ANATOMY Flashcards
Layers of body tube
Lumen
Mucosa - epithelium, sub epithelial connective tissue (lamina propria),muscularis mucosa
Submucosa
Muscularis externa
Serosa / C.T adventitia
Plexus in gut tube
Meissner’s plexus - Submucosa
Auerbach’s plexus/ Myenteric plexus- Muscularis externa
Hirschsprung disease peculiarity
Congenital aganglionic megacolon due to absence of NCC in Muscularis externa; Auerbach’s plexus
Glands are present in which layer of gut tube
Lamina propria except in esophagus where glands are located in submucosa
Strongest layer of esophagus and small intestine
Submucosa
Peritoneal lining is absent in which part of gut tube
Esophagus
Peculiarity of stomach wall layers
3 layers of muscles- oblique, circular and longitudinal
simple columnar epithelium with gastric glands
Cells of gastric glands
Surface mucous cells - mucus
Parietal cells - HCl
Chief cells - Pepsin
Endocrine cells - Gastrin
Small intestine peculiarities
Columnar epithelium- villi and microvilli
Plica semilunaris
Microvilli
Peritoneal serosa with mesothelium
Respiratory tubes peculiarities
Lining- Pseudostratified ciliated columnar epithelium (also seen in epididymis with stereocilia)
Hyaline cartilage seen in respiratory tubes to maintain the patency
Smooth muscles
Immotile cilia syndrome
Kartagener syndrome
Urinary bladder peculiarities
Transitional epithelium
Muscle- Detrusor
Skin epithelium peculiarities
Keratinized stratified squamous epithelium
Epidermis - Sweat and Sebaceous glands
Dermis - papillary dermis and reticular layer
Epithelium of thyroid follicles
normal follicle - simple cuboidal
Active - simple columnar d/t increased ER
Inactive - simple squamous
Glands and Ducts lined by
simple cuboidal epithelium
Respiratory tubes
Pseudostratified Ciliated Columnar epithelium with Goblet cells
Stratified Squamous epithelium
Mainly found in external openings and site prone for injury like vocal cords
Vagina Linings
Upper Mesoderm
Lower Endoderm
All lined by stratified squamous epithelium
Oral cavity linings
Tongue and hard palate - keratinized - orthokeratinization and parakeratinization- supercficial layer nucleus seen
tongue, epiglottis and soft palate - Non keratinized
Urethra of male lined by
Simple cuboidal epithelium and tip by stratified squamous epithelium
Anal canal peculiarity
Strat. squamous epithelium below dentate line
Barret’s esophagus
Intestinal metaplasia in lower esophagus
As a result of GERD
>5 cm of squamocolumnar junction metaplasia
Types of gland
Merocrine - pancreas
Apocrine - mammary gland (secretory vesicles)
Holocrine - Sebaceous gland (whole cell destroyed)
Sweat gland is type of
Eccrine (merocrine)
Apocrine (Rare) - axilla, perigenital area, seruminous gland
Salivary gland types
Serous - Parotid
mucinous- Sublingual
Mixed - Submandibular
Serous demilunes are found in
Both submandibular(large in number) and sublingual(chiefly mucinous.
Serous acinus
Cuboidal cells
Darkly stained
Central spherical nucleus
Mucous acinus
Columnar cells with oval basal nucleus
Lightly stained
Serous demilune peculiarity
Mucinous acinus with serous cap
Connective tissue fibres types
Collagen fibres
Elastic Fibres
Reticular fibres
Elastic fibres (3S B)
Short
Straight
Single
Branching
Provides elasticity
Collagen fibres
Long
Wavy
Bundle of fibres
Non branching
Provides strength
Reticular fIbres
Type iii collagen fibres
Network of fibres
Give framework
Loose areolar connective tissue
Cells - Fibrocytes, Macrophage, Mast cells
Fibres - collagen fibres and elastic fibres
Ex- Lamina propria
Reticular connective tissue sites
Spleen
Liver
Lymph node
Dense regular connective tissue
Tendon
Ligament
Aponeurosis
Dense Irregular Connective Tissue
Seen in coverings like Periosteum, perichondrium , deep reticular dermis, nerve and muscle sheaths
Type I collagen fibres
M/C
Bone
Tendon
Ligaments
Fibrocartilage
Old scar tissue
Dermis
Type II collagen fibres
Cartilages - hyaline and elastic
Type III collagen fibres
Reticular Fibres - liver, LN, Spleen except Thymus
Granulation tissue
Type IV collagen fibres
Basement membrane
Types of cartilages
Hyaline cartilage
Elastic cartilage
Fibrocartilage - Atypical
Features of typical cartilage
Type II collagen fibres
No NVB
Exchange through diffusion
Features of atypical cartilage
Type I Collagen fibres
NVB present
Hyaline cartilage peculiarity
Islands of chondrocytes in lacunae and matrix
Perichondrium absent in articular cartilage
Site - Fetal cartilage, articular cartilage, Growth plates, costal cartilages, Respiratory tubes except larynx
Elastic cartilage Peculiarity
Rarest
3E - external ear pinna, eustachian tube , epiglottis
3T 2C -tip of arytnoid, corniculate and cuneiform
tip of nose, Tritaite cartilage
Elastic fibres in matrix
Type ii collagen fibres can be seen
Single chondrocyte in lacuna
Fibrocartilage peculiarity
Type I collagen fibres- extremely dense
Perichondrium absent
chondrocytes in row far apart in between fibres - shock absorber
intervertebral disc, pubic symphysis, menisci, articular disc in TMJ and SCJ
Primary lymphoid organs
With stem cells forms lymphocytes
Ex - Red bone marrow(B lymphocytes), Thymus (T lymphocytes)
Di George Syndrome
Absence of thymus, so no T lymphocytes. Babies dies d/t severe infections.
Secondary lymphoid organ
MALT - Tonsils, Aggregated lymphoid nodules and appendix
Capsulated - Lymph nodes, spleen
Skin epidermis layers
- Stratum corneum
- Stratum lucidum (thick skin)
- Stratum granulosum - Kerato hyaline granules- helps in formation of keratin for top layers.
- Stratum spinosum (Prickle cell layer)
- Stratum basale (Stratum germinatum)
Langerhans cells found in
Stratum spinosum. APC
Melanocytes found in
From NCC. In stratum basale layer. Other receptor is Merkel cell- light touch.
Why spinous cells in Stratum spinosum? Disorder related to this layer
Due to desmosomal attachment at end, while preparation of skin specimen it is disrupted resulting in spinous cells.
Similar condition in Pemphigous vulgaris
3 cells in Stratum basale
Stem cells
Melanocytes
Merkel cells
Cell in Stratum spinosum
Dendritic cell - APC
Skin receptors
- Free nerve endings- St spinosum for nociception, Type C fibres.
- Merkel cells - St. basale for light touch (slow adapting)
- Meissner corpuscle - Dermo epidermal junction for 2 point discrimination. (rapid adapting)
- Paccinian corpuscle - Deep reticular dermis for pressure and rapid vibration. (rapid adaption)
- Ruffini’s receptor- Deep reticular dermis for dermal stretch (slow adapting)
Receptors for braille reading
Precise - Merkel
Rapid - Meissner’s corpuscle
Types of cell junctions
- Zona occludens (tight junction)- very narrow gap
- Zona adherens - 20nm
- Macula Adherens - desmosomes- +5nm - 25nm - spot welding - CAM is Adherins
- Gap junctions - can act as electrical synapses - tunnel for exchange of ions - functional syncitium
- Hemidesmosomes -attach cell to basement membrane - CAM is integrin
Hemidesmosomes and desmosomes autoimmune disorder in
Hemidesmosomes change in bullous pemphigoid - subepithelial lesion
Desmosomes change in Pemphigus vulgaris - intraepithelial lesion- Nikolsky’s sign +ve - Tomb stone appearance - fish net appearance in immunofluorescence
Gap junctions peculiarity
Tunnel called cannexons with 6 components
Skeletal muscle peculiarities
cells are long, striated, cylindrical, multinucleated. anatomical syncitium .
Cardiac muscle peculiarity
Cells are short, branched, striated with single nuclei connected by intercalated discs (gap junctions). Perinuclear halo +(no myofibrils).
Smooth muscle peculiarity
Short, spindle shaped, non striated with central nucleus.
Partitions of respiratory tube and gut tube
upper - palate
lower - epiglottis
Lining epithelium of adenoids
Respiratory epithelium
Respiratory epithelium is absent in
nasal vestibule
vocal cords
lingual surface of epiglottis
All are lined by stratified squamous epithelium
Roof of nasal cavity - Olfactory epithelium - with bipolar neurons
Palate - s parakeratinized and non keratinized.
Features of epiglottis
Double epithelization
Elastic cartilage
Type of cartilage in larynx
Hyaline cartilage
Cartilage of respiratory tube
Hyaline cartilage which disappear from terminal bronchioles (lumen size 1mm)
Lumen sizes and peculiarity of respiratory tube
Trachea 2.5mm
Terminal bronchiole 0.5 to 1 mm - both goblet cells and hyaline cartilage disappear
Cilia disappears after respiratory bronchiole level
Alveolus lined by
simple squamous epithelium
Respiratory bronchiole lined by
Ciliated cuboidal epithelium with no goblet cells and hyaline cartilage
Bronchiole division
Conducting pathway
-large
-small
-terminal bronchiole
Respiratory pathway
-respiratory bronchiole
Clara cells
At the terminal divisions of respiratory tube, goblet cells will be replaced by Clara cells(club cell) - for surfactant production, stem cells and detoxifying cell.
Respiratory zone peculiarities
Lining epithelium changed to cuboidal and squamous epithelium. Cartilage replaced by smooth muscles. Clara cells present.
Cells in respiratory tube
Brush cells - receptor
Kulchitsky cells - Neuroendocrine cells - serotonin
Clara cells
What is lung histiocytosis?
Large number of Langerhans cells in lungs.
Lung alveoli peculiarities
Type I pneumocyte - simple squamous epithelium - fully lines alveolus
Type II pneumocyte - Surface active agent - simple cuboidal epithelium.
Alveolar macrophages (dust cells)
Alveolar pores of Kohn
Stomach parts
Cardia
Fundic - Fundus , body
Pylorus
Type of muscle in esophagus
Upper 1/3rd - Skeletal muscles
Middle 1/3rd - Skeletal + smooth muscles
Lower 1/3rd - Smooth muscles
Glands in stomach
Cardia and pylorus - Mucus secreating cells
Fundic region - fundus - Parietal cells (HCl, Intrinsic factor), Chief cells (pepsinogen)
Pernicious anemia peculiarity
Due to deficiency of Intrinsic factor for B12 absorption. Reduced HCl, megaloblastic anemia. Parietal cells compromised.
Stomach histology peculiarity
Gastric pit opening to gastric glands and isthumus/neck in between
Cells in stomach
Lumen - surface mucous cells - alkaline fluid
Stem cell - isthumus of stomach
Mucous neck cells - acidic fluid
Parietal cells - pink - cuboidal - secreates HCl and IF - fried egg appearance
Chief cells/Zymogen cells/Peptic cell - Blue and towards base - pepsin, lipase - columnar
Endocrine cells - G cells - Gastrin
Maximum absorption of small intestine
Jejunum
Peculiarities of different parts of small intestine
Duodenum - submucosal glands - Brunner’s gland - Urogastrone hormone - prevent ulcer and heal ulcer
Jejunum - maximum villi(finger like), microvilli and plica circularis - for absorption of food
Ileum - decreased or absent villi - Peyer’s patches -for absorption of water and electrolytes - villi leaf like
Cells of intestinal gland (Crypts of Leiberkuhn)
- Enterocyte - columnar cells for absorption
- Mucus secreating cells - goblet cells
- Paneth cells - maintain intestinal flora - kills excessive pathogens - bacteria and protozoa - apical eosinophilia due to lysozymes
- Microfold cell - APC
- Neuroendocrine cells -secretin , CCK - short cells
- Stem cell - Repair
Urogastrone function
Prevents Ulcer inhibits Parietal cells and reduce acid secretion
Heals ulcer by HEGF (Human Epidermal Growth Factor)
Large intestine features
Taenia coli - Thickening of outer longitudinal muscle - 3 bands
Maximum goblet cells
Colonocyte - absorb water and electrolytes
Anal canal features
Colorectal zone - simple columnar epithelium
Transitional zone - transitional epithelium from columnar to cuboidal epithelium
Dentate line
Squamous zone - stratified squamous epithelium
White line of Hilton - mucocutaneous junction
Perianal skin - true skin with sweat and sebaceous glands
*Anal canal does not have muscularis mucosa
Inner circular layer of rectum modifies to internal anal sphincter
Hepatic circulation
Hepatic artery - Liver sinusoids - central veins - hepatic veins - IVC - Heart
portal vein - liver sinusoids - central veins - hepatic veins - IVC - Heart
Portal triad
DAV
bile Duct
hepatic Artery
portal Vein
Hepatic sinusoid features
Fenestrated endothelial lining - blood moves out to space
Perisinusoidal space of Disse - contains lymph - microvilli of hepatocytes- also contain hepatic stellate cells of ITO - storage of fat and vitamin A
Kupffer cells - inside sinusoid - macrophage
Contents of perisinusoidal space of Disse
Villi of hepatocytes
Hepatic stellate cell of ITO
Pseudopodia of Kupffer cells
Lymph
Classic lobule
Sinusoid drain to central vein
Portal lobule
Bile drains to bile duct. Portal area is center
Portal acinus
Tissue supplied by terminal branches of hepatic artery and portal vein. Cells nearest these vessels were first to receive oxygen and nutrients - zone 1
Long axis - central vein
Short axis - portal triad
Renal medulla made of
Loop of Henle
Simple squamous epithelium lines which part of nephron
Glomerulus, Bowman’s capsule, Loop of Henle
PCT and DCT lined by
Simple cuboidal epithelium
Brush border microvilli seen in PCT(thick descending limb)
DCT function
Aldosterone based Na absorption
Loop of Henle function
Descending loop permeable to water and ascending limb permeable to NaCl
; More hypertonic urine in deeper medulla
Collecting ducts lined by
Simple columnar epithelium with principal cells and intercalated cells(microvilli)
Transitional epithelium lines
Minor calyx
Major calyx
Renal pelvis
Ureter
Urinary Bladder
Proximal half of prostatic urethra except in females
Urethra parts
Prostatic urethra - passing through prostate (1/2 lined by transitional epithelium)
Membranous urethra - passes deep perineal pouch
Spongy Urethra - i) Bulbous spongy urethra ii) Penile spongy urethra
* All lined by stratified columnar epithelium
* Tip lined by non keratinized stratified squamous epithelium
Grey matter and white matter
neuron body - grey matter
axons - white matter
white matter of CNS
Tract
Fascicles
Lemniscus
Capsule
White matter of PNS
Nerve
Grey Matter of CNS
Cortex
Nuclei
Grey matter of PNS
Ganglion
Axon sheath formed by
Oligodendrocytes in CNS and Schwann cell in PNS
Why optic nerve a misnomer?
It is tract from CNS, hence not a peripheral nerve. It is affected in Multiple Sclerosis - d/s affecting myelination of CNS ; oligodendrocytes.
Ectodermal placodes
These are neurectoderm cells migrating to surface ectoderm. They form Ganglia like trigeminal and vestibulocochlear ganglia
Anterior and posterior neuropore close on
Day 25 and day 28
