Mcat Bio Ch.7

Front 1

What is the systematic circulation?

Back 1

It is the part of the blood circulation that brings oxygen and collects CO2 from the cells.
Pathway:
Left ventricle--> aorta--> arteries--> arterioles--> capillaries--> venules--> veins--> superior and inferior vena cava--> right atrium
note: left ventricle pumps with the most force, more than right

Front 2

What is the difference between a vein and an artery?

Back 2

Veins go toward the heart whereas arteries lead away from the heart.
DO NOT think that it is defined based on oxygenated vs. not oxygenated blood. The pulmonary artery carries non-oxygenated blood away from the heart.

Front 3

What is the pulmonary circulation?

Back 3

It leads from the heart to the lungs and re-oxygenates the blood.
Pathway: right atrium--> right ventricle--> pulmonary artery--> arterioles--> capillaries of the lungs--> venuoles--> veins--> pulmonary veins--> back into the left atrium

Front 4

How does the heart beat with a regular rhythm?

Back 4

The heart is made up by specialized cells called sinoatrial node, which is located in the right atrium.
The SA node is autorhythmic, spreading its contractions to surrounding heart muscle via electrical synapses made from gap junctions.
The SA node creates a faster baseline beat from which the vagus nerve sends signals to slow down.
The SA node causes both atria to contract simultaneously.
The AP generated by the SA node also spreads to the atrioventricular node located in the interatrial septa
The AV node is slower to contract allowing the SA node to squeeze the blood into the ventricles before the ventricles push it out

Front 5

Bundle of His and Purkinje fibers --> research

Back 5

,

Front 6

What are some properties of arteries?

Back 6

Elastic, keeps blood moving smoothly, under high pressure.
They are wrapped in smooth muscle and are innervated by the sympathetic nervous system. Epinephrine can either cause vasorestriction or dialation of arteries.
Medium sized arteries are more constrict enough under sympathetic signals that they can reroute blood.
Arterioles are also wrapped in smooth muscle and can be used to reroute blood or increase blood pressure

Front 7

Capillaries

Back 7

Are only one cell thick
4 ways to cross capillaries:
1.pinocytosis
2.diffusion or transport
3.movement thru fenestrations
4.movement thru space between cells
hydrostatic pressure is greater than osmotic pressure causing the fluid to flow out
10% loss of fluid
only place for gas exchange

Front 8

What is the path of the air to the lungs?

Back 8

nasal cavity, pharynx, larynx, trachea (composed of ringed cartilage), bronchi, bronchioles, alveoli.
The nasal cavity warms and moistens the air.
Cilia are located in the trachea and help clean the air.
Problems with the cilia may cause breathing problems.

Front 9

Oxygen dissociation curve

Back 9

Shows percent saturation of hemoglobin with oxygen vs. pressure of atmospheric oxygen.
Curve has a sigmoidal shape. If pressure of oxygen is high enough, saturation does not increase with an even higher pressure.
If pressure of co2, basicity or temp. rises, the graph shifts to the right. This indicates a lowering of hemoglobin's affinity for oxygen

Front 10

Carbon dioxide exists in the blood in three different forms

Back 10

in physical solution, bicarbonate, carbamino compounds (combined with hemoglobin and other proteins)
Most is carried in bicarbonate form
It is turned into the bicarbonate form by carbonic anhydrase

Front 11

breathing rate

Back 11

acidosis caused by dissolved co2--> increase breathing