Blood Vessels pt. 1 Flashcards
What are the 2 main artery systems?
Pulmonary + Systemic
What are the 3 layers of the vessel wall and what are they made of?
Tunica Intima - elastic fiber
Tunica Media - collagen fiber
Tunica Externa - collagen + elastic fibers
What is Lumen and is there more lumen in arteries or veins?
Lumen is the space inside the vessel and there’s more lumen in veins because of more elastic recoil
What is vasoconstriction/vasodilation?
When smooth muscles contract and dilate
What are the 3 main arteries and what do they do?
Elastic (conducting) carries blood out of the heart
Muscular (distributive) distributes to the body
Arterioles (resistance) maintain resistance/blood pressure
What is an aneurysm?
A bulge in the wall of an artery
What are the 2 types of capillaries and what characteristics do they have?
Continuous and Fenestrated.
Continuous - supplies most parts of body, prevents blood loss
Fenestrated - have pores/”windows” to allow quick exchange of nutrients
What is vasa vasorum?
Small blood vessels that supply the walls of arteries and veins
What are Precapillary sphincters?
They guard the entrance of capillaries
What are the precapillary arterioles and thoroughfare channels used for?
Precapillary arterioles regulate blood flow into capillaries, and thoroughfare channels provide a direct route for blood flow to bypass capillaries when necessary.
What is angiogenesis and why is it important?
When new blood vessels are formed from pre-existing vessels and this helps repair or replace damaged blood vessels
What is vasomotion?
changes in vessel diameter
What are the functions of venous valves?
One-way flow prevents backflow
Improves venous return
Compartmentalize blood to contract and push it toward the heart
What happens when you hemorrhage
Systemic veins constrict - vasoconstriction keeps more blood in arteries and capillaries
Constriction of the lungs, skin, and liver redistributes blood to more important organs like the brain
What are the three kinds of pressure in your body?
Blood pressure (BP) - arterial pressure
Capillary Hydrostatic Pressure (CHP) - pressure within capillaries
Venous pressure - pressure in venous system
What 3 factors does total peripheral resistance consist of?
Vascular resistance, Blood viscosity, and Turbulence
What is vascular resistance and if the diameter of a vessel gets smaller, does friction increase or decrease?
Increasing vessel length and decreasing vessel diameter increases resistance (friction), less diameter = more friction
What is turbulence (total peripheral resistance) and how does it affect resistance?
Turbulence consists of high flow rates, irregular surfaces, and sudden changes in vessel diameter so blood wont flow as smoothly, causing more resistance
What factors affect cardiovascular pressure?
Vessel Diameter
Total cross-sectional area
Pressures
Velocity of blood flow
What’s the difference between hypotension and hypertension?
Hypertension - high blood pressure
Hypotension - low blood pressure
When blood travels against gravity, what 2 factors help push it to the heart?
muscular compression of peripheral veins - contractions from skeletal muscles
respiratory pump during inhalation - pressure rises to force air out of the lungs
How do capillaries contribute to homeostasis?
Diffusion, Filtration, Absorption
What is diffusion and when does it occur?
Diffusion: movement of ions from higher to lower concentration
Occurs when - distances are shorter, concentration is large, ions/molecules smaller
What is filtration and where does it occur?
Filtration: removing solutes from a solution
Takes place at the arterial end of a capillary
Define osmosis
higher concentration of water to lower concentration
What is osmotic pressure and why is it important to the body?
Osmotic pressure - the pressure required to keep a solute from diffusing from solution
Helps extract nutrients from food
Why is moving water through the capillaries important?
- It accelerates the distribution of nutrients, hormones, and dissolved gasses throughout tissues
- Assists the transport of lipids and tissue proteins that cant enter the bloodstream by crossing the capillary walls
- A flushing action carrying toxins and other chemicals to tissues and organs responsible for providing immunity to disease.
What is tissue perfusion?
mechanisms that make sure blood flows through tissues.
