finally Flashcards
Bud stage, cap stage, bell stage, root formation
Describe the whole process of tooth formation.
- Bud stage: formation of the tooth bud
neuro-ectoderm cell migrates from neural crest, induce the formation of epithelial tooth buds - Cap stage-early: (pre-formation of enamel organ)
-The epithelial structure (Oral ectoderm) form the future enamel organ
-Neuro-ectoderm cells mix with mesoderm cells. From the neural crest mesoderm. - Cap stage-late: formation of the second bud for the permanent tooth, differentiation and formation of outer inner dental epithelium
-Future enamel organs remain connected to the oral ectoderm by the dental lamina and originate a second bud for the permanent tooth.
-Enamel organ differentiates into defined layer (outer and inner dental epithelium)
-Some cells of the neural crest mesoderm start differentiating into odontoblast. - Bell stage
-Enamel organ differentiates into stratum intermedium and stellate reticulum
-The inner dental epithelium formed by ameloblasts, synthesize enamel
-The cervical loop marks the position of the neck of the tooth
-Odontoblast become aligned and the primitive dental papilla if formed (future pulp) - Root formation
-Odontoblast grows inward
-ODE and IDE disappear and odontoblast induce the mesenchyme to form cementoblast and cementum.
-Perioodental ligament formed
-Permanent tooth awaits further development until the baby tooth is scheduled to fall out.
-Permanent tooth develops in the same manner as the baby tooth
-Odontoclast erode the root of the baby tooth and the new permanent tooth grows as the root of the baby tooth is eroded.
Describe the juxtaglomerular apparatus.
- Juxtaglomerular cells: Cells in the afferent arteriole that are modified smooth muscle cells, that are responsible for renin secretion, which react on plasma angiotensinogen (plasma protein)
- Macula densa of DCT: Densely packed epithelial cells that detect the Na+ concentration, produce NO and other factors
- Extraglomerular mesangial cells: Cells outside of the glomerulus that provide some structural support
Describe the function of mesangial cells
Intraglomerular mesangial cells:
1. Phagocytosis of particles, germs and BM
2. Structural support of capillaries
3. Produces cytokines
Extraglomerular mesangial cells: Cells outside of the glomerulus that provide some structural support
Describe the structure and function of the terminal bouton.
At the end of the axon, they will branch out into circular structures called terminal boutons.
-Function: as a part of the neuromuscular junction. They release acetylcholine.
-Structure: Synaptic vesicles, surround by BM and myelin, presynaptic membrane, mitochondrion, ER
Describe the structure, epithelial components and function of the gastric gland(fundus-body)
Pits 1:4 gland.
Pit: surface mucous cells (simple columnar cells), produce mucigen droplets.
Gland region contains parietal cells that secrete HCl and intrinsic factors, have mucous neck cells, zymogenic cells, zymogen granules(lipase and pepsinogen), at the base stem cells.
All these on BM.
After that is LP (loose CT.), M.M. (smooth muscle), submucosa (dense irregular), tunica muscularis, adventitia/serosa (dense irregular).
The main function: digestive enzyme and pH~2 to digest food.
Describe the structure and function of the epiphyseal plate.
Structure: 5 zones
-resting cartilage: hyaline cartilage, resting chondrocytes;
-proliferation, active diving chondrocytes, stack of coin structure, interstitial growth, lengthen the bone;
-hypertrophy, cell swelling in the lacuna; cell death
-mixed of spicules: woven formation, osteoblast, osteocytes, osteoclast, calcified cartilage)
Function: secondary ossification center of long bone formation. Lengthen the long bone.
Describe and compare cartilage and compact bone
Cartilage:
Collagen II, chondrocytes/blast
Chondrocytes: isogenic groups
Appositional growth (chondroblast secrete ECM) and interstitial growth (isogenic group)
Perichondrium
Compact bone:
Collagen I
Osteocytes (non-dividing)/blast
periosteum
inter/outer circumferential lamellae
interstitial system
endosteum (osteoblast)
Intercalated disc
Structure only in cardiac muscle, separate two cardiac muscle cells
-Have zonula adherence, desmosome and gap junction. Place for cell linkage (by actin filament attached to alpha-actinin in the zonula adherence (z line)), and transport of Ca2+ by gap junction.
Muscular artery
Medium size artery transports oxygenized blood to different organs. Intima(ILEM), media (4-10 layers of smooth muscle cells ), and adventitia (contain vasa vasorum to transport nutrients for the artery).
Intercellular junctions of epithelial cells
Tight junction: almost no extracellular space, cells tightly linked together by proteins(transmembrane: ZO-1 and actin) inside has occludin and claudin.
Zonula adherence: 15nm bigger extracellular space, cells linked by cadherin. Inside cell has alpha-actinin and vinculin
Gap junction: 6 connexins form a connexon, and 2 connexons linked to a channel for cell communication and transport.
Desmosome: strongest cellular junction complex. 25 nm Inside the cell has tonofilament(intermediate filament) between cells have cadherins (desmoglein and desmocollin)
Hemidesmosome: the junction between cells and basement membrane, also has tonofilament inside the cell, transmembrane proteins like (alpha6-integrin and beta4-integrin and BP180) attached to BM inside plaque have BP 200
Triad structure, T-tubules, Sarcoplasmic Reticulum
Representing invaginations of the sarcolemma, occur at regular intervals (in register with the junctions of A and I bands of the sarcomeres, and at right angles to the myofibrils. They penetrate throughout the fibre, thus providing an extension of the unit membrane and the extracellular space into the fibre interior
The “sarcoplasmic reticulum” (smooth endoplasmic reticulum), is a network of canals
running in parallel with the sarcomere filaments, transverse to the T-tubules. Each section of the sarcoplasmic reticulum spans the length of one sarcomere, and is bounded on either side by (but is not continuous with) a transverse tubule. Where the sarcoplasmic reticulum abuts the transverse tubules, the reticulum tubules expand into terminal cisternae. Thus, each sarcoplasmic reticulum has two terminal cisternae, one at each end. A T-tubule together with its two adjoining terminal cisternae is referred to as a “triad”. A place for Calcium storage.
Compare arterioles and venules
Small blood vessels. They all have 1 layer of endothelial cells. Arterioles has 1-3 layers of smooth muscle cells. Venules no smooth muscle. Limited or no adventitia. No ILEM.
Respiratory epithelium
Trachea: ciliated pseudostratified epithelium with goblet cell
Intrapulmonary bronchus: ciliated pseudostratified epithelium with fewer goblet cell
Regular bronchiole: simple ciliated columnar epithelium
Terminal bronchiole: simple ciliated cuboidal epithelium with non-ciliated cuboidal club cells
Respiratory bronchiole: discontinuous simple cuboidal epithelium with more club cells
Alveolar duct: fist-like projections less club cells
Alveoli: Simple squamous
Taste buds
Located in circumvallate papilla
Pore
Basal cells/ type I: supporting darker/type 2: Sensory
Connect to Schwann cell
(Familial dysautomia: lack of tast buds
PTC: chemical compound that only part of the population can taste the bitter)
Circumvallate papilla
Contain taste buds, large circular shaped, lamina propria under epithelium. Have a groove, allowing taste pores to open deep in the papilla at the back of the V-shape. Von Ebner gland (100% serous gland) in submucosa near circumvallate papilla. Duct in epithelium.
Pneumocyte type-II cell
Cuboidal epithelial cells in lung tissue.
Function: secrete surfactant, reduce surface tension.
Hair follicle
From IRS to glassy membrane, epithelium surrounds the hair shaft.
Cuticle layer of IRS
Huxley’s layer of IRS: trichohyalin granules, acidophilic
Henle’s layer
External root sheath
Glassy membrane
Actin filaments
Thin filaments in sarcomere, slide on the thick filaments when there is a contraction happening for skeletal muscle movement. Associated proteins troponin and tropomyosin, which aid in the initiation of contraction.
Contraction of muscle
On actin filament TnC: bind Ca2+, move away tropomyosin, allows myosin to bind with actin filaments. Then ATP hydrolysis to ADP, let the head of myosin bend back toward the center of sarcomere, with pull the actin filament to move.
Alpha-actinin
Actin binding protein, found in zonula adherence and z line of sarcomere for striated muscle
Melanocytes
Cells inserted in stratum germinativum and make projections to stratum spinosum. It contains melanosomes are vesicles with melanin. Tyrosinase catalyst tyrosine to melanin. Cells in spinosum phagocytose the projections and release the melanin on the top of the nucleus, absorb UV and protect the DNA of spinosum cells.
Haversian canal and volkmann’s canal
Harversian canal has blood vessel and lymph and nerve fiber.
Voklmann’s canal are horizontal canal that connect Haversian canals. Provide nutrients and blood to the bone.
Carbonic anhydrase
Carbonic anhydrase is an enzyme that breaks CO2 and H2O to H + and HCO3-, creating an acidic environment.
Osteoclast work
Osteoclast receives signal, and find a bone to bind to.
Carbonic anhydrase (enzyme in osteoclast) is an enzyme that breaks CO2 and H2O to H + and HCO3-, creating an acidic environment.
Lysosomes go into the circumferential clear zone, Acid Phosphatase (only work in acidic environment) breaks down phosphate and calcium
Osteoclast packed Ca to the blood vessels.
Ach-cholinesterase
An enzyme in Ach receptor that breaks acetylcholine into acetate and choline in the synaptic cleft. Prevent accumulation of acetylcholine and overstimulation.
Aneurysm:
bulging of artery (mainly in brain) might cause rupture of artery, lead to uncontrol bleeding.
Microtubules
One of the cytoskeleton, made of tubulin, have polarity.
cilia=basal body（9*3 microtubules）+upper structure（9（13+9）+2 microtubule） each microtubule has 13 tubulin
The wall of a microtubule is composed of 13 tubulin molecules (or tubulin
dimers) arranged in spiral. Each linear row of tubulin dimers is referred as a
protofilament. Microtubules contain a plus and a minus end. Microtubules not only
form cilia but also participate in intracellular transport of vesicles and organelles.
Microtubules also form the mitotic spindle which allows the displacement of
chromosomes during mitosis. The transport guided by microtubules is due to the
presence of motor proteins such as dynein and kinesin. This process is particularly
important in axoplasmic transport in neurons. Microtubules are components of cilia,
basal bodies and centrosomes. In cilia and flagella, the peripheral microtubules are
associated to dynein molecules (dynein arms) which are motor proteins that use energy
and provide motion. The cilia contain other microtubule associated proteins that form
the radial spokes and the inner (central) sheath. These proteins contribute to the
structural integrity of cilia, and mutations in the genes encoding these proteins may also
result in “immotile cilia”.
Zymogenic granules
Vesicles produced by many cells (zymogenic cells, exocrine pancreas, Paneth cells, parotid gland)
Contains proenzyme and enzymes (lipase and pepsinogen, amylase, RNA/DNAase) for digestion.
Entero-endocrine cell
Stomach and small intestine. Produce gastrin and cholecystokinin.
Gastrin
Hormones produced by stomach entero-endocrine cells in the gastric glands, and stimulate the release of gastric acid (mainly HCl).
CCK(Cholecystokinin)
Hormone, responsible for gall bladder and pancreatic secretion, produced by small intestine
Enterocytes
Simple columnar epithelial cells with brush border (microvilli).
Paneth cell
Secrete Lysozyme, in small intestine crypts.
Intercalated ducts:
Small intralobular duct in the exocrine pancreas and salivary glands. The duct for transportation of the exocrine merocrine product.
podocytes
In Visceral layer of Bowman’s capsule, spider shape cells have primary and secondary processes. Secondary processes surrounding the capillaries in glomerulus.
Huntington chorea:
neuron disease, motion disorder
Angiotensin:
Renin cleaves angiotensinogen to angiotensin I, and converting enzyme (in lung) cleave to angiotensin II.
hormone, stimulates contraction of arteriole, increase blood pressure (fast)
stimulates the production of aldosterone (slow)
Renin:
An enzyme secreted by juxtaglomerular cells in the kidney (juxtaglomerular apparatus). It will go into the blood and target at plasma angiotensinogen.
Acromegaly:
: a disease caused by excess growth hormone production in adulthood, cause periosteal growth
Ehlers-danlos syndrome :
a disease caused by the lack of fibulin-5 glycoprotein, the skin will be very stretchy
Bullos Phemphigoid
hemidesmosome is not working, skin will peel off and the epidermis will peel off from BM
PAS.
Glucose reacts with periodic aldehyde, the Schiff reagent, then stains it to dark purple.
PAS is used to stain carbohydrates.
Enterokinase
An enzyme produced in duodenum.
Activate Trypsinogen to trypsin; pro-carboxypeptidase to carboxypeptidase; Pro-Elastase to elastase; pro-phospholipase-A to phospholipase-A
Centroacinar cells
Secrete trypsin inhibitor, trypsin is an enzyme for digestion
Secretin
Stimulate the secretion of H2O and bicarbonate. Regulate digestion and water balance in body.
BP 180
Transmembrane protein in hemidesmosome, helps anchor plaque to BM, and keep the cell attached.
Kupffer Cell
Liver macrophage, located in the liver
composition and structure
Axoneme
α Tubulin
β Tubulin
Wall of a single microtubule is composed by 13 Protofilaments
9(M1+M2)+ Central Pair
M1: complete 13 M2: imcomplete 10
Dynein Arm: make mycrotubile move
Tectins: protein inside microtubile
Radial Spokes: keep M1 M2 in position
Central Sheath: aroun the central pair
Nexin: connections betwen (M1M2)
cilium
basal body(Centriole, M1 M2 M3) + axoneme
function of endotheliam
permeability
site of metabolism （angiotensin convertion）
inactive of Bradykinin and of serotonin
production of vasoactive substance： endothelin and NO
Anti-thrombogenic funciton
