Cardiovascular Flashcards
what are the two major subdivision of the ciruclatory system
cardiovascular system
lymphatic system
cardiovascular system
- a closed system that pumps blood from the heart to tissues back to heart
- contains the heart, blood, blood vessels
lymphastic system
- open, pumpless system of lymph cessels and lymph organs that are vital to ridding excess waste + fluid between cells
elephantiasis
swelling in areas due to leaking of lfuid into intersititial fluid
anatomy of arteries and veins
- tunica intima
- tunica media
- tunica externa
tunica intima
- composed of endothelium + subendothelial layer of areolar connective tissue
- aka lumen
tunica media
- comprised of circulatory arranged smooth muscle (larger arteries)
- innervated via sympathetic and parasympathetic NS
tunica externa
- connective tissue that helps anchor the blood vessels to an organ
- requires their own blood suppply via vaso vasorum
vaso vaorum
smaller arteries that supple the larger artieries/veins with blood
arteries
carry blood away from heart and become progressively smaller as they branch
what are the three types of arteries
elastic arteries
muscular arteries
arterioles
elastic arteries
- more elastic fibers found in all 3 tunics
- largest arteries
- stretch under increased pressure generated by blood ejected by the heart
- branch into mucsular arteries
muscular arteries
- medium sized arteries
- posses elastic fibers in two concentric rings (internal and external elastic lamina)
do muscular arteries have more muscle?
no just proportionally due to decreased diameter but maintained muscles in the lamina
arterioles
- smallester arteries
- few elastic and muscle fibers
what does innervation affect in the arterioles
the constriction and dilation
veins
- drains capillaries and return blood to the herat
- become progressively larger as it reaches the heart
how much blood do veins hold at rest
approx 60% body’s blood
venules
- companion vessels to arterioles
- merge to form veins
postcapillary venules
collect blood from capillaries + drain to veins
characteristics of arteries
lumen diameter: narrower than vein lumen
general wall thickness: thicker than companion vein
cross sectional shape: retains its circualr cross sectional shape
elastic and collagen fivers in tunics: more than in vein
valves: none
blood pressure: higher than in veins
blood flow: trasnports blood away from heart
blood oxygen levels: systemic arteries trasnport nlood high in O2, pulmonary arteries transport blood low in O2
characteristics of veins
lumen diameter: wider tahn artery lumen often appears collapes when cut in cross section
general wall thickness: thinner than companion artery
cross sectional shape: tends to flatten
elastic and collagen fibers in tunics: less than in artery
blood pressure: lower than in arteries
blood flow: transports blood to heart
blood oxygen levels: systemic veins trasnport nlood low in O2, pulmonary veins transport blood high in O2
capillaries
smallest blood vessels
- wall only consists of tunica intimia with single layer of endothelial cells
- more metabolic exchange occurs
what are the factors that affect venous return
- skeletal muscle pump
- respiratory pump
skeletal muscle pump
veins within skeletal muscle are constricted when contracion occurs pushing blood up
- relaxation allows for more blood to flow (valves stop backflow) and contraction occurs again
respiratory pump
- inhalation decreases the pressure in thoracic cavity due to diaphragm contraction increasing pressure in abdominopelvic cavity
- creates a greater pressure gradient drawing up blood towards the heart
blood pressure
the force per unit area that blood places on the inside of a blood vessel
- generated through alternate cycles of heart wall contraction and relaxation
average arterial BP
above 60 mmHg
average venous BP
less than 40 mmHg
what is the equation for pressure
P = F/A
what is blood pressure measured with
sphygmomanometer
systolic blood pressure
pressure during ventricular systole (contraction)
diastolic blood pressure
pressure during ventircular diastole
function of blood
transportation (O2, nutrients, waste)
- regulation (temp, pH)
- protection (leukocytes guard against infection, antibodies, platelettes)
what are the components of blood
44% RBC
<1% buffy coat
55% plasma
hematocrit
the percent of the 4 elements (red blood cells, white blood cells, platelets, plasma) w respect to the whole volume
erythropoetin
used by athletes to increase recovery & O2 transport during exercise
the approx weight of the heart
< 1 lb
position of the heart
- slightly to the left of midline, deep to sterum, in the medistinum
- apex slightly turns posteriorly during development
charactersitics of pericardium
- helps to restrict movement so that it moves only slightly within thorax
- 2 layers (fibrous pericardium, serous pericardium)
fibrous pericardium
tough outer sac
serous pericardium
composed of parietal and visceral layers to form pericaridal cavity
what are the pericardial layers of the heart walls
- epicardium
- muocardium
- endocardium
epicardium
visceral layer of serous pericardium and areolar connective tissue
myocardium
cardiac muscle that is the thickest of the three layers
endocardium
internal surface of the heart chambers external surface of heart valves
epicarditis
inflamation of the epicardium
myocarditis
inflamation of the myocardium
endocarditis
inglamation of endocardium
how does contraction of the heart occur
cardiac fibers are involuntary, straited, nucelated muscle fibers that form atrial and veintricular networks
- contract as a single unit due to low resistance cell to cell junctions
- allow for electrical impules and distribute immedietly and spontaneously throughtou mycoardium
role of gap junctions in the heart
comprose the intercalated discs that allow for the disperion of the nerve impulse
external heart anatomy
- auricle
- coronary sulcus
- anterior interventircular sinus
- posterior interventiruclar sinus
- left coronary artery (anterior interventircular branch of LCA, circumflex branch of LCA)
- right coronary artery (posterior interventircular branch of RCA, marginal branch of RCA)
internal heart anatomy
- right atrioventricular valve
- pulmonary semilunar valves
- left atrioventricular vale
- aortic semilunar valve
- fossa ovalis
- opening for coranry sinus
right atrioventricular valve characteristics
structure: 3 triangular shaped cusps of dense connective tissue covered by endothelium + attached via chordae tendinae
location: betweem right atria + venticle
function: prevent backflow of blood into right atrium when ventricles contract
pulmonary semilunar valve
structure: 3 semilunar shaped cusps of dense connective tissue covered by endothelium (no chordae tendinae)
location: between right ventricle and pulmonary trunk
function: prevent backflow of blood into right ventricle upon ventricular relaxation
left atrioventircular valve characteristics
structure: 2 triangular shaped valves composed of dense connnective tissue covered by endothelium connnected to chordae tendinae
location: between left atria and ventricle
function: prevents backflow of blood into left atrium during venticular contraction
aortic semilunar valve characteristics
structure: 3 semilunar shaped valves composed of dense connective tissue covered by endothelium
location: between left ventircle and ascending aorta
function: prevent backflow of left atrium during ventricular relaxation
what are the different types of heart valve conditions
prolapse
incompetence
stenosis
prolapse
blood enters through flaps into atria
- can cause shortness of breath, permanent damage, death
incompetence
when semilunar valves no longer prevent arterial blood from re-entering the ventricle
stenosis
the opening becomes narrowed due to valve thickening + insufficient blood escapes
- mainly seen in semilunar valves
- increases BP
what are the types of circulation
pulmonary circulation
systemic circulation
coronary circulation
what are the two main types of circulation
pulmonary and systemic
pulmonary circulation
right side of heart and pulmonary arteries+veins convey blood to lungs and the left side of the heart
systemic circulation
left side of the heart, arteries and veins convey blood to most body tissues and back to the right side of the heart
coronary circulation
blood supply to the heart
what are the chambers of the heart
R atria and ventricle
L atria and ventricle
where does the right atrium receive blood from
superior vena cava, inferior vena cava, coronary sinus
where does the right ventricle recieve and deliver blood to
recieves from right atria and delivers to pulmonary trunk/lungs
conus arteriosus
the smooth roof part of the left ventricle that marks the end of the ventricle and the beginning of the pulmonary trunk
left atrium
recieves blood from lungs
where does the left ventricle receive blood from
right atrium and delivers to the entire body
how does coronary circulation work
- coronary arteries branch off from the ascending aorta
- right marginal artery: right border
- posterior interventricular artery: posterior surface of L+R ventricles
- anterior interventricular artery: anterior surface of both ventricles + most of septum
- circumflex artery: left atrium + ventricle
- blood returns to the heart through the great cardiac vein: runs alongside anterior interventricular artery, middle cardiac vein: runs alongside posterior interventricular artery, small cardiac vein: travels close to marginal artery which merges to the coronary sinus and enters the right atrium
autorhythmicity
capable of initiating its own heartbeat independent of external nerves
conducting steps of the hearts conducting system
- muscle impulse generated at SA node and spreads throughout atria and atrioventricular node (located by fossa ovalis) via internodal pathway
- AV node cells delay the muscle impulse as it passes to the atrioventricular bundle
- AV bundle/bundle of His conducts muscle impulse into interventricular septum
- within septum L/R bundles split from AV bundle
- impulse is delivered to purkinjie fibers in each ventricle & distributed throughout ventricular myocardium
how does the sympathetic NS affect the heart
increases HR and force of contraction
how does the parasympathetic NS affect the heart
decreases HR
what is the cardiac cycle
the time from start of one heartbeat to the initiation of the next
Steps to cardiac cycle in terms of ventricular pressure
- AV valves open semilunar valves closed AV valves close (systole begins/isovolumetric contraction)
- Aortic valve opens (end of isovolumetric contraction)
- contraction occurs = ejection
- Aortic valve closes (isovolumetric relaxation occurs, systole ends)
- AV valves open (rapid inflow)
- diastole occurs
- atrial systole occurs
how does the blood pressure change throughout a cardiac cycle in terms of ventricular pressure
begins very low at close to zero and peaks to around 120 mmHg during conraction of the ventricles
- once the AV valves close steep spike in pressure and rapid decrease once isovolumetric relaxation occurs
- pressure slightly rises to about 10 mmHg during atrial systole
what is the range of mL of blood during a cardiac cycle
around max 130 and min 50
why is there still 50 mL if blood in the ventricles post systole
there is residual bc not all blood is able to be pumped out of the chamber
describe the ventricular volume during cardiac cycle
- venticles are at the highest volume during AV valve closure at the end of isovolumetric contraction volume decreases due to ejection
- residual is left and rapid inflow bring volume back up
- max volume is reached after atrial systole occurs
general steps to cardiac cycle
- atrial systole: atria contracts and ventricles relax, vent. press < art. press, AV valves open semilunar valves close
- early ventricular systole: atria relax ventricles contract, vent. press > atrial press, AV valves closed semilunar valves closed
- late ventricular systole: atria relax and ventricles contract, vent press > atrial pressure, AV valves closed, Semilunar valves open
- early ventricular diastole: Atria relax ventricles relax, vent press> atrial press, AV valves closed and semilunar valves closed
- late ventricular diastole: atrial relax and ventricles relax, vent press < atrial press, AV valves open and semilunar valves closes
general arterial blood flow to posterior toes
heart –> ascending aorta –> aortic arch –> descneding thoracic aorta –> descending abdominal aorta –> R/L common iliac artery –> R/L external iliac artery –> femoral artery –> popliteal artery –> posterior tibial artery –> R/L lateral plantar artery or R/L medial plantar artery –> plantar arch –> digital arteries
arterial blood flow anterior and to toes
heart –> ascending aorta –> aortic arch –> descneding thoracic aorta –> descending abdominal aorta –> R/L common iliac artery –> R/L external iliac artery –> femoral artery –> popliteal artery –> anterior tibial artery –> dorsalis pedis artery –> plantar arch –> digital arteries
what are the branches of the internal iliac artery
- superior vesical artery
- superior gluteal artery
- inferior gluteal artery
- middle rectal artery
- internal pudendal arter
- vaginal artery
- uterine artery
- obturator artery
femoral triangle
borders: sartorius, inguinal ligament, adductor longus
floor: pectineus, iliopsoas, adductor longus
contains: femoral vein, femorla artery, femoral nerve
popliteal fossa
borders: muscles/tendons of hamstrings and gastrocnemius
floor (superficial to deep): fibular/tibial nerve, popliteal vein, popliteal artery
deep venous return of toes/lower body
digital veins + deep veins –> medial/lateral plantar veins –> pair of posterior tibial veins –> popliteal vein –> femoral vein –> external iliac vein –> common iliac vein –> ingerior vena cava
superficial venous return of toes/lower body
dorsal venous arch –> great saphenous or small saphenous vein –> popliteal vein –> femoral vein –> external iliac vein –> common iliac vein –> inferior vena cava
arterial blood flow through upper limb
asending aorta –> aortic arch –> brachiocephalic trunk or L subclavian –> R subclavian (if brachiocephalic) –> axillary artery –> brachial artery –> radial artery (lateral) or ulnar artery (medial) –> deep or superficial palmar arch –> digital arteries
superficial venous drainage of upper limb
dorsal venous network –> basilic vein of cephalic vein –> median cubital vein (if cephalic which goes to the basilic vein) –> axillary vein –> subclavian vein brachiocephalic vein –> superior vena cava
deep venous drainage of upper limb
digital veins –> superficial venous arch/deep venous arch –> ulnar vein (deep palmar venous arch) or radial vein (superficial venous arch) –> brachial veins –> axillary vein –> subclavian vein –> braciocephalic vein –> superior vena cava
superior blood flow through thoracic abdominal walls
subclavian artery –> internal thoracic artery —> anterior intercostal arteries –> superior epigastric artery –> superior abdominal wall
inferior blood flow through abdominal awalls
external iliac arty –> inferior epigastric artery –> infrerior abdominal wall
venous drainage of thoracic and abdominal walls
all drain on left side into hemizygous + accessory hemiazygous veins which goes to azygos vein
- all right side drains into the azygous vein
how does blood flow through thoracic organs
descneding thoracic aorta –> bronchial arteries ( lungs), esophageal arteries (esophagus), superior phrenic + muscuolophrenic + inferior phrenic (diaphragm)
what are the three branches o the descneding abdominal aorta
celiac trunk, inferior mesenteric artery, superior mesenteric artery
celiac trunk branches
- left gastric artery
- splenic artery
- common hepatic artery (heptaic artery proper, left hepatic artery, right hepatic artery, right gastric artery
- gastroduodenal artery
superior mesentaric artery branches
- middle colic artery
- intesitnal arteries
- right colic artery
- ileocolic artery
inferior mesenteric artery and branches
- left colic artery
- sigmoid arteries
- superior rectal artery
what are the paired arteries that go posteriorly
middle suprarenal arteries
renal arteries
gonadal arteries
blood flow to head and neck
at superior border of thyroid cartilage common carotid splits into external and internal carotid arteries
branches of the external carotid artery
- superior thyroid artery
- ascending pharyngeal artery
- lingual artery
- facial artery
- occipital artery
- posterior auricular artery
- maxillary artery
- superficial temrporal artery
venous return for head
internal jugular or exterenal jugualr vein into subclavian then brachiocephalic vein
blood flow through cranium
vertebral arteries branch from subclavian arteries and enter cranium through forament magnum = basilar artery when they merge
internal carotid and basilar artery form anastomosis = cerebral arterial circle (circle of willis)
parts of the circle of willis
(posterior to anterior)
- posterior cerebral arteries (goes to back of head)
- posterior communicating arteries
- internal carotid artery
- anterior cerebral arteries
- anterior communicating artery (connects the R and L anterior cerebral arteries)
role of the lymphatic system
return interstitial fludis back to the bloodstream
why are fluids located outside of the blood vessels
the closed system of the cardiovascular system sometimes is leaky
- fluid is pushed out at arterial end of capillary bed and reabsorbed into bloodstream at venous end
- but not all blood is able to return
what happens if fluid accumulates
edema
where does the lymphatic system absorb lipids from
intestines
main organs of the lymphatic system
lymph nodes
thymus
spleen
role of the lymph nodes
filter the lymph
role of thymus
stimulate production by thymus
role of spleen
cleanse the blood
lymph capillaries
dont have valves but endothelium has overlap = natural valves
