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CYTOLOGY
HISTOLOGY
Four Primary Tissue
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Epithelial Tissue
Connective Tissue
Muscular Tissue
Nervous Tissue
EPITHELIUM
Definition
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closely apposed cells with little intercellular substances and occurs
as membranes and glands
- glandular epithelium
- covering epithelium
- sensory epithelium
Function
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-
protection
absorption
secretion
excretion
sensation
EPITHELIUM
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Characteristics
- little intercellular substance
☞ cement substance
- intercellular junction
- avascular
- polarity
- metaplasia
- regeneration
* Type
- 층에 따른 분류 & 모양에 따른 분류
simple
squamous
cuboidal
stratified
columnar
- Transitional epithelium (이행상피) :
- Pseudostratified columnar epithelium (거짓중층원주상피)
EPITHELIUM - Specialized structure
Free surface
Basal surface
Lateral surface
1. Free surface
1) microvilli (미세융모)
2) stereocilia (부동모)
3) cilia & flagella (섬모 & 편모)
2. Basal surface
1) basal infolding
2) basal process
3. Lateral surface
= cell junction, intercellular junction
세포집단의 형성, 세포의 부착 및 교통에 도움
- occluding junction (폐쇄결합)
: 세포사이 공간을 막고 막이 융합
- adhering junction (부착결합)
- communicating junction (교통결합)
EPITHELIUM - GLANDULAR EPITHELIUM
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exocrine gland
endocrine gland
mixed gland
Exocrine gland의 분류
- number of cells
unicellular gland
multicellular gland
- shape of duct
simple
compound
- shape of secretory portion
alveolar
tubular
EPITHELIUM - GLANDULAR EPITHELIUM
1) Simple tubular gland
intestinal gland
2) Simple coiled tubular gland
sweat gland
3) Simple branched tubular gland
stomach의 fundic gland, pyloric gland, uterus의 uterine gland
4) Simple alveolar gland
amphibian의 poison gland
5) Simple branched alveolar gland
sebaceous gland
6) Compound tubular gland
stomach의 cardiac gland, duodenum의 Brunner's gland
7) Compound alveolar gland
mammary gland, prostate gland
8) Compound tubuloalveolar gland
pancreas, salivery gland
EPITHELIUM - GLANDULAR EPITHELIUM
* nature of secretion
① serous secretion - serous acinus
② mucous secrection - mucous acinus
③ mixed gland - ‘serous demilune’
* mode of secretion
① holocrine : 분비물이 세포체 자체와 함께 분비 (온분비)
sebaceous gland (피지샘 / 기름샘)
② apocrine : 분비물이 세포체 일부와 함께 방출 (부분분비)
large sweat gland (겨드랑), mammary gland의 일부
③ merocrine : granule이 세포외 유출에 의해 분비 (샘분비)
나머지 대부분의 gland
*분비작용의 조절
유전적 조절
환경적 조절 nervous system 통해: by neurotransmitter
endocrine 통해: by hormone
CONNECTIVE TISSUE
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Characteristics
1. abundant intercellular substance
2. diversity of cellular components
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Classification
Embryonic CT
Connective Tissue Proper
Loose connective tissue
Dense connective tissue
dense regular connective tissue
dense irregular connective tissue
Adipose T.
Elastic T.
Specialized Connective Tissue
Bone
Cartilage
Blood
CONNECTIVE TISSUE
CONNECTIVE TISSUE PROPER
- Cellular Components
Fixed cells
Wandering cells
- Intercellular Substance (Matrix)
Fibers
Ground substance
Cellular Components
1. Fibroblast - Fibrocyte
2. Macrophage system
3. Mast cell
4. Plasma cell
5. Adipose cell
6. Mesenchymal cell
7. Others: leukocytes, smooth muscle cell
CONNECTIVE TISSUE
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Fibroblast - Fibrocyte
blastic activity - intercellular substance
limited activity in resting stage (fibrocyte)
-blast, -cyte change
osteoblast - osteocyte
chondroblast - chondrocyte
cementoblast - cementocyte
Fibers (collaen, elastic) & ground substance production.
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Macrophage System
high phagocytic activity – secondary lysosome
Mononuclear phagocytic system (MPS)
histiocyte / Kupffer cell / dust cell (alveolar macrophage)
osteoclast / microglia / Hofbauer cell
CONNECTIVE TISSUE
Mast Cell
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Large cell, 20-30 mm in diameter
with small nucleus, prominent Golgi
filled with abundant secretory granules
- storage of chemical mediators of immediate type immune
response
Plasma Cell
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Antibody (Ab)producing cell
cytoplasmic basophilia - abundant rER
perinuclear halo ----- Golgi complex
Chronic inflammatory cell
humoral immune response
Precursor cell ----- B lymphocyte
CONNECTIVE TISSUE
Adipose (Fat) Cell
- 20-100 mm in diameter
- single central lipid droplet , peripheral nucleus
- signet ring cell
- under skin, around kidneys and eyeballs, breasts
- abundant mitochondria and lipid droplet
- heat generation, energy store
Mesenchymal Cell
- small stellate cell, 7-10 mm in diameter
- precursor of connective tissue cell of embryonic
mesenchyme
CONNECTIVE TISSUE
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Connective Tissue Fiber
1. Collagen fiber ----type I collagen
2. Reticular fiber ----type III collagen
3. Elastic fiber -------elastin, fibrillin
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Collagen Fiber
White in color, Acidophilic, thick
Very resistant to traction
- extensibility ---- 5%, very high tensile strength
Most abundant proteins of the body
- 20% of total body proteins
Abnormal collagens
cause many Dz.
CONNECTIVE TISSUE
Collagen defects
Scurvy – deficiency of Vitamine C, cofactor for proline hydroxylase
Ehlers-Danlos syndrome typeVI
– faulty lysyl hydroxylation, kyphoscoliosis
Ehlers-Danlos syndrome typeIV
– defects in type III collagen, vascular abnormalities
Ehlers-Danlos syndrome typeVII
– defects in procollagen peptidase, articular abnormalities
Osteogenesis imperfecta – type I collagen gene mutation
Chondrodysplasia – type II collagen gene mutation
Collagen excess
Fibrosis
Kelloid
Cirrhosis
CONNECTIVE TISSUE
Reticular Fiber
Composed of reticular tissue
Argyrophilic, thin (0.5-2m) fiber
Fc. - support
Immature Fiber - Abundant in embryonic tissues and wound healing
Location - glands, lymph nodes, thymus, spleen
Elastic Fiber
0.1-10 mm thick fiber
High Elasticity (rubber-like consistency)
Distribution – lung tissue, wall of aorta
Elastic Fiber – Elasticity , stretch and relaxation
Defects in Fibrillin – Marfan syndrome
CONNECTIVE TISSUE
Ground Substance
amorphous material that fills the space between cells and fibers
Fc. – a molecular “sieve”
Proteoglycan
glycosaminoglycan (GAG)
Structural Glycoprotein
fibronectin, laminin, chondronectin
Specialized CT
Elastic cartilage
composed of elastic fibers
Location – external ear, epiglottis
Fc. – maintenance of shape plus flexibility
Specialized CT
Fibrous cartilage
less firm than hyaline or elastic cartilage
Location – intervertebral disc, pubic symphysis
Fc. – tensile strength plus shock absorber
Bone
Hard, calcified matrix with collagen fibers and osteocyte
Location – bones
Fc. – protection, support, movement, calcium store and
hemopoiesis
Highly vascular
fast healing
Blood
erythrocytes, leukocytes, and platelets in a fluid matrix called
plasma
Location – within heart and blood vessels
Fc. –transport of gases, nutrients, wastes
Muscular tissue
• All muscle cells are elongated
• Contractility
• 3 types
Skeletal m.
Smooth m.
Cardiac m.
muscle fibers
Skeletal muscle tissue
• structure – long, thin cells with many nuclei
alternating areas of light and dark (striation)
• location – attached to bones
• Fc. – move bones of skeleton, heat production
• control - voluntary
Muscular tissue
Smooth muscle tissue
• structure – spindle shaped cells with one centrally located nu.
no striation
• location – walls of hollow visceral organs, BV,
attached to hair follicles in the dermis
• Fc. – movement of food through digestive tract
• control – involuntary
Skeletal muscle tissue
• structure – network of cells with one centrally located nu.
intercalated disc, striation
• location – heart, aorta
• Fc. – pump blood from heart to lung & body
• control - involuntary
Nervous tissue
• structure – neurons
neuroglias – supporting cells
• location – brain, spinal cord, nerves
• Fc. – coordination or integration of body parts
• No reproduction of neurons, only neuroglia can divide