Exam 3 Flashcards
What is the cessation of bleeding?
Hemostasis
Excessive blood loss could result in diminished blood volume & pressure in an ever-decreasing cycle until
Death
What is the immediate but temporary constriction of a blood vessel ?
Vascular Spasm
In vascular spas, what does smooth muscle in vessel walls do?
Contract
In vascular spasm, what can it do to the vessel that can stop completely & half flow of blood ?
Can close the vessel.
The vascular spasm is initiated by what stimulation?
NS stimulation in response to blood vessel damage.
Chemicals released by cells of the damaged vessels.
Chemical released by platelets.
What is the accumulation of platelets that
can seal small breaks in blood vessels?
Platelet Plug.
(important step in clot formation)
What can close small tears in smaller vessels & capillaries?
Platelet plug
In platelet Plug formation, When a blood vessel is damaged, collagen is exposed and a protein, what is released from endothelial cells?
Von Willebrand factor
(vWF) binds exposed collagen
What has surface receptors on their membrane that ALSO binds vWF ?
Platelets
In platelet plug formation, 2. after platelets adhere to collagen, they become…?
Activated
In platelet plug formation, what do they release in the 2nd step.
Release ADP, thromboxanes, & other chemicals via exocytosis
- ADP & thromboxane bind receptors on surface of other platelets, activating them
- These platelets are now activated… & release additional
chemicals => creates a cascade=> more platelets
In platelet plug formation, 3. After platelets are activated, they change shape & express fibrinogen receptors that can bind what?
Bind fibrinogen, a plasma protein
Fibrinogen forms a bridge between fibrinogen receptors of different platelets which creates ?
Creates platelet plug.
Activated platelets also release phospholipids (platelet factor III) and coagulation
factor V, which are imp. in clot formation
Vascular spasms & platelets plugs can only close small tears/ cuts in
Vessel walls
What happens in case of a severe damage in blood vessel walls?
coagulation results in formation
of a blood clot- a network of fibrin, a threadlike protein fiber that traps blood cells, fluid, & platelets at the injury site.
In coagulation, blood cot formation occurs through activation of
Clotting factors, proteins that are normally in the plasma in their inactive state.
Activation is the result of many
chemical reactions.
In Coagulation, Some reaction require additional molecules such as Ca2+ and
platelet surface molecules
How are clotting factor activated?
Extrinsic pathway and Intrinsic pathway.
begins with chemicals outside the blood
Normally triggered by trauma
Extrinsic pathway
begins with chemical inside the blood
Triggered by internal damage to vessel wall
Intrinsic pathway
2 pathways converge to form common pathway—> forms a
a fibrin clot
Common pathway starts with activation of
Factor X
formed through combination of
activated Factor X, Factor V,
platelet phospholipids, &
Ca2+ on surface of platelets
Prothrombinase
Prothrombinase converts plasma protein
prothrombin to the enzyme …
Thrombin
Thrombin converts plasma protein fibrinogen to insoluble protein …
Fibrin
forms the fibrous network of the
blood clot
Fibrin
is required for formation of many factors like diet, gut microbes
Vitamin K
What can reduce Vitamin k?
Antibiotics can kill intestinal bacteria also
Reduce #s of clotting factors formed
- Increase bleeding
is a lipid soluble vitamin
Vitamin K
Req’s bile for absorption from
large intestine.
* Obstruction of bile flow can decrease Vit K absorption
What does blood contain to prevent uncontrolled formation of clots throughout the circulatory system?
Anticoagulants
Clotting factors must exceed a threshold in a localized region to
form clot
What happens after forming clot retraction occurs?
Platelets contain actin & myosin, which operate similarly to how they contract in muscle
- Extensions of platelets that bound fibrinogen (information of clot) contract, therefore retracting the clot
- Serum, plasma without much of the fibrinogen & clotting factors, is squeezed out of clot
Clot retraction
Clot retraction pulls edges of damaged vessels closer together
- Fibroblasts move in & new connective tissue forms
- Epithelial cells in region divide & repair damaged area
Process of dissolving clot
Fibrinolysis
Fibrin broken down by enzyme..?
Plasmin
is a mechanism of action for some substances (ex. tPA) used to treat abnormal clot formation
Plasmin Activiation
Excessive blood loss can cause chock or death
TRUE
is the transfer of blood from one
person to another
Transfusion
is the introduction of a fluid other than
blood
Infusion
Can be used to increase volume of blood. Often sufficient to prevent shock… RBC
production will follow
Infusions
3 main function of lymphatic systems?
Fluid balance, lipid absorption, and defense.
lymphatic capillaries collect fluid that has previously left circulation
Fluid balance
from digestive tract
lipid absorbption
microorganisms/foreign bodies are
filtered from lymph & blood
Defense
Clear fluid in lymphatic vessels is called
Contains water & solutes (ions, nutrients, gases,
proteins, hormones, enzymes, waste products)
* Ultimately passes back into circulation
Lymph
lymphatic vessels located in lining
of digestive tract that absorb lipids
Lacteals
Lymph with absorbed fats, traveling in
lacteals, is called
CHyle
- Recall that fluid moves out
of capillaries into
interstitial spaces - Not all fluid returns via
circulatory system - Some enters into
lymphatic capillaries - Fluid now called
lymph
lymph
Lymphatic vessels
originate in most bodily
tissues as small, dead-
end
Lymphatic capillaries
More permeable than blood capillaires
Lymphatic capillaries
Allows fluid to enter capillary
but prohibits it from passing
back into interstitial spaces
Lymphatic capillaries
Lymphatic capillaries join to form
larger
lymphatic vessels
Inner layer- endothelium surrounded
by elastic membrane
- Middle layer- smooth muscle cells & elastic fibers
- Outer layer- thin layer of fibrous
connective tissue
Lymphatic Vessels
drain lymph from head & neck
Jugular trunks
Lymphatic vessels converge to form larger
vessels called
Lymphatic trunks
drain lymph from upper limbs, superficial thoracic wall, & mammary glands
Subclavian trunks
drain lymph from thoracic organs & deep thoracic wall
bronchomedoastinal trunks
drains lymph from some abdominal organs (intestines, stomach,
pancreas, spleen, liver)
Intestinal Trunk
drain lymph from lower limbs, pelvic & abdominal walls, ovaries/
testes, kidneys, adrenal glands
Lumbar Trunks
Lymphatic trunks drain into large veins in the thorax or to larger vessels called
lymphatic
ducts which drain into large veins
Largest lymphatic vessel (~38-45 cm) is the
Thoracic duct
- Lymphatic Capillaries
—> - Lymphatic Vessels —>
- Lymphatic Trunks —>
- Lymphatic ducts
—> - Large veins
FLOW OF LYMPH
filters lymph
lymph nodes
Round/Oval/Bean shaped bodies located
along Lymphatic vessels
lymph nodes
Lymph moves through vessels via 3 mechanisms
Contraction of lymph vessels, contraction of skeletal muscles, and thoracic pressure changes