Introduction to Histology

Question 1

Cells

Answer 1

functional units of living organisms

Question 2

differentiate

Answer 2

to perform special functions

Question 3

Tissue

Answer 3

cells with similar morphology and or function form tissue

Question 4

organs

Answer 4

anatomically discreet collections of tissues that perform certain functions

ex. liver ; kidney

Question 5

Parenchyma

Answer 5

cells that makeup the functional elements of an organ

Question 6

stroma

Answer 6

structural framework of an organ / background tissue

Question 7

Systems

Answer 7

larger units that tissues and organs are organized into

may be discreet entities like CNS
diffuse aggregates like immune system

Question 8

Basic tissue types (5)

Answer 8

Blood
connective tissue
epithelium
muscle
nervous tissue

Question 9

Blood

Answer 9

fluid tissue contained within vessels of circulatory system

technically a connective tissue

Question 10

Connective tissue

Answer 10

surrounds and supports other tissue

Question 11

epithelium

Answer 11

covers body surfaces, lines cavities, and forms glands

Question 12

muscle

Answer 12

contains specialized contractile cells responsible for movement

Question 13

nervous tissue

Answer 13

contains modified cells responsible for intercellular communication

Question 14

Hematoxylin and Eosin (H&E stain)

Answer 14

for routine diagnosis H&E is preferred for viewing cellular and tissue structure detail by pathologists

Question 15

Hemtoxylin dye

Answer 15

blue
basic dye
stains acids

ex. DNA in nuclei ; RNA in ribosomes ; rER –> basophilic = blue / purple

Question 16

Eosin

Answer 16

red pink
acidic dye
stains bases

ex. proteins = eosinophilic

Question 17

Gram stain

Answer 17

differentiates bacterial species used to determine the causative organism in a bacterial infection

stains bacterial cell wall

Question 18

gram positive

Answer 18

organisms that retain the primary color and appear purple/brown under microscope

Question 19

gram negative

Answer 19

organisms that do not take up primary stain appear red under a microscope

Question 20

Giesma Stain

Answer 20

used in hematology for its superior ability to stain bone marrow plasma cells and mast cells

identifying blood parasites

visualize chromosome abnormalities through giemsa based banding

Question 21

Periodic acid schiff reaction stain (PAS)

Answer 21

stains carbohydrates

way to examine structures with high amounts of carbohydrate molecules such as the intestinal brush border renal tubular cells mucus and reticular fibers of connective tissue

stains a red MAGENTA color

Question 22

Silver stain

Answer 22

used in neurology

stains nerve tissue

silver stains are very known for detecting amyloid beta-protein in alzheimer’s disease

Question 23

Nissl stain

Answer 23

only stains neurons

also called cresyl violet stain

uses basic aniline due to study neuronal structure in the brain and spinal cord

blue

Question 24

Cell membrane (plasmalemma)

Answer 24

functions as a semi-permeable membrane

Question 25

phospholipid bilayer

Answer 25

amphoteric and/or amphipathic composed of molecules with hydrophilic (polar) heads and hydrophobic (non-polar) tails

Question 26

Cell membrane forms

Answer 26

2 distinct layers hydrophilic heads point outward and hydrophobic tails point inwards

Question 27

hydrophilic portion contains

Answer 27

positive charged N groups and negative charged phosphate groups

Question 28

hydrophobic layer portion contains

Answer 28

2 long chain fatty acids covalently linked to glycerol

Question 29

tri-laminar appearance of cell membrane on EM

Answer 29

caused by 2 election dense layers hydrophilic phospholipid heads separated by electron lucent layer hydrophobic fatty acid tails

Question 30

fluid mosaic model

Answer 30

fluidity of membrane increases with temp and decreases with saturation of fatty acids

Question 31

Cholesterol does what to cell membranes

Answer 31

helps regulate fluidity and stabilize membrane increase in cholesterol stiffens membrane decreasing the fluidity 1:1 ratio with phospholipids

Question 32

Proteins on surface of membrane are

Answer 32

extrinsic or peripheral proteins

Question 33

proteins incorporated within the membrane are

Answer 33

intrinsic or integral protiens

Question 34

some intrinsic membranes can be

Answer 34

transmural extending from one side of membrane to other called transmembrane proteins

Question 35

what are pores

Answer 35

transmembrane proteins that have openings also called channels (can open and close) Pores are ALWAYS open

Question 36

pores and channels are used for what transport

Answer 36

active or passive transport of hydrophilic molecules

Question 37

Pump

Answer 37

serve to transport ions across membrane ex. Na-K pump NEEDS energy source

Question 38

Channel

Answer 38

allow passage of water soluble molecules via diffusion

Question 39

Receptor proteins

Answer 39

allow for cell recognition and binding on cell membrane ex. immune mediate rxn

Question 40

Transducers

Answer 40

initiate enzymatic rxn following binding with ligand molecules ex. hormones

Question 41

Enzymes

Answer 41

components of ion pumps and digestive action

Question 42

structural proteins

Answer 42

add mechanical stability to membrane

Question 43

Glycocalyx

Answer 43

the formation of glycoproteins and glycolipids on the outside of the cell

Question 44

purpose of the glycocalyx

Answer 44

protects surface of the cell membrane may be involved in cell recognition and adhesion mediating exchange between internal and external cell environment

Question 45

Principle types of transport (4)

Answer 45

simple (passive) diffusion facilitated diffusion active transport bulk (vesicular) transport

Question 46

Simple diffusion

Answer 46

NO ENERGY down a concentration or ionic gradient lipids gases (O2 CO2) and some small hydrophilic molecules (water urea bicarbonate)

Question 47

Facilitated diffusion

Answer 47

passive and concentration dependent but requires carrier molecules reversible binding and unbinding to transport water soluble hydrophilic molecules ex. glucose and amino acids

Question 48

ion channels can be

Answer 48

gated - channels can be open or closed allows selective permeability ungated - channels are always open (PORES)

Question 49

Voltage gating of ion channels

Answer 49

requires change in membrane potential to open

Question 50

chemical gating

Answer 50

requires binding of signaling molecule or neurotransmitter ex. Ach

Question 51

Passive and Facilitated diffusion are enhanced by

Answer 51

increased cell membrane surface area via folding / microvilli

Question 52

Aquaporins

Answer 52

channel that uses facilitated diffusion to allow water to cross plasma membrane faster than by simple diffusion

Question 53

Active transport

Answer 53

Independent of concentration (usually against concentration gradient) requires energy Na pump - one ion is exchanged for another

Question 54

Bulk (vesicular) transport

Answer 54

Requires energy engulfment of molecules or particles by cytoplasmic extensions AKA endocytosis

Question 55

types of endocytosis (2)

Answer 55

Phagocytosis - engulfment of solid particulate matter Pinocytosis - engulfment of liquids

Question 56

what are Endosome / Phagosomes?

Answer 56

membrane endocytic vacuoles

Question 57

receptor mediated endocytosis

Answer 57

import macromolecules from the extracellular fluid extracellular mlecules ligands bind to receptor proteins (clathrins) located in coated pits = caveolae of cell membrane

Question 58

Transcytosis

Answer 58

transport of material across or through cell via sequential endocytosis followed by exocytosis