Histology

1
Histology

• Chapter 5

2
Histology

• Study of Tissues
• Intercellular Junctions, Glands and Membranes
• Tissue Growth, Development, Death and Repair

3
The Study of Tissues

• 200 Different cell types
• Four primary tissue classes
• ______________________
• connective tissue
• ______________________
• nervous tissue
• ____________ (microscopic anatomy)
• Organ __________________________
• composed of 2 or more tissue types

4
Features of Tissue Classes

• _______ similar cells with given function
• Differences between tissue classes
• types and functions of cells
• ___________________________________
  (extracellular material)
• _________________________________
• _________________________________
• clear gels (ECF, tissue fluid, interstitial
  fluid, tissue gel)
• rubbery or stony in cartilage or bone
• Number of cell layers

5
Epithelial Tissue

• ___________________________________________
  ___________________________________________
• ________________________________
• Attach to basement membrane
• collagen and adhesive proteins
• anchors epithelium to connective tissue

• _____________________
• contains one layer of cells
• named by shape of cells

• ____________________
• contains more than one layer
• named by shape of apical cells

6
Simple Squamous Epithelium

• _____________________________
• _____________________________
• Secretes serous fluid
• Alveoli, glomeruli, endothelium, and serosa

7
Simple Cuboidal Epithelium

• Single row cube-shaped cells (microvilli)
• ______________________________________
• ______________________________________,
  bronchioles, and kidney tubules

8
Simple Columnar Epithelium

• __________________________________________
• oval nuclei in basal half of cell
• __________________________________________
• Lining of GI tract, uterus, kidney and uterine
  tubes

9
Pseudostratified Epithelium

• _____________________________________
• nuclei give layer stratified look
• Secretes and propels respiratory mucus

10
Stratified Epithelia

• More than one layer of cells
• _________________________________
• _________________________________
• exception is transitional epithelium
• Deep cells on basement membrane

11
Keratinized Stratified Squamous

• Multilayered epithelium covered with dead
  squamous cells, packed with ______________
• epidermal layer of skin
• ________________________________________

12
Nonkeratinized Stratified Squamous

• Many living layers
• ____________________________
• Tongue, oral mucosa, esophagus and vagina

13
Stratified Cuboidal Epithelium

• Two or more cell layers surface cells square
• ______________________________________
  ______________________________________

14
Transitional Epithelium

• __________________________________________
  __________________________________________
• allows for filling of urinary tract
• ureter and bladder

15
Connective Tissue

• ___________________________________
  ___________________________________
• Most abundant and variable tissue type
• Functions
• connects organs
• support and protection (physical and immune)
• _____________________________________
• _____________________________________

16
Cells of Connective Tissue

• _________________________
• produce fibers and ground substance
• Macrophages
• phagocytize foreign material and activate immune
  system
• arise from monocytes (WBCs)
• ________________________________
• wander in search of bacteria
• Plasma cells synthesize antibodies
• arise from WBCs
• Mast cells secrete
• ______________________________
• histamine that dilates blood vessels
• ____________________
• store triglycerides

17
Fibers of Connective Tissue

• _____________________________
• tough, stretch resistant, flexible
• tendons, ligaments, deep layer of skin
• Reticular fibers
• thin, collagen fibers coated with glycoprotein
• ________________________ ________________________
• ___________________________
• ______________________
• stretch and recoil like rubberband (elasticity)
• skin, lungs and arteries stretch and recoil

18
Fibrous Connective Tissue Types

• Loose connective tissue
• ___________________ ___________________
• types
• _________________
• _________________
• adipose
• Dense connective tissue
• fibers fill spaces between cells
• types vary in fiber orientation
• dense regular connective tissue
• dense irregular connective tissue

19
Areolar Tissue

• Loose arrangement of fibers and cells in ground
  substance
• __________________________________________
  __________________________________________

20
Reticular Tissue

• Loose network of ________________________
• _______________________________________
• Found in lymph nodes, spleen, thymus and bone
  marrow

21
Adipose Tissue

• Empty-looking cells with thin margins nucleus
  pressed against membrane
• _________________________________________
• subcutaneous fat and organ packing

22
Dense Regular Connective Tissue

• ________________________________________
• compressed fibroblast nuclei
• _________________________ hold bones together and
  attach muscles to bones

23
Dense Irregular Connective Tissue

• _______________________________________
  _______________________________________
• withstands stresses applied in different
  directions
• deeper layer of skin capsules around organs

24
Cartilage

• Supportive connective tissue with rubbery matrix
• Chondroblasts
• produce matrix
• ? _____________________
• _______________________
• diffusion brings nutrients and removes wastes
• _________________________
• Types of cartilage vary with fiber types
• _______________________________________

25
Hyaline Cartilage

• Rubbery matrix scattered collagen fibers
  clustered ________________________________________
  ____
• supports airway, eases joint movements
• ____________________________ sternal ends of
  ribs supportive material in larynx, trachea,
  bronchi and fetal skeleton

26
Elastic Cartilage

• Cartilage with lots of elastic fibers
• __________________________________
• ______________________________

27
Fibrocartilage

• __________________________________ (never has
  perichondrium)
• Resists compression and absorbs shock
• ______________________________________________

28
Bone

• ______________ - spongy in appearance
• delicate struts of bone
• covered by compact bone
• _______________________________
• _______________________________
• ___________________ - solid in appearance
• more complex arrangement
• cells and matrix surround vertically oriented
  blood vessels in long bones

29
Bone Tissue (_____________)

• ____________________________________________
• ______________in lacunae between lamellae
  ___________
• Skeletal support leverage for muscles mineral
  storage

30
Blood

• Variety of cells and cell fragments some with
  nuclei and some without
• _____________________________ or nucleated white
  blood cells
• Found in heart and blood vessels

31
Nerve Tissue

• _______________________________________
• surrounded by smaller _________________
• internal communication between cells
• in brain, spinal cord, nerves and ganglia

32
Muscle Tissue

• Elongated cells stimulated to contract
• __________________________________
• move limbs
• push blood through a vessel
• expel urine
• ___________________________________
• 3 histological types of muscle
• skeletal, cardiac and smooth

33
Skeletal Muscle

• _____________________ _____________________
  _____________________ ______________________
• movement, facial expression, posture, breathing,
  speech, swallowing and excretion

34
Cardiac Muscle

• ___________________ ___________________
  ___________________ ___________________
• one central nuclei
• Pumping of blood by cardiac (heart) muscle

35
Smooth Muscle

• ________________________________________________
• _____________________________ iris hair
  follicles and sphincters
• swallowing, GI tract functions, labor
  contractions, control of airflow, erection of
  hairs and control of pupil

36
Intercellular Junctions

• All cells (except blood) anchored to each other
  or their matrix by intercellular junctions

37
_______________

• Encircle the cell join it to surrounding cells
• zipperlike complementary grooves and ridges
• __________________ __________________
• GI and urinary tracts

38
Desmosomes

• _______________________________
• Uterus, heart and epidermis

39
___________________

• Ring of proteins form a channel
• __________________________________
• in embryos, cardiac and smooth muscle

40
Endocrine and Exocrine Glands

• Secrete substances
• composed of epithelial tissue
• Exocrine glands ____________________
• Endocrine glands secrete (hormones)-______________
  ___________
• Unicellular glands endo or exocrine
• _____________________________________

41
Types of Exocrine Glands

• Simple glands - unbranched duct
• Compound glands - branched duct
• Shape of gland
• acinar - secretory cells form dilated sac
• tubuloacinar - both tube and sacs

42
Types of Secretions

• Serous glands
• ___________________________________
• sweat, milk, tears and digestive juices
• _________________________________
• produce mucin that absorbs water to form a sticky
  secretion called mucus
• Mixed glands contain both cell types
• Cytogenic glands release whole cells
• sperm and egg cells

43
Holocrine Gland

• _______________________________________
  _______________________________________
• oil-producing glands of the scalp

44
Merocrine and Apocrine Secretion

• ______________________ ___________________________
  _________________
• tears, gastric glands, pancreas, etc.
• Apocrine glands are merocrine glands with
  confusing appearance (apical cytoplasm not lost)
• mammary and armpit sweat glands

45
Mucous Membranes

• ___________________________________________
• __________________________________________
  reproductive, respiratory, urinary and digestive
• Mucous trap and removes foreign particles and
  bacteria

46
Membrane Types

• Cutaneous membrane skin
• stratified squamous epithelium over connective
  tissue
• relatively dry layer serves protective function
• ________________________________________
• connective tissue layer only, secretes synovial
  fluid
• Serous membrane (serosa) internal membrane
• covers organs and lines walls of body cavities

47
Tissue Growth

• ____________________ tissue growth ? cell
  multiplication
• Hypertrophy _____________________
  __________________________________
• muscle grow through exercise
• _________________ abnormal growth (tumor
  benign or malignant)

48
Stem Cells

• Undifferentiated cells with developmental
  plasticity
• _______________________________
• totipotent (any cell type possible)
• ________________ (tissue types only possible)
• Adult stem cells
• ________________(bone marrow producing several
  blood cell types)
• unipotent (______________________________)

49
Tissue Shrinkage and Death

• ____________________________________
• disuse atrophy from lack of use (leg in a cast)
• Necrosis _________________________
• _________________ - insufficient blood supply
• gas gangrene - anaerobic bacterial infection
• infarction - death of tissue from lack of blood
• ________________ - bed sore or pressure sore
• ____________________________________
• cells shrink and are phagocytized

50
Tissue Repair

• ________________________
• replacement of damaged cells with original cells
• skin injuries and liver regenerate
• ________________________
• replacement of damaged cells with scar tissue
• function is not restored
• healing muscle injuries, scarring of lung tissue
  in TB or healing of severe cuts and burns of the
  skin
• ___________________________________ (raised shiny
  scars)

51
Wound Healing of a Laceration

• Damaged vessels leak blood
• _________________________ ________________________
  _ _________________________
• dilates blood vessels
• increases blood flow
• increases capillary permeability
• Plasma carries antibodies, clotting factors and
  WBCs into wound

52
Wound Healing of a Laceration

• _____________
• Scab forms on surface
• _____________ clean up debris

53
Wound Healing of a Laceration

• New capillaries grow into wound
• _______________ _______________ _______________
• Fibroblastic phase begins in 3-4 days and lasts
  up to 2 weeks

54
Wound Healing of a Laceration

• _________________ _________________
  _________________
• Scab falls off
• Epithelium thickens
• Connective tissue forms only scar tissue
  (fibrosis)
• Remodeling phase may last 2 years