HDM Final Practical

what are the abdominal lymph nodes?

• pre-aortic

  • sup. + inf. mesenteric

  • coeliac

• para-aortic

what does the celiac lymph node drain?

• splenic

• right gastroepiploic group —> stomach

• left gastric —> stomach

• hepatic group —> liver + bile duct

  • either side of duodenum

• pyloric —> pancreas

what does the superior mesenteric lymph node drain?

• midgut

  • cecum

  • jejunum

  • ileum

  • appendix

  • (2/3 upper) ascending colon

what does the inferior mesenteric lymph node drain?

• hindgut

  • (distal 1/3) descending colon

  • sigmoid colon

  • upper rectum

where do the celiac + mesenteric lymph nodes drain?

pre-aortic —> intestinal lymph trunk —> cisterna chyli —> thoracic/right duct —> subclavian vein

what does the para-aortic lymph node drain?

• adrenal gland, kidney, gonads

• common iliac lymph node

• note: behind peritoneum

what does the para-aortic lymph node drain into?

lumbar trunk —> cisterna chyli —> duct —> vein

what are the pelvic lymph nodes?

• external (yellow) + internal (green) iliac

• sacral (red)

• common iliac (orange)

what does the sacral lymph node drain? what does it drain into?

• lower rectum, lower vagina, pelvic wall

• drains into —> common iliac —> para-aortic —> lumbar

what does the internal iliac lymph node drain? what does it drain into?

• lower bladder, prostate, penis, cervix, post. vagina, deep perineum

• drains into —> common iliac LN —> para-aortic —> lumbar trunk

what does the external iliac lymph node drain? what does it drain into?

• sup. bladder, lower uterus, ant. vagina, cervix (not main)

• male urethra

• deep inguinal LN

• drains into —> common iliac —> lumbar trunk

• near femoral nerve

what do the sacral, internal iliac and external iliac drain into?

common iliac —> para-aortic —> lumbar trunk

what are the lymph nodes of the lower limb?

• popliteal

• superficial inguinal

• deep inguinal

what does the popliteal lymph node drain? what does it drain into?

• skin over lat. leg + foot, post. leg

• deep post. leg + knee

• anterior tibial lymph node (deep ant. lower leg)

• drains into deep inguinal —> external iliac —> common iliac —> para aortic

what does the superficial inguinal- horizontal lymph node drain?

• gluteal region + lat. thigh

• skin penis, scrotum, vulva

• tip of uterine fundus + uterine tube

• perineum, abdominal wall

what does the superficial inguinal- vertical lymph node drain?

• skin of lower limb (NOT buttock or saphenous region)

• medial leg + foot, bottom of foot

• superficial

what do the superficial inguinal + popliteal lymph nodes drain into?

deep inguinal —> external iliac —> common iliac —> para-aortic

what structures does the deep inguinal lymph node drain? what does it drain into?

• glans of penis/clitoris

• deep thigh

• drains into —> external iliac —> common iliac

what are the barriers against pathogen?

• microbiome

• chemical —> AMP, IgA, mucous

• physical —> epithelium

• immuno —> LP, immune cells

what is mucous composed of?

• glycosylated proteins (mucins)

• AMP, lysozyme, IgA

what are the diffuse and organized lymphoid cell structures of MALT?

• diffuse: lymphocytes, mast cells, MO, DC in LP + epithelia

• organized: mucosal tracts in LP —> contain BALT

what type of epithelium does the upper respiratory tract (nose, sinus, larynx) + trachea have?

ciliated pseudostratified columnar

what type of epithelium is the nose, pharynx, and esophagus (upper tract) composed of?

stratified squamous epithelium

what are the alveoli composed of?

• simple squamous

• goblet 

• clara cells —> surfactant

• pneumocytes

• MO

what is the function of surfactant?

• ease alveolar expansion (tension)

• prevent collapse

what is the function of pneumocytes T1?

• squamous

• wall nuclei

• gas exchange

what is the function of pneumocytes T2?

• can replace T1

• cuboidal

• wall nuclei

• surfactant —> lamellar bodies

what is the mechanism of asthma?

• allergens cross link IgE —> mast cell —> bronchoconstrictors + leukotrienes + PGD2

• thickened BM + mucous plug 

what type of epithelium composes the stomach and intestine?

• stomach: simple columnar —> secrete alkaline mucosa

• intestine: simple columnar w/ microvilli for digestion

where are crypts of Lieberkühn found? what are they composed of?

• between microvilli (intestine)—> digestion + renewal

• epithelium

• paneth —> stem cells + AMP

• contain CT, lacteal, capillaries, SM

what type of epithelium are the esophagus and rectum composed of?

stratified squamous

where are peyer’s patches found?

ileum (SI) —> in LP

what is are peyer’s patches composed of?

• M cells —> microfolds phagocytose antigen

• DC intra-epithelial T cells

• plasma cells —> IgA

• mesenteric LN —> drain LP via lacteals

what is the difference between the morphology of large intestine + small intestine tissue?

• small intestine: crypts, lacteals, villi

  • ONLY one w/ M cells

• large intestine: crypts

what sections of the small intestine are these?

• duodenum

• jejunum

• ileum

what are the functions of commensal bacteria in the gut microbiota?

• nutrition: K2, B12, SCFA

• detox

• barrier

• develop GALT

what are the characteristics of crohn’s disease?

• Th1 +Th17

  • granuloma + lymphoid aggregate

• skip lesion ileum + colon

• ILC + dec. IL-10

what are the characteristics of ulcerative colitis?

• Th2 —> crypt abscess + ulcer

• continuous lesions in rectum

• ILC + dec. IL-10

what is the change of tissue from rectum to anus?

• abrupt

• simple columnar —> stratified squamous 

what are 3 layers of blood vessels?

• adventitia —> CT

• media —> SM + elastic

• intima —> simple squamous

what are the 3 classes of blood vessels?

• arterial —> away from heart

• capillary —> site of exchange, drain ECF/ISF

• venous —> back to heart

what is the function of lymph vessels?

• drain ISF to CV system —> prevent edema

• uptake high molecular weight protein

• transport chyle to bloodstream via lacteal

what is the composition of the conjunctiva?

• non-keratinized, stratified squamous + columnar

• goblet cells

• high vascularization

what are the two parts of the conjunctiva?

• palpebral —> eyelid

• bulbar —> ant. eye

what are CALT/DALT (NALT) associated with?

• conjunctiva + lacrimal drainage

• T cell + IgA

what is the function of the lacrimal apparatus?

• tears -→ eliminate pathogens

• via mucins, lysozyme, lactoferrin, sIgA, B-defensin

what are the different tears that are produced?

• basal

• hyper lacrimation

• basal: constant

• hyper lacrimation: sympathetic (fight/flight) innervation

where is the lacrimal gland located? what is the drainage path?

• ant. lat. roof of orbit

• med. orbit —> nasaolacrimal duct —> inf. meatus of nasal cavity

  • valve of hasner guards ostium between

where is the meibomian gland located? what does it secrete?

• holocrine inside tarsal plate (bottom + top lids)

• secrete meibum (lipid rich on tear film)

  • prevents tear spillage + evaporation

what is blepharitis?

• bacterial or demodex infection

• obstructed meibomian gland —> eyelid (blephar-) inflammation (-itis)

what is dacryocystitis?

• inflamed lacrimal sac

• 2ndary to nasolacrimal blockage

• edema over medial canthus

what is dacryoadenitis?

• bacterial/viral infection of lacrimal (dacryo-) gland (aden)

• palebral inflammation (-itis)

what is keratoconjunctivitis?

• inadequate basal tears via lacrimal gland

• dry eyes —> sjogren’s syndrome

what epithelium are the renal pelvis, ureters, and bladder composed of?

transitional urothelium

what are umbrella cells?

• outer layer of urothelium

• tight barrier withstanding stretching + shedding

what type of epithelium composes the urethra?

pseudostratified

what are the immune functions of the urinary tract?

• flushes microbes

• exfoliation —> urothelial shed

• epithelium —> AMP, IL-6, B-defensin

• IgG + IgA

UTI cause + result

• cause: catheterization, E. coli, Klebsiella, Proteus

• compromised innate urination + altered epithelium

what are the structures of the female genital tract?

• vaginal mucosa —> strat. squamous, w/ DC + MO

• endocervix + uterine mucosa —> columnar (mucous) EXCEPTION

• acidic PH + microbicidal secretion

what is bacterial vaginosis?

• loss of lactobacilli

• inc anaerobes —> inflammation

• ascending infection risk

what is vaginal candidiasis?

via candida albicans

what is an STI?

• pathogens —> chlamydia, gonorrhea, HSV, HPV

• evade innate —> damage mucosa

what causes cervical cancer?

persistent HPV infection

what is the structure of the male genital tract?

• terminal urethra —> strat. squamous epithelium

• testes + epididymis —> immune privilege

• fewer MALTs

what are the components of the chemical barrier of the epithelial barrier?

• AMPs —> keratinocytes

• Mucins

• pH

• ceramides + cholesterol (lipids)

• lamellar bodies —> B-defensins + cathelicidians 

what tissue is the epidermis composed of? what are the layers?

• stratified keratinized squamous

• layers

  • stratum corneum

  • stratum lucidum —> thick

  • stratum granulosum —> keratohyalin, filaggrin, lamellar

  • stratum spinosum —> langerhans

  • stratum basale —> stem cells

what does the stratum baslae contain?

• stem cells w/ cytokeratin

• merkel —> ectoderm

• melanocyte —> ectoderm

what does the stratum spinosum contain?

• polyhedral keratinocytes —> protection, bound together via desmosome

  • keratinization

• langerhans cells —> mesoderm

what is the process of keratinization?

• basale —> stem cell

• spinosum —> polyhedral, live

• granulosum —> live

• lucidum —> dead

• corneum —> corneocytes (dead)

what is the function of keratohyalin granules keratinocytes produce in the stratum granulosum layer?

contain filaggrin —> cross-link keratin (insoluble structure protein) —> protein envelope/cell membrane (inner PM)

NOTE: contain loricrin

what is the function of lamellar bodies keratinocytes produce in the stratum granulosum layer?

lipid rich (ceramides, cholesterol, FA) —> secrete into EC space —> water proof lipid membrane (cell surface)

what is developmental origin of langerhans cells? what is its markers?

• HSCs in BM —> mesoderm

• CD1a IHC marker

• stratum spinosum

what is the developmental origin of melanocytes? what is it’s function?

• neural crest —> ectoderm

• produce + transfer melanin to keratinocytes

• stratum basale

what makes skin darker?

• inc. melanocyte DC

• inc. melanosomes

• inc. melanin

NOTE: light + dark —> same # melanocytes

what is waardenburg syndrome (WS)?

• mut. in melanocyte gene (PAX3)

• faulty neural crest cells

• symptoms: white forelock, heterochromia, white skin patch

what is albinism?

• congenital hypopigmentation

• tyrosine defect

what is vitiligo?

• acquired depigmentation

• dec. melanocyte activation via T cell autoimmune reaction

what is the function of the following skin sensory receptors?

• free nerve ending

• merkel

• pacinian

• meissner

• ruffian

• free nerve ending —> pain + temp

• merkel —> s. basale , sustained light touch

• pacinian —> firm touch

• meissner —> dermis, vibration

• ruffian —> stretch

what is the purpose of the 2 pt. discrimination test?

• for meissner

• test density of tactile receptor

• somatosensory integrity

what can cause a decrease in meissner receptor efficiency?

• age

• scleroderma via excess collagen from fibroblast

• CT/dermal sclerosis

what is atopic dermatitis (AD)?

• pruritic inflammation in epidermis

• Langerhans —> Th2 —> eosinophils + mast

• excoriation —> 2ndary infection in dermis

what is psoriasis?

• epidermis

• Th17 +Th1—> IFN-y, IL-17, IL-22

• silvery plaques via inc keratinization + desquamation

what is SLE?

• epidermis

• defect in classical (C1, C2, C4)

• innate immune act. via NA, inc. cytokines, FcyRIIB mut.

how does the epidermis + dermis interlock?

• dermal papillae

• epidermal pegs

what does the dermis hold?

• hair follicles

• macrophages

• lymphocytes

• fibroblasts —> mesoderm

what is the papillary layer of the dermis composed of? what does it contain?

• loose areolar CT

• fibroblast —> type 1 + 3 collagen + elastin

• dermal papillae —> finger print

• arrector pilli —> follicle + dermis

what is the reticular layer of the dermis composed of?

• dense irregular CT

• Type 1 collagen + elastin

  • collagen —> langer/skin tension lines

• hair follicles

what is the vascularity of the dermis?

• superficial papillary plexus —> pinkness, capillaries

• reticular/cut. —> hair follicle + gland, arterioles + venules 

what does the anteroventral anastomoses do?

prevents blood flow to superficial plexus when cold

what does the subcutaneous layer hold?

• adipose —> energy + insulation

• SM —> loose plexus (wrinkles)

• striated muscle (carnosus)—> platysma muscle + facial expression

what is the process of cutaneous wound healing?

• clot —> PDGF release —> MO + neutrophil enter

• inflammation —> MO release GF —> fibroblast inc

• granulation (capillaries) —> excess collagen (scar)

what is a sebaceous gland?

• non-glabrous skin

• secrete sebum near hair follicle

• sebocytes distend cell —> apoptosis

what is sebum?

• form lipid barrier, bacteriostatic effect, AMP

• holocrine secretion —> entire cell dies

what are sweat glands?

• sudoiferous glands

• composed of H2O, salt, lactic acid, urea

• bacteriostatic

what are eccrine sweat glands?

• in dermis

• watery

• cooling

• surface

what are apocrine sweat glands?

• in axillae + perineum

• after puberty

• protein-rich

• wider lumen

what is hidradenitis suppurativa?

• apocrine region

• inflammation, abscesses, fistulating

• sinus, chronic infection

what is miliara (heat rash)?

blocked eccrine sweat ducts

what is bromhidrosis?

• abnormal odor via apocrine gland

• secretion w/ bacteria 

what is hyperhidrosis?

eccrine gland excessive activation