Exam 3 Flashcards
(113 cards)
Angiotensin II is a potent what?
vasoconstrictor
What causes arrhythmias?
Electrolyte imbalance, hypoxia, structural damage, acidosis, cardiac drugs
Blood Pressure
the pressure of blood pushing against the walls of your arteries
Systolic BP
- the top number
- measures the pressure in your arteries when your heart beats
Diastolic BP
- the bottom number
- measures the pressure in your arteries when your heart rests between beats
Pulse Pressure
- the difference between the upper and lower numbers of your blood pressure.
- helps to predict heart attack or stroke
- tends to increase with age
- normal: 40-60
- wide pressure associated with heart attack
- narrow pressure associated with heart failure
Cardiac Output
- how many liters of blood your heart can pump in a minute
- multiply stroke volume and heart rate
- determines the heart’s strength and health
- need more cardiac output when exercising since body’s cells need more oxygen
- measured when difficulty exercising arises or heart failure present
- normal: 4 to 8 L/min
Perpheral Vascular Resistance
- force that resists the flow of blood through the vessels, mostly determined by the arterioles, which contract to increase resistance; important in determining overall blood pressure
- heart rate, stroke volume, and peripheral vascular resistance are factors that determine BP
- when there is low pressure on the baroreceptors, the medulla is stimulated to increase the sympathetic nervous system to constrict the blood vessels and increase peripheral vascular resistance
What do we need to have a blood pressure in our body?
the amount of blood the heart pumps and how hard it is for the blood to move through the arteries
EKG
- detects the patterns of electrical impulse generation and conduction through the heart and translates that information into a recorded pattern, which is displayed as a waveform on a cardiac monitor
- a measure of electrical activity; it provides no information about the mechanical activity of the heart
Edema
- swelling caused by excess fluid trapped in your body’s tissues
- usually seen on hands, arms, feet, ankles and legs
- occurs when tiny blood vessels in your body (capillaries) leak fluid
- risk factors: CHD, lung diseases, venous insufficiency, long periods of sitting and standing
- treatment of the underlying cause (if possible), reducing the amount of salt (sodium) in your diet, and, in many cases, use of a medication called a diuretic to eliminate excess fluid, using compression stockings and elevating the legs may also be recommended
Endothelial Layer of the Heart
- the innermost layer of the heart and lines the chambers and extends over projecting structures such as the valves, chordae tendineae, and papillary muscles
- endothelial cells release substances that control vascular relaxation and contraction as well as enzymes that control blood clotting, immune function and platelet (a colorless substance in the blood) adhesion
Heart Electrical Conductivity
property of heart cells to rapidly conduct an action potential of electrical impulse
1. starts when your sinoatrial (SA) node creates an excitation signal
2. tells atria (top heart chambers) to contract
3. The atrioventricular (AV) node, delaying the signal until your atria are empty of blood.
4. The bundle of His (center bundle of nerve fibers), carrying the signal to the Purkinje fibers.
5. The Purkinje fibers to your ventricles (bottom heart chambers), causing them to contract.
Hypertension
- Intermittent or sustained elevation of diastolic or systolic blood pressure
- HTN: Systolic blood pressure of 139 mm Hg or higher or a diastolic blood pressure greater than 89 mm Hg
- Pre-HTN: systolic pressure from 120–139 and diastolic from 80-89
Determined by
* amount of blood pumped from ventricles w/ each heartbeat
* Total PVR – resistance of muscular arteries to blood being pumped
* Baroreceptors
* RAAS
Hyperlipidemia
Causes
* When the levels of lipids in the blood increase, hyperlipidemia occurs
* This can result from excessive dietary intake of fats or from genetic alterations in fat metabolism, leading to a variety of elevated fats in the blood
* Hypercholesterolemia, hypertriglyceridemia, alterations in LDL and HDL concentrations
Best Ways to Combat
* reduce intake of saturated fats in dairy and red meat
* Niacin, Fenofibrate, Omega-3
Troponin Labs
chemical in heart muscle that prevents the reaction between actin and myosin, leading to muscle relaxation; it is inactivated by calcium during muscle stimulation to allow actin and myosin to react, causing muscle contraction
Normal Values:
* Troponin I: 0 - 0.04 ng/mL.
* Troponin T: 0 - 0.01 ng/mL.
High Levels Correlate with
* Heart surgery.
* Infections or inflammation in your heart.
* Cardioversion (this is the use of an electric shock to make an irregular heart rhythm return to normal).
Creatine Kinase Labs
An enzyme that’s found in your skeletal muscle, heart muscle and brain.
When any of these tissues are damaged, they leak creatine kinase into your bloodstream.
Elevated CK levels may indicate muscle injury or disease.
Normal
* 22 to 198 U/L
Three Types
* These are CK-MB, CK-MM, and CK-BB. CK-MB is the substance that rises if your heart muscle is damaged. CK-MM rises with other muscle damage. CK-BB is found mostly in the brain.
Myoglobin Labs
measures the amount of myoglobin, a protein found in your skeletal and heart muscles, in your blood or urine.
* Myoglobin is a protein that’s found in your striated muscles, which includes skeletal muscles (the muscles attached to your bones and tendons) and heart muscles. Its main function is to supply oxygen to the cells in your muscles (myocytes).
* High levels generally indicate muscle damage; though, the test cannot determine the cause or location of the muscle damage.
Normal
* For men: Less than 91 ng/mL (nanograms per milliliter).
* For women: Less than 63 ng/mL.
Triglycerides
lipids that give the body energy from the food we eat
Pure cholesterol cannot mix with or dissolve in the blood. Instead, the liver packages cholesterol with triglycerides and proteins called lipoproteins. The lipoproteins move this fatty mixture to areas throughout the body.
* High triglycerides combined with high cholesterol raise your risk of heart attack, strokes and pancreatitis
Levels: 150 or less
Phospholipids
a class of lipids whose molecule has a hydrophilic “head” containing a phosphate group and two hydrophobic “tails” derived from fatty acids, joined by an alcohol residue
antiphospholipid syndrome
* autoimmune disorder that causes blood clots by the body’s immune system attacking proteins bound to phospholipids
* These antibodies make it much more likely that you will have blood clots in your arteries or veins
Cholesterol
found in large quantities in the membrane, and it works to keep the phospholipids in place and the cell membrane stable
* necessary component of human cells that is produced and processed in the liver and then stored in the bile until stimulus causes the gallbladder to contract and send the bile into the duodenum via the common bile duct; a fat that is essential for the formation of steroid hormones and cell membranes; it is produced in cells and taken in by dietary sources
* Normal: less than 200 mg/dL
Chylomicrons
carrier for micelles or lipids in the bloodstream, consisting of proteins, lipids, cholesterol, and so forth
* chylomicrons pass through the wall of the small intestine, are picked up by the surrounding intestinal lymphatic system, travel through the system to the heart, and then are sent out into circulation
VLDL
produced in the liver and released into the bloodstream to supply body tissues with a type of fat (triglycerides)
* High levels of VLDL cholesterol have been associated with the development of plaque deposits on artery walls, which narrow the passage and restrict blood flow.
* An elevated VLDL cholesterol level is more than 30 milligrams per deciliter
IDL
are formed from the degradation of very low-density lipoproteins as well as high-density lipoproteins
* enable fats and cholesterol to move within the water-based solution of the bloodstream
* refers to a density between that of low-density and very-low-density lipoproteins.