Cardiogenic Shock

WHAT WENT WRONG?

A drop in blood pressure and blood flow caused by the heart’s inability to pump

blood as a result of a cardiac emergency, such as cardiac tamponade, myocardial

ischemia, myocarditis, or cardiomyopathy (a disease of the heart that deteriorates

the heart muscle). Blood pools in the left ventricle, which causes a back up of blood

into the lungs, resulting in pulmonary edema. Contractions increase to compensate

for the decreased cardiac output, causing an increase in demand for oxygen by

the heart. However, the lungs are not oxygenating the blood sufficiently due to

decreased blood flow; and therefore heart muscles are starved for oxygen.

Cardiomyopathy

WHAT WENT WRONG?

The middle layer of the heart wall that contains cardiac muscle (myocardium)

weakens and stretches, causing the heart to lose its pumping strength and become

enlarged. The heart remains functional; however, contractions are weak, resulting

in decreased cardiac output. Most are idiopathic and not related to the major causes

of heart disease. The three types of cardiomyopathy are:

1. Dilated cardiomyopathy (common): The heart muscle thins and enlarges,

which leads to congestive heart failure. Progressive hypertrophy and dilatation

result in problems with pumping action of ventricles.

2. Hypertrophic cardiomyopathy: The ventricular heart muscle thickens, resulting

in outflow obstruction or restriction. There is some blood flow present.

3. Restrictive cardiomyopathy (rare): The heart muscle becomes stiff and restricts

blood from filling ventricles, usually as a result of amyloidosis, radiation,

or myocardial fibrosis after open-heart surgery.

Cardiac Tamponade

WHAT WENT WRONG?

A large amount of liquid accumulates in the sack around the heart (pericardium),

creating pressure on the heart that reduces the filling of ventricles with blood. This

results in a low volume of blood being pumped with each contraction. The accumulating

pressure within the pericardium may be due to fluid, pus, or blood. The

end result is decreased stroke volume and cardiac output.

The cause of tamponade may be trauma, postoperative, post-MI, uremia, or

cancer. The fluid may develop rapidly or over time, depending on cause. Tamponade

is a life-threatening condition. The seriousness is related to the amount of pressure

within the heart and the resulting decrease in ventricular filling.

Coronary Artery Disease (CAD)

WHAT WENT WRONG?

Cholesterol, calcium and other elements carried by the blood are deposited on the

wall of the coronary artery resulting in the narrowing of the artery and the reduction

of blood flow through the vessel. This impedes blood supply to the heart muscle.

These deposits start out as fatty streaks and eventually develop into plaque that

inhibits blood flow through the artery. Elevated cholesterol levels and fat intake

can contribute to this plaque build-up, as can hypertension, diabetes, and smoking.

When the plaque builds up within the artery, the heart muscle is deprived of oxygen

and nutrients ultimately damaging the heart muscle.

Peripheral Arterial Disease (PAD)

 

WHAT WENT WRONG?

Large peripheral arteries become narrowed and restricted (stenosis) leading to

the temporary (acute) or permanent (chronic) reduction of blood flow to tissues

(ischemia). This is most commonly due to atherosclerosis (plaque on the inner

walls of arteries), but may also be caused by a blood clot (embolism), or from an

inflammatory process. Severe peripheral arterial occlusive disease can lead to skin

ulceration and gangrene. Peripheral arterial occlusive disease is more common in

patients with diabetes or hypertension, in older adults, in those with hyperlipidemia,

and in those who smoke, as these conditions can predispose to diminished

circulation. Vascular disease that happens in one area of the body, e.g. coronary

arteries, is not an isolated process. The plaque build-up caused by long-term elevated

cholesterol levels will happen throughout the body. The most common area

of involvement is the lower extremities.

Myocardial Infarction (MI)

WHAT WENT WRONG?

Blood supply to the myocardium is interrupted for a prolonged time due to the blockage

of coronary arteries. This results in insufficient oxygen reaching cardiac muscle,

causing cardiac muscles to die (necrosis). MI is commonly known as a heart attack.

The area of infarction is often due to build-up of plaque over time (atherosclerosis).

It may also be due to a clot that develops in association with the atherosclerosis

within the vessel. Patients are typically (not always) symptomatic, but some

patients will not be aware of the event; they will have what is called a silent MI.

Angina (Angina Pectoris)

WHAT WENT WRONG?

A narrowing of blood vessels to the coronary artery, secondary to arteriosclerosis,

results in inadequate blood flow through blood vessels of the heart muscle, causing

chest pain. An episode of angina is typically precipitated by physical activity,

excitement, or emotional stress. There are three categories of angina.

Aortic Aneurysm

WHAT WENT WRONG?

A weakening in the wall of a portion of the aorta results in a balloon-like bulge as

blood flows through the aorta. The blood flow within this bulging area of the aorta

becomes very turbulent. Over time this turbulence can cause the dilated area to

increase in size, creating an aneurysm. The aneurysm can rupture causing a disruption

in blood flow to everything below the affected area, and may even result

in death.

Cardiovascular System

 

How the Cardiovascular System Works

The cardiovascular system is responsible for delivery of blood, which carries oxygen

and other nutrients, to the tissues of the body. The heart pumps the blood to

the body where it delivers nutrients and oxygen, picks up waste products, and then

returns to the heart.

Definitions and Terminology

A Drug

drug is defined as any chemical (substance) that can affect living processes (lehne , 2007)

Pharmacology 

Pharmacology is defined as the study of drugs and their interactions with living systems.(Lehne , 2007)

Clinical Pharmacology

Clinical Pharmacology is defined as the study of drugs in humans.It gives data,about indications,the potency ,doses and toxicity of drugs,for their safe clinical use.(Lehne , 2007)

Neurons

As we earlier discussed in our day to day physical activities the coordinating fun ction of our muscles to do those activities is a necessity.Have you ever considered how the muscles involved in those physical activities?When we consider this we can see that there is a scientific system to activate and coordinate the muscle to perfrom those activities.In this process it necessary for the body to transmit messages to eneble the muscles to produce the complex movements for  successful physical activity.Such messages are transmitted through specialized cells called neurons. Neurons are the basic elements of the nervous system.They are the cells that are specialized for communicating information.It is estimated that they are 100 -200 billion neurons in the brain itself (Feldman,1993)

Neurons have a basic structure of

     Cell body

     One axon

     One or more dendrites

Biology and Behaviour

The purpose of this study post is to help you Understand the biological basis of human behaviour.Hence, in this post you will have to study the biological structures of the body which influence behaviour such as the nervous systems functions in influencing behaviour.

You must understand that behaviour means actions of an individual as a result of biological , psychological and social interactions.

In other words, behaviour is a product of man’s biological ,psychological and socio-cultural environment.Biology means bodily structures or systems such as nervous system , muscular systems and its  functioning.

Cognative Model

“People are disturbed not by things,but by the views which they take of them”

The cognative model focus on how people acquire and interprets information and use it in problem solving.Each person develops schemata, which contain information about different domains in a person’s life, and assist in information processing  and strategy development.In the study of maladaptive behaviour,self-schemata are particularly important.

Humanistic model

The psychological model says that people are in a position to control their lives.Rejecting the views that behaviour is determined largely by automatic biological process , unconscious process of solely by environment it suggests that people are in control of their lives.Humanistic model stresses the role of psychology in enriching peoples’ lives and helping them self-fulfilment.Humanistic psychologists say that people are naturally inclined to develop towards higher levels of maturity and if they are given the opportunity they will strive to reach their full potential.Carl Rogers rejected the psychodynamic approach saying that it has given much emphasis to unconscious process.Rogers developed a new humanitarian theory called “self theory”.In theory he has mentioned that personality development is guided by each of has a personal need for positive regard.Abraham Maslow also  a famous psychologist who has contributed tremendously for the advancement of this model.His theory emphasized two things.

       i.          

Functionalism

In early of 20 century,structuralism was replaced by functinalism which was advocated by functionalists led by american psychloogist-william james."rather than focusing on mind's components Functionalism concentrated on what mind does-the function of mental activity.Functionalists asked what roles behaviour plays in allowing people to adapt to their environment better.Also william james examined the ways in which behaviour allows people to satisfy their needs".

Properties of Lung Tissue

Physical Factors Influencing Pulmonary Ventilation

As we have seen, the lungs are stretched during inspiration and recoil passively during expiration. The inspiratory muscles consume energy to enlarge the thorax. Energy is also used to overcome various factors that hinder air passage and pulmonary ventilation. These factors are listed below.

Changes in volume

Lung Volumes

There are several lung volumes and capacities that are useful to understand respiratory physiology and they are briefly described below.

Tidal Volume

Is the amount of air that moves into the lungs with each inspiration (or the amount that moves out of the lungs with each expiration). 

Location, Relation and Structure - Part 2

The Thoracic cage

The thoracic cage is formed by the vertebral column behind, the ribs and intercostal spaces on either side laterally and the sternum and costal cartilages anteriorly in front. Above, it communicates with the root of the neck through the ‘thoracic inlet’; and below, it is separated from the abdominal cavity by the diaphragm. 

                                                                      (The thorax)

Location, Relation and Structure

The Thoracic Cavity

The structure and functions of the major organs of the respiratory system are described below:

(Right median saggital section of the head showing the upper portion of the respiratory tract) 

The structures of the nose are divided into the external nose and the internal nasal cavity.

The surface features of the external nose include the root (area between the eyebrows), bridge, and dorsum nasi (anterior margin). The external openings of the nose, the nostrils or nares, are bounded laterally by the flared alae.

The internal nasal cavity lies in and posterior to the external nose. The nasal cavity is divided by a midline nasal septum, The nasal cavity continues posteriorly with the nasal portion of the pharynx through the posterior nasal apertures. It is lined by the mucosa which secretes mucus. The roof of the cavity has olfactory (smell) receptors.

Anatomy of Respiratory System

                                         

                                                 A human being can survive without food for as much as several weeks and without water for several days, but the body cannot survive without air even for three to six minutes.  A constant supply of oxygen to the tissues of the body (especially to the heart and brain) is essential to maintain life. To supply this air, respiration continues to occur from the moment a new born infant takes its first breath until the death of the individual.