UNIT 3 - Cardiovascular Flashcards
What is the function of the cardiovasular system?
Transport system
for O2, nutrients, hormones, regulatory chems to all cells
trans CO2 and other products of metabolism from cells to lungs, liver and kidney,
distributes heat from inside body to extremities
What does the circulatory consist of?
Which way is blood carried in veins, arteries and lymphatic vessels?
Consists of
- heart (pump)
- vessels (distribution system)
- Blood (transport fluid)
Arteries carry blood AWAY
Veins carry bloog TOWARDS
Lymphatic carry tissue fluid to lger veins
Where are the location of the heart in dogs,
K9 - 3rd-6th intercostal space
Forms 45 degree angle w/ sternum but varies in breeds
Deep chested breeds have LGer angle, Barrel chested breeds have lower angle
Where is the heart loc in cats?
Fel - up to 1+ IC space
Extends from 3/4 to 6/7 IC space
Forms an acute angle so has increased sternal contact compared to dogs
Where is the heart loc in equine/bovine?
- -1 iC space
heart is asym -mostly on L side of thorax
loc from 2-5th IC space
apex is level of point of elbow
bovine os cordis within the heart to support valves
What are the three heart layers?
Pericardium
myocardium
endocardium
Explain what the pericardium layer is
The thin fibro-serous covering of the heart
outermost layer, extends to diaphragm and covers major blood vessels at heart base
serous pericardium lines fibrous pericardum to make the parietal layer, the visceral layer cont. over the vessels and the heart
fluid filled space between these layers is pericardial space/cavity
Explain the myocardium heart layer
The muscle layer
lies between visceral pericardium and endocardium
Explain the endocardium heart layer
The thin membrane covering the Internal surface of the heart
What is the alt names for tricuspid and mitral valve?
R AV valve
L Av valve
What does the use of chordae tendinae prevent in the hear?
Prevents valves from flipping into atria when the vents contract
The AV valves closes and blood in vent pushes the valve leaflets together so blood must leave by aortic or pulom trunk
What do the two semi lunar valves do?
Prevents blood from returning into vents when vents relax
What makes veins and arteries different from each others?
Arteries send blood away, thicker and muscular, does not have valves
Veins carry blood towards, thinner, more superficial, contain valves where 2+ veins unite to make a bigger one
Explain fluid balance in the cardiovascular system
Drives a constant circulation of the ECF
Blood pumped into caps, fluid forced out of arterial end by hydrostatic pressure generated by heart = filtration, only water + sml molecules get through these gaps in cells
Fluid reabsorbed into caps at venule end - hydrostatic pressure low, plasma proteins more conc. their osmotis pressure draws water back in, oncotic pressure generated by molecules too lg to escape cap pores
Explain blood flow, how it starts and ends
Unox blood from tissues -> veins -> cranial/caudal vena cava -> R atrium -> R AV valve -> R vent -> Pulmon semilunar valve -> Pulmon trunk -> R + L pulmon arteries
OX blood to body - > L + R pulmon veins -> L Atrium -> L AV valve -> Left vent -> Aortic semilunar valve -> Aorta -> arteries -> body tissues
What are the colors of unox blood and ox bloo?
Dark red = Un ox
Bright red = Ox
What are the two branches from th aortic arch?
Brachiocephalic trunk to supply head + R thoracic limb.
- branches off for common corotid artery to supply head and R subclavian artery to supply R thoracic limb
L Subclavian artery to supply L thoracic limb which will continue to axillary arteries to brachial arteries to median arteries
What are the rest of the body supplied by the descending aorta? list the arteries and what they supply
Celiac artery - unpaired, starts caudal to diaphram and splits to
- Hepatic - liver
- L gastric artery - stomach
- Splenic artery - spleen
Cranial mesenteric artery- unpaired, caudal to celiac artery supply most of intestines
Renal - paired, kidneys
Gonad arteries - paired, testes/ovaries, caudal to renal
Caudal mesenteric artery - unpaired, descending colon
Iliac art - pelvis and pelvic limg
INT iliac - paired, branch caudal to ext iliac and supply gluteals
Medial sacral art - unpaired, supply tail
Explain the k9 hindlimb arteries
Ext iliac arteries - paired, continue down pelvic limb as femoral art, popliteal art, and cranial tibial art
Explain what the cranial and caudal vena cava veins drain from the body
Cranial - returns blood from head + thoracic limbs, formed by convergence of L + R brachiocephalic veins
formed by ext and Int jug veings from head + subclavian veings from thoracic limbs
Caudal - returns blood from pelvis, pelvic limbs, abdomen, thoracic cavity
Common iliac veins - pelvic limbs
Gonad vein - R side caudal to renal veins, L side joins renal vein prior to draining into caudal vena, drain testes/ovaries
Renal - kidneys
Portal vein - trans blood from spleen + digestive tract to liver
hepatic - liver
Azygous - thoracic and abdominal cavities
Explain the hepatic portal circulation
Portal circulation carries blood from caps of one organ to caps of another
Blood from caps of stomach, spleen, intestines, and pancreas enter mesenteric, gastroduodenal and splenic veins and are collected in hepatic portal vein which are then trans to liver where blood enters sinusoids(lg caps)
Once in liver, can be modified or stored for future use, also for detoxification from digestive tract
Passed from sinusoids into central veins of each liver lobule and from hepatic veins and empty to caudal vena
Explain fetal circulation
Circulates thru placenta. CO and waste in fetal blood exchanged for O2 and nutrients from blood of mother
Lungs are collapses and resistant to blood blood
blood diverted through hole btw atrea called foramen ovale
artery directly connects pulmon trunk to aorta thru ductus arteriosus
Blood returns from placenta to fetuc thru umbilical vein that passes abdomen, thru ductus venosus to bypass liver and drains thru caudal vena
Describe at birth fetal circulation
Air expands in lungs to make blood flower easier
Foramen ovale + ductus arteriosus close by muscle contraction and later fibrosis.
Attachment to placenta is lost, umbilical arteries and veins atrophy and ductus venosus closes
Which circulation is highpressure, lowpressure and why?
Systemic is high bc it requires hydrostatic pressure to force blood thru caps in tissues and to pump against gravity
pulmon is low bc little resistance in vessels of lungs and can easily get fluid leaks in caps if pressure too high
What is the total blood volume distribution out of 100%?
lungs 15
body has 80
heart 5
What is systole and diastole defs
Systole - contract of vent and ejection of blood
diastole - relax of vent and heart fills