Unit 2: Gross Anatomy of the Heart

Question 1

Define Biological Pump

What kind of pump is the Heart and how dose it work

Answer 1

Heart = A double Pump
* Left = Pulminary Circ.
* L. side = stronger because systemic loop encounters more resistance
* Right = Systemic Circ.

Pumps create pressure gradient need to move through a set of capillaries (High → Low)

Cardiac Muscle Contractions

Valves prevent the eversion of blood backwards (keep blow flowing in one direction)

Work in Series and pump the same volume of blood. If didn’t could lead to ??????

Question 2

Orientation of Heart

What do we call inferior vs superior regions

Answer 2

Base (with great vessles) = Superior
Apex = Inferior (the litte tip)

Question 3

Why do Valves Open?

Answer 3

Due to Pressure

Not due to Corae tendinae

Question 4

Overview:

Define the function of
1. Atria
2. Venacava
3. Pulminatry Artery
4. Ventricals
5. Aorta
6. Pulminary Veins

Answer 4

1. R Atria: Pulm. Circit, receives O2 poor
2. L Atria: Gets O2 rich blood from lungs
3. Large Veins (vena cava): Brings O2 poor blood to R Atria
4. Pulmonary Artery: Brings O2 poor blood to Lungs
5. R Vent.: Blood to lungs
6. L Vent.: Sends O2 rich blood to body
7. Aorta: Brings O2 rich blood to tissues
8. Pulm. Veins: O2 rich blood to L Atrium

Artery = bring blood Away from Heart

Question 5

Compare and Contrast the AV valve and the Semilunar Valves

Answer 5

AV Valves:
* Tricuspid (Right)
* Bicuspid/ Mitral (Left)
* Chordae Tendineae; Attach the AV valves to Papillary muscles → Stabilize valves/ prevent eversion (blood flow in wrong direction)

Semilunar Valves:
* Aortic
* Pulmonary
* No Chordae tendineae

AV Valve = Atria Ventricular Valves

Question 6

Describe the 3 layers of the Pericardium from most superficial to deepest

Also define Cardiac Tamponade

Answer 6

1. Fibrous Pericardium (Dense Connective Tissue)
   Protects heart from high internal or external pressure

Serous Pericardium (double Layer of loose connective tissue)

2. Parietal Pericardium

Pericardial fluid separates + lubricates the 2 layers
Physical (friction) and Chem. Buffer
Abt 50 mL; ↑ vol = Pericardial effusion
Pericardial synthesis: extract the excess fluid, pressure squeezes heart ( ↓ contractility/ ability to pump blood)
AKA Cardiac Tamponade

3. Visceral Pericardium (around heart itself)

The Serous Pericardium is the same tissue but splitting it up into 2 is easier

Question 7

Describe the 3 layers of the Heart wall

Answer 7

1. Epicardium (loose connective tissue); same as visceral pericardium → Can store some fat around heart
2. Myocardium: Cardiac Muscles
   Thickest
   Pacemaker cells
3. Endocardium: connective tissue, stem cells
   Scaffolding, creates Seal, Continuous with blood vessels & makes inner camber

Question 8

Walk through the path of Blood

Starting from L. Atria

Answer 8

Large Veins (vena Cava)
R Atrium
Tricuspid Valve
R Ventricle
Pulmonary Valve
Pulmonary Artery
Lungs
Pulm. Veins
L Atrium
Bicuspid Valve (mitral)
L Ventricle
Aortic Valve
Aorta
Tissues ( → return to heart via Vena Cava #1)

Can start anywhere

Question 9

Explain the Fetal Shunt System

Answer 9

Fetal Shunt System: So gas exchange can happen at placenta instead of lungs → Systemic Circ. (both L&R = pumping)

1. Foramen (hole) ovale: connects right and left atria
   * Hole in interatrial septum
2. Ductus arteriosus: pulmonary artery + aorta
   * Can cross from pul. Artery into aorta = syst. Circ.

Question 10

Describe Coronary Circulation and what happens when there is a blockage in this circulation

Answer 10

Coronary Circulation = Blood flow to heart tissues
Anastomosis = interconnected blood flow path → to prevent heart attack/ interruptions in flow (like brain)

Blockage at base = heart attack → cells die (ischemic) → scar tissue replaces → cant contract → other parts of heart compensate → heart failure
Leading cause of death in USA + killer of women

Heart Attack AKA Myocardial infarction

Question 11

What is the Cardiac Skeleton

Answer 11

Cardiac Skeleton = Connective tissue, in development; creates overall architecture of chambers/valves, insulating

Question 12

Describe the relationship between Volume and Pressure in relation to biological pumps

Answer 12

Pumps create pressure gradient need to move through a set of capillaries (High → Low)

Inverse relationship between volume and pressure ( Pressure↑ = ↓Volume) (Pressure↓= ↑Volume)
Pressure ↓ is more space available to be filled; think abt. Lungs; ↑ pressure sends out