Types of Cartilage

3 Main Types of Cartilage

1) Articular cartilage

>> Seen in -
● arytenoid cartilage
● most synovial joints
● cricoid,costal
● throid ,tracheobronchial
● nasal septum and lateral wall
● ephiphyseal plate

>> has no nerves,no vessels,no perichondrium,no ossification

>> provides smooth articular surface

>> degenerated surface cells are replaced by underlying growing cells

2) Elastic cartilage :

>> present in structures reveiving or producing sounds

>> seen in
● auricle and acoustic meatus
● corniculate and cuneiform laryngeal cartilage
● epiglottis

3) Fibroelastic cartilage :

>> seen in
● intervertebral disc
● symphysis
● glenoid labrum and acetabular labrum

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Histology of Spleen

Spleen consist of
1) Capsule : Connective tissue covering of spleen consisting of collagen and elastin

2) Trabeculae : Holds capsule with inner splenic pulps

3) White pulp :

• Consist of B & T lymphocytes around central arteries.
• Blood moves out from central artery and reaches to marginal zone.
• @ marginal zone antigen presenting cells are present which process and present antigen from blood>>>this stimulates B & T lymphocytes

(Imagine Very thirsty couple(B/T lymphocytes) are present praying around Well(central artery) filled with plenty of water but with bacteria within.Impure water in well is purified by Antigen presenting cells in marginal zone and then provided to hungry couple.Getting water they are activated)

4) Red pulp : consist of 

• leaky Vascular sinuses : blood cells are engulfed here.Remaining debris is engulfed by phagocytic lining
• Splenic cords of bilroth

HISTOLOGY OF THYMUS GLAND

• Simila to spleen consist of capsule,trabeculae,cortex and medulla
• Cortex has free lymphocytes and no lymphatic nodules
• Medulla has epithelial reticular cells,hassal corpuscles
• Starts involuting after puberty

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Histology of Liver

Imagining liver histologically,consist of...

• Epithelial hepatocytes arranged in cords
• This cords are seperated from eact other by vascular sinusoids(4 structures in body with sinusoids are endocrine glands,liver,spleen,lymph nodes)
• Vascular or hepatic sinusoids are lined by fenestrated endothelium
• Space of disse - space between fenestrated endothelium and hepatocyte is called space of disse
• Blood from sinusoids pass easily through fenestrated endothelium into space of disse.Thus we can say hepatocytes are in direct contact with blood
• Kupffer cells -¤This are macrophages in liver¤star shaped,branched cytoplasm,large nuclei
• Liver lobule - portion of liver tissue drained by single central vein(br of hepatic vein),hexagonal structure on crossection
• Liver acini - potion of liver tissue supplied by single central artery(br of hepatic artery),forms diamond shaped triangular structure,is functional unit of liver
• Liver has dual blood supply - 1) all blood from spleen and intestine is drained via portal vein to liver 2) oxygenated blood by hepatic artery

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Types of Epithelium

A) Squamous Epithelium

     1) Simple Squamous : (mnemonic - all MEn are Ant)

• All - alveoli of lungs
• M - mesothelium of pleura,pericardia,peritoneum
• En - endocardium,endothelium
• An - ansa nephroni (renal loop of henle)

    2)  Keratinised stratified squamous

• Skin(epidermis)
• ducts of sebaceous gland(all ducts of glands are lined by cuboidal epit except sebaceous gland duct)

   3) Non keratisnised stratified squamous

• Mouth,tongue,tonsil,pharynx,esophagus
• Cornea
• Vagina

B) Columnar epithelium

   1) Simple columnar 

• Stomach
• Large intestine
• Cervical canal

   2) columnar with striated border(regular microvilli)

• Small intestine

   3) columnar with brush border(irregular microvilli)

• Gall bladder

   4) columnar with cilia(mnemonic - U Race)

• U - Uterus and uterine tubes
• R - respiratory epithelium
• A - auditory tube and parts of middle ear
• C - cervical canal and ventricles
• E - efferent ductules

   5) Pseudostratified columnar (mnemonic : all/ol trachea and auditory ducts are ur MP)

• Ol - olfactory epith
• Trachea and large bronchi
• Auditory tubes
• Ducts - ductus deferens
• Ur MP- urethra membranous and penile

   6) secretory columnar(goblet cells)

• Stomach,small intestine,large intestinee
• Trachea ,bronchi

C) Cuboidal epithelium (Mnemonic  DEFG)

• D - ducts of glands
• E - eye
• F - follicles of thyroid
• G - germinal epithelium

D) Transitional epithelium

• Urothelium( calyx ,pelvis,ampulla,ureter,bladder,part of uretha)

Bartholin gland

• Homologous to bulbourethral gland of male
• Ducts open outside hymen on inner surface of labia minora
• Acini lined by cuboidal,mid portion by transitional and outer portion by squamous epithelium

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