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Histology 1
Histology
Question | Answer |
---|---|
What is a terminal web? | a network of actin filaments at the apical surface of epithelial cells w/ microvilli (at the base of microvilli) |
Where are sterocilia found? | epididymis, proximal ductus deferens, and sensory (hair) cells of the ear |
What is the basal lamina made of? | 50% is type IV Collagen; laminin, proteoglycans and glycoproteins |
What are the two types of glands? | Exocrine and Endocrine |
What is the difference between the two types of glands? | Excorine glands have ducts and secrete products directly onto target. Endocrine glands are ductless and secrete products (hormones) into the bloodstream via Connective Tissue |
What embryonic germ layer is the epidermis derived from? | surface ectoderm |
What type of epithelium does the endoderm give rise to? | respiratory; GI tract; liver; pancreas; tympanic cavity; pharynx |
What type of epithelium does mesoderm give rise to? | kidney & gonads; pericardial, pleural, and peritoneal cavities; lining of vascular and lymphatic vessels |
What is the difference between serous and mucous glands? | |
What is the function of troponin? | troponin regulates tropomyosin attchment to actin's myosin binding site. In response to Ca2+, troponin changes conformation causing the tropomyosin to dislocate from the actin binding site allowing for myosin to bind and contraction to occur. |
What are the steps of muscle contraction? | Action potential moves on axon --> acetylcholine released from presynaptic membrane to synaptic cleft --> postsynaptic membrane depolarized --> Na+ channels open--> action potential in sarcolema --> Ca2+ released --> Ca2+ released from sarcoplasmic reticu |
What is Preder-Willi Syndrome? | overproduction of ghrelin hormone --> causes eating and morbid obesity |
What are the functions of adipose tissue? | insulation, cushion, secretion of hormones, energy reserve |
What are appetite stimulating hormones? | Ghrelin |
What are appetite suppressant hormones? | leptin, peptide YY |
What organ do appetite suppressing and stimulating hormones act on? | hypothalamus |
What fat-soluble dye can you stain adipose cells w/? | Oil Red O |
what is an isogenous group? | a group of up to 8 condrocytes resulting from the division of a single condrocyte |
what is the territorial matrix? | in hyaline cartilage, it is the region that surrounds isogenous groups (i.e. newly formed chondrocytes) and is high in sulfated proteoglycans (negative & basophilic) |
what are the two growth modes for cartilage and the difference between them? | interstitial growth: division of chondrocytes w/in cartilage appositional growth: addition of chondrocytes from the perichondrium (addition of new cartilage on surface of old) |
what is the perichondrium? | dense Connective Tissue surrounding hyaline and elastic cartilage, except on articular surfaces |
What is the articular surface of the epiphysis covered w/? | hyaline cartilage |
Osteopetrosis | osteoclasts lack ruffled borders and bone resorption is defective |
what is the periosteum | fibrous connective tissue capsule that covers the outside surface of bone |
what are the different types of muscle cells and characteristics of each? | |
Bone matrix contains mainly what type of collagen? | Type I |
what is a papilloma? | benign surface epithelial tumor |
what is an adenoma? | benign glandular epithelial tumor |
what do osteoblasts secrete? | type I collagen and bone matrix proteins |
What cells are responsible for maintaining the bone matrix? | osteocytes |
each osteocyte occupies a space called what? | lacuna |
what is the Howship's lacuna? | a shallow bay where osteoclasts are located |
what are osteoclasts derived from? | hemopoietic cells (monocytes) |
what is osteomalacia? | impared mineralization/calcification of bone matrix due to calcium/vitamin D deficiency (rickets in children) |
what is the role of calcitonin? | lower elevated blood Ca2+ levels by inhibiting bone resorption via inhibiting effects PTH on osteoclasts |
what is the role of PTH? | rsises blood Ca2+ levels by stimulating osteoclast activity |