Circulation Flashcards
The systematic circulation delivers
Blood rich in oxygen from the left side of the heart to most body tissues
Returns blood low in oxygen to the right side of the heart
The pulmonary circulation delivers
Blood low in oxygen from the right side of the heart to the lungs
Returns rich in oxygen to the left side of the heart
What are the three layers of the blood vessel
Tunica intima
Tunica media
Tunica externa
Arteries carry blood
Away from the heart
Blood returns to the heart in the
Veins
What do the pre-capillary sphincters located at the end of each capillary bed do
Control the blood flow to individual beds
What do venules do
Collect blood from capillary beds and deliver it to small veins
What do valves do
Prevent blood from flowing backwards
What is precardium
A sack of dense connective tissue that wraps around the heart and prevents it from overfilling
What are the three layers of the heart wall called
Endocardium - inner layer
Myocardium - middle layer
Epicardium - outer layer
Capillaries connect
Arteries and veins
The SA node is also know as
The pacemaker - sets the rythem
An electrocardiogram (ECG)
Records the spread of electrical activity through the heart muscle
Cardiac output =
Stroke volume X heart rate
What is stroke volume
Volume of blood ejected per beat
Resting heart rate should be
64-80bpm in young adults
120bpm in newborn
What is tachycardia
Persistent resting heart rate above 100bpm
What is bradycardia
Persistent resting heart rate below 60bpm
Where is heart rate modified by
The cardiac centre of the medulla oblongata
The cardioaccelerator centre
Sends sympathetic impulses to increase rate of firing at SA node
The cardioinhibitory centre
Sends parasympathetic impulses to decrease rate of firing at SA node
What is Blood pressure
Force that blood exerts on the walls of the blood vessels
Blood pressure =
Cardiac output (CO) X total peripheral resistance (TPR)
Baroreceptors reflexes act to help restore blood pressure by
Increasing heart rate
Systolic BP is
The force pressure on arteries
The diastolic BP is
Pressure in the arteries when the heart rests between beats
What is a myocardial infarction
Heart attack
Extracellular fluid differs from intracellular fluid in adults because
It’s volume is smaller
What does the cardiovascular system do
Delivers gases nutrients and hormones to the cells and tissues
Removes waste products
Consists of blood, circulating system, and the heart
