Primary Homeostasis (Final Exam)

Question 1

hemostasis defintition

Answer 1

process by which the body spontaneously stops bleeding and maintains blood in the fluid state within the vascular compartment

Homeostasis strives to keep the body in blance and maintain homeostasis

Question 2

an imbalance causes

Answer 2

bleeding that doesn’t stop = hemorrhage

too much coagulation = thrombosis

Question 3

primary hemostasis

Answer 3

• injury
• vasuclar phase
• platelet adhesion
• platelet aggresgation
• temporary plug

Question 4

second hemostasis

Answer 4

• coagulation cascade
• fibrin clot forms
• healing
• fibrinolysis

Question 5

major systems involved with hemostasis

Answer 5

vascular
platelets
coagulation
fibrinolytic

Question 6

minor systems

Answer 6

kinin
serine proteas
complement

Question 7

primary homeostasis

Answer 7

vascular phase and components
platelet plug formation

Question 8

secondary hemostasis

Answer 8

coagulation factors form fibrin clot
fibronolysis

Question 9

blood vessel

Answer 9

smooth, continious endothelial lining
- “nonwettable”
- facilitiates blood flow

Under normal conditions, hemostasis is prevent by
- endothelium as a physical barrier
- endothelial secretions of platelet inhibitors prostacyclin (PGI2) and Nitric Oxide (NO)

Question 10

blood vessel layer

Answer 10

inside out:

Tunica intima
Tunica media
Tunica adventitia

Question 11

tunica initima

Answer 11

• broad flat endothelial cells
• supports migration of cells
• subendothelium = collages, connective tissue, fibroblasts

Question 12

Tunica media

Answer 12

• elastic tissue and snooth muscle
• vasoconstriction

Question 13

Tunica adventitia

Answer 13

• connective tissue
• support

Question 14

vasoconstruction

Answer 14

smooth muscle constricts

diverts blood flow around damaged vasculature

Question 15

Breached blood vessel

Answer 15

• sub-membranous collagen is exposed
• platelet and coagulation factors are able to be activated = contact activation

Question 16

Blood vessels secrete cytokines

Answer 16

ADP releases from endothelium
- promotes platelet aggregation (platelet plug)

Tissue thromboplastin (aka tissue factor / factor III) released from vessel wall
- initiaties fibrin formation through extrinsic cascade (initiates secondary hommeostasis)

Question 17

Platelet facts

Answer 17

normal count: 150,000-400,000 micro L

30% are sequestered in spleen as functional reserve

Aged or non-viable platelets are removed by the spleen and liver

Question 18

platelet function

Answer 18

adhesion and aggregation

Coagulation factors and proteins absorb into platelet

Question 19

open canalicular system

Answer 19

helps in releasing granules

Question 20

glycoprotein on surface coat called

Answer 20

Glycocalyx

• Contains blood group and tissue compatability antigens

Question 21

Surface of platelet help with fibrin clot formation

Answer 21

type V and VIII

Question 22

former demarcation membrane of parent

Answer 22

membrane

Question 23

Platelet membrane

Answer 23

Phospholipids
Adhesion receptors
aggregation receptors

Question 24

Phospholipids (platelet membrane)

Answer 24

• helps make platelet sticky
• Platelet 3 (PF3) - allows assembly of vitamin K dependent coagulation –> secondary homeosasis

Question 25

Adhesion receptors

Answer 25

GP1b - Von Willebrand factor (vWF)

Fibronectin

Question 26

Aggregation receptors

Answer 26

• GPIIb/Illa (normally inaccessible) - binds fibrinogen
• ADP
• Thrmobin
• Epinephrine
• Collagen
• Thromboxane A2 (TXA2)
• Serotonin

Question 27

Sol-gel zone , Platelet

Answer 27

Function: help support membrane

Cytoskeleton contains:
- Microfilaments and microtubiles

contractile proteins: actin, myosin, actomyosin and “thrombosthenin”

Capable of contracting within seconds

Question 28

platelet - organelle zone

Answer 28

Function: Metabolic reserve

Contains storage granules

Aid in Prostaglanding/Thromoxane A2 synthesis

Dense tubular system

Mitochondria
- 10-16 / platelet
- has glycogen (storage form of glucose)

Question 29

most numerous granules

Answer 29

alpha, up to (200/plt)

Question 30

Alpha granules

PLT specifc proteins (stays on membrane post secretion)

Answer 30

• platelet factor 4 - inhibits heparin
• beta-thromboglobulin and platelet derived growth factor - promotes vessel smooth muscle vessel
• thrombospondin - promoties PLT-PLT interaction
• factor V - coagulation

Question 31

alpha granules
Plasma protiens

Answer 31

become soluble post secretion
- albumin
- vWF - promotes adhesion
- Fibrinogen, factor V, Factor VIII, high molecylar weight kininogen - coagulation
- plasminogen - fibrinolysis
- a2 antiplasmin - inhibits fibrinolysis

Question 32

dense granules

Answer 32

• 2-10/plt
• nonmetabolic ATP
• nonmetabolic ADP - promotes aggregation
• calcium - regulates PLT activation/aggregation
• seretonin - vasconstriction

Question 33

lysosomes

Answer 33

proteases - breaks down protein/peptide
hydrolases - used water to break chemical bond
bactericidal enzymes

Question 34

platelet plug - adhesion (GPIb-vWF)

Answer 34

Reverseible process where platelets stick to foreign surfaces

Subendothelium is exposed due to injury
- composed of adhesive molecules: collagen, vWF and others

vWF attaches to platelet membrane GPIb = adhesion

Question 35

platelet plug shape

Answer 35

platelets become activated and changes from circle disc to “spiny” spherepseudopods

Shape change allows GPIIb/IIIa and platelet factor 3 (platelets thromboplastin) to be accessible

Question 36

Platelet plug - aggregation - 1st wave

Answer 36

GPIIb/IIIa-fibrinogen-GP IIb/IIIA

Energy dependent process - requires ATP
Fibrinogen binds the now usable GPIIb/Illa receptors

Briges of fibrinogen and Ca2+ form between GPIIb/Illa receptors on adjacent platelets = aggregation

Question 37

platelet plug secretion - 2nd wave

Answer 37

secretion requires a strong stimulus
- thrombin (from coagulation) is great candidate

platelets secrete their granueles
- promote