Module 4 Cardiovascular system Flashcards
Define cardiovascular system
closed circulatory system: fluid pumped from heart throughout the body and back to the heart
study of muscular heart, blood vessels, and blood
What does cardio mean
heart
What does vascular mean
vessels
What is the function of the cardiovascular system
transport gas, nutrients and waste throughout the body
prevents loss of blood from ruptured vessel through clotting mechanisms
fights invasion of body by foreign pathogen
Describe the anatomy of the heart
fist sized: 300 grams
cone shaped organ in pericardial cavity
lies in anterior portion of mediastinum between lungs
Describe pleural cavities
2 lateral
each contain a lung on either side of mediasteinum
Describe pericardium
encloses heart in tough sac and protects heart and anchors to diaphragm
inner and outer layer is covered by epithelium
Describe myocardium
bulk of heart
cardiac muscle- contracts
highly branched attached by collagen connective tissue
has cardiac fibers
what do cardiac fibers do
link parts of heart together
Describe endocardium
line heart
is white endothelium
continuous with blood vessel linigs
How many chambers in the heart and what are they called
4 chambers split into L and R
upper: atria: smaller: receive blood
lower: ventricles: larger: pump and send
Define fossa ovalis
shallow depression on septum separate atria
mark opening between atria-present in develop fetus
allow fetal blood to move between both atria
closes during birth
What is function of pulmonary valve
regulate blood flow one way
control flow leaving R ventricle into pulmonary trunk
What is function of aortic valve
control blood out of L ventricle into aorta
stronger than pulmonary because of increased BP needed to send blood through body
What is function of mitral valve
also called bicuspid
control flow blood from L atrium to L ventricle
What is function of tricuspid valve
control blood flow R atrium to R ventricle
What are the 3 types of blood vessels
arteries
veins
capillaries
Describe arteries
palpable pulse
carry blood away from heart
elastic, thick walled, expand and contract to accommodate Lg blood volume flowing from the heart @ end of heart beat
Lg arteries expand and recoil to help heart pump blood through systemic circulation
Describe arterioles
small arteries- constricted and dilated by muscles controlled by sympathetic and parasympathetic nervous system
control BP
How does arteriole control BP
contract arteriole increase BP through decreased blood volume
relax arteriole lowers BP as increased available blood volume
primary vessel responsible for different levels of peripheral resistance( vary BP) to blood flow on external and internal conditions affect body
Describe veins
thinner vessel under lower pressure
don’t have pulses
internal valve open toward heart and close @ end of heartbeat to prevent blood flow backward
have compliance: stretch with little recoil
have lg amount of blood in CV
What is the opening in the center of a vessel called
lumen
What are the 1 layers of arteries
tunica externa( adventitia) most superficial layer of vessel help anchor vessel to surrounding structures
What is the 2nd layer of an artery
tunica media
middle muscular layer of vessel has external elastic membrane
layer of smooth muscle
layer of internal elastic membrane
What is 3rd layer of artery
tunica intima
layer of vessel contains layer of sub endothelial tissue and layer of endothelium
What are capillaries
branches of arterioles that cause formation of narrow tubes
interconnect to form capillary beds
responsible for exchange of materials within cells of the body
blood collected from capillary beds by small veins( venules)
What are venules
small veins
may join vein to return blood to the heart
How does blood get to heart- basic overview
2 artery system
L and R: arise at base of aorta and supply O2 and nutrients to heart tissue
Describe Left Coronary Artery
runs L side of heart
divides into anterior interventricular branch and circum flex branch
Where does anterior intrerventricular branch of L coronary artery supply blood to
supply blood to both L and R ventricle
Where does circum flex branch of L coronary artery supply blood to
Left atrium and L ventricle
Describe Right Coronary Artery
runs right side of heart and divides into posterior interventricular artery and marginal artery
Where does posterior interventricular branch of coronary artery supply blood to
right atrium and right ventricle
Where does marginal branch of right coronary supply blood to
right atrium and right ventricle
How does blood get to the body
from heart goes through aorta, spread to rest of the body
Where does aortic arch turn and what does it lead to
aortic arch turns posteriorly and lead to descending aorta
Where is thoracic aorata
thoracic aorta in thoracic cavity above diaphram
What does descending aorta become
abdominal aorta below diaphram
What is function of inferior vena cava
return deoxygenated blood from lower body
what is function of superior vena cava
return blood to heart from upper body
How are the major blood vessel named
named for region located or where supply blood
What is brachiocephalic trunk
vessel that is 1rst branch off aortic arch
supplies blood to right arm and neck
What are the R and L subclavian artery and vein
run parallel to each on L and R sides of the body
What is the circle of willis
cerebral arterial circle
able to provide alternate circulation in case one of arteries becomes blocked
Why is alternate circulation important in the brain
neurons must be continuously suppled with oxygen or die in minutes
Where are the 2 vertebral arteries and how named
rise superiorly along both sides of spinal cord
Basilar artery
posterior communicating arteries
Describe the basilar artery and where does it branch
found at base of Pons
branches into L and R posterior cerebral arteries
Describe the posterior communicating arteries
connect L and R internal carotid arteries in neck
terminate in L and R middle cerebral arteries
Where do the anterior cerebral arteries branch off middle
connected by anterior communicating artery
thus completing the circuit
How is blood classified
connective tissue
What makes up blood compositon
plasma: liquid
formed elements: cell portion: RBC, WBC, platelets
Describe serum
identical to plasma: protein removed
accomplished by letting blood sit in a tube until it clots and then centrifuging sample to separate solid and liquid portion
What are the functions of plasma
- buffer pH blood near 7.4
- assist in transport Lg organic molecules and aids in blood clotting
- plasma maintain blood osmotic pressure because of presence of protein
What is osmotic pressure
net pressure in blood moves fluid from tissues into circulatory system
What is function of osmotic pressure
driven by proteins in plasma that remain in capillaries
opposes hydrostatic pressure of blood: pushes fluid into tissues by pressure of blood pumping from heart
Why is osmotic pressure important for homeostasis
to have ongoing balance between osmotic and hydrostatic pressure so fluids flow into tissues and return to circulatory system
Describe RBC
Red blood cells
small biconcave disks carry O2
4-6 million per 1.0mm of whole blood
each RBC contain 250 million hemoglobin molecules
Define hemoglobin
contains iron combines loosely with O2 help carry O2 in blood
Where are RBC manufactured
red bone marrow of skull, ribs, vertebrae, ends of long bone
What is anucleate
mature RBC w/o a nucleus
What must happen to a RBC before being released into blood
must lose nucleus and synthesize with hemoglobin
How long do RBC live and what happens at end of their life
live for 120 days then destroyed in liver and spleen
after destroyed hemoglobin is released so iron recycled and returned to red bone marrow for reuse
What happens to heme portion after hemoglobin released
undergoes chemical degradation and excreted by liver as bile pigment
What are WBC
White blood cells
leukocytes
How are WBC differ from RBC
WBC have larger nucleus
lack hemoglobin
What is an inflammatory response
happens when unwanted organisms enter due to injury
will see swelling, redness, increase in blood flow to injured site
What happens during inflammatory resposne
WBC squeeze through capillary walls and enter tissue fluid where destroy foreign material
What are the contents of pus seen after injury
thick/yellow: contain lg proportion of dead WBC fought the infection
what are the types of wbc
granulocyte: have granules in cytoplasm
agranuloyte: don’t have granules in cytoplasm
lymphocyte: T cells, B cells
What are platelets
thrombocytes
involved in process of blood clotting: coagulation
not true cells
fragment of Lg bone marrow processor called megakarocyte
help stop bleeding by sticking to edge of wound
how do platelets start to heal broken blood vessels
platelets clump @ site of puncture and begin to partially seal the leak
once they stick to the tear- release chemicals to signal coagulation cascade- blood clotting
platelets and injured tissue release clouting factor called prothrombin activator- converts prothrombin to thrombin
What is needed to assist the blood clotting process
fibrinogen
Describe fibrinogen
protein manufactured in liver freely float in blood
thrombin help convert fibrinogen to fibrin
How does fibrin assist in blood clotting
fibrin threads wind around platelet and plug in damaged area of blood vessel and provide framework for clot
RBC trapped in fibrin make clot appear red
What is a platelet plug
network of fibrin and platelets working together to stop bleeding- but present only temporarily
What happens once blood vessel repair is initaited
plasmin( enzyme) destroy fibrin network and restore fluidity of plasma
what results in malfunction of clotting mechanisms
clotting disorders
What are the 4 heart valves that control blood flow and what direction does blood flow
flow only one direction: through heart, lungs and body
flow forward: vessels: atria: into ventricle: out of ventricle
How many circuits in circulatory system
2: double pump
R: pulmonary: send deoxygenated blood to lung to get O2
L: systemic circuit: send oxygenated blood from heart to cells of the body
Process for blood return( deoxygenated) to heart
- ) blood from superior and inferior vena cavae goes to R atrium
- ) from R atrium blood flow through tricuspid valve to R ventricle
- R ventricle pump blood through pulmonary valve into pulmonary artery to lung
- after blood in lung is oxygenated(lose CO2)-carried by pulmonary vein to heart enter L atrium
- blood flow through bicuspid valve to L ventricle- pumps to aortic valve in aorta
- Aortic arch turns posterioly, carry oxygenated blood to supply cells of all body tissue w/O2 and nutrients
- Deoxygenated blood returned to R atrium through vena cavae
What is average HR
70 bpm
What is systole
contraction of heart chamber
what is diastole
relaxation of chamber
What are the 3 phases of cardiac cycle
- atria contract .15 seconds while ventricle relax
- ventricle contract .30 second atria relax
- all chamber relax for .40 second
Why does short systole of atria occur
atria send blood short distance into ventricle
Why does ventricle contract longer
has to pump to larger systemic and pulmonary circulatory pathways
What are heart sounds
hear “lub-dub” as valves of heart close
first “lub” when atrioventricular ( bicuspid and tricuspid valves close)
2nd “dub” heard when semilunar valves close
What is blood pressure
level of contraction of L ventricle force blood into arteries under pressure
What is systolic
blood forced into arteries during ventricular systole
what is diasotlic
pressure in arteries during ventricular diasole
How do you measure BP
sphygmomanometer
measures amount of pressure required to stop flow of blood through an artery- usually taken on brachial artery
How do you take a BP
place cuff on patient with arrow pointing up over brachial artery
bladder is held in place by the cuff
put stethoscope in ears and place end over brachial artery
squeeze bulb to inflate bladder with air
watch manometer- displays pressure in mm hG
pressure slowly released with valve and watch numbers
the systolic is the first sound of HB
diastolic reading is when HB goes away
reading is 2 numbers: systolic/diastolic
normal is 120/80
What factors enable blood return to heart from vein
- low resistance in venous walls
- internal valves prevent backward flow of blood
- assistance of muscular contraction in limbs and chest enable blood in veins to maintain a flow rate signifacte to return blood to the heart
what is contraction of cardiac muscle
begins in heart muscle: somewhat independent of nerve supply from CNS
heart can beat on its own with proper nutrients and O2
How is HR regulated
by nerves and endocrine system
neurotransmitters: norepinephrine and acetylcholine
allow change in BP due to emotional and physical stressors
What is the SA node
electrical impulse
sinoatrial node
found in R atrium: pace maker
small mass of cardio muscle: contain nervous and cardiac tisue
What is the path for electrical impulses
begin at SA node, travel through atria, create L and R atrial systole
travel AV node and bundle of His
travel ventricular apex
final travel through purkinje fiber: cause L and R ventricle to contract
What is AV node
atrioventricular node
What is an EKC/ECG
electrocardiogram
What is measured in an EKG
measure electrical impulse in heart
What are the waves seen on EKG
P wave: atrial depolarization and atrial systole
QRS Complex: ventricular depolarization and ventricular systole
T wave: ventricular depolarization( return to rest) and ventricular diastole
no way to depolarize atria: activity lost in QRS complex
What is syncope
reduced flow of blood and oxygen to brain: faint
often result of standing for long periods of time with straight legs: blood pool to legs
What is edema
fluid accumulation
What are causes of L side Heart failure
pulmonary edema
backup fluid in lung : CHF
What is hypertension
high BP
higher than 120/80
What are causes of high BP
atherosclerosis
thrombus
embolus
thromboembolism
Describe atherosclerosis
accumulation of soft masses of fatty materials
often cholesterol in arteries
plaque
accumulate beneath lining of arteries
as build: protrude through vessel interfere with blood flow
cause blood clot to form on irregular atrial wall
may stop blood flow in immediate area of clot dislodge and travel, clogs small artery in its path
what is a thrombus
stationary blood clot
what is embolus
blood clot dislodge and move with blood
what is thromboembolism
embolus lodge in vessel as it travels
what is a pulmonary thromboembolism
blockage of major artery in lungs: cause shortness of breath and angina( chest pain)
What is infarction
occur if blood vessel entirely blocked by thrombus or embolism cause tissue death
if unresolved= fatal
What is myocardial infarction
heart attack
portion of heart muscle dies due to lack of O2
what is angina pectoris
chest pain: could be felt if coronary artery partially blocked due to plaque
pain radiate L arm
lots of other symptoms
What is treatment for thromboembolism
2 drugs given by IV to dissolve clot
1. streptokinase: normally produced by bacteria
2. T-PA genetically engineered
both meds convert plasminogen to molecule in blood to plasmin to dissolve clot
if symptomatic may be given aspirin- reduces coagulation of platelet and decrease probability of clot forming
What is an angioplasty
surgeon spread plastic tube into artery of arm/leg
tube guided to heart through blood vessel
when reaches segment closed by pique in coronary artery, balloon inflated forces vessel open
What is a coronary bypass
segment of blood vessel of patients body stitched to one end of aorta and other end to artery past obstruction
once heart exposed: dr uses laser to open clogged coronary artery
What are other symptoms of heart attack
head: lightheaded arm/back/jaw/neck/shoulder: pain, numb chest: pain pressure fullness skin: cold sweat lung: trouble breathing stomach: upset and nausea women: tired and weak for days/weeks before MI, heartburn, cough, heart flutter
What is the right circuit of the heart called
pulmonary: bring deoxygenated blood to the lungs to get oxygen
What is the left circuit of the heart called
systemic: bring oxygenated blood from the heart to the rest of the body
what do the lub dub sounds of the heart mean
lub: atrioventricular: tricuspid and bicuspid valves close
dub: semilunar valves close
