Structure and function of the blood vessels and heart Flashcards
A myocardial infarction causes and caused from
death of cells due to lack of nutrients and oxygen-Cause - acute obstruction
of coronary artery - often blood clot
The cardiovascular system (CVS) speeds
up gas and solute transport over long distances (convection)
Diffusion is fast over
short distances, very slow over >1 mm
Function of the Cardiovascular System
delivery of O2 and nutrients to each cell
removal of CO2 and waste products from each cell
communication between organs through transport of hormones and other extracellular mediators
temperature regulation
crucial hydrodynamic device in sexual reproduction!
Blood pressure is determined by three main factors
cardiac output (pumping of the heart), the blood vessels or vasculature which not only carry the blood but are responsible for the resistance that creates the blood pressure and the various fluid compartments
peripheral resistance and blood volume
Blue color represents
blood that is only
partially oxygenated.
Cardiovascular circulation can be divided into
the systemic and pulmonary (lung) circuits with the heart as the central pump
What is the composition of blood?- 70kg individual 5.5l blood
Plasma (water, ions, proteins, nutrients, hormones, metabolic wastes, gases, etc)- 55%
Leucocytes
and = “ buffy coat ”
Platelets- immunity cells
oxygen transport- Erythrocytes = 45%
(Hematocrit = 45%)
Most of blood is distributed in
the veins and venules (act as a blood reservoir)
Blood Flow (at rest)- most of the blood id where
skeletal muscle, kidney and abdominal organs
Majority of pumping is in parallel ….
which means that all flow through organs is not linked. Some exceptions including intensines which run into liver….carry food
A change in heart flow can lead to
reduction of oxygen which causes a pain called angina
All blood vessels contain endothelial cells ….
but vary in the thickness of the smooth muscle and connective tissue
away from the heart- arteries to arterioles to capilllaries ( exchange )
venules to veins towards the heart
Arteries contain- structure
a large lumen and a thick layer of
smooth muscle (tunica media) and connective tissue (tunica adventitia)
Thick layer of elastic smooth muscle acts as
a pressure reservoir
contraction- systole
stretch (absorbing pressure)
relaxation- Diastole
passive recoil( releasing pressure)
Arterioles contain -structure
a thin muscular wall and a small lumen