue
Elongated cells called muscle fibers or myocytes
Use ATP to generate force
Skeletal muscle tissue
Long cylindrical striated fibers (alternating light dark bands) nucleus at periphery
Voluntary
Found: attached to bones by tendons
Function; motion posture heat production protection
Cardiac muscle tissue
Branches striated fibers, central nucleus, intercalated discs, Desosomes, gap junctions
Involuntary
Found: heart wall
Function: pump blood
Smooth muscle tissue
Non striated fibers, central nucleus
Involuntary
Found: iris, walls of hollow internal structures (BV, stomach intestines etc)
Function: motion (construction of BV contractor of bladders)
Structure/function of nervous tissue
Neurons: nerve cells, sensitive to stimuli, convert it to electrical signals called nerve action potentials, conducted to neuron, muscle tissue or glands
-cell body: contains nucleus/organelles
-dendrites: receiving/input section,branched
-axons: output, long thin conducts nerve impulses
Neuroglia: doesn’t generate nerve impulses has supporting functions
Concept of electrical excitably
Excitable cells: neurons muscle fibers
Electrical excitability: ability to respond to certain stimuli by producing electrical signals
Basement membrane
Thin extracellular membrane, attach/anchor epithelial/connective tissue, surface for wound healing, prevent passage of larger molecules, blood filtration in kidneys
Basal lamina: closer to epithelial cells
Reticular lamina: closer to connective tissue
Chondrocytes
Cells of mature cartilage
Lacunae
Spaces filled with chondrocytes
Perichondrium
Dense irregular connective tissue
Membrane covering cartilage
Interstitial growth
Growth from within tissue (childhood/adolescence)
Appositional growth
Growth at the outer surface of the tissue (adolescence/adulthood)
Lamellae
Rings of extracellular matrix with mineral salts/collagen fibers
Lacunae
Small spaces between lamellae containing osteocytes
Canaliculi
Project from lacunae proving nutrient/waste routes
Central canal
BV and nerves
