Circulatory System Flashcards
Blue Blood on a Diagram is:
Deoxygenated Blood going towards the heart and lungs from cells.
Red blood on a diagram is:
Oxygenated blood pumped towards tissues to deliver oxygen.
Blood returns to the heart through the ________
Superior and interior vena cava
The 4 chambers of the heart are:
The right/left atria
And
The right/left ventricles
The valve(s) that separate the atrium and ventricle is:
The atrioventricular (AV) valves
Pulmonary means:
Lungs
ex. The pulmonary arteries/veins connect the heart to the lungs
Arteries
Carry oxygenated blood away from the heart.
- Elastic connective tissue (outer/inner layers)
- Smooth muscle (middle)
Smaller but elastic, you can feel your heartbeat.
The largest artery in the body
Aorta
Blood story starting at the superior/interior vena cava:
Vena Cava -> Right Atrium -> Atrioventricular valve -> Right Ventricle -> Semilunar valve -> Left/Right pulmonary arteries -> Lungs -> Left/Right pulmonary veins -> Left atrium -> Atrioventricular valve -> Left ventricle -> Semilunar valve -> Aorta -> Arteries -> Arterioles -> Capillaries -> Tissues -> Venuoles -> Veins
Atheriosclerosis (aka Heart Disease)
Excess fat is deposited on the walls of arteries (plaque).
- Narrows blood vessels
- Decrease area for blood to flow
- High blood pressure
Can cause blood clots
Define myocardial infarcation
A heart attack
Site of fluid &gas exchange
Capillaries
Veins
Carry deoxygenated blood from cells toward the heart.
Blood flow depends on:
-Valves (one-way)
-Skeletal muscle contraction
Aneurysm
Bulge that forms in the wall of a weakened blood vessel (usually arteries)
- Eventually ruptures
- Less oxygen/nutrients delivered to cells -> cell death
Aneurysm leads to internal bleeding
-in the brain can cause strokes
Pulmonary Circulation
Vessels that carry blood to/from the lungs.
Systemic Circulation
Vessels that carry blood to/from the body.
Myogenic muscle
A muscle that contracts without external nerve stimulation. (ex. Heart)
Pericardium
Fluid filled membrane surrounding the heart
Septum
Muscles that separate the right and left side of the heart. (Divider)
Characteristics of atria and ventricles
Atria:
-Thin walled
Ventricles:
-Thick walled (for contraction)
Vasoconstriction
Narrowing of blood vessels
-decreases blood flow to tissues
Increases blood flow when there is low blood pressure
Vasodilation
Widening of blood vessels
-increases blood flow to tissues
Usually during exercise
Autonomic Nervous System (ANS)
Regulates the diameter of arteries through vasoconstriction and vasodilation
Sinoatrial (SA) Node
Located in the right atrium
- acts as the pacemaker
- sets heart rate ~ 70 beats per minute
Diastole
Relaxation of heart
- relaxed atria fills with blood
- contracts, forces AV valves to open
- blood flows to ventricles
- AV valve shuts (LUBB sound)
Systole
Contraction of the heart
- blood rushes out of heart
- decreased pressure causes SL valve to shut
- SL valve shuts -> DUBB sound
Heart murmurs
Occurs when valves do not close completely
(left AV valve especially susceptible to defects)
Produces a gurgling sound
Superior/Interior Vena Cava
Carries deoxygenated blood back to the right side of the heart.
Right Atrium
Collects deoxygenated blood from vena cava.
Left atrium
Collects oxygenated blood from the lungs via the pulmonary veins
Coronary Artery
Supplies oxygenated blood to the brain and heart muscles.
One Way Valves
- direct blood towards the heart
- do not allow blood yo flow back in other direction
Skeletal Muscles in veins
- Pressure in veins increase when muscles contract
- muscle contraction > reduces vein diameter > pressure in vein increases > valve opens > blood flow towards heart
Atrioventricular (AV) node
- located in R atrium
- Acts as conductor, passing nerve impulses
Heart Beat Pathway
- Set by sinoatrial (SA) node
- Contractions travel to AV Node
- Nerve impulses travel via Purkinje fibres > septum > ventricles
