Introduction Flashcards
1
Q
study of cells
A
histology
2
Q
5 basic tissue types
A
blood, connective tissue, epithelium, muscle, nervous tissue
3
Q
functional units of living organisms
A
cells
4
Q
cells with similar morphology and/or function form __
A
tissue (nervous, muscle)
5
Q
what do cells do in order to perform special functions?
A
differentiate
6
Q
anatomically discreet collections of tissues that perform certain functions
A
organs (ex: kidney, liver)
7
Q
cells that make up the FUNCTIONAL elements of an organ
A
parenchyma
8
Q
STRUCTURAL framework of an organ, background tissue
A
stroma
9
Q
tissues and organs are organized into larger ___ that may be __ entities (CNS) or ___ aggregates (immune system)
A
systems
discreet
diffuse
10
Q
blood is the only
A
fluid tissue
11
Q
blood location
A
contained within vessels of the circulatory system
12
Q
function of connective tissue
A
surrounds and supports other tissue
13
Q
this tissue covers body surfaces, lines cavities, and forms glands
A
epithelium
14
Q
this tissue contains specialized contractile cells responsible for MOVEMENT
A
muscle
15
Q
epithelium function
A
covers body surfaces
lines cavities
forms glands
16
Q
this tissue contains modified cells responsible for intercellular communciation
A
nervous tissue
17
Q
general process of tissue preparation
A
Formalin Cut tissue in cassettes Dehydrate with alcohol baths Clear with xylene Embed in liquid paraffin or plastic resin Microtome or grind if plastic Mount on slides Deparaffinize Rehydrate with alcohol and xylene (reverse order) Stain Coverslip (protection)
18
Q
What happens to unfixed tissue?
A
autolyzes/denatures (rots)
19
Q
How do you prevent denaturing of unfixed tissue?
A
fixation in formalin (37% formaldehyde)
cross links protein to preserve tissue
20
Q
function of tissue cassettes
A
Helps identify
Prevent from mixing
Fixed tissue placed inside
21
Q
function of automated tissue processor
A
dehydrates tissues through series of alcohol baths
22
Q
most popular embed technique
A
paraffin (not water soluble so needs to be dehydrated)
23
Q
example of plastic resin embedding material
A
methyl methacrylate (mma) good results but difficult to stain and expensive
24
Q
most common stains
A
hematoxylin
eosin
(H & E)
25
characteristics of hematoxylin
blue, basic dye
stains acids
(ex: nuclei)
basophilic (blue/purple)
26
characteristics of eosin
red/pink, acidic dye
stains bases
(ex: proteins)
eosinophilic (red/pink)
27
animal cells surrounded by flexible cell membrane
plasmalemma
28
function of plasmalemma
semi-permeable membrane (SPM)
29
what type of bilayer does the cell membrane form
phospholipoid bilayer
30
What makes up the phospholipid bilayer?
molecules with hydrophilic (polar) heads and hydrophobic (non-polar) tails
(amphoteric/amphipathic)
31
Which direction do the __ head and the __ tails point?
hydrophilic (outward)
| hydrophobic (inward)
32
The hydrophilic portion of membrane contains
positively charged N groups
| negatively charged phosphate groups
33
Where is the hydrophilic portion of the membrane present?
BOTH inside and outside of membrane
34
The hydrophobic portion of the membrane contains
2 long chain FA's covalently linked to glycerol
35
Describe the hydrophilic and hydrophobic layers in terms of electron density.
heads: electron dense
tails: electron lucent
36
The cell membrane is responsible for the ______ appearance on EM
tri-laminar
37
Describe the tri-laminar appearance of the cell membrane
2 electron dense layers (hydrophilic phospholipid heads)
| separated by electron lucent layer (hydrophobic, FA tails)
38
What affects membrane fluidity
Increased: increase temp and decrease saturation of FA's
Decreased: cholesterol stiffens membrane, close packing of FA's
39
Role of cholesterol in membrane fluidity
regulates fluidity and stabilizes membrane
40
cholesterol ratio to phospholipids
1:1
41
membrane proteins are
large, mobile protein molecules scattered throughout the membrane
42
function of some membrane proteins
cell-cell recognition
| surface proteins
43
extrinsic/peripheral proteins
proteins on surface of membrane
44
intrinsic/integral proteins
proteins incorporated within the membrane
45
transmural proteins
some intrinsic proteins
extend from one side of membrane to other
"transmembrane" proteins
46
Pores in membrane proteins
transmembrane proteins with openings
| always open
47
channels in membrane proteins
transmembrane proteins
can open and close
selective
used for active or passive transport of hydrophilic molecules
allow passage of water-soluble molecules via diffusion
48
What are the categories on membrane proteins?
```
pumps
channels
receptor proteins
transducers
enzymes
structural proteins
```
49
serve to transport ions across membrane (give example)
pumps
| Na-K pump
50
allow passage of water-soluble molecules via DIIFFUSION
channels
51
allow for CELL RECOGNITION and BINDING on cell membrane (give example)
receptor proteins (immune mediated reactions --> WBCs)
52
initiate ENZYMATIC RXNs following binding with LIGAND molecules (give example)
transducers
| hormone
53
components of ION PUMPS and DIGESTIVE ACTION
enzymes
54
add MECHANICAL stability to membrane
structural proteins
55
many membrane proteins and some lipids are conjugated with SHORT POLYSACCHARIDE CHAINS containing glucose molecules containing glucose molecules which form ____ and _____.
glycoproteins
| glycolipids
56
glycoproteins + glcyolipids = ______
glycocalyx (outside of cell)
57
functions of glycocaylx (3)
protects surface of cell membrane
cell recognition
mediates EXCHANGE between internal and external cell environment
58
types of transport (4)
simple (passive) diffusion
facilitated diffusion
active transport
bulk (vesicular) transport
59
what type of diffusion occurs DOWN a concentration gradient?
simple
60
What passes directly through plasma membrane via diffusion?
lipids
gases (O2, CO2)
some small hydrophilic molecules (water, urea, bicarbonate)
61
how do large water-soluble molecules pass through membrane?
pores or channels in transmembrane proteins
62
what type of diffusion is passive and concentration dependent, but requires "carrier molecules?"
facilitated (carrier-mediated)
63
What is the function of facilitated diffusion?
reversible binding and unbinding to transport water-soluble, hydrophilic molecules (glucose and AA's)
64
What type of diffusion uses ION CHANNELS in transmembrane proteins, which can be gated or ungated?
faciliated
65
Which channels are always open in facilitated diffusion?
ungated (pores)
66
Which channels can be open or closed and allow for selective permeability in facilitated diffusion??
gated
67
Which channel in facilitated diffusion requires the presence of a stimulus to open?
What does the stimulus do?
gated
| causes conformational change of protein
68
What type of gating requires change in membrane potential to open?
voltage gating
69
What type of gating requires binding of signaling molecule or NT (Ach)?
chemical gating
70
How are both passive and facilitated diffusion enhanced?
increase in surface area of cell membrane via folding (microvilli)
71
Important type of channel that uses FACILITATED diffusion and allows WATER to cross plasma membrane FASTER than by simple diffusion alone?
Where can this be found in the body?
Aquaporins
Renal tubules in kidneys
72
What type of transport is INDEPENDENT of concentration (usually against gradient)
active transport
73
What type of transport requires energy from ATP --> ADP?
| give example.
active transport
| Na pump
74
Where does active transport occur?
specialized "dynamic pore sites"
| usually transmembrane proteins
75
What type of transport is endocytosis, phagocytosis and pinocytosis?
Bulk (vesicular transport)
76
engulfment of molecules or particles by cytoplasmic extensions
endocytosis
77
forms of endocytosis (2)
phagocytosis
| pinocytosis
78
engulfment of solid, particulate matter
phagocytosis
79
engulfment of liquids
pinocytosis
80
What does endocytosis result in?
endosomes (phagosomes/endocytic vacuoles)
81
membrane-bound, endocytic vacuoles
endosomes
82
What is the type of endocytosis where extracellular molecules (ligands) bind to receptor proteins, or clathrins, located in coated pits (caveolae) of cell membrane?
receptor-mediated
83
any bulk transport, or vesicular movement from cytoplasm to ECS is ___.
exocytosis
84
transport of material across or through cell, via sequential endocytosis follow by exocytosis
transcytosis
