Heart 2 Flashcards
What is the ‘infarction’ phase? When does it occur?
Significant Q wave - much wider than normal
Q may be 1/3 of the height of the QRS
May last for many years after the infarction
Some drugs can cause effects similar to this significant Q
(3rd PHASE)
If someone has an EKG with a ‘Significant Q Wave’ that is much wider than normal. What can be assumed?
That the person has had a previous heart attack in their life.
During a myocardial infarction (heart attack), there are 7 things that may occur. What are they?
- Pain (radiates from neck, jaw, back, shoulder, and left arm)
- Nausea and vomiting
- Catecholamines are released
- Blood sugar usually increases
- Cardiac troponins (I and T found in the blood)
- Enzymes (Creatine kinase / lactic dehydrogenase)
- Troponin/Creatine kinase amounts correlated w/ severity of infarction
What are the two factors that determine the blood flow through a vessel?
Pressure / Resistance
What is the normal pressure of the heart? Where is it usually measured?
- 120/80 mm Hg
2. Arteries
Blood flows from an area of ____ pressure to an area of ____ pressure.
- High
2. Low
The pressure in the right atrium is nearly what?
Zero
Resistance in a blood vessel proportional to two things. What are they?
Length of the blood vessel AND viscosity of the blood
What is laminar flow?
The velocity flow is greater at the center of the vessel than along the outer edges.
There are 2 types of NERVES that affect vascular diameter.
What are they and how do they affect vascular diameter?
Sympathetic:
1. Alpha-adrenergic = (Vasoconstriction)
2. Beta-adrenergic = (Vasodilation) 3. Cholinergic = (Vasodilation)
Parasympathetic nerves = (Vasodilation)
There are 3 HORMONES that affect vascular diameter.
What are they and how do they affect vascular diameter?
- Angiotensin II = (Vasoconstriction)
- ADH (Vasopressin) = (Vasoconstriction)
- Histamine = (Vasodilation)
Circulation is divided into two parts.
- (Not involving lungs)
- (Involving lungs)
What are they?
- Systemic (All parts except lungs)
2. Pulmonary (Lungs)
Systemic circulation is responsible for __% of the blood volume?
79% of the blood volume
Pulmonary circulation is responsible for __% of the blood volume?
12% of the blood volume
What is the average pressure of the ‘capillaries’ when it enters enters and then when it leaves?
30 - 10 mm Hg
What is the average pressure of the ‘arterioles’ when blood enters and when it leaves?
85 - 30 mm Hg
*This is the most important in regulation of blood pressure
What is the most important blood vessel in regulation of blood pressure? (Constricting / Dilating)
Arterioles
What is the function of precapillary sphincters?
Regulate blood flow to capillaries.
Provide intrinsic, loclized regulation of blood flow in capillary beds.
Precapillary sphincters have mechanisms that help regulate blood flow in relation to the local tissues’ need for oxygen.
What is this ability called?
Autoregulation
Water flow across the capillary wall is due to two factors. What are the two factors?
- Capillary Hydrostatic Pressure (CP)
2. Osmotic Force (OF)
The ability for water to diffuse ‘IN’ to the vessel is usually caused by what? This ability is also helped by what protein?
Osmotic Force (OF)
Protein = Albumin
The ability for water to diffuse ‘OUT’ to the vessel is caused by what?
Capillary Hydrostatic Pressure (CP)
True or False:
Osmotic Force (OF) generally changes, but Capillary Pressure (CP) remains the same.
FALSE
Osmotic Force (OF) stays the SAME.
Capillary Pressure (CP) is DIFFERENT.
The ‘constant’ pressure of Osmotic Force (OF) is usually ____ mm Hg. (*In the Left A/V Valve)
23 mm Hg