Exam 1 Flashcards
ello mate, what is a mediastinum?
the space between the lungs that holds the heart, aorta, and vena cava….. DUH.
percardium?
the membrane enclosing the heart, consisting of an outer fibrous layer and an inner double layer of serous membrane.
cardiac innervation is…
regulation of the heart… done by: The autonomic division of the PNS, via the Vagus nerve (Xth cranial)
cardiac innervation regulates what 3 things?
Heart rate
Force of each contraction
Cardiac output
what is sympathetic innervation?…3 things
Increases heart rate
Increases the force of contraction
“Fight or flight response”
Parasympathetic Innervation…3 things
Decreases heart rate
Reduces force of contraction
Constricts the coronary arteries
talk to me about the Primary Sinuatrial Node»_space;>4
- it is a group of cells positioned on the wall of the right atrium
- the node generates depolarization, which spreads across atrium and causes the muscles to contract
- cells in the SA node spontaneously depolarize, resulting in a contraction of approximately 100 times a minute
- this native rate is constantly modified by the activity of sympathetic and parasympathetic nerve fibres, so that the average resting cardiac rate in adults is about 70 beats per minute
heart rate… FACTS! 3 OF THEM, in fact.
- describes frequency of cardiac cycle
- the most common vital sign (which includes HR, blood pressure, respiratory rate, temperature)
- calculated by number of heart contractions in one minute (bmp)
factors affecting heart rate… 8 hahahah
Age Gender Environmental Temperature Infection Physical Activity Emotional Status Medications Cardiopulmonary Disease
resting heart rate ranges
- The reference range is between 60 bpm (less is bradycardia) and 100 bpm (greater is tachycardia)
- When resting, the adult human heart beats at about 70bpm (males) and 75bpm (females), but varies among people
- heart rate adapts depending on need for oxygen
resting heart rate…. tidbits haaaaa 4
- best time to find it, right in the morning!
- usually rises higher with age
- lower in athletes
- is used to determine someone’s training target heart rate zone
infant, toddler, and adolescent» resting heart rate
infant- 130-150 bmp
toddler-100-130 bmp
older toddler-90-110 bmp
adolescent-80-100 bmp
heart rate- MAXIMUM
3 facts
HR Max is conventionally calculated as 220 – age = theoretical maximum based on age
- HR Max can also be determined during a maximal stress test
- Used in the calculation of Target Heart Rate Zone (THR zone) for training
Cardiac Arrythmias… let’s talk about it.
- muscle contraction is either irregular or faster/slower than normal
- some arrythmias are life-threatening and can cause cardiac arrest and sudden death
- others only cause aggravating symptoms, such as different heart beat, palpitations (benign and normal)
pulse points-3
carotid- between SCM and trachea
femoral pulse- groin area
popliteal pulse-behind popliteal fossa while holding knee bent
pulse points… 2 more, ho ho ho!
radial pulse- radial side of the wrist
brachial pulse-in the cubital fossa just medial to the biceps tendon, used for infants
pulse points…. footsies
Dorsalis pedis pulse- on top of the foot
Tibialis posterior pulse- back of the ankle behind the medial malleolus
pulse quality
described according to:
rate, rhythm, volume
words used to describe pulse
Strong and Regular
Weak and Regular
Irregular
Thready
4 facts about cardiac pacemakers
electronic device that analyzes function of the heart
when necessary, pacemaker sends timed electrical signals to the heart on demand
most pacemakers are designed to correct bradycardia
the battery life is usually 8 years
ICD
Implantable Cardioverter Defibrillator (ICD)
- small device placed in chest or abdomen
- uses electrical impulses or shocks to control life threatening arryhythmias, (especially those that could cause sudden cardiac death due to ventricular fibrillation)
Implantable Cardioverter Defibrillator maximum output
At maximum output, a defibrillator can deliver about 830 volts in a tenth of a second to restore the heart rhythm back to normal
normal blood pressure
Systolic between 90 and 135mmHg
Diastolic between 50 and 90mmHg
abnormal readings of bp
If a person has higher readings it is termed hypertension and lower readings is called hypotension
measuring blood pressure…4
- mercury manometer is used for blood pressure measurement
- cuff must be properly sized to circumference of arm (cuffs are marked with min and max)
- cuff is inflated to a pressure of excess of the systolic blood pressure)
- the pressure is then gradually released over a period of about 30 seconds while auscultating the brachial artery
measuring blood pressure.. nil or unimpeded
When blood flow is nil (cuff pressure exceeding systolic pressure) or unimpeded (cuff pressure below diastolic pressure), cuff pressure will be essentially constant
measuring blood pressure…restricted
When blood flow is present, but restricted, the cuff pressure, which is monitored by the pressure sensor, will vary oscillate in synchrony with the cyclic expansion and contraction of the brachial artery
common types of blood pressure medication…4
diuretics- water pills, work in the kidney to flush excess water and sodium from body
beta-blockers-reduce nerve impulses to heart and blood vessels (makes heart beat slower and with less force) bp drops and heart works less hard
ACE inhibitors- (angiotensin converting enzymes) inhibitors prevent formation of angiotensin II, which normally causes blood vessels to narrow. ACE inhibitors cause vessels to relax and blood pressure goes down
calcium channel blockers- (CCBs) keep calcium from entering the muscle cells of the heart and blood vessels. this causes the blood vessels to relax and pressure goes down.
pulse oximetry
- simple, non-invasive method of monitoring the percentage of haemoglobin (Hb) which is saturated with oxygen
- probe is attached to finger or ear lobe which is linked to computerized unit. the unit displays percentage of Hb saturated with oxygen along with audible signal for each pulse beat, a calculated heart rate
more on pulse oximetry
- oximeter detects hypoxia before the patient becomes clincally cyanosed
- oxygen saturation should always be higher than 95% (patients with long standing respiratory disease or cyanotic congenital heart disease may have lower readings and reflect severity of underlying disease)
Some Cardiac Evaluation Tools…6
History
Heart rate, pulse and blood pressure
Auscultation
Laboratory tests i.e. Chest Xrays EKG, cholesterol, echocardiogram
Cardiac Stress Testing: Maximal, Sub Maximal
Fitness Testing
Cardiac Auscultation..2
- reveals the normal audible cardiac cycle, which allows the clinician to assess the heart rate, rhythm, and regularity
- cardiac murmurs that have characteristic sounds within the phases of the cardiac cycle can be demonstrated
Coronary Artery Disease (CAD)…4
- Occlusion of a major coronary artery leads to an inadequate oxygenation of an area of myocardium and cell death (i.e. myocardial infarction). The severity depends on the size and location of the artery involved and whether or not the blockage is complete.
- Partial blockages may produce pain (angina) during or after exercise.
- Several procedures are now available to improve blood flow in partially or completely occluded coronary arteries
Angina….2
- it’s not a disease, it’s a symptom of an underlying heart problem
- usually a symptom of CAD, the most common type of heart disease