Platelet Ultrasctructure

Question 1

Platelet is anatomically divided into four areas:

Answer 1

1. Peripheral Zone
2. Sol Gel Zone
3. Organelle Zone
4. Membranous System

Question 2

Under the Peripheral Zone

Answer 2

a. Glycocalyx
b. Plasma Membrane

Question 3

Under the Sol Gel Zone

Answer 3

a. Microtubules
b. Microfilaments

Question 4

Under the Organelle Zone

Answer 4

a. Mitochondria
b. a-granules
c. Dense granules
d. Lysosomes

Question 5

Under the Membranous System

Answer 5

a. Dense tubular system
b. Surface connecting canalicular system

Question 6

Outer surface, fuzzy containing primarily composed of glycoproteins

Answer 6

Glycocalyx

Question 7

Bilayer of phospholipids

Answer 7

Platelet Membranes

Question 8

Predominant lipids in Platelet Membrane:

Answer 8

a. Phospholipids
b. Cholesterol

Question 9

A predominant lipid that forms the basic structure

Answer 9

Phospholipids

Question 10

A predominant lipid that distributes asymmetrically throughout the phospholipids

Answer 10

Cholesterol

Question 11

What are the Neutral Phospholipids (Predominant in the plasma layer)

Answer 11

1. Phosphatidyl choline
   B. Sphingomyelin

Question 12

Anionic or polar phospholipids (Predominates the cytoplasmic layer)

Answer 12

1. Phosphatidylinositol
2. Phosphatidylethanolamine
3. Phosphatidylserine

Question 13

Supplies arachidonic acid

Answer 13

Phosphatidylinositol

Question 14

Flips to the external surface and is responsible in the assembly of the coagulation factor complexes in the surface.

Answer 14

Phosphatidylserine

Question 15

Stabilizes the membrane, maintains fluidity, and helps control the transmembranous passage of materials through the selectively permeable plasma membrane.

Answer 15

Cholesterol

Question 16

Maintains the platelet’s discoid shape

Answer 16

Microtubules

Question 17

Microfilaments is composed of

Answer 17

Actin and Myosin

Question 18

Intermediate filaments is a ropelike polymers of

Answer 18

desmin and vimentin

Question 19

Connects with the actin and the tubules, maintaining platelet shape

Answer 19

Intermediate Filament

Question 20

Stains medium-gray in osmium-dye transmission electron microscopy preparations.

Answer 20

Alpha Granules

Question 21

Alpha granules fuse with ______ in activated platelets

Answer 21

Surface-Connected Canalicular System

Question 22

Appears later than alpha granules

Answer 22

Dense granules

Question 23

Stain black (opaque) when treated with osmium in transmission electron microscopy

Answer 23

Dense Granules

Question 24

Contents of Dense Granules

Answer 24

CAAS

1. Calcium and Magnesium
2. ADP
3. ATP
4. Serotonin

Question 25

Are condensed remnant of the rough ER

Answer 25

Dense Tubular System (DTS)

Question 26

"Control center" for platelet activation

Answer 26

Dense Tubular System (DTS)

Question 27

Is the route of endocytosis and for secretion of alpha granule contents upon platelet activation

Answer 27

Surface Connecting Canalicular System (SCCS)