M2 L1 Flashcards
(126 cards)
1
Q
Where is the heart located?
A
Within the thoracic cavity between the lungs. Behind the sternum in the mediastinum
2
Q
What is the base of the heart?
A
3
Q
What is the apex of the heart?
A
4
Q
Which arteries can be seen of the heart from the anterior view?
A
5
Q
What can be seen from the posterior view of the heart?
A
6
Q
Role of intraventricular septum?
A
Separates left and right ventricles
7
Q
3 layers of heart from outer to inner?
A
Epicardium —> myocardium —> endocardium
8
Q
Role of epicardium?
* where derived from?
A
It surrounds the myocardium.
* derived from mesothelial layer
9
Q
What is the myocardium
A
Thickest heart layer
10
Q
What is the endocardium?
* what made of
A
Inner heart layer
* made of endocardial cells
11
Q
Purpose of pericardial cavity?
A
It is serious fluid that reduces surface tension during movement
12
Q
What is the pericardial cavity
A
It is serous fluid that reduces surface tension during movement
13
Q
What is the pericardium?
A
a sac-like membrane that surrounds the heart, acting as a protective layer and helping the heart function properly.
It consists of a fibrous outer layer and a serous inner layer, which includes the parietal and visceral pericardium
14
Q
What is the myocardium made up of?
A
Cardiomyocytes, fibroblasts (extracellular
matrix), vascular smooth muscle cells and
pericytes, endothelial cells
15
Q
Where do arteries deliver blood?
A
Away from the heart
16
Q
Where do veins deliver blood?
A
To the heart
17
Q
Where does gas exchange for deoxygenated blood occur?
A
In the pulmonary circulation in the lungs
18
Q
What type of pressure/resistance does the right side of the heart have? Why
A
Low pressure and low resistance because it is going to the pulmonary circulation
19
Q
What type of pressure does the left side of the heart have? Why
A
High pressure and high resistance
20
Q
What is the pulmonary semilunar valve on top of?
A
Right ventricle
21
Q
What valve does the right atrial ventricle have
A
tricuspid valve
22
Q
what valve does the left AV have
A
bicuspid or mitral valve
23
Q
what does the aortic semilunar valve sit on
A
the left ventricle
24
Q
What do the chord tendineae do and what do they connect to?
A
When the ventricles contract pressure pushes the AV valves (mitral and tricuspid) closed. The chordae tendineae hold the valve flaps in place, preventing them from flipping backward into the atria.
They connect the cusps (flaps) of the mitral and tricuspid valves to the papillary muscles in the ventricles.
25
Purpose of papillary muscles with the chordae tendineae?
The papillary muscles also contract, pulling on the chordae tendineae to keep the valve shut tight.
26
Why is it necessary for the
AV valves to be closed during
ventricular contraction?
Prevent backflow of blood into the atria
Ensure one-way flow of blood from the ventricles to the arteries
27
what happens as the atria fills with blood? (explain pressure too)
As the blood flows in, pressure builds up inside each atrium.
When the pressure in the atria gets higher than in the ventricles, the AV valves (tricuspid on the right, mitral on the left) open.
28
Is the semilunar valve closed or open during atrial (left and right) diastole
semilunar valves are closed
because the pressure in the ventricles is still lower than in the arteries (aorta and pulmonary artery), so the semilunar valves stay closed to prevent blood from flowing backward into the heart.
* would flow backward bc we go from high to low pressure and the pulmonary artery has high pressure bc of the blood its holding
29
What does the left coronary artery split into
circumflex artery and LAD
30
What happens during diastole? explain pressure
During diastole (relaxation phase), blood fills the ventricles from the atria.
* pressure in atria increases
31
What leads to systole?
Once the ventricles fill this leads to a contraction. this raises their pressure. this causes the AV valves to close to prevent black flow.
32
What is the lub sound?
once ventricles are full they contract and raise their pressure which causes the AV valve to close (bc LV pressure is higher now)
Lub = AV valves closing due to ventricular contraction.
33
What is the dub sound?
Once LV contracts its pressure goes down which means they cant force the semilunar valve open
"Dub" = Semilunar valves closing when the ventricles finish ejecting blood and begin to relax.
34
What causes the semilunar valves to open and what happens after?
As the ventricles contract and the pressure rises, it eventually becomes greater than the pressure in the pulmonary artery and aorta
This pressure difference forces the semilunar valves (pulmonary and aortic valves) to open, allowing blood to be pumped from the ventricles into the lungs
35
Fetal circulation: purpose of 3 shunts that close in adults? list them
purpose of the shunts in fetal circulation is to bypass certain organs (mainly the lungs and liver) that are not yet functional. These shunts allow the fetus to prioritize the flow of oxygenated blood to heart/brain
1) foramen ovale
2) ductus arteriosus
3) ductus venosus
36
What is the foramen ovale?
a hole between the right and left atria. This allows blood to bypass the lungs by flowing directly from the right atrium to the left atrium
37
What is the ductus arteriosis?
a blood vessel that connects the pulmonary artery (which would normally carry blood to the lungs) to the aorta (which then carries blood to the rest of the body).
* bypass the lungs and go directly into the systemic circulation
38
What is the ductus venosus
This vessel allows oxygenated blood from the umbilical vein to bypass the liver and flow directly into the inferior vena cava.
* liver is not yet fully functional for processing nutrients and detoxifying substances in the fetus
39
goal of fetal circulation?
maximize the delivery of oxygenated blood from the placenta to the fetal body, especially the brain and heart, while bypassing non-functional organs like the lungs and liver
40
What does the umbilical vein do?
Transports oxygenated,
nutrient-rich blood from
placenta to fetus
41
whats chd
Congenital Heart Disease
a structural problem with the heart that is present at birth.
42
What are the first and second heart field progenitor cells?
Mesoderm-derived cardiac progenitor cells that contribute to different parts of the developing heart.
43
What does the First Heart Field Progenitor Cell do?
gives rise primarily to the left ventricle (LV) and portions of R/L atria
44
What does the Second Heart Field Progenitor Cell do?
contributes to the right ventricle (RV), both atria, and the outflow tract.
45
At which stage does the linear heart tube form?
stage 21
46
What major event occurs at stage 28 of cardiac development?
Rightward looping of the heart and neural crest cell migration to the aorta and pulmonary trunk.
47
What are atrial and Ventricular Septal Defects?
holes or gaps in the septum—the walls that separate the left and right sides of the heart.
48
Explain the 2 types of ventricular septal defects
ASD = Atrial Septal Defect (hole between atria)
VSD = Ventricular Septal Defect (hole between ventricles)
49
What does abnormal development of the second progenitor cell lead to?
leads to improper septum formation
50
What do atrial and ventricular septal defects result from?
problems in SHF-derived tissue, worsened by genetic mutations (e.g. GATA4) and chromosomal abnormalities
51
What are contruncal defects?
abnormal development or misalignment of the outflow tracts of the heart (what later becomes the aorta)
52
What are two types of contruncal defects?
Tetralogy of fallot
D-looped transposition of the great arteries
53
What is tetralogy of fallot
A congenital heart defect with four key structural abnormalities that result from improper separation and alignment of the outflow tract during development
54
What are the four abnormalities of tetralogy of fallot?
1) RV outflow tract obstruction (pulmonary stenosis)
2) Ventricular Septal Defect
3) Overriding Aorta
4) RV hypertrophy
55
Explain the RV outflow tract obstruction for tetralogy of fallot
* what effect does it have
This is the narrowing/narrowing of the right ventricular outflow (to the pulmonary artery).
This leads to less blood to the lungs which leads to an oxygen shortage which results in CYANOSIS
56
Explain the ventricular septal defect for tetralogy of fallot
* what effect does it have
A hole in the septum that separates the left and right ventricles of the heart (diff than foramen ovale btw atrias)
leads to the mixing of blood from the RV (deoxygenated) and LV (oxygenated). This leads to decreased efficiency of the heart which makes it work harder
57
Explain the overriding aorta for tetralogy of fallot
* what effect does it have
the aorta normally comes from the left ventricle. but with the overriding aorta, it shifts to the left and sits on top of the ventricular septal defect. this means it receives blood from the LV and RV (oxygen rich and poor). leads to cyanosis
58
Explain the Right Ventricular Hypertrophy for tetralogy of fallot
thickening of right ventricular muscle due to increased workload
leads to decrease volume and efficiency
59
What is the D-Looped Transposition of the Great Arteries (D-TGA)
A conotruncal defect where the positions of the aorta and pulmonary artery are switched, but the ventricles are normally looped tho.
Aorta arises from the right ventricle
Pulmonary artery arises from the left ventricle
60
61
What is D-Looped Transposition of the Great Arteries (D-TGA)
A conotruncal defect where the positions of the aorta and pulmonary artery are switched (transposed), but the ventricles are normally looped (D-looped)
Aorta arises from the right ventricle
Pulmonary artery arises from the left ventricle
62
What is Left Ventricular Outflow Tract Obstructions (LVOTO)
congenital heart defects that affect the flow of blood from the left ventricle to the aorta and body
63
Two common types of Left Ventricular Outflow Tract Obstructions (LVOTO)
Aortic stenosis
Hypoplastic left heart syndrome (HLHS)
64
What is aortic stenosis of Left Ventricular Outflow Tract Obstructions
Narrowing of the aortic valve.
65
What is Hypoplastic left heart syndrome (HLHS) of Left Ventricular Outflow Tract Obstructions
Underdevelopment of the left ventricle, mitral valve, and/or aortic valve.
66
What are the 4 characteristics of Left Ventricular Outflow Tract Obstructions
1) Hypoplastic aorta (Ao): Too small to carry enough blood.
2&3) Hypoplastic mitral valve & LV: Underdeveloped → cannot pump blood effectively.
4) Patent ductus arteriosus (PDA): A fetal vessel that temporarily connects the pulmonary artery and aorta, allowing blood to bypass the faulty LV during fetal life.
67
What is trabeculation in cardiac development?
Trabeculation is the early spongy structure of the developing ventricular wall that allows oxygen to diffuse passively to the myocardium before coronary circulation is established.
68
Why is the early heart trabeculated rather than compact?
Because the fetal heart is hypoxic and lacks coronary arteries, trabeculae increase surface area to help oxygen diffuse into the heart tissue.
69
What is the functional reason for the transition from trabeculated to compact myocardium?
To support efficient pumping as the heart matures and coronary blood supply is established.
70
What is Left Ventricular Noncompaction Cardiomyopathy (LVNC)
the left ventricular muscle does not compact properly during development. Instead of becoming a smooth, solid wall, the myocardium remains excessively trabeculated (spongy with deep recesses).
71
Why would excessive trabeculation reduce cardiac function?
It prevents proper muscle compaction, leading to inefficient contractions and impaired ejection of blood.
72
What are the benefits of increased trabeculation in adults?
an adaptive response to increased preload
73
What is the blood made of?
Plasma, RBCs, WBCs, platelets
74
another name for red blood cells
erythrocytes
75
another name for white blood cells
leukocytes
76
What is the hematocrit
a measurement of the proportion of red blood cells (RBCs) in your blood
77
What does the plasma do?
Transport medium for inorganic and
organic substrates
(inorganic: Na+ etc)
(organic: glucose, amino acids, etc)
78
What are the 3 plasma protein types?
1) albumins - affects diffusion
2) globulins - involved in clotting and immune system
3) fibrinogen - involved in clotting
79
Where do blood cells derive from
pluripotent stem cells
80
what is innate immunity
* what gives rise to it
fast general response to antigens
* myeloid lineage
81
what is adaptive immunity
* what gives rise to it
slow but specific response to antigens
82
What do leukocytes do?
Aide in the body’s immune response
1) Destroy/neutralize invading disease-producing
microorganisms
2) Removal of old or damaged cells
83
Elements of the blood: What do platelets contribute to?
Contribute to hemostasis
(blood stopping)
84
Elements of the blood: What do Neutrophils, Eosinophils, and Basophils do?
clear infections, allergic
reactions
85
Elements of the blood: What do monocytes do?
precursor for macrophages, which engulf cells/debris
86
Elements of the blood: What do B lymphocytes do?
antibody production
87
What do T lymphocytes do?
cell mediated immune response
88
What do erythrocytes do?
a type of blood cell that primarily function to transport oxygen from the lungs to the tissues and organs
89
characteristics of erythrocyte structure
biconcave - large surface area
thin - quick diffusion
flexible membrane
90
where is hemoglobin
in the red blood cells
91
What is the function of hemoglobin?
Hemoglobin loosely and reversibly binds with oxygen (O2), allowing RBCs to transport oxygen from the lungs to tissues and organs.
92
what is Erythropoiesis
the process of producing red blood cells (erythrocytes) from stem cells in the bone marrow.
93
Role of the spleen and macrophages in producing new red blood cells?
The spleen acts as a filter, trapping these old or damaged RBCs.
These trapped RBCs are then engulfed and broken down by macrophages (type of WBC) within the spleen.
This breakdown process releases components like iron and amino acids, which can be recycled for the production of new RBCs.
94
what is erythropoietin
a hormone that plays a crucial role in the regulation of red blood cell (RBC) production, a process known as erythropoiesis. It is primarily produced by the kidneys in response to low oxygen levels in the blood (hypoxia)
95
What is anemia?
Low hematocrit (blood volume)
96
Causes of anemia?
1) Nutritional deficiencies
2) Aplastic (bone marrow not make RBCs)
3) Renal (not enough EPO)
4) Hemmoraghic (blood loss)
5) hemolytic (RBC rupture from external conditions)
97
What is Polycythemia
Increased RBCs leading to an elevated hematocrit
98
What are the four blood types and their antibodies?
A (anti-b)
B (anti-a)
AB (none)
O (anti-a and anti-b)
99
What is a transition reaction
A transfusion reaction occurs when a person receives incompatible blood—that is, blood that doesn't match their blood type.
100
What leads to oxygen and nutrient flow reduced in a transaction reaction?
The recipient’s immune system recognizes the donor red blood cells (RBCs) as foreign if they carry antigens that the recipient's antibodies attack. This causes the donor RBCs to agglutinate (clump together)
the clumping blocks blood flow.
101
What is the RH blood group?
a protein that can be present on the surface of red blood cells (RBCs)
If your red blood cells have the Rh protein, you are Rh positive.
No Rh protein = Rh negative
102
Explain the relationship between Rh pos and negative
Rh negative people dont have antibodies to protect them from Rh positive.
if Rh⁻ people are exposed to Rh⁺ blood (such as from a blood transfusion or pregnancy), their immune system sees it as foreign and begins to produce anti-Rh antibodies.
this can cause a transfusion reaction
103
what is Erythroblastosis Fetalis
An Rh⁻ mother is pregnant with an Rh⁺ baby (from an Rh⁺ father). During pregnancy/birth , some of the baby's Rh⁺ blood cells may enter the mother's bloodstream.
The mother's immune system sees the Rh⁺ cells as foreign and starts making anti-Rh antibodies.
Not affect first baby bc antibodies take time. It can affect the second baby RBCs and lead to anemia.
104
another name for platelets
thrombocytes
105
where do platelets come from?
Bone Marrow contains large cells called megakaryocytes.
These megakaryocytes shed small fragments of their cytoplasm into the bloodstream.
These fragments are the platelets
106
What is homeostasis
the process your body uses to stop bleeding and maintain blood vessel integrity after injury
107
What are the 3 main steps of hemostasis
1) vascular spasm
2) platelet plug formation
3) blood coagulation (clotting)
108
What is vascular spasm?
The damaged blood vessel constricts (narrows), reducing blood flow to the injured area.
The vascular walls become stickier, which helps them seal more easily and also helps platelets adhere.
109
what is Platelet plug formation
platelets are activated and then actin and myosin (contractile proteins inside platelets) help them stick together and contract to form a plug.
110
what is blood coagulation
forms a mesh that reinforces the platelet plug, creating a stable blood clot.
111
What is the first step of hemostasis and platelet plug formation following vessel damage?
Step 1: Platelet Adhesion
Trigger: Vessel injury exposes collagen fibers in the subendothelial layer.
Mechanism: Platelets adhere to the exposed collagen via von Willebrand factor (vWF).
Result: Platelets become activated.
112
What is the second step of hemostasis and platelet plug formation following vessel damage?
Step 2: Platelet Activation
Activated platelets release:
ADP (adenosine diphosphate)
Thromboxane A₂ (TXA₂)
These substances amplify the response and recruit more platelets.
113
What is the third step of hemostasis and platelet plug formation following vessel damage?
Step 3: Platelet Recruitment
ADP and TXA₂ act as chemical messengers to activate additional passing platelets, causing them to stick to the area.
114
What is the fourth step of hemostasis and platelet plug formation following vessel damage?
Step 4: Platelet Aggregation
Newly activated platelets stick to each other and to the initial plug, forming a growing platelet plug.
These new platelets release more ADP and TXA₂, creating a positive feedback loop.
115
What is the fifth step of hemostasis and platelet plug formation following vessel damage?
Uninjured/distal endothelial cells release prostacyclin and nitric oxide to prevent platelet activation at distal sites
116
What proteins does blood coagulation use
Factor I = fibrinogen (turns into fibrin via thrombin)
Factor II = prothrombin
117
Why is thrombin important and what makes it?
Thrombin converts fibrinogen (soluble) into fibrin (insoluble mesh)
Made by either extrinsic or intrinsic pathways
118
What is the intrinsic pathway?
Intrinsic Pathway = Slower, triggered by internal vessel damage
* Triggered by collagen exposure, rough surfaces, or trauma inside the vessel
119
What is the extrinsic pathway?
Extrinsic Pathway = Fast response to external injury
Triggered by Tissue Factor (TF) from damaged tissue outside the blood vessel.
* needs external stimulus to form thrombin
120
Dysfunctions in blood clotting: Thromboembolism
condition where a blood clot (thrombus) forms and then travels through the bloodstream, becoming an embolus that can block blood flow in another part of the body.
Ex: Atherosclerosis
121
What is hemophilia
Deficiency in clotting factors
* Severe hemorrhage
122
Why is the left ventricular myocardium thicker than the right?
It pumps against higher resistance in the systemic circulation
123
The ductus arteriosus in fetal circulation connects which two structures?
Pulmonary artery and aorta
124
During ventricular contraction or diastole, which valve remains open? allowing continuous blood flow into the ventricles from the atria.
AV valve
125
what can increase erythropoiesis in response to hypoxia?
Stimulation of bone marrow by erythropoietin (EPO)
126
Which plasma protein is essential in both blood clotting and fibrin mesh formation?
fibrinogen
