Anatomy & Physiology Flashcards
(25 cards)
Auricle
corresponds to the primitive atrium of embryonic heart; on RIGHT atria; contains pectinate muscles
Crista terminalis
in right atrium; where the pectinate muscle and the sinus venarum meet
Superior end marks the SA node
Fossa ovalis
embryonic hole (foramen ovale) where blood freely passed through from the right atrium to the left atrium
monitored by the Eustachian tube/valve of inferior vena cava
Closes once the baby breathes air
Papillary muscles
located in the right and left ventricles
responsible for closing the AV valves during systole to prevent regurgitation of blood into the atria
Chordae tendinae
located in right and left ventricles
fibrous strands that connect the papillary muscles to the cusps of the AV valves
Normal cardiac sounds
S1 (lub - low pitched) = start of systole = closing of the AV valves (tricuspid & mitral)
**heard loudest at the mitral valve area (5th intercostal)
S2 (dub - high pitched) = end of systole = closing of the pulmonary & aortic valves
(aka semilunar valves)
Abnormal cardiac sounds
S3 = as the ventricle fills, heard EARLY in diastole; it is the sound of vibrations of the blood bouncing off the walls
S4 = heard at the time of atrial contraction, LATE in diastole during “atrial kick”; due to accelerated rush of blood into the ventricles
**both are low-frequency abnormal DIASTOLIC sounds that occur w/ rapid ventricular filling
Pericardium (3 layers)
- Fibrous pericardium - outer, thicker layer, resistant to stretch
Serous pericardium - secretes fluid between parietal & visceral layer
- Parietal layer
- Visceral layer - adheres to heart muscle itself
Innervated by the phrenic nerve
Pericardial friction rub
decreased fluid between the visceral and parietal layer, increasing roughness, causing friction & vibrations that can be heard w/ each cardiac cycle
(sounds like squeaky leather)
typically due to viral infections
Rib movement during ventilation
Upper ribs = pump handle (upward and forward)
Lower ribs = bucket handle (upward & outward)
Muscles of inspiration
Primary = diaphragm (+ external & interchondral intercostals to elevate ribs (quiet))
- greatest excursion in supine
Accessory = scalenes, SCM (forced)
Muscles of expiration
Primary = PASSIVE recoil of lungs & thoracic cage (quiet)
Accessory = abdominals (depress lower ribs), internal intercostals (forced)
Pleura and Pleural cavity
- abnormalities
Pleural cavity is the space between the visceral & parietal pleura, containing fluid to prevent irritation/friction
- visceral pleura: adhere to surface of the lung
- parietal pleura: line the wall of pleural cavity
In abnormal circumstances the pleural cavity may contain air (pneumothorax), blood (hemothorax), pus, or increased amounts of serous fluid, compressing the lung and causing respiratory distress
Pulmonary ligament
Not a true ligament; it is a extra reflection of the pleural membrane that adheres onto eachother and attaches to the lung inferior to the hilar region
provides some added stability
Bronchopulmonary segment
Each bronchi, pulmonary artery & vein of a segment of a lung
(8 in left, 10 in right)
important to know for postural drainage
Innervation of the Heart
- autonomic NS regulation
PNS control - Vagus nerve - release of acetylcholine to slow the HR
- cholinergic receptors
SNS control - sympathetic nerves, T1-T5 - release of epinephrine & norepinephrine to increase the HR and increase force of contractility
- adrenergic receptors (alpha & beta)
Stroke Volume
- normative values
amount of blood pumped out of the ventricle/beat
Calculation: end diastolic volume MINUS end systolic volume
OR ejection fraction/end diastolic volume
Norm @ rest = 70mL/beat
Norm w/ exercise = 100-200mL/beat
Cardiac output
- normative values
amount of blood pumped out of the heart per minute
Calculation = SV x HR
Norm @ rest = 5L/min
Norm w/ exercise = 20L/min
A-V O2 difference
- normative values
gas exchange in the periphery; the difference in the amount of oxygen in the arterial blood versus the amount in the venous blood
Norm @ rest = 15
Norm w/ exercise = 5
affects the VO2, determines how efficient your periphery is at extracting and utilizing O2 during exercise
Ejection Fraction
- normative values
proportion of the blood pumped out of the ventricles per beat (what percent of the blood that is in the heart at the end of diastolic filling is actually pumped out)
Calculation = SV/EDV
Norm = 60-70% CMD = 30-40% CHF = less than 30%
Anaerobic threshold
corresponds to how efficient your periphery is at removing waste products during exercise;
this relates to the rise in CO2 disproportionate to the rise in O2
can increase the efficiency of removing byproducts by doing interval training
Respiratory Exchange Ratio
Volume of CO2/Volume of O2
Determines what your body is using for fuel & if it is aerobic or anaerobic metabolism
.5 = carbs & fats
.75 = predominantly carbs
> 1.0 = anaerobic metabolism (corresponds w/ anaerobic threshold)
> 1.1 = max effort
Control of Ventilation: Regulatory centers
- three areas they receive and integrate info from…
insp/exp centers in medulla… determine rate & depth of breathing
- Chemoreceptors in brain, carotid body and aorta detect changes in Co2 and O2 levels –> inc/dec RR
- Sensors in alveoli detect fluid in tissue –> increase RR, decrease depth
- Mechanoreceptors in periphery (joint/muscles) detecting physical activity –> inc RR and depth
Vesicular breath sound
normal breath sound that is soft and quiet, heard over the entire lung surface EXCEPT beneath the manubrium and in the interscapular region
- inspiration is longer than expiration
