Location of the Heart

Describe the following locaions

• Apex
• Base
• Anterior Surface
• Pericardial Sac

Approx the size of a fist

5" Long

3 1/2" Wide

2 1/2" Thick

1. Right Atrium
2. Right Ventricle
3. Left Atrium
4. Left Ventricle

Right side of the heart is low pressure pumping venous blood to the lungs.

Left side fo the heart is high pressure pumping arterial blood to the systemic circulation

What seperates the left and right ventricles?

How much fluid can the ventricle hold?

Interventricular septum

approx 150ml

1. Endocardium
2. Myocardium
3. Epicardium

Middle layer of hear

Thick Muscular Layer

Responsible for pumping action

Also called the visceral pericardium

External layer of the hear

Includes blood capillaries, lymph capillaries, nerve fibers and fat

Smoothe and glistening

• Double walled sac that encloses the heart
• Fibrous parietal perietal pericardium - rough outer layer of the pericardial sac
• Pericardial space contains approx 10ml of serous fluid

Pericardial Sac

Describe Pericarditis and Pericardial Tamponade

• Pericarditis - inflamation of the pericardium
• Pericardial Tamponade - pericardial sac is filled with blood due to trauma

• Two sets of atrioventricular valves seperating the atria/ventricles
• Two sets of semilunar valves prevent backflow from the aorta and pulmonary arteries

• Tricuspid -
  • Lies between R Atrium and R Ventricle
  • Consists of 3 seperate leaflets
  • Larger in diameter and thinner than the mitral valve
• Mitral (Bicuspid)
  • Lies between L Atrium and L Ventricle
  • Has only two cusps

• Semilunar valves have three cusps shaped like half-moons
• Do not have chords/papillary muscles.

• S1- Closure of tricuspid and mitral valves
• S2- Closure of pulmonic and aortic (semilunar) valves

1. R Atrium receives blood from the
   1. Superior Vena Cava
   2. Inferior Vena Cava
   3. Coronary Sinus
2. Tricuspid Valve
3. Right Ventricle
4. Pulmonic Valve
5. Pulmonary Arteries
6. Lungs
7. Left Atrium
8. Mitral Valve
9. Left Ventricle
10. Aortic Valve
11. Systemic Circulation

Describe the following terms:

Incompetence

Regurgitation

• Incompetence - Valve does not close completely
• Regurgitation - Blood leaking back because of open valve

• Right (Posterior descending) and left (anterior descending) coronary arteries supply the heart with oxygenated blood.
• Coronary veins drain myocardial blood into the right atrium via the coronary sinus

• Angina Pectoris is associates with atherslerotic disease that produces a fixed obstruction of the coronary arteries.
• Pain caused when the metabolic demands of the myocardium exceed the ability to deliver adequate blood flow

Angina causes by spasming of the coronary arteries.

Usually occurs during rest or minimal activity and most often at night

• Results from athersclerotic plaque disruption. Because of its propensity to lead to infarction it is sometimes referred to as preinfarction angina

• (Heart Attack) ischemic death of myocardial tissue
• MI usually results from rupture or fissuring of atherosclerotic plaque.

What are the intrisic rates of the following:

SA Node

AV Node

Purkinje Fibers

• SA Node - 60-80 bpm
• AV Node - 40-60 bpm
• Purkinje Fibers - 15-40 bpm

• Depolarization is the electrical activity that triggers the contraction of the heart muscle
• Repolarization is the electrical activity that "resets" the muscle and prepares it for the next contraction

Basic ECG

Describe the following:

• P wave
• QRS complex
• PQ segment
• PR interval
• ST segment
• ST interval
• QT interval

Describe the following Cardiac Parameters:

• Systole
• Diastole
• Stroke Volume (SV)
• Heart Rate (HR)
• Cardiac Output (CO)
• Venous Return (VR)
• End Diastolic Volume (EDV)
• End Systolic Volume (ESV)

• Systole - Period of contraction / emptying
• Diastole - Period of rest / filling
• Stroke Volume (SV) - quantity of blood pumped out of either ventricle per beat (rest 70ml/beat max 120ml/beat)
• Heart Rate (HR) - #times heart beats /min (72-230)
• Cardiac Output (CO) - Quantity of blood pumped be either ventricle per min - HRxSV=CO
• Venous Return (VR) - Quantity of blood returned to heart/min  - VR=CO
• End Diastolic Volume (EDV) - Quantity of blood remaining in ventricle at end of V diastole (approx 130ml)
• End Systolic Volume (ESV) - Quantity of blood remaining in ventricle at end of V systole

• Heart Rate
• Conductivity
• Contractility

The Right and Left Vagus Nerves. The Vagus Nerve innervates the heart at the SA and AV nodes.

Preload

Sympathetic Nervous System

Afterload

A positive inotropic effect is an increas in contractility

allows for an increase in SV with a constant preload through a more powerfull contraction and greater ejection of blood.

Afterload is the back pressure exerted on the aortic and pulmonic semi lunar valves.

The heart must overcome this pressure in order for circulation to take place.

• Cold, Clammy skin
• Color changes in skin/mucous membranes
• Dyspnea
• Orthopnea
• Crackes
• Changes in mental status
• Changes in blood pressure
• Dysrhythmias
• JVD
• Fatigue
• Restlessness

• Tunica Intima (innercoat) Endothelial cells (simple squamous)
• Tunica Media (middle layer) smoothe muscle
• Tunica Adventitia (outercoat) collagen and elastic fibers.

• Conducting arteries - Large elastic arteries (Aorta)
• Distributing arteries - small to medium sized arteries (Muscle tissue)
• Arterioles (smallest arteries)

• Both have a Tunica Intima, Tunica Media, and Tunica Adventitia
• Veins are thinner than arteries (not as much pressure and not as much muscle)
• Veins have venous valves (semilunars) to prevent the backflow of blood.

• Blood from the right ventricle is pumped in to the pulmonary trunk
• Blood is distributed to the right and left pulmonary arteries and transported to the lungs
• After the exchange of O₂ and CO₂ two pulmonary veins exit each lung and enter the left atrium

• Blood enters the heart from the pulmonary veins into the left atrium
• The left atrium sends the blood to the left ventricle
• The left ventricle pumps blood out through the aorta

• Veins from the spleen, pancreas, stomach, gall bladder, and intestines send blood to the Hepatic Portal Vein
• This vein emties in to the liver
• Blood from the liver drains into the hepatic veins which drain into the inferior vena cava.
• (The liver is the first organ to see anything you digest

• Maximizes the uptake of glucose and conversion of glucose to glycogen
• Maximizes the detoxification properties of the liver.

Mean Arterial Pressure (MAP) is the actual pressure that propels blood to tissue.

This is calculated by ²/₃ (Diastolic Pressure) + ¹/₃ (Systolic Pressure)

• Lymphatic Capillaries
• Lymphatic Venules and Veins
• Lymphatic Ducts (Right Lymphatic Duct and Thoracic Lymphatic Duct)

• Right Lymphatic Duct drains the upper right (quadrant) of the body
• The Thoracic Duct drains the rest of the body

• Breasts
• neck
• abdomen
• thorax
• pelvis
• groin

Thymus

Describe the location and function of the Thymus

The thymus is located in the Mediastinum

Produces WBCs especially T-Lymphocytes

Tonsils are clusters of WBCs

• Pharyngeal (adenoid) - back of throat
• Palatine - posterior lateral side of mouth
• Lingual - back of tounge

The spleen is located in the LUQ

• Filtration of bacteria
• Destruction of dead or deteriorating RBCs
• Recycling of Iron

• Skin
• Mucus
• Tears
• INFLAMATION (Most important)

Causes:

• Redness
• Swelling
• Pain
• Heat
• Diminished Function of the Tissue
• ***Attracts WBCs

• Neutrophils
• Monocytes
• Macrophages

Describe the following:

B-Lymphocyte

T-Lymphocyte

B-Lymphocyte- produces antibodies and acts as an immune memory cell

T-Lymphocytes act as a recognition for foreign bodies and calling on phagocytes