Anatomy and Histology Flashcards
Tay Sachs disease
Lysosomal dysfunction
Chediak-Higashi disease
Abnormal microtubular assembly, leading to decreased PMN phagocytosis and frequent infections
Kartagener syndrome
Dynein arm defect that causes recurrent lung infections due to decreased mucus clearing, hearing loss, and infertility.
Drugs that act on mictrotubules
Mebendazole/thiabendazole, taxol, griseofulvin, vincristine/vinblastine, colchicine
Principle types of cell junctions
Zona occludens (tight junctions), zona adherens (intermediate junctions), adherens junctions (desmosomes), hemidesmosomes, gap junctions (communicating junctions)
Zona occludens
Aka tight junctions. Determine epithelial cell polarity, separating apical from basolateral pole. Regulate passage of substances across epithelial barrier (paracellular transport)
Cadherins
Calcium-dependent adhesion proteins
Cells of adenocarcinomas
Often lose usual eptihelial cell junctions allowing them to infiltrate basal membrane of surrounding tissues, converting it from in situ to invasive leading to metastatic
Zona adherens
Located just below tight junctions, near apical surface of epithelial layer. Occurs periodically around circumference of cell
Hemidesmosome
Connects cells to underlying extracellular matrix
Gap junction
Allows adjacent cells to communicate for electric and metabolic functions. Connexon fromed from six connexin proteins.
Hematocrit
Percentage of erythrocytes in blood
Buffy coat
Leukocytes
Serum
Plasma without platelets and clotting factors
Erythrocytes
Only contain plasma membrane, cytoskeleton, Hb, glycolytic enzymes that help them survive by anaerobic respiration (90%) and hexose monophosphate shunt (10%)
Reticulocytes
Immature cells that are produced in bone marrow and replace mature erythrocytes. Still have nucleus and slightly larger diameter. Expel nucleus and mature 1-2 days after entering circulation
Promyelocyte lineage
Produces neutrophils, basophils, mast cells, eosinophils
Monoblast lineage
Produces monocytes
Increased reticulocyte count
When increased bone marrow production to replenish RBC levels in response to bleeding or hemolysis
RBC destruction
Removed by macrophages in spleen and to lesser extent, liver. Globin degraded to amino acids, iron released from heme and reused, tetrapyrrole (part of heme) converted to bilirubin which is mostly excreted in bile.
Neutrophils
Myeloid lineage. Act as acute phase granulocytes. Large spherical size, multi-lobed nuclei, azurophilic primary granules (lysosomes). Aka PMNs (polymorphonucleocytes) due to multilobed nucleus. Phagocytose via ROS.
Eosinophils
COntain azurophilic granules with myeloperoxidase. Larger than neutrophils and have cationic proteins e.g. major basic protein (antibacterial) and eosinophilic cationic protein (antiparasitic) with acidophilic granules. Once mature, possess large bilobed nucleus and sparse ER and Golgi vesicles.
Basophils
Produce peroxidase, heparin, histamine. Also release kallikrein (eosinophil chemoattractant during hypersensitivity rxns). Considered “blood-borne counterpart” of mast cell (which resides in tissues)
Mast cells
Similar to basophils but are larger and contain serotonin
Monocytes
Myeloid precursor to mononuclear phagocte (tissue macrophage). Large motile cell that marginates along vessel wall in response to expression of specific cell adhesion proteins. During inflamm response, cell adhesion proteins (esp PECAM-1) facilitate monocyte diapedesis across vessel walls into surrounding tissues. Once close to inflamm foci, differentiates into macrophage with increased phagocytic and lysosomal activity.
Macrophages
Contain large number cell surface receptors which differ based on tissue which monocyte matured in.
Multinucleated giant cells
Sites of chronic inflamm–macrophages sometimes fuse into these, Can be produced in-vitro via IFN-gamma or IL-3 stimulation
Dendritic cells
APCs, essential to adaptive immune system. Monocyte-derived phagocytic cells take up antigens, process them, and display them to MHC II cell surface marker, and travel to lymph nodes where they recruit other immune cells. Esp important in initial exposure to new antigen.
Kupffer cells
Mononuclear phagocytes-liver
Alveolar macrophages
Mononuclear phagocytes-lungs
Histiocytes
Mononuclear phagocytes in connective tissue
Red pulp macrophages
Mononuclear phagocytes in spleen
Lymphocytes
Large nucleus (90% of cell cytoplasm) whose chromatin stains deep blue or purple.
B cells
“Long range artillery” in adaptive (humoral) immune response. From lymphocyte lineage. Develop in bone marrow and then migrate to other lymphoid organs. Express IgM and IgD on surface. B-cell antigen receptor complexes allow for recognition of foriegn antigens and subsequent activation of B cell. Downstream cell signaling leads to expression of necessary genes for terminal differentiation to plasma cells that produce and secrete antibodies to aid in specific immune response.
T cells
“infantry” of adaptive immune response. Mature in thymus. Early T cells express several surface receptors simultaneously, e.g. the t cell receptor (TCR), CD4, CD8. If one of these receptors recognizes receptors of thymic APCs, either MHC I or II, then the t cell is positively selected, proliferates, and matures.
Helper t cells
Derived from CD4+ progenitor. TH1 and TH2 subtypes.
Respond when recognize foreign antigens bound to MHC II. Once activated, secrete cytokines-interleukins-which specifically attract B cells. After immune response some helper t cells become memory cells
TH1
Respond during presence of intracellular pathogens. Innate immunity and cytolytic responses.
TH2
Respond to helminthic or parasitic infections. Humoral immunity and asthma.
Cytotoxic t cells
CD8+. Also proliferate in response to cytokines, but only recognize antigens in association with class I MHC.
Rovign CD8+ cell recognizes signal and attaches to infected cell via cell adhesion molecules.
When activated, release perforin.
Spleen
Made up of two types of parenchymal tissue: red and white pulp. Red pulp removes senescent and damaged RBCs. White pulp is where activation of humoral immune system occurs
Acute lymphadenitis
Brisk germinal center expansion in response to a local bacterial infection, leading to painfully swollen lymph nodes
Lymph nodes
Contain APCs, T cells, B cells. Possess multiple afferent lymphatic channels which enter node through its capsule near cortex. Efferent lymphatics exit at hilum along with artery and vein
Right lymphatic duct
Drains R arm, R half head, R thorax
Thoracic duct
Drains all regions except R arm, R half head, R thorax
Major LN drainage of head and neck
Submental, submandibular, retroauricular, parotid, occipital, superficial, deep cervical
Major LN drainage of lateral breast, upper limb
Axillary (pectoral, subscapular, humeral, apical, central)
Major LN drainage of parasternal breast
Supra and infraclavicular
Major LN drainage of stomach
Celiac
Major LN drainage of duod, jej, perineum
Superior mesenteric
Major LN drainage of sigmoid colon
Colic (drains to inferior mesenteric)
Major LN drainage of lower rectum, anal canal above pectinate line
Internal iliac
Major LN drainage of anal canal below pectinate line
Superficial inguinal
Major LN drainage of testes
Para-aortic
Major LN drainage of scrotum and thighs
Superficial inguinal
Major LN drainage of lateral side of dorsum of foot
Popliteal
Epineurium
Most external layer of a nerve. Dense layer of CT that covers the entire nerve, incl its vascular supply
Perineurium
Deep to epineurium. Permability barrier, regulating nutrient transport from capillaries to nerve fibers underneath. Invests a number of nerve fascicles-bundles of individual nerves surrounded by endoneurium.
Lesion to upper trunk of brachial plexus
Waiter’s tip (Erb’s pasly)
Lesion to lower trunk of brachial plexus
Claw hand (Klumpke’s palsy)
Lesion to post cord of brachial plexus
Wrist drop
Lesion to LTN
Winged scapula
Lesion to musculocutaneous nerve
Difficulty flexing elbow, variable sensory loss
Damage to median nerve
Decreased thumb function, Pope’s blessing
Lesion to ulnar nerve
Intrinsic muscles of hand, claw hand
Epidermis
Made predominantly from keratinocytes. Five layers: stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basalis (“Californians Like Girls in String Bikinis”)
Albibism
Deficiency in tyrosinase leading to congenital lack of melanin
Bullous pemphigoid
Autoantibodies against cellular adhesion molecules
Langerhans cells
Bone-marrow derived dendritic cells in skin.
Merkel cells
Found in stratum basalis. Contribute to function of mechanoreceptors in epidermis.
Ciliated epithelial cells
Coordinated ciliary motion –> helps expel resp secretions that have collected pathogens and debris from inspired air
Goblet cells
Produce mucus and protect airway and lung tissue from inspired particles
Basal cells
Provide structural support to airway
Type II pneumocytes
Produce surfactant and have ability to differentiate into Type I pneumocytes
Type I alveolar cell
Simple squamous epith cell. Forms first layer or blood-air barrier
Mucosa layer of SI
Absorption. Polarized eptih cells specialized in transport. Plicae circularis, cilli, glands, microvilli.
Submocosa layer of SI
Vascular and lymph supply. Loose CT. Lymph drainage starts as blind ended channels (lacteals) within core of villi. In duod, also has Brunner glands which secrete alkaline fluid to neutralize acidic chyme. Peyer’s patches/GALT in intestines. Also houses two neural plexuses-plexus of Meissner and myenteric plexus of Auerbach, which are extensively interconnected.
Muscularis externa layer of SI
Mechanical mixing, dissociation, and propulsion.
Serosa layer of SI
Protection
Hirschsprung disease
Congenital absence of plexus, leading to decreased intestinal mobility
Angiotensin II
Produced in lung, can trigger release of aldosterone and hypertrophy of zona glomerulosa
Measurement of systemic catecholamine levels
Urine. VMA (vanillylmandelic acid) and metanephrine -both of which are breakdown products of catecholamines.
Chromaffin cells
Located in adrenal medulla. Synthesizes either epinephrine (80%) or NE but not both. From tyrosine.
Adrenal medulla-derivation
From neuroectoderm
Most common tumors of adrenal gland
Adenomas (cortex), neuroblastomas (medullary crest cells) pheochromocytomas (medullary chromaffin cells)
Barrett esophagus
Columnar
Medulloblastoma
N&V, nystagmus, truncal ataxia.
Kids.
Pseudorosettes
Burkitt lymphoma
Starry sky
Heinz bodies
G6PD deficiency. Aka bite cells
Ringed sideroblasts
Fe accumulation in mitochondria. Chronic alcoholism, B6 def, Pb poisoning
Spherocytes
AD. Mutation in ankyrin or spectrin.
Auer rods
AML. if sudden release, DIC.
DIC
Helmet shaped cells, schistocytes
Target cells
Asplenia, liver disease, thalassemia
Teardrop cells
Myeloid dysplasia, myelofibrosis
Drepanocyte
Sickled RBC
Howell-jolly
Asplenia
Pappenheimer bodies
Siderosomes. Iron bodies. In those with excess Fe.
Sideroblastic anemia
Fe deposited in ring around nucleus of erythroblast. Microcytic, microchromic.
Spherocytes
Small RBCs with characteristic lack central pallor.
Multiple myeloma
Off center nuclei and clock faced chromatin.
Bence jones protein
Sister Mary Joseph node
Umbilical nodes
Blumers shelf node
Superior rectum
Urethra-lymph
Deep inguinal nodes
Bladder-lymph
External iliac
Deep buttock-lymph
Gluteal nodes
Scrotum-lymph
Superficial inguinal
Schwannomas
Spindle cells palisading
Meningiomas
Psammoma bodies or calcification
Neurofibromas
Loosely arranged spindle cells with intervening collagen
Oligodendriomas
Homogenous sheets of cells with uniformly rounded nuclei
