a&p lecture chap 4

  1. 2 Kinds of Epithelium tissue
    • Covering and Lining Epithelium
    • - outter layers of skin, lines the cavities of cardiovascular, digestive, respiratiry systems and covers the walls and organs of the closed ventral body cavity

    • Glandular Epithelium
    • - fashions the glands of the body
  2. Special Characteristics of Epithelium
    • 1) Polarity
    • -Apical Surface, basal surface, basal lamina
    • 2) Specialized Contacts
    • -tight junctions
    • 3) Supported by Connective Tissue
    • -deep to the basal lamina is the reticular lamina. both are the basement membrane
    • 4) Avascular, but Innervated
    • -nurished by substances diffusing from blood vessels in connective tissue
    • 5) Regeneration
    • -high regenerative capacity
  3. Classification of Cells
    Either by number of cell layers or by shape

    Simple vs. stratified

    Squamous vs. cuboidal vs. columnar
  4. Simple Squamous Epithelia
    flat, sparse cytoplasm, filtration

    Endothelium- provides slick, friction reducing lining in the lymphatic system. Also, in the hollow organs of the cardiovascular system (heart and blood vessels)

    Mesothelium- found in the serous membranes lining the ventral cavity and its organs
  5. Simple Cuboidal

    important functions: secretion and absorbtion

    ex: kidney tubules
  6. Simple Columnar and Pseudostratified Columnar
    • Simple Columnar- tall,
    • -function: secretion and absorbtion
    • - dense microvilli on the apical surface of absorbative cells
    • -goblet cells secrete mucus

    • Pseudostratified Columnar- vary in height, all cells touch basment membrane but only tallest reach apical surface, have cilia
    • -they absorb and secrete like simple
    • -ex: lining of trachea
  7. Stratified squamous epithelium
    • -most widespread epithelium
    • -apical surface is squamous, may be cuboidal or columnar deeper
    • -top layer constantly rubbed off
    • -skin is keratinized to make the surface harder
    • -forms the external layer of sin and a short way into all orephaces directly attached to the skin
  8. Stratified cuboidal epithelium
    • -quite rare in the body
    • -typically two layers

    ex: ducts of sweat glands, mammery glands
  9. Stratified Columnal
    • -also rare
    • -found in small quantities in the pharymx, make urethra, and lining of some glandular ducts
  10. Transitional Epithelium
    • -forms the lining of hollow urinary organs, which stretch to fill with urin
    • -basal layer is cuboidal and columnar
    • -when bladder is filled, the apical layer thins out, allowing for more urine
  11. Glandular Epithelium
    • Endocrine: internally secreting
    • -called ductless glands
    • -producde hormones secreted by exocytosis
    • -structurally diverse

    • Exocrine: externally secreting
    • -numerous
    • -secrete products onto skin or into body cavities
    • -ex: mucus, swear,oil, salviary gland, live, pancreas
    • -unicellular:mucous or goblet cells
  12. Classification of glandular epithelium
    • 1. Tubular: secretory cells form tubes
    • -simple: intestinal glands
    • -branches: stomache glands
    • -compound:glands of small intestine

    • 2. Alveolar: secretory cells form small, flasklike sacs
    • -simple: non in humans
    • -branched: sebaceous glands
    • -compund-mammery glands

    • 3. Tubularalveolar-have both
    • -salivary glands
  13. modes of Secretion of glandular epithelium
    • 1. Mesocrine: secrete by exocytosis and sectrory cells are not altered
    • -ex: pancreas, salivary glands, most sweat glands

    • 2. Holocrine: accumulate product within the secretory gland until they rupture. dead cell fragments are released as well
    • -ex: oil glands

    • 3. Aprocrine glands: might not exist in humans, possibly the mammery glands
    • -glands accumulate product just below free surface, apex pinches cell off; released the product and small amounts of cytoplasm
  14. Connective Tissue
    • -Found everywhere in hte body
    • -Most abundant and wifely distributed of all the primary tissues

    • 1. Connective Tissue Proper
    • 2. Cartilage
    • 3. Bone Tissue
    • 4. Blood

    • Major Functions:
    • 1. Binding and Support
    • 2. Protection
    • 3. Insulation
    • 4. Transportation
  15. Common Characteristics of Connective Tissuee
    1. Common Origin: all connective tissue arise from the embyronic mesenchyme

    2. Degrees of Vascularity: cartilage is avascular, dense connective tissue is poorly vascularized, wile other have rich blood flow

    3. Extracellular Matrix: large portions are matrix, which bears weight, endures abuse, and withstands great tension
  16. Structural Elements of Connective Tissue
    • 3 Main Elements:
    • -Ground Subtance
    • -Fibers
    • -Cels
  17. Ground Substance
    • -unstructured material that fills the space between cells
    • -contains the fibers
    • -holds large amounts of fluid
    • -acts as molecular sieve or medium through which nutrients nad other dissolved substances can diffuse between blood capillaries and cells
  18. Fibers of Connective Tissue
    Provide Support

    • Collagen fibers: white fibers
    • -strongest and most abundant
    • -constructed of collagen
    • -provide high tensile strength

    • Elastic Fibers: yellow fibers
    • -long, thin and form a network
    • -elastin allows them to stretch like rubber bands

    • Reticular Fibers:
    • -short, fine, collagenous fibers
    • -branch extensively to form networks
    • -netlike
  19. Cells of Connective Tissue
    • Blasts: miotically active and secretory cells
    • - fibroblast
    • -osteoblast
    • -chondroblast
    • *hematopoietic stem cells in bone marrow produce blood cells

    • Cytes: matures blasts
    • -fibrocytes, osteocytes, chondrocytes

    • White Blood Cells
    • Fats
    • Mast cells- detect foreign microorganisms
    • Macrophage- eat up foreign and dead materials
  20. Embyronic Tissue
    All connective tissues arise from mesenchyme
  21. Connective Tissue Proper
    list them
    • 1. Areolar Connective Tissue
    • 2. Adipose
    • 3. Reticular Connective Tissue
    • 4. Dense Connective Tissue Proper
    • - Dense Regular
    • -Dense Irregular
    • - Elastic
  22. Areolar Tissue
    Image Upload 1
    • Function:
    • 1. supporting and binding other tissues
    • 2. holds body fluids
    • 3. defends against infection
    • 4. storing nutrients as fats

    • Description
    • Gel-like matrix with..
    • -all 3 fibers
    • -cells
    • -fibroblasts
    • -mascrophages
    • -mast cells
    • -some white blood cells (when effected area becomes puffy its called edema)

    • Location:
    • -widely distributed under the epithelia of the body
    • ex: surrounds capillaries, packages organs, forms lamina propria of mucous membranes
  23. Adipose
    Image Upload 2
    • Function:
    • -provides reserve food fuel
    • -insulates against heat loss
    • -supports and protects (cushions) organs

    • Description:
    • -Very closely packed
    • -signet ring look because the nuclei are pushed to the sides due to oil droplet

    • Location:
    • -genetically dispositioned areas
    • -behind eyes
    • -around kidneys
    • -underskin in hypodermis
  24. Reticular Connective Tissue
    Image Upload 3
    • Function:
    • -fibers form a soft internal skelton that supports other cell types including white blood cells, mast cells, and macrophages

    • Description:
    • -network of reticular fibers
    • -reticular cells lie on network

    • Location:
    • lympoid organs
    • -lymphg nodes
    • -spleens
    • -bone marrow
  25. Dense Regular Connective Tissue
    Image Upload 4
    • Function:
    • -attaches muscles to bone or bone to muscles
    • -withstands great tensile stress when pulling force is applied in one direction

    • Description:
    • -primarily collagen fibers
    • -a few elastic fibers
    • -major cell type is the fibroblast
    • -run in the same direction

    • Location:
    • -tendons
    • -most ligament
    • -aponueroses
  26. Dense Irregular Connective Tissue
    Image Upload 5
    • Function:
    • -provides structural strength
    • -able to withstand tension exerted in many directions

    • Description:
    • -primarily irregularly arranged colagen fibers
    • -some elastic fibers
    • -major cell type is the fibroblast

    • Location:
    • -dermis of the skin
    • -fibrous capsules of organs and of joints
    • -submucosa of digestive tract
  27. Dense Connective Tissue-Elastic
    Image Upload 6
    • Function:
    • -allows recoil of tissue after its been stretched
    • -maintains pulsatile flow of blood trhough arteries
    • -aids in passive recoils of lungs following respirtation

    • Description
    • -contains a high proportion of elastic fibers

    • Location:
    • -walls of large arteries
    • -within walls of bronchial tubes
    • -within certain ligament associated with the vertebral column
  28. Cartilage Charactertistics
    • -tough but flexible
    • -avascular
    • -lacks nerve fibers
    • -up to 80% water
    • -recieves nurtients by diffusion of connected tissue
    • -chondroblasts and chondrocytes are primary cells
  29. Hyaline Cartilage
    Image Upload 7
    • Function:
    • -supports and reinforces
    • -resists compressive stress
    • -has resilient cushioning properties

    • Description:
    • -amorphous but firm cartilage
    • -collagen fibers form iomperceptible network
    • -chondroblasts produce matrix
    • -when chondorblasts mature, chondrocytes are found in lacunae

    • Location:
    • -nose, trachea, larynx
    • -costal cartilage
    • -covers the ends of longbones in joint cavities
    • -forms most of the embryonic skeleton
  30. Elastic Cartilage
    Image Upload 8
    • Function:
    • -maintains shape while allowing flexibility

    • Description:
    • -similar to hyaline, but more elastic fibers in matrix

    • Location:
    • -supports the external ear
    • -epiglottis
  31. Fibrocartilage
    Image Upload 9
    • Function:
    • -tensile strength with the ability to absorb compressive shock

    • Description:
    • -matrix similar to less firm than hyaline cartilage
    • -thick collagen fibers predominate

    • Location:
    • -intervertebral discs
    • -discs of knee joint
    • -pubic symphisis
  32. Osseous Tissue (Bone)
    Image Upload 10
    * osteoblasts and osteocytes main cells

    • Function:
    • -bone supports and protects
    • -provides levers for muscles to act on
    • -stores calcium and other minerals and fat
    • -marrow inside spongy bone in where blood cells are made

    • Description:
    • -hard, calcified matrix
    • -collagen fibers
    • -very well vascuarlized
    • -osteocytes lie in lacunae

    • Location:
    • -Bones
  33. Blood
    Image Upload 11
    *does not "connect" but develops from mesenchyme

    • Function:
    • -transport respiratory gases, nutrients, waste, and other substances

    • Description:
    • -red and white blood cells in a fluid (plasma) matrix

    • Location:
    • -Inside blood vessels
  34. Neurvous Tissue cell Types
    • 1. Neurons: highly specialized nerve cells that generate and conduct nerve impulses
    • -respond to stimuli
    • -transmit electric impulses over long distances in the body
    • -dendrites recieve message
    • 2. Axon: distributes potential message
    • -Schwann Cells around Axon (cell membrane insulates)

    *fatty sheath around neuron
  35. Nervous Tissue
    Image Upload 12
    • Function:
    • -transmit electrical signals from sensory receptors and to effectors which control their activity

    • Description:
    • -neurons are braching cells
    • -cell processes that may be quite long extend from the nucleus-containing the cell body

    • Location:
    • -brain, spinal cord, and nerves
  36. Muscle Tissue
    • -highly cellular
    • -well vascularlized
    • -responsible for most types of body movement
    • -possesses Myofilaments
  37. Skeletal Muscle
    Image Upload 13
    • Function:
    • -locomotion and voluntary movement
    • -manipulation of the enviornment
    • -facial expression
    • -voluntary control

    • Description:
    • -long and cylindrical
    • -multinucleate cells (muscle fibers)
    • -obvious striations

    • Location:
    • -skeletal muscles attached to the bone
    • -occassionally skeletal muscles attached to the skin
  38. Cardiac Muscle
    Image Upload 14
    • Function:
    • -as it contracts, it propels blood into circulation
    • -involuntary control

    • Description:
    • -branching and striated
    • -generally uninucleate cells
    • -joined at intercalated discs

    • Location:
    • -walls of the heart
  39. Smooth Muscle
    Image Upload 15
    • Function:
    • -propels substances and objects (food, baby) along internal passageways
    • -involuntary control

    • Description:
    • -spindle shaped
    • -central nuclei
    • -cells arranged closely to form sheets

    • Location:
    • -mostly in walls of hollow organs
  40. Covering and Lining Membranes
    • Continuous, multicellular sheets compose of at least 2 types of tissue:
    • 1. An epithelium bound to..
    • 2. an underlying layer of connective tissue
  41. Cutaneous Membrane
    • -skin
    • -exposed to air = dry membrane
    • - protectoin
    • -keratinized simple squamous epithelium
    • -attached to a thick layer of irregular connective tissue (dermis)
  42. Muscous Membrane
    • -line the open body cavities
    • -"wet" or moist membrance
    • -protection and lubrication
    • -often adapted for secretion and absorbtion
    • -most mucosae contain either: stratified squamous or simple columnar
    • -epithelial sheet directly underlain by loose connective tissue (lamina propria)
  43. Serous Membrane
    • -moist membrane
    • -found in closed ventral cavities
    • -simple squamous on top of a thin layer of loose connective tissue (Areolar)
    • -serous fluid lubricates the face visceral and paietal layers so they glide against each other
    • -parietal covers cavity, visceral covers organ
  44. Inflammatory response
    non-specific to injurt, while immune response is very specific but takes longer to kick in
  45. Steps to Tissue repair
    • 1. Inflammation sets the stage
    • 2. Organization restores blood supply
    • 3.Regeneration and Fibroblasts effect permenant repair
  46. Inflammation sets the stage
    -capillaries dialate and become permeable, allowing white blood cells, antibodies, platelet rich plasma, and other substances to site of injury

    • -leaked clotting protiens create clot
    • -stops bleeding
    • -holds wound together
    • -protection

    -clot exposed to dry air creates a scab
  47. Organization restores blood supply
    • -Granulation tissue replaces clot
    • ->contains capillaries which grow from other areas, restoring the blood supply to the site of the injury

    -fibroblasts and granulation tissue produce collagen fibers that fill the gap

    -macrophages digest debris and the original clot

    -epithelium regenrates
  48. Regeneration and fibrosis effect permenant repair
    -scab detaches

    -fibrosed area matures and contracts

    -epithelium thickens

    -underlying scar tissue
  49. Developmental Aspects of Tissue
    3 primary germ layers in embryonic development:

    • 1. Ectoderm
    • 2. Mesoderm
    • 3. Endoderm

    • Ectoderm --> nervous tissue
    • Mesoderm --> muscle and connective tissue
    • All 3 --> Epithelium
  50. Tissues during a lifespan
    -at 2 mo after conception, primary tissues have appeared and all major organs are in place

    -division of nerve cells stops or nearly stops during fetal period

    -In adults, only epithelial and blood tissue are highly miotic

    • -In old age...
    • - epithlia thins
    • -bone, muscle, and nervous tissue begin to astrophy
    • -these things often result from a deteriorating diet or decreased circulatory effiency
    • -higher risk of DNA mutations and cancer
Card Set
a&p lecture chap 4
epithelial tissue, muscle tissue, nervous tissue, and connective tissue