Biology Chapter 7: The Cardiovascular System Flashcards
What makes up the cardiovascular system?
Muscular four-chambered heart, blood vessels and blood
What circulations does the heart support?
pulmonary circulation and the systemic circulation
What are the two atrioventricular valves?
tricuspid on the right
mitral on the left
How are the ventricles separated from the vasculature?
by the semilunar valves
What are the two semilunar valves?
pulmonary on the right
aortic on the left
What separates the atria?
atrioventricular valves
What is the pathway of blood?
right atrium –tricuspid-> right ventricle –pulmonary-> pulmonary artery –> lungs –> pulmonary veins –> left atrium –mitral-> left ventricle –aortic valve-> aorta –> arteries –> arterioles –> arterioles –> capillaries –> venules –> veins –> venae cavae –> right atrium
Why does the left side of the heart contain more muscle than the right side of the heart?
Systemic circulation has much higher resistance and pressure.
What is the mode of travel for the electrical current of the heart?
sinoatrial node –> atrioventricular node –> bundle of His –> purkinje fibers
Systole
The period during ventricular contraction when the AV valves are closed
Diastole
the heart is relaxed and the semilunar valves are closed.
Cardiac output
product of heart rate and stroke volume
Arteries
thick, highly muscular structures with an elastic quality. This allows to recoil and helps to propel blood forward within the system.
Capillaries
walls that are one cell thick, making them so narrow that red blood cells must travel through them in single-file lines - sites of gas and solute exchange
Veins
inelastic, thin-walled structures that transport blood to the heart. They are able to stretch in order to accommodate large volumes of blood but do not have recoil capability. Veins are compressed by skeletal muscle
Hepatic portal system
blood travels from the gut capillary beds to the liver capillary bed
hypophyseal portal system
Blood travels from the hypothalamus to the anterior pituitary
Renal portal system
blood travels from the glomerulus to the vasa recta
Erythrocytes (red blood cells)
lack mitochondria, a nucleus, and organelles in order to make room for hemoglobin
Hemoglobin
A protein that carries oxygen
Hematocrit
the percent of blood composed of erythrocytes
Leukocytes (White blood cells)
formed in the bone marrow - help in the immune system
Granular leukocytes
Play a role in nonspecific immunity (neutrophils, esinophils and basophils)
Agranular leukocytes
Play a role in specific immunity (lymphocytes and monocytes)
Thrombocytes
Cell fragments from megakaryocytes that are required for coagulation
Rh Factor
Dominant – An Rh negative individual will only create anti-Rh antibodies after exposure to Rh positive blood
Blood pressure
the force per unit area that is exerted on the walls of blood vessels by blood - systolic and diastolic components
How can blood pressure be measured?
sphygmomanometer
How is blood pressure maintained?
baroreceptor and chemoreceptor reflexes
Low pressure promotes:
aldosterone and antidiuretic hormone release
High blood pressure promotes:
atrial natriuretic peptide release.
Starling forces:
hydrostatic pressure and osmotic pressure
hydrostatic pressure
pressure of the fluid within the blood vessel.
Osmotic pressure
sucking pressure drawing water toward solutes.
Oncotic pressure
Osmotic pressure due to proteins.
Pressure at the capillary bed
hydrostatic pressure forces fluid out at the arteriolar end of a capillary bed; oncotic pressure draws it back in at the venule end.
`Oxygen gradient in the lungs
High partial pressure of oxygen, leading to the loading of oxygen onto hemoglobin.
Oxygen pressure in the tissues
Low partial pressure of oxygen, resulting in unloading
Cooperative binding
Each successive oxygen bound to hemoglobin increases the affinity of the other subunits, while each successive oxygen released decreases the affinity of the other subunits.
What is carbon dioxide generally carried in the blood as?
carbonic acid or bicarbonate and hydrogen ions
What can cause a decreased affinity for oxygen?
A high PaCO2 High H+ Low pH High temperature High concentrations of 2,3-BPG ----> All cause a right shift in the oxyhemoglobin dissociation curve
What causes a coagulation cascade?
when the endothelial lining of a blood vessel is damages, the collagen and tissue factor underlying the endothelial cells are exposed. – cascade
