LESSON 1: BLOOD VESSELS, STRUCTURE, & PHYSIOLOGY/ENDOTHELIUM Flashcards
Microcirculation is composed of what?
Arterioles, the microscopic continuation of the arteries, and venules, the continuation of veins.
The arterioles and venules anastomose to form what?
Capillaries
What are the smallest of blood vessels?
Capillaries
What occurs in the capillaries?
This is where exchange of gases and metabolites occur.
What is the cycle of the circulatory system?
- Circulatory System
- Arteries
- Arterioles
- Metarterioles
- Capillaries
- Venules
- Veins
- Heart
The maintenance of circulatory hemostasis is achieved
through the process of balancing what?
Bleeding (hemorrhage) and clotting (thrombosis)
What are the 4 components of hemostasis?
- Vascular System
- Platelets (Thrombocytes)
- Blood Coagulation Factors
- Fibrinolysis and ultimate tissue repair
What are the 5 processes involved in hemostasis following
injury to a small blood vessel? Pag nasugatan ka, ano mangyayari?
- Blood vessel spasm
- Formation of platelet plug
- Contact among damaged blood vessel, blood platelet, and coagulation proteins
- Development of a blood clot around the injury
- Fibrinolytic removal of excess hemostatic material to reestablish vascular integrity
Blood Vasculature: What are the Types of Blood Vessels?
- Arteries and Veins
- Arterioles and Venules
- Capillaries
Blood Vasculature: What are the 3 Tissue Zones?
- Tunica Adventitia/Tunica Externa
- Tunica Media
- Tunica Intima/Tunica Interna
It is a reflex in which blood vessels narrow to
increase blood pressure
Vasoconstriction
What are the 2 neurotransmitters/hormones that promote vasoconstriction?
Epinephrine and Serotonin
Vasoconstriction is caused by what chemical?
Thromboxane A2
How is thromboxane a2 produced?
It is from activated platelets and injured epithelial cells, nervous system reflexes from pain, and direct injury to vascular smooth muscle
What is the function of thromboxane A2?
mediate activation of additional platelets, resulting in the formation of a platelet plug.
What are the 4 roles of Endothelium?
- Regulates the permeability of the inner vessel wall and provides the principal stimulus to thrombosis following injury to a blood vessel.
- Involved in the clotting process by producing or storing clotting components
- Rich with PLASMINOGEN ACTIVATOR, which if appropriately stimulated, is released and activated plasminogen which ensures rapid lysis of fibrin clots
- Elaborates PROSTACYCLIN, which is synthesized by the endothelium from PROSTAGLANDIN precursors and strongly inhibits platelet aggregation and adhesion
These are produced in a variety of tissues, where they act
as modulators of vasomotor tone, cell proliferation, and hormone production.
Endothelins
What are the 3 members of the Endothelin Family?
Endothelin 1, 2, and 3
It is the only family member produced in endothelial cells and is also produced in vascular smooth muscle cells.
Endothelin 1
It has been found in high concentrations in the brain and may regulate important functions, such as proliferation and development in neurons and astrocytes. It also is found throughout the gastrointestinal tract and in the lung and kidney.
Endothelin 3
It is produced predominantly within the kidney and intestine,
with smaller amounts produced in the myocardium, placenta, and uterus
Endothelin 2
It plays an important role in the initiation,
progression, and clinical complications of various forms of
inflammatory and degenerative vascular diseases
Endothelial Dysfunction
What are the 4 stimuli of Endothelial Dysfunction?
- Immunoregulatory Substances (Tumor Necrosis Factor/TNF & Interlukin-1/IL1)
- Viral infection and Transformation
- Bacterial Toxins
- Cholesterol/Oxidatively modified lipoproteins
Disruption of the endothelium directly activates all four
components of hemostasis.
True or False
TRUE
