Chapter 21: The cardiovascular system Flashcards
What carries the blood AWAY from the heart?
Arteries
What carries the blood BACK to the heart?
Veins
What layer of the arterial wall responsible for vasoconstriction?
Tunica media
Which layer of the arterial wall is primarily composed of elastic and collagen fibers?
Tunica externa
When an artery or arteriole is damaged, its smooth muscle layer contracts producing what?
Vascular spasm
Elastic arteries function as?
Pressure reservoirs
In a resting individual, what vessels serve as a large blood reservoir from which blood can be quickly diverted to other vessels as needed?
Veins and venules
What type of blood vessel plays a key role in regulating blood flow into capillaries?
Arterioles
What structures are found in veins but NOT in arteries?
Valves
Capillaries are also referred to as?
Exchange vessels
What important method does capillary exchange use?
Diffusion
What structure is used to control the flow of blood through a capillary bed?
Precapillary sphincter
What type of tissues contains continuous capillaries?
- Skeletal Musles
- Smooth muscle
- Connective tissue
-Lungs
The alternate route of blood flow to a body part through an anastomosis is called what?
Collateral circulation
The largest driving force for pulling fluid from the interstitial spaces back into the capillaries is what?
Blood colloid osmotic pressure
The pressure driven movement of fluids and solutes from blood into interstitial fluid is what what?
Filtration
The volume of blood that circulates through the systemic blood vessels per minute is called?
Cardiac output
Cardiac output is dependant on both what?
Heart rate and stroke volume
What doesn’t result in an increase in arterial blood pressure?
Increased arteriolar vasodilation
What would NOT result in an increase in systemic vascular resistance?
Decreased length of the systemic circulatory route.
What characteristic of blood depends mostly on the ratio if RBCs to plasma volume?
Blood viscosity
What contributes to the cardiovascular system to other body system?
- Blood delivers clotting factors and WBCs that aid in homeostasis when skin is damaged
- Blood delivers calcium and phosphate ions that are needed for building bone extracellular matrix
- Blood carries newly absorbed nutrients and water to the liver
- Blood circulates cells and chemical that carry out immune functions
Where is the cardiovascular centre located?
Medulla oblongata
What aids in venous return of blood to the heart?
- Skeletal muscle pump
- The respiratory pump
- Venoconstriction
- Venous valves
What is the response to the cardiovascular system to a decreased frequency of action potentials arising from the baroreceptors?
Increased systemic vascular resistance
What hormones stimulate changes that lead to an increase in arterial blood pressure?
- Antidiuretic hormone
- Aldosterone
- Angiotensin
- Epinephrine
What happens when chemoreceptors in blood vessels detect high levels of carbon dioxide in the blood?
- Increase vasoconstriction of arterioles
- Increased blood pressure
- Increased sympathetic stimulation
- Arterioles and veins
- Increased vasoconstriction of veins
What results in the myogenic response of smooth muscle?
- More forceful contractions when relaxed
- Tetany
- Relaxation of smooth muscle when stretched
- Formation of new desmosomes
Abnormal conditions such as atherosclerosis and patent ductus arteriosus cause a large increase in what?
Pulse pressure
Which blood vessels in blood pressure pulsing?
- Arteries
- Arterioles
What type of shock is due to decreased blood volume?
Hypovolemic
