Cardiovascular Flashcards
Pulmonary Circulation
-lower pressure -from heart to lungs and back to the heart
Systemic Circulation
-higher pressure -distributed from heart throughout body and back to the heart
Arteries carry blood…
AWAY from heart
Veins carry blood…
TOWARD heart
What is special about portal systems? Give examples.
Blood flows through 2 capillary beds before returning to heart. Ex - - Hepatic Portal System - Hypothalamico-hypophyseal Portal system
Location of the Heart
-Roughly from 3rd to 6th intercostal space -Will vary slightly for swallow, normal, or deep chested dogs
Where is the trabecula septomarginalis? What does it do?
Location: Right ventricle Conducts Purkinje fibers across lumen of right ventricle
Papillary mm
conical-shaped muscular projections that give rise to chordae tendinae
Chordae tendinae
prevent eversion of the A-V valves (“parachute cords”)
Systole
cardiac contraction
diastole
cardiac relaxation
S1 “Lub”
Closure of AV valves
S2 “Dub”
Closure of Semilunar valves
What causes a murmur?
-leaky valves -narrow valves Due to the valves either remaining open when they should be closed (“leaky”) or not opening fully (“narrow”) , there is an aubile turbulent blood flow
Best location to hear Pulmonary valve
low in left 3rd intercostal
Best location to hear aortic valve
high in left 4th intercostal
Best location to hear left A-V valve
low in left 5th intercostal
Best location to hear right A-V valve
low in right 4th-5th intercostal
Blood Flow through heart
Venous Return (CrVC, CdVC, Coronary Sinus) -> Right Atrium -> Right A-V orifice -> right ventricle -> pulmonary trunk orifice -> pulmonary trunk -> pulmonary arteries -> lungs -> pulmonary veins -> left atrium -> left a-v orifice -> left ventricle -> aortic orifice -> ascending aorta
How is lymph returned to the venous system?
-Thoracic Duct - Right Lymphatic Duct
Where does the Thoracic Duct empty back into the venous system? Where is it getting lymph from?
-Empties near left venous angle -Receives lymph from 3/4 of body
Where does the Right Lymphatic Duct empty back into the venous system? Where is it getting lymph from?
- Empties near right venous angle - Receives lumph from right half of head, neck, right thoracic limb, and right shoulder
Why is it necessary for fetal circulation to differ from adult circulation?
- Lungs are shrunken, nonfunctional, and present a considerable resistance to blood flow 2. Oxygenation (and nutrient-waste exchange) occurs in the placenta
Umbilical Arteries (pair)
-originate internal iliac aa. -carry fetal blood out through umbilical cord to placenta for nutrient-waste exchange
Umbilical Vein
-returns fetal blood from placenta to fetus - runs through umbilical cord to liver and continues through liver as a channel, the ductus venosus
Foramen ovale
-passage through interatrial septum -allows some blood to bypass lungs by flowing directly from right atrium to left atrium
ductus arteriosus
-vascular connection between pulmonary trunk and aorta -allows most of blood from right ventricle to bypass nonfunctional lungs and pass directly into aorta
Changes in blood flow at birth
- lungs inflate resulting in decreased pulmonary resistance and increased pulmonary blood flow 2. increased [O2] causes smooth muscle contraction in the wall of the umbilical arteries, umbilical vein, ductus venosus, and ductus ateriosus
Ductus arteriosus becomes __________ after birth
ligamentum arteriosum
Foramen ovale becomes ___________ after birth
fossa ovalis
Ductus venosus becomes __________ after birth
ligamentum venosum
Umbilical vein becomes ____________ after birth
round ligament of liver
Umbilical arteries become _________ after birth
round ligament of urinary bladder
What are “P.M.I.’s”?
-Points of Maximal Intensity - These are the spots where the 4 heart valves are best heard through the thoracic wall
