histology Flashcards
list 4 main tissue types
nervous
muscle
epithelial
connective
epithelium: vascular or nah?
avascular
main function of simple squamous epithelium
diffusion
very thin and flat, think blood vessels
endothelium vs mesothelium
endothelium lines circulatory system
mesothelium lines body cavities
(both are simple squamous)
differentiate a continuous capillary, fenstrated capillary, and sinusoid
continuous capillary: makes up a majority of capillaries in the body, have a continuous basement membrane (ex. skin, muscle)
fenestrated capillary: has continous basement membrane, cells have fenestrations (small pores allowing transport of larger molecules across membrane). located in kidneys, choroid plexus, endocrine glands, and intestines
sinusoid: found in bone marrow, liver, and spleen. has discontinuous membrane. allow reentry of the RBC into capillaries from spleen as long as they are healthy and flexible enough to fit (keeps sickle cells out of circulation but can cause congestion in splee –> autosplenectomy)
list the various resident cells of connective tissue
fibroblasts (make collagen)
adipocytes (store fat)
immune cells (macrophages and mast cells)
Blood cells (RBC, WBC, platlets)
what is the most abundant protein in the body and in all connective tissues
collagen
reticular fibers
supports the stroma (acts as scafolding/structural support)
in most lymphoid and hematopoietic organs and many endocrine glands(support the spleen)
also called type III collagen
elastic fibers
polypeptide of elastin
important in lungs and circulatory system
extracellular matrix of connective tissue
the space between resident cells and fibers and acts as a lubricant and barrier
made up of ground substance and protein fibers (elastic, collagen, and reticular)
ground substance can range from liquid to solid but is highly hydrated
list 4 main types of connective tissue
connective tissue proper (loose and dense)
cartilage
bone
blood
list types of cartilage
hyaline
elastic
fibrocartilage
list types of loose connective tissue
areolar
adipose
reticular
list types of dense connective tissue
dense regular
dense irregular
elastic
list components of hematocrit
plasma: water, proteins, electrolytes (top layer, majority of blood)
buffy coat: platlets and leukocytes (small band middle layer)
erythrocytes: RBC (sinks to bottom)
life span of RBC
120 days in circulation
list WBC types and norm values by percentage
Neutrophils: 54-64%
lymphocytes: 25-33
monocyte: 3-7
eosinophil: 1-3
basophil: 0-1
“Never Let Monkeys Eat Bananas”
neutrophils: segs vs bands vs hyper segmented; function, nuclei and granules?
polymorphonuclear (PMN)
granular
phagocytic first responder, primary mediator of acute inflammation (high counts signify recent infection)
segs: mature neutrophils with segmented nuclei
bands: immature, unsegmented nuclei, indicate recent immune response
hyper-segmented: B12 and folate deficiences
B cells: function
plasma cells that produce antibodies
monocyte: granular? function
agranular
phagocytic, become macrophage when enters tissues
acts as garbage truck in chronic infections and destroys pathogens
eosinophills: granular? nuclei? function
eosinophilic (pink) granules
bi lobed nuclei
phagocytic, high concentrations during parasitic infections, modulate hypersensitivity (allergies), release cytokines and chemokines
basophils: granules? function
basophilic granules
secrete histamine, heparin, prostaglandins, and leukotrienes; mediate hypersensitivity and allergic reactions (asthma)
thrombocytes
aka platlets
small cell fragments
microcytic RBC: indications
small RBC may be associated with: thalassemia, iron deficiency anemia chronic disease anemia sideroblastic anemia
macrocytic RBC: indications
vitamin B12 or folate deficiency
liver disease
MDS (myeloid dysplastic syndrome)
chemotherapy
bite cell RBC: indications
G6PD deficiency
unstable hemoglobin disorders
oxidative drugs
target cell RBC: indications
thalassemia
hemoglobinopathies
post-splenectomy
liver diease
sickle cell RBC: indications
hemoglobin SS disease
Hemoglobin SC disease
Hemoglobin SD disease
S-beta thalassemia
which muscle type(s) is/are striated
skeletal and cardiac
which muscle type(s) is/are multinucleated
skeletal (peripheral), cardiac (1-2 in middle)
smooth has single central nuclei
satellite cells
reserve progenitor myocytes which are imparative for regeneration
(cardiac cells have poor regeneration because lack satellite cells)
tissue type of tendon
dense regular connective tissue
desmosomes
hold cells tightly together (located at intercalated discs of cardiac muscle cells)
gap junctions
allow spread of action potentials (located at intercalacted discs of cardiac muscles)
what are the only arteries in the body to carry deoxygenated blood
pulmonary arteries
tunica intima
innermost layer of arteries and vein
endothelium
tunica media
middle layer of arteries and veins
smooth muscle
larger in arteries than veins
(location of atherosclerosis)
tunica adventitia
outermost layer of arteries and veins connective tissue (collagen and elastin) vasa vasorum (vessels of the vessels)
differentiate parietal pericardium epicardium, myocardium, and endocardium
parietal pericardium: outer layer against chest wall
meothelium, loose CT and dense fibrous layer
epicardium (viscerial pericardium): against the organ/heart
meothelium and loos CT with coronary vessels
myocardium: cardiac muscle
endocardium: endothelium/inside of heart
purkinje fibers
conducting myofibrils in subendocarium and reach into myocardium
fewer contractile filaments than myofibrils so appear more pale
lots of mitochondria and glycogen
common function of simple squamous epithelium and ex of location
diffusion
lung alveoli, Bowman’s capsule, blood vessels endothelium, lymphatic vessels
stratified squamous epithelium function and ex of location
protective
cornea, esophagus, epidermis, esophagus, mouth, vagina, urethra, anus
simple columnar epithelium function and location
absorbs and secretes
GI tract from stomach to colon, uterus, excretory ducts of some glands
sometimes ciliated: small bronchi, fallopian tubes
pseudostratified columnar epithelium location
respiratory and male reproductive tract
ciliated in trachea
cuboidal epithelium function and location
absorb and secrete
line glands and ducts (ex. collecting ducts in kidney)
transitional epithelium function and location
allow distention and protects underlying tissue
in the urinary tract from the renal pelvis to the outside
endocrine glands: ducts or nah?
endocrine glands are ductless
differentiate between exocrine glands: merocrine, holocrine, apocrine
merocrine: secrete products via exocytosis and makes up most exocrine glands
holocrine: “whole” cell disintegrates, ex. sebaceous glands
apocrine: loss of apical cytoplasm, ex. mammary glands
differentiate between serous and mucous acinar glands
mucous acini: secrete mucous
serous acini: secrete watery
differentiate between merocrine and apocrin sweat glands
merocrine: more widely distributed, secrete onto skin surface, small lumen
apocrine: in axilla, perianal, and genital areas, influenced by sex hormones and secrete into hair follicles a viscous milky fluid, large lumen
sebaceous glands
associated with hair follicles and secrete sebum which provides mositure for hair and skin, create pimples when inflammed
holocrine: have pyknotic nuclei which indicate cell death
hair follicles
invagination of surface epithelium, lined with stratified squamous epithelium
list layers of epidermis from bottom to top
stratum basale
stratum spinosum
stratum granulosum
stratum corneum
merkel cells function
sensory mechanoreceptors
langerhans cells function
immune function
melanocytes function
pigmentation
meissner’s cells
skin receptors in papillary dermis sensitive to fine touch
pacinian corpuscles
skin receptor deep in dermis sensitive to deep pressure
