Chap 19 Study Guide
What is blood flow? How are blood flow and CO related?
- Measured as ml/min
- Equivalent to Cardiac Output (CO)
- Constant at rest
- Varies Through individual organs
What is blood pressure?
- Force per unit area exerted on the wall of a blood vessel by the blood
- What is resistance?
- Opposition to flow
- Measure of the amount of friction blood encounters
- Mostly in the systemic circulation
What are the three important sources of the resistance to blood flow?
- Blood viscosity
- Total blood vessel length
- Blood vessel Diameter
What is the relationship between blood flow, blood pressure, and resistance?
- F= ▲P/R
How does blood pressure change as blood travels from arteries to veins?
- It declines as it travels
Clinically, the term blood pressure usually refers to?
- Systemic arterial Blood Pressure
What is MAP? Learn how to calculate MAP?
- MAP: Mean arterial pressure, Pressure that propels the blood to tissues
- MAP= (SBP+DBP+DBP)/3
What is pulse pressure? How to calculate it?
- PP= Difference between systolic and diastolic pressure
- Systolic-Diastolic= PP
Where is the vasomotor center located?
What is baroreceptors? Where are they located and how are they stimulated?
- Pressure receptors
- Located: Carotid sinuses, Aortic Arch, wall of large arteries of the neck and thorax
- Stimulated By: Increased Blood Pressure
Learn the mechanism of blood pressure regulation when baroreceptors are stimulated.
- Increase input to the cardiovascular center
Learn the mechanism of blood pressure regulation when baroreceptors are inhibited.
What are the mechanisms that can regulate blood pressure?
- Baroreceptor Reflex
- Chemoreceptors Reflex
- Hormonal Control
- Long Term; Renin à Angiotensin
Learn how the renin-angiotensin mechanism regulate blood pressure
What instrument used to determine blood pressure?
When measuring BP by the auscultatory method what does the first sound represent?
- Systolic Pressure
Which artery is commonly used to record blood pressure?
- Brachial Artery
What are common places to take one's pulse?
What is hypertension?
- High Blood Pressure (↑ 140/90)
What are primary and secondary hypertension?
- Primary hypertension: 90% of hypertension conditions; Heredity, Diet, Obesity, Age, Smoking
- Secondary hypertension: Less Common; Kidney disease, hyperthyroidism, Cushing’s, Arteriosclerosis
What is hypotension? What are the types of hypotension?
- Low Blood Pressure
- Orthostatic: temporary low BP and dizziness when suddenly rising from a sitting or reclining position
- Chronic: hint of poor nutrition and warning sign for Addison’s disease or hypothyroidism
- Acute: important sign of circulatory shock
What is tissue perfusion involved in?
Delivery of O2 and nutrients, Removal of wastes, Gas exchange, Absorption of nutrients, Urine formation
What is blood colloid pressure?
- Pressure inside capillaries due to non-diffusible plasma proteins, which draws water toward themselves
What pressure moves fluid out of capillaries? And what is the opposing force that draws water back inside the capillaries?
- Fluid Out: Capillary hydrostatic pressure (HPc), Fluid In: Interstitial Fluid Hydrostatic Pressure (HPif)
Learn how to calculate NFP.
- NFP= ( HPc-HPif )-( OPc-OPif ) If HPif =0, OPif =0 à MFP = (HPc – OPc)
What is a circularity shock?
- Any condition that results in inadequate blood flow to meet tissue needs
- Blood Flow cannot circulate normally
What are the types of circulatory shock? What do they result from?
- Hypovolemic Shock: Results from Large scale blood loss
- Vascular Shock: Results from extreme vasodilation and decreased peripheral resistance
- Cardiogenic Shock: Results when an inefficient heart cannot sustain adequate circulation