Exam 2 Flashcards
(30 cards)
ecto/meso/endo - derms
- Ectoderm: covers external surfaces
- Mesothelium: lines internal cavities and vessels
- Endothelial: lines tubes
microvilli vs cilia
- microvilli: fingerlike extensions of pm, seen in small intestine/kidney, increase surface area for absorption
- cilia: highly motile extensions of apical surface membrane. Made of axoneme (9+2 MT). Coordinated movement to move surface fluids.
Simple squamous epithelium
Simple squamous epithelium: single layer of flat cells, little resistance to passage diffusion/filtration, found in alveoli of lungs, lining of blood/lymph vessles. Look for the “spiderweb” look on slides.
Simple cuboidal epithelium:
Simple cuboidal epithelium: secretion or absorption, found in kidney tubules, secretary portions of glands
Simple columnar epithelium:
Simple columnar epithelium: often have cilia/microvilli, absorptive cells, secrete mucus, found in uterus, oviducts, GI tract, epididymis
Stratified squamous epithelium:
Stratified squamous epithelium: many layers of cells, squamous superficial cells, deeper cells cuboidal/columnar, thickest epithelial tissue, serves for protection from abrasion. There are keratinized (outer cells lose nuclei and other organelles, accumulate cytoskeleton protein keratin, found in dry surfaces like skin) and non-keratinized (keratin doesn’t take over outer cells, found in wet body surfaces like esophagus and vagina).
Stratified cuboidal epithelium:
Stratified cuboidal epithelium: double layer of cube cells, protects gland surfaces, found in sweat/mammary/salivary glands
Stratified columnar cells:
Stratified columnar cells: single layer of column shaped cells on top of layer of polyhedral to cuboidal cells, uncommon, found in transition areas like in conjunctiva of eye, ducts of large glands, and male urethra
Transitional epithelium:
Transitional epithelium: several layers of cells, cell shape varies w distension of tissue, found lining of urinary bladder. Superficial cells dome-shaped, may be bi-nucleated. Secretes protective glycoproteins
Pseudostratified epithelium:
Pseudostratified epithelium: nuclei at varied positions, may have cilia/microvilli, all cells attached to basement membrane. Serves for protection, mucous secretion, mucus movement. Found in URI, kidney tubules, secretory portions of glands
eccrine (merocrine) vs apocrine vs holocrine
TYPES OF CELL SECRETIONS
- eccrine (or merocrine): most common, releases product in small membranous packets or vesicles. Sweat/pancreas
- apocrine: apical cytoplasm released with vesicles, sweat glands in axilla and mammary glands
- holocrine: entire cell released. Seen in sebaceous glands
CT: dense irregular, dense regular, loose irregular
-Dense irregular: Dermis of skin, sheaths of nerves, capsules of spleen, kidney, lymph nodes,
testes and ovaries
-Dense regular: tendons and ligaments
-Loose irregular: Fills spaces just deep to skin, mesothelial lining of body cavity, blood vessel
adventitia, surrounds parenchyma of glands, lamina propria of gastrointestinal tract
Collagen:
- whats it made of?
- types?
-flexible, high tensile strength
-generally ~10μm, wavy fibers that stain pink w H+E
-formed from tropocollagen. Each tropocollagen made of triple helix of 3 α chains, every 3rd
aa is glycine, other aa’s are proline, hydroxyproline, and hydroxylysine
I. Large banded – general CT/tendon/bone/ligaments/capsules of organs. Resists tension
II. Small banded – hyaline/elastic cartilage, vitreous of eye. Resists pressure
III. Small banded – lymphoid/bone/spleen/liver/lung/CV/skin – structural framework
IV. Sheet-like layers – basement membrane/basal lamina – meshwork of lamina densa, support/filtration
V. Thin fibrils – dermis/tendon/bone/ligaments/capsules of organs/placenta- placental ground substance, assoc w type I collagen
VII. thin fibrils – junction epidermis/dermis – anchoring fibrils in basement membrane
What are the different fibers of CT?
Collagen, reticular, elastic
fixed/resident cells of CT
●Fibroblast: principle CT cell
-Myofibroblasts: resemble smooth muscle cells, wound closure/healing
-Pericytes: undifferentiated mesenchymal cells assoc w capillaries and small venules
●Adipocyte
-Unilocular: white/yellow fat. Lipid storage from liver via VLDL. Single fat droplet
-Multilocular: brown fat, due to cytochromes in mitochondria. Thermogenesis- mito’s contain thermogenin which allows back flow of H+, thermogenesis controlled by sympathetic innervation. Rich capillary bed. Mult fat droplets
**hypertophic (adult, inc cell size) vs hypercellular (childhood, inc cell #) obesity
●Mast cell – 20-30μm in diameter (huge!), originate in bone marrow, mediate inflammatory response (primary mediators heparin/histamine/eosinophil/neutrophil chemotactic factors followed by secondary mediators leukotrienes/thromboxanes/prostaglandins). Also involved w hypersensitivity/anaphylactic shock
-mast cell activation: ligand binds IgE-receptor complex, activates cAMP cascase, results in both release of granules w primary mediators AND direct secretion of secondary mediators
transient/wandering cells of CT
●Histiocyte (macrophage in CT) – principle phagocytic cell in CT, originate in bone marrow as monocytes, fuse to form foreign body giant cells. Types of phagocytes originate from circulating monocytes, part of mononuclear phagocyte system. types are: Histiocyte, Kupffer, Alveolar, plural/peritoneal, oteoclast, microglia, Langerhan’s cell
[mononuclear phagocyte system= part of immune system composed of phagocytic celss located in reticular CT, composed of monocytes and macrophages]
●Plasma cells – originate from B lymphocytes, “cartwheel” nucleus, basophilic cytoplasm. Abundant at site of chronic inflammation, synthesize/secrete immunoglobulins. Slide: look up for dark cell with lighter region which is golgi
●Monocyte: origin of macrophages, made in bone marrow, then migrate into CT
●Lymphocyte (T, B cells)
●Granulocytes (neutrophils, eosinophils, basophils)
what makes up cartilage?
Cartilage is made of cells and ground substance
Cells:
-chondrogenic cells
-chondroblasts
-chondrocytes
Ground substance:
-GAGs and PGs
-fibers
●Hyaline cartilage – type II collagen
●Elastic cartilage – type II collagen and elastic fibers
●Fibrocartilage – type I collagen
what makes up bone?
Bone is made of Bone matrix and cells:
Bone matrix
-Osteoid (Type I collagen, GAGs, PGs)
-hydroxyapatite (mineralization, makes it hard!)
Cells
-Osteoprogenitor cell
-osteoblast: synthesize osteiod (organic components of bone matrix), deposit inorganic components, located at surface of bone tissue
-osteocyte: “trapped osteoblast” in lacunae, connect to each other via gap junctions bw processes in canaliculi, maintains bone matrix
-osteoclast: large motile/multinucleate cells, contact bone matrix via ruffled border, secrete enzymes that breakdown bone matrix resulting in depression called Howship’s lacuna
hematocrit
●Hematocrit: packed cell volume or erythrocyte volume fraction. Heavy elements erythrocytes (45-50%) spin to bottom, light element is plasma (50%), buffy coat comprised of platelets and leuks is in bw (1%)
erythrocyte
-7.5μm diameter, biconcave discs filled w hgb (that picks up eosin and stains pink)
-anucleate, no organelles
-men have about 5million, women 4.5million
-lifespan about 120 days (removed by macrophages in spleen/bone marrow/liver)
-transports O2 and CO2
-strictly aneorobic metabolism (glycolysis makes ATP), no mitochondria!!
-strucuture: actin/spectrin cytoskeleton anchored to pm by ankyrin and Band 4.2. Glycophorin
C extends extracellulary, glycosylation causes neg charge, thus RBCs wont clump
reticulocyte
- immature RBCs that leak from bone marrow
- 1-2% circulating RBCs
- contains residual ribosomes/other organelles (hasn’t matured yet!) thus stains pink/blue bc residuals
- lower conc hgb than mature cells
leukocyte types: Granulocytes vs Agranulocytes
Granulocytes – neutrophils, eosinophils, basophils
Agranulocytes – Lymphocytes and monocytes
whats % of each cell in WBCs?
WBC’s: neutrophils 60-70%, lymphocyte 20-25%, monocyte 3-8%, eosinophils 2-4%, basophils <1%
neutrophil
-60-70% of circulating leukocytes
-12-15 μm diameter (1.5x RBC)
-Distinct multilobed segmented nucleus
-Neutrophilic granules (dont stain!!)
-Phagocytose microorganisms
-Barr body/drumstick appendage
Inactive X chromosome (only seen in women!)
-Band/stab cell
0-3% of circulating leukocytes
-granules: primary – acid hydrolases, more
Secondary(cell secreted) – lactoferrin(binds iron and dec bact growth rate) and
lysozyme (punches hole in bacterial membrane)
Tertiary – Gelatinase (breaks ground substance)
Cathepsin (proteinases)
