Structures/Functions of Circulatory System pt.2 Flashcards
The stimulus that triggers a heartbeat is an _____ that originates ____
electrical signal , originates from the heart itself
What is a Sinoatrial Node (SA)
Bundle of specialized nerves and muscle tissues that act as a pacemaker for heart
Where is SA node located
in the wall of right atrium
What dose SA node do
generates electrical signals that spread over the two atria that makes them contract
what is Atrioventricular Node (AV)
receiver of electrical signal from SA node and transmits it through a bundle of His (specialized nerve fibres )
Where is AV node located
in bottom of the right atrium
When AV nodes transmit signal through the bundle of specialized nerve fibers where do the nerve fibers relay signal
they relay signal through two branches of conducting fibres called Purkinje fibres
when the purkinje fibers recive signal what happens
ventricle contract simultaneously
Whats a ECG electrocardiogram
a device that records the electrical activity of heart as it contracts and relaxes
where is electrocardiogram placed when recording electrical activity
on body surface connected to recording device
ECG P wave part
just before atrial contraction (pump)
ECG QRS wave part
electrical impulse that spreads through ventricles = ventricle contraction (pump)
ECG T wave part
ventricles recovering before next SA stimulation (filling)
Lubb
sound produced when AV valves close ( when ventricles contract blood is forced up and cause the AV valves to close)
Dubb
sound produced when semilunar valves close
What is blood pressure measured in
mm of Hg (mercury)
when measuring blood pressure whats the two measures you are looking for and how is it written
systolic / diastolic
whats systolic blood pressure
pressure blood exerts during ventricular contraction (when ventricle contracts)
whats diastolic blood pressure
pressure blood exerts during ventricular relaxation (ventricle relaxes)
systolic/ diastolic avg good measurements
120/80 mm Hg
when measuring blood pressure what are you measuring arteries or veins
arteries
whats cardiac output
amount of blood flowing from the heart each min
cardiac output is affected by
stroke volume and heart rate
stroke volume
the quantity of blood pumped with each hearveat (70mL/beat)
whats heart rate
number of beats per minute (70 beats per min)
Measuring Cardiac Output
stroke volume x heart rate
increased cardiac output =
increased blood flow
decreased cardiac output =
decreased blood flow
Factors Affecting Cardiac output
size of person (bigger mass =bigger output), excercise , psychological factors such as age gender
What is the SA node known as
The pacemaker of the heart
when you train more what increases and what decreases
stroke volume increases and heart rate decreases
Whats pulmonary circulation
vessels that carry blood to and from the lungs
whats systematic circulation
vessels that carry blood to and from the body
Whats hearts separate blood supply called
coronary pathway
whats coronary pathway
hearts separate blood supply
what supplies cardiac muscle with O2 and other nutrients
coronary arteries
whats a diastole
heart relaxation when heart fills with blood
whats systole
heart contraction when the heart is pumping the blood out
why are coronary arteries called coronary
the heart is encircled in a network of blood vessels like a crown (coronary =corona=crown)
whats atherosclerosis
condition when there is a build up of plaque (fatty deposits, calcium, fibrous tissue) inside of artery walls
what can atherosclerosis lead to
narrowing = higher pressure which can cause (angina) chest pain , blood clots, shortness of breath, heart attack or failure
atherosclerosis treatment options
aspirin- reduce formation of clots
clots busting medication
angioplasty- ballon inserted
stent- permanent metal tube inserted
coronary bypass surgery- (a healthy artery used to create new pathway)
Whats a heart murmur
a misflow of blood in the heart due to valves not opening or closing properly
congenital- born with
heart murmur risk / causes
lack of exercise , diets high in saturated fats , smoking, genetics, obesity, high blood pressure
what is hypertension
high blood pressure
what dose hypertension (high blood pressure ) cause
blood vessels to weaken or even rupture and buildup of connective tissue as body tries to repair , making arteries hard and less elastic
Hypotension
low blood pressure
What does hypertension ( low blood pressure) cause
reduces bodies ability to transport blood which creates a problem for the brain because blood pressure has to work against gravity yo get up there causing dizziness
what happens to blood pressure as blood moves from arteries to the veins
lowers
what circulatory system organ is responsible for supplying the pressure for the blood
heart
why dose pressure change as blood moves from arteries to the veins
This is because arteries have muscular walls and more resistance where as veins have no muscles
why dose the blood pressure going from arteries to veins lower ?
Because it has to go through capillaries which are more smaller openings requiring less pressure
why is a sheeps heart used to study anatomy of human heart
anatomically similar
which chambers are the pumping chambers of the heart
ventricles
what chambers are receiving chambers of the heart
atria
how are the walls of atria and ventricle different
atria: thin
ventricles: thick
what is the pourpose of heart valves
to open and close so that blood dosent flow backwards
vessels that carry blood away from heart are _____ and that carry blood towards are ____
artery , veins
what is the biggest artery
aorta
Whats the pourpose of coronary artery and whats the result of a blockage of this vessel
This is the artery in heart and results in heart to stop pumping
