Cardiovascular Flashcards
Main functions of the system
Serves the body with nutrients and oxygen for energy output
Removes CO2 and waste products from tissues
Maintenance of body temperature
Prevention of infection
Three layers of the heart
Epicardium outer layer that helps to protect
Myocardium thick middle layer responsible for pumping blood
Endocardium innermost smooth muscle that lines chambers of the heart and allows blood to flow smoothly
Sympathetic influence (tachycardia)
Stimulation of heart to speed up caused by hormone epinephrine or adrenaline in brain
Parasympathetic influence (bradycardia)
Acetylcholine is the hormone responsible for slowing down the heart rate
ECG Electrocardiogram
P wave- depolarization through the atria
QRS-represents depolarization of the ventricle
T- represents repolarization of the ventricle
Blood pressure
Blood pressure is the force exerted by the blood against the walls of the artery
Normal is 120/80
Numbers in blood pressure represent
Systolic top number, it is the contraction of the heart
Diastolic is the bottom number it is the relaxation Of heart
Two main components of blood
Plasma
And blood cells
Plasma
Fluid component made of mostly water 55%
Blood cells
45%
Red blood cells (erythrocytes)
White blood cells (leukocytes)
Platelets
Parts of conductive zone
Mouth and nose Pharynx and larynx Primary and secondary bronchi Tertiary and terminal bronchioles Structure that bring air from outside the body through the lungs
Parts of respiratory zone
Respiratory bronchioles
Alveolar ducts and sacs
Gas exchange between breathed in and blood
Sacs like grapes allow diffusion of gases
Control centres in brain
Medulla oblingata and pons
Medulla oblongata
Responsible for inspiration and expiration
Pons
stops and inhalation so expiration can occur
both allow smooth transition from inhalation to exhalation
Fine tune breathing
What slows heart down
Bradycardia
Acetylcholine
What speeds heart up
Trachycardia
Epinephrine
Pericardium
Protective sac that loosely surrounds the entire heart allowing it to expand and contract freely
Sinus node
Small bundle of nerve fibre that generates automatic action potentials that govern the beating of the heart
Action potential
The rush of positive ions into a particular region of the cell membrane when a stimulus reachers the nerve fibre AKA depolarization
SA node and the bundle of his
SA node is on the posterior wall of the right atrium
10 seconds after the AV node triggers ventricular contraction
Then the bundle of his carries the electrical impulses to the purkinjie fibres that help transmit simultaneous contractions
What happens to heart when it exercises
Becomes larger and chambers increase as does stroke volume, beats faster
Stroke volume
The volume of blood pumped from the left ventricle in one contraction
With the heart rate it determines the output of blood by the heart per min
Ventilation
Amount of air moved by Lungs in one minute
