Blood and the Heart Flashcards
What is the circulatory system subdivided into?
Cardiovascular and lymphatic system.
What are the functions of blood?
1 - Transportation of respiratory gases, hormones, nutrients
2 - Regulation against disease and excessive blood loss
Describe the role of blood and regulation of body temperature.
The regulation of body temperature is related to the skin.
Dilate to have temperature leave from the skin.
Vasoconstrict to prevent heat from escaping when cold.
Why is blood a specialized connective tissue?
Doesn’t have fibers, doesn’t bind or support things.
What is blood composed of?
Blood cells - formed elements - most are RBCs - less are WBCs Plasma - mostly wate - also ions, nutrients and proteins
Erythrocytes and platelets are not _____ cells.
true
Why are platelets not true cells?
Do not divide, formed of cell fragments.
If we were to spin blood down, the heavier things would go to the bottom but there would be layers.
What are they?
Bottom layer
Buffy coat in the middle - WBCs and platelets
Fluid on top
Erythrocytes are the most ________ of the formed elements.
They transport ______.
There are filled with ____, an oxygen-carrying protein.
Since they aren’t real cells, they do not have _______ or a ______.
The plasma membrane is _____ and ______ to allow them to go through blood vessels.
They have a ________ shape.
They originate in the ______ ________.
Common Oxygen Hb Organelles Nucleus Strong Flexible Biconcave Bone marrow
Why do RBCs not have organelles or nuclei?
Allows for a greater capacity to carry oxygen.
- won’t use up the oxygen they are carrying
Why does the plasma membrane have to be strong and flexible for an erythrocyte?
The size of a RBC is that of a capillary,
As it goes through the blood vessels, rubs up against the walls, dont want friction to cause damage to, have to be strong and flexible to not jam up the vessels.
What is the purpose of the biconcave shape?
Makes it more efficient for oxygen transport since it allows rapid diffusion of oxygen in and out.
What is blood doping?
What is the purpose?
What is the danger?
How is it detected?
Injecting previously stored RBCs before an athletic event.
More cells available to deliver oxygen to the tissues.
Dangerous since it increases blood viscosity and forces the heart to work faster.
Detect by measuring ratio of mature vs. immature RBCs in circulation.
- if not relatively equal –> means mature RBCs have been artifically introduced via transfusion
WBCs are also called _________.
They _______ the body from infections.
They function ______ the bloodstream.
They are formed inside the ______ ______.
Leukocytes
Protect
Outside
Bone marrow
What is diapedesis?
Process by which circulating leukocytes leave the capillaries
What are the two groups of leukocytes?
Granulocytes and agranulocytes
What cells types are granulocytes? Agranulocytes?
Gran - NEB
- neutrophils, eosinophils, basophils
Agra - LM
- lymphocytes and monocytes
What are the cells from least to most abundant?
NLMEB
Never let monkeys eat bananas
Neutrophils - Lymphocytes - monocytes - eosinophils - basophils
Describe neutrophils.
Granulocytes
- most abundant
- phagocytic
- granules filled with digestive enzymes specialized to destroy bacteria
Describe eosinophils.
Granulocyte
- second least abundant
- plays roles in ending allergic reactions and parasitic infections (most imp.)
Describe basophils.
Granulocyte
- least abundant
- granules secrete histamine to mediate inflammation during allergic reactions and parasitic infections
What drugs are used to combat allergies?
Antihistamines
What is pus?
Dead neutrophils, tissue debris and dead bacteria - indicates bad infection
Lymphocytes are _________.
They are the most _________ cells of the immune system.
They are the ______ most abundant.
They function in ________ tissue.
They act against a _______ foreign molecule (________) by attacking it ________ or by producing ________.
Agranulocytes important Second most abundant connective Specific antigen directly antibodies
What is one difference between a lymphocyte and monocyte?
When a monocyte leaves the blood, it becomes a macrophage.
Describe monocytes.
3rd most/least abundant leukocyte
Agranulocyte
Transform into macrophages
largest leukocyte
What are the functions of platelets?
Clot blood by creating a platelet plug
How to platelets clot the blood?
Go to site of injury and shoot out fibres to make a meshwork.
These fibres contract to pull the fibres closer to heal the wound.
The heart is a muscular ______ pump.
double
What is the pulmonary circuit?
Takes blood to and from the lungs.
What is the systemic circuit?
Vessels transport blood to and from the body tissues.
What are atria?
Receive blood from the pulmonary and systemic circuits.
What are the ventricles?
Pumping chambers of the heart which send blood to the pulmonary and systemic circuits.
What vessels feed the heart with oxygen rich blood?
Coronary arteries
Right side of the heart receives ______ blood.
Deoxygenated
The blood in our systemic veins isn’t actually blue, explain.
What makes it look blue is the fact that it is deoxygenated, makes it more red, crimson. When light refracts through the skin, makes them look blue.
Veins are more superficial.
Do veins always carry deoxygenated blood?
No, example pulmonary veins.
A normal heart is slightly to the _____ and has ____ around it that serves as an energy reserve.
Left
fat
What is the serous membrane of the heart called?
pericardium (parietal and serous)
What is the fibrous pericardium?
Strong layer of dense irregular CT.
Prevents overstretching, protection and anchors the heart
What are the different layers of the heart wall?
Epicardium
Myocardium
Endocardium
What is the epicardium?
Visceral layer of the serous pericardium
What is the myocardium?
Consists of cardiac muscle
Muscle arranged in circular and spiral patterns.
What is the endocardium?
Sheet of endothelium resting on a layer of CT.
Lines the heart chambers and covers the heart valves.
Endothelium is what kind of tissue?
Simple squamous
What is the advantage of the spiral pattern of the heat myocardium?
Ventricles are against gravity, spiral pattern causes the heart to get wrung out to force blood out of the ventricles.
How many pulmonary veins are there? What are they divided into?
4
2 left and 2 right
Blood pressure is related to the pressure in the _______ in general.
aorta
The right atrium receives blood from the systemic circuit via the _______ ____, ____ and _____.
coronary sinus
IVC
SVC
Blood flows from the right atrium through the ________ ______ into the right ventricle.
tricupsid valve
The superior vena cava drains from above the ________, the inferior vena cava from below.
diaphragm
What is a sinus?
Large vein
What are pectinate muscles?
Extra muscle ridges to add contractile force.
For the atria, the majority of the force needed to empty the chamber is provided by ________, but _______ muscles also contract slightly to add some force.
gravity
pectinate
The right ventricle pumps blood to the ________ circuit.
Blood is pumped from the right ventricle through the ________ valve to the __________ _______. This branches into the left and right ________ ________.
pulmonary
pulmonary semilunar valve
pulmonary trunk
pulmonary arteries
What special structures does the internal walls of the right ventricle have?
Trabeculae carneae
Papillary muscles
Chordae tendinae
What are the trabeculae carneae?
Ridges, don’t add contractile force but, make wall of ventricle rough so the blood doesn’t suction against it
What are papillary muscles?
Cone-shaped, come off the walls of the heart and attach to the valves via chordae tendineae
What are chordae tendineae?
Control the opening and closing of valves.
The left atrium receives blood from the ________ _____. It dumps blood to the left ventricle through the ________ or _________ ______.
Although it has _________ muscles, there are less than in the right atrium.
Pulmonary veins
bicuspid or mitral valve
pectinate
The left ventricle forms the ______ of the heart.
It pumps blood through the ________ circuit.
Blood is pumped to the _______ via the ________ _________ valve.
Apex
Systemic
Aorta
Aortic semilunar
Describe blood flow through the heart, starting from the body.
Body –> IVC, SVC, Coronary sinus –> RA –> TV –> RV –> PSLV –> PT –> PA –> lungs –> PV –> LA –> B/M V –> LV –> ASLV –> A –> Body
What is systole?
Diastole?
Systole - contraction of a heart chamber
Diastole - expansion/filling of a heart chamber
What is a heart beat?
Single sequence of atrial contractions followed by ventricular contractions.
i.e. one in systole, other in diastole
Describe the difference in the muscle walls of the right and left ventricles.
Left has more muscle since it needs to pump to the whole body, right only needs to pump to the lungs.
Left is completely encircled by muscle, right has a half circle of muscle.
Left is thicker than right.
What is the purpose of valves?
Ensure blood flows goes in a one-way direction.
What is each valve composed of?
Endocardium with a dense CT core
2 or 3 cusps
Endocardium is made up of what tissue type?
simple squamous
Describe how AV valves work.
Open when blood comes into the atrium, trickles into the ventricles through gravity.
- pectinate muscles contract to push additional blood out
Right ventricle contracts, papillary muscles pull on the chordae tendinae, causing them to close.
- Blood pressure further closes the valves
How do the semilunar valves function?
When the ventricles contract, pressure pushes the cusps away from each valve.
When the ventricles relax, the cusps join back together to catch any trickling blood.
What is the most common heart valve disorder. Why?
Mitral valve prolapse.
Subjected to great force from left ventricle contraction.
What is a characteristic symptom of mitral valve prolapse?
swish sound (backflow of blood)
What is a septum?
Muscle between ventricles.
What is transposition of the great vessels?
Oxygenated blood pumped to the lungs, deox to the body
What is coartification of aorta?
Narrowing of the aorta
What is a myocardial infection?
local death in heart muscle due to lack of oxygen
What is brachycardia?
Tachycardia?
Rate is slow
Rate is fast
Cardiac muscle tissue forms a thick layer called the __________.
It is ________, like skeletal muscle.
Myocardium also obeys the ________-________ mechanism of contraction.
myocardium
striated
sliding-filament
Cardiac muscle cells:
- Short and branched
- Have one or two ______
- These are connected at ________ _______ and are bound by ________ _______
- Separated by __________.
Nuclei
Intercalated discs
fasciae adherens
endomysium
Cardiomyocytes have ___ _______ to allow cells to communicate.
gap junctions
How are cardiomyocytes triggered to contract?
- Ca2+ enters the sarcoplasm
- Signals SR to release Ca2+
- Ions diffuse into sarcomeres
- Trigger sliding filament mechanism
Not all cardiac cells are ___________.
Innervated
What is autorhythmicity?
Basis for rhythmic heartbeat.
Involuntary
Automatic heartbeat without ANS innervation
What are anastomoses?
Connections between arteries supplying blood to the same region.
These provide an alternate route if one artery becomes blocked.
Idea is that a bunch of blood vessels come together so that if one gets blocked, there are other routes available
What is the difference between a heart attack and cardiac arrest?
Heart attack - plumbing issue - blood vessel blockage, if enough myocardium dies, heart cannot beat
- generally, older people
Cardiac arrest - electrical issue - nodes that control autorhythmicity go funky, heart doesn’t get proper contraction
- mostly young/seemingly healthy
Coronary arteries:
Left and right coronary arteries branch off the ______ above the aortic semilunar valve to supply ________.
aorta
myocardium
Describe cardiac veins?
What do they do?
Where do they drain into?
What do they empty?
Collect wastes from cardiac muscles.
Drain into coronary sinus on posterior surface of heart.
Coronary sinus empties into RA.
