• York University

• KINE 3012

Kine 3012 midterm 2 review

Kine 3012 midterm 2 review

Topic #22 Cardiovascular Structure and Function

- Circulation of blood is responsible for transport (main responsibility)

o O2 and CO2

o Substrates

o Hormones

o Immunological agents

- Temperature control (second function)

o Blood goes to skin to evaporate water

- Blood is 55% plasma, 45% RBC, <1% buffy coat (platelets/wbc)

o This balance gives best between oxygen carrying capacity and blood viscosity

 Remember increased viscosity is ↑resistance, ↓Flow

 Just like air, blood moves by bulk flow

 F=ΔP/R

o If you increase RBC to 55% for example, more O2 carrying capacity but blood is thicker

because less plasma, increasing resistance

 Like lungs, if you increase R, to generate flow, need greater ΔP

Design of System

- Pulmonary system – low pressure  in order for diffusion to occur (low ΔP means lower flow)

o lungs and heart

o brings oxygen air to heart, deoxygenated air to lungs

- Arterial System – high pressure, low volume o Takes blood away from heart o 11% of blood in arterial system

- Venous System – low pressure, high volume

o Takes blood towards heart

o 60% of blood in venous system

o Unlike respiratory system, the CV system is CLOSED

 Harder to control ΔP in respiratory because we can’t control external

environment, it is indirectly influenced, in CV system we can directly influence

ΔP

- Made up of myocardium (muscle walls)

o Remember lungs have no muscle, rely on intercoastal and diaphragm surrounding lungs

as muscles, heart IS a muscle

 This allows direct control of pressure in system as opposed to lungs o 2x atria, 2x ventricle (L & R)

o 2 AV valves (bicuspid (LV), tricuspid (RV)), pulmonary valve, aortic v