Histology Fall 08: Ch 1&2: Histology History And Cell Membrane

Front 1

The science of histology was brought about by (1) of (2) and (3) (the "Age of Enlightenment")

Back 1

1) mechanistic thinking
2) physics
3) astronomy

Front 2

Who classified tissues according to the way they cut and healed during and after surgery which ultimately led to the development of histology?

Back 2

Xavier Bichat

Front 3

What 3 contributions did Xavier Bichat (1793) make that were crucial?

What did the craftsmen of the Renaissance give histologists?

Back 3

1) he promoted a MECHANISTIC VIEW OF THE HUMAN BODY that encouraged research and critical thinking
2) he ORGANIZED the facts that good surgeons knew
3) he created a VOCABULARY that made communication possible

4) Craftsmen brought: Engraving and the microscope

Front 4

Science is the art of (1).
Is blood a connective tissue?

Back 4

1) ordering observation
2) Yes

Front 5

T/F: Mathematics, astronomy, art, and glassblowing influenced histology and medicine?

Back 5

True. Achromatic microscopes/telescoped were big.

Front 6

Who concluded that the cell is the basic unit of life by saying "All cells arise from cells?"

Back 6

Theodor Schwann. His cell theory SHOULD have led instantly to a cellular theory of disease, but it took Virchow 20 years to develop a cellular theory of disease. Hippocrates had said body fluids had the diseases, Virchow said bleeding didn't help the patient. Cellular pathology is the offspring of histology.

Front 7

A (1) has no herarchy, a (2) does and is an (3: open/closed) system.

Back 7

1) tissue
2) cell
3) open

Front 8

Histology studies how (1) and thanks to the electron microscope and the confocal microscope histology is far more (2).
3) Define histology?

Back 8

1) how cells differ
2) cellular
3) Histology is the study of the relationship of microscopic structure to function.

Front 9

Histology depends on what 3 technologies?

Back 9

Microscopes, pictorial reproduction, and a specilized vocabulary.

Front 10

Ancient and medieval medicine owed much to the idea that ____ are made up of ____.

Back 10

organs are made up of tissues.

Front 11

Describe the cell membrane?

Back 11

It is a selectively permeable lipid bilayer found in all cells. It contains a wide variety of biological molecules, primarily proteins and lipids, which are involved in a vast array of cellular processes such as cell adhesion, ion channel conductance and cell signaling. The plasma membrane also serves as the attachment point for both the intracellular cytoskeleton and, if present, the cell wall.

Front 12

The cell membrande is how many layers of what? Break down these layers into the correct names.

Back 12

2 layers of lipids. the lipid bilayer is called a UNIT MEMBRANE and each layer is called a LEAFLET.

Front 13

What is the diff b/w a transmembrane protein, integral membrane protein, and peripheral membrane protein?

Back 13

Transmembrane protein passes through BOTH layers of lipid. It also classified as an integral membrane protein
Integral membrane proteins are proteins PERMANANTLY attached to the membrane and mild detergents DO NOT remove them.

Peripheral membrane proteins are proteins that adhere only TEMPORARILY to the biological membrane because they are linked to integral membrane proteins or lipids only by ionic or H-bones or Van der Waals forces thus are weak.

Front 14

Half of the cell surface is composed of what two things?

Back 14

Proteins and lipids.

Front 15

What are the 3 classes of lipids that make up the lipid bilayer?

Back 15

phoSpholIpIdS, sterols, and isoprenoids (a long chain unsaturated alcohol or thiol)

Front 16

Which only sterol is found in human cell membranes? Describe it, it's function, and what it protects.

Back 16

CHOLESTEROL. iit is nearly a flat molecule consisting of 4 fused carbon rings. small amounts of cholesterol are essential to the integrity of the membrane and protect if from CATHELICIDIN secreted by WBC.

Front 17

Describe a phospholipid. these make up the human cell membrane.

Back 17

A glycerol triesterfied by two fatty acids and the monophosphate ester of an amino alcohol.

Front 18

Why does the cell membrane appear as 9 nm instead of the true 5nm thickness?

Back 18

Because of OSMIUM PLATING. amino alcohols and glycerol are readily oxidized by OSMIC ACID which reduces the osmic acid to a black deposit of osmium metal on the outsides of the membrane thus making it appear thicker.

Front 19

What can and cannot pass through the lipid bilayer: alcohol, large lipids, gases, steroids, neutral fats, water, small lipids, small hydrocarbons

Back 19

anything polar and large typically dont.
small lipids, alcohols, small hydrocarbons, and steroids DO. water and gases are slightly permeable. H-bonding prevents bulk water from pasing through, but single water molecules are small enough to behave like gas molecules in the cell membrane.

large lipids (ex: neutral fats) do NOT pass through.

Front 20

what is facilitated diffusion?

Back 20

diffusion through a special channel that does NOT require energy. the channel proteins are transmembrane proteins (ex: they pass through both lipid layers)

Front 21

The kidneys regulate osmolarity of the blood at what value?

Back 21

280 milliosmolar

Front 22

what part of the cell membrane allow water to diffuse?

Back 22

AQUAPORINS (an integral membrane protein). MOST cells have this.

Front 23

ALL cell membranes have a (1) channel which converts what to what via what?

Back 23

Glucose channel that keeps the internal glucose concentration low by converting glucose to glucose-6-phosphate or glycogen via facilitated diffusion.

Front 24

all cells maintain a (high/low) interior concentration of potassium ions and a (high/low) concnetration of sodium? DESCRIBE what regulates this in the cell membrane?

Back 24

HIGH K
LOW NA
"naught my kin"--> "Na+ out, K+ in"

Na+/K+ ATPase uses ATP to ACTIVELY TRANSPORT sodium out and potassium in. each cycle of change in the shape of ATPase uses up one molecule of ATP and pumps OUT 3 SODIUM IONS and BRINGS IN 2 POTASSIUM IONS into the cell.

Front 25

what is the charge on the inside of the cell membrane? why?

Back 25

-60 millivolts because of the potassium channels in the cell membrane in which potassium diffuses out and sodium can NOT pass through this because the hydrated sodium ion is LARGER than the hydrated potassium ion (lower charge density).

Front 26

MOST cells possess a (1) ATPase that activates after a muscle has contracted and it uses __ ATP to transport ______.

Back 26

Calcium ion ATPase transfers calcium after a muscle has contracted and is a membrane protein that uses 1 ATP TO TRANSPORT 2 Ca++ ions OUT of the cell.

Front 27

the cell membrane has many receptors. the simplest membrane receptors are ___1___.

Back 27

transmitter-gated channels

Front 28

the stimulatory receptors of neurons are transmitter-gated ____ channels and the inhibitory receptors of neurons are ____ channels.

Back 28

sodium, potassium
'you need sodium for energy'

Front 29

___1___ channel is where the transmitter is in an electric field.

__2__ receptors bind to another cell or a substrated and alter cell shape, how?

3) some receptors are catalytic proteins, give an example of one and when it is activated.

Back 29

1) voltage-gated
2) anchorage-linked, by placing the cytoskeleton under tension
3) platelet derived growth factor (PDGF) receptor is a tyrosine kinase. is is active ONLY when the receptor domain on the extracellular end of the protein is occupied by PDGF.

Front 30

a tyrosine kinase _____ the tyrosine residues of proteins which causes it to be active.

Back 30

phosphorylates. phosphorylation of an enzyme usually activates it.

Front 31

what makes the PDGF receptor? why is this important?

Back 31

the SIS proto-oncogene makes the PDGF receptor. its defective, oncogenic (cancer causing) form is permanently active. this can be the first step in the production of cancer.

Front 32

the largest class of membrane receptors is the ____. what does this consist of and where is it located?

Back 32

G-protein. it consists of a RECEPTOR, an EFFECTOR, and the G-PROTEIN that links them. the receptor and the effector are integral membrane proteins but the G-protein is entirely in the CYTOSOL, bridging the gap bw the cytosolic ends of the receptor and the effector. the products of these effectors are known as SECOND MESSENGERS for hormones.

Front 33

the largest class of membrane receptors is what? where is it located and what does it consist of?

the only receptors that are NOT in the cell membrane are what? and where are they located.

Back 33

G-protein linked receptors. it consists of: a receptor, an effector, and the G-protein that links them. the receptor and effector are integral membrane proteins, the G-protein is entirely in the cytosol. the products of these effectors are often called SECOND MESSENGERS for hormones.

receptors NOT in cell membrane: steroid hormone receptors (lipid soluble and dissolved in the cytosol) and thyroid hormone receptors (located in the nucleus)

Front 34

how do organs stay together? give a specific example and how this specific example sticks to each other.

Back 34

the cells stick to each other via TISSUE-SPECIFIC CELL ADHESION MOLECULES (CAMS) in their cell membranes. these CAMs are integral membrane glycoproteins or transmembrane glycoproteins. LIKE CAMs stick to each other, hence why your liver doesn't stick or grow into your stomach!
CADHERINS are also glycoproteins and are tissue spefice. like cadherins stick to each other only in the presence of CALCIUM ions (hence muslce contraction is due to Ca+)
"think of sticky glucose/sugar when you think of GLYCOproteins"
"CAdherin and CAlcium"

Front 35

the cell membrane of every human cell carries several ____ proteins which are important in immune health, explain.

Back 35

class I major histocompatibility complex (MHCI). there are 10^14 different possible combinations of the seven MHC genes since there are 100 alleles for each of the seven. none of them have the same combination of MHC proteins (except identical twins).
if a cell is virus-infected, fragments of DENATURED virus protein will appear on its surface attached to one of the MHCI proteins. the MHCI protein presents the antigenic virus protein to a T-lymphocyte which kills the infected cell. the T-lymphocyte then proliferates and the daughter T-lymphocytes hunt for other cells or virus particles with the same AA sequence. (notice how you can't kill every single virus infected fragment which is why viruses are so bad!). there is a catch though, MHCI protein presents the virus protein in its denatured form, one becomes immune to an amino acid sequence rather to a protein folding pattern. T-lymphocytes respond similarly to the exposed AA sequence of a foreign MHCI protein.

Front 36

MHC proteins are what type of proteins? the protruding outer end (the amino terminal) carries an oligosaccharide (oligo=few) chain.

what is the glycocalyx? fcn?

Back 36

glycoproteins.

the glycocalyx consists of the oligosaccharide side chains of MHC, CAMs, cadherin, and glycolipids and it is as roughly as thick as the membrane itself. it helps cells recognize each other and it may be a catalyst for extracellular reactions. (ex: the slime on a fish is a glycocalyx)