Showing posts with label FREE BOOKS. Show all posts
Showing posts with label FREE BOOKS. Show all posts

Wednesday, April 9, 2014

Anatomy and Physiology Notes: Conduction System of the Heart

   Key Concepts
1. The electrical activity of cardiac cells is caused by the selective opening and closing of plasma membrane channels for sodium, potassium, and calcium ions.

2. Depolarization is achieved by the opening of sodium and calcium channels and the closing of potassium channels.

3. Repolarization is achieved by the opening of potassium channels and the closing of sodium and calcium
channels.

4. Pacemaker potentials are achieved by the opening of channels for sodium and calcium ions and the closing of channels for potassium ions.

5. Electrical activity is normally initiated in the sinoatrial (SA) node where pacemaker cells reach threshold first.

6. Electrical activity spreads across the atria, through the atrioventricular (AV) node, through the Purkinje system, and to ventricular muscle.

7. Norepinephrine increases pacemaker activity and the speed of action potential conduction.

8. Acetylcholine decreases pacemaker activity and the speed of action potential conduction.

9. Voltage differences between repolarized and depolarized regions of the heart are recorded by an electrocardiogram (ECG).

10. The ECG provides clinically useful information about rate, rhythm, pattern of depolarization, and mass of electrically active cardiac muscle.

Pathway
SA Node
|
Walls of the Atrium (Atrial Contraction)
|
AV Node
|
Delay in transmission
(To provide ample time for ventricular filling)
|
Bundle of His
|
Left and Right Bundle Branch
|
Purkinje Fibers
|
Ventricular Contraction

Saturday, March 15, 2014

Anatomy and Physiology Notes: The Heart

Heart and heart wall layers
1. The heart is located in the left side of the mediastinum.
2. The heart consists of three layers.
a. The epicardium is the outermost layer of the heart.
b. The myocardium is the middle layer and is the
actual contracting muscle of the heart.
c. The endocardium is the innermost layer and lines
the inner chambers and heart valves.


Pericardial sac
1. Encases and protects the heart from trauma and infection
2. Has two layers
a. The parietal pericardium is the tough, fibrous outer membrane that attaches anteriorly to the lower half
of the sternum, posteriorly to the thoracic vertebrae, and inferiorly to the diaphragm.
b. The visceral pericardium is the thin, inner layer that closely adheres to the heart.
3. The pericardial space is between the parietal and visceral layers; it holds 5 to 20 mL of pericardial fluid, lubricates the pericardial surfaces, and cushions the heart.


There are four heart chambers
1. The right atrium receives deoxygenated blood from the body via the superior and inferior vena cava.
2. The right ventricle receives blood from the right atrium and pumps it to the lungs via the pulmonary artery.
3. The left atrium receives oxygenated blood from the lungs via four pulmonary veins.
4. The left ventricle is the largest and most muscular chamber; it receives oxygenated blood from the lungs via the left atrium and pumps blood into the systemic circulation via the aorta.

There are four valves in the heart.
1. There are two atrioventricular valves, the tricuspid and the mitral, which lie between the atria and ventricles.
a. The tricuspid valve is located on the right side of the heart.
b. The bicuspid (mitral) valve is located on the left side of the heart.
c. The atrioventricular valves close at the beginning of ventricular contraction and prevent blood from flowing
back into the atria from the ventricles; these valves open when the ventricle relaxes.

2. There are two semilunar valves, the pulmonic and the aortic.
a. The pulmonic semilunar valve lies between the right ventricle and the pulmonary artery.
b. The aortic semilunar valve lies between the left ventricle and the aorta.
c. The semilunar valves prevent blood from flowing back into the ventricles during relaxation; they open during
ventricular contraction and close when the ventricles begin to relax.

Sinoatrial (SA) node

1. The main pacemaker that initiates each heartbeat
2. It is located at the junction of the superior vena cava and the right atrium.
3. The sinoatrial node generates electrical impulses at 60 to 100 times per minute and is controlled by the sympathetic and parasympathetic nervous systems.

Atrioventricular (AV) node
1. Located in the lower aspect of the atrial septum
2. Receives electrical impulses from the sinoatrial node
3. If the sinoatrial node fails, the atrioventricular node can initiate
and sustain a heart rate of 40 to 60 beats/min.

The bundle of His
1. A continuation of the AV node; located at the interventricular septum
2. It branches into the right bundle branch, which extends down the right side of the interventricular septum, and the left bundle branch, which extends into the left ventricle.
3. The right and left bundle branches terminate into Purkinje fibers.

Purkinje fibers
1. Purkinje fibers are a diffuse network of conducting strands located beneath the ventricular endocardium.
2. These fibers spread the wave of depolarization through the ventricles.
3. Purkinje fibers can act as the pacemaker with a rate between 20 and 40 beats/min when higher pacemakers fail


Coronary arteries 
1. The coronary arteries supply the capillaries of the myocardium with blood.
2. The right coronary artery supplies the right atrium and ventricle, the inferior portion of the left ventricle, the posterior septal wall, and the sinoatrial and atrioventricular nodes.
3. The left main coronary artery consists of two major branches, the left anterior descending and the circumflex arteries.
4. The left anterior descending artery supplies blood to the anterior wall of the left ventricle, the anterior ventricular septum, and the apex of the left ventricle.
5. The circumflex artery supplies blood to the left atrium and the
lateral and posterior surfaces of the left ventricle.

Friday, February 28, 2014

Human Immunodeficiency Virus / Acquired immunodeficiency syndrome Lecture Notes

This is a Medical Surgical Nursing lecture note on AIDS/HIV in outlined format. Information and concepts are compressed to provide a quick review of the topic. Some information are so compressed that some concepts are not expounded in detail. If it is your first time to meet such information please refer to your textbook for further explanation of the concept. This review material requires a student to have a prior knowledge and good foundation of the subject matter for this only emphasizes important/ key information deemed important in understanding concepts in Pathophysiology and Medical Surgical Nursing.



Acquired immunodeficiency syndrome (AIDS)

  •  AIDS is a viral disease caused by human immunodeficiency virus (HIV), which destroys T cells, thereby increasing susceptibility to infection and malignancy
  •  The syndrome is manifested clinically by opportunistic infection and unusual neoplasms.
  • AIDS is considered a chronic illness.
  • The disease has a long incubation period, sometimes 10 years or longer.
  • Manifestations may not appear until late in the infection.


High-risk groups
Heterosexual or homosexual contact with high-risk individuals
Intravenous drug abusers
Persons receiving blood products
Health care workers
Babies born to infected mothers

Assessment
Malaise, fever, anorexia, weight loss, influenza-like symptoms
Lymphadenopathy for at least 3 months
Leukopenia
Diarrhea
Fatigue
Night sweats
Presence of opportunistic infections
Protozoal infections (Pneumocystis jiroveci pneumonia, major source of mortality)
Neoplasms (Kaposi's sarcoma, purplish-red lesions of internal organs and skin, B-cell non-Hodgkin's lymphoma, cervical cancer)
Fungal infections (candidiasis, histoplasmosis)
Viral infections (cytomegalovirus, herpes simplex)
Bacterial infections

Interventions
1. Provide respiratory support.
2. Administer oxygen and respiratory treatments as prescribed.
3. Provide psychosocial support as needed.
4. Maintain fluid and electrolyte balance.
5. Monitor for signs of infection.
6. Prevent the spread of infection.
7. Initiate standard precautions.
8. Provide comfort as necessary.
9. Provide meticulous skin care.
10. Provide adequate nutritional support as prescribed.


"Success is not final, failure is not fatal: it is the courage to continue that counts"

Tuesday, December 10, 2013

Historical Background of Nursing 1

This post pertains to the historical background of the nursing profession-on how nursing evolved from a mere responsibility of women before to an evolving discipline. From a being a job of slaves during the dzrk period in Europe to being a noble job today. 

The contemporary nursing is far different from nursing as it was practiced years ago, and it is expected to continue evolving during the 21st century. To comprehend present-day nursing and at the same time prepare for the future, one must understand not only past events but also contemporary nursing practice and the sociological and historical factors that affect it.

HISTORICAL PERSPECTIVES
Nursing has undergone dramatic change in response to societal needs and influences. A look at nursing's beginnings reveals its continuing struggle for autonomy and professionalization. In recent decades, a renewed interest in nursing history has produced a growing amount of related literature. This section highlights only selected aspects of events that have influenced nursing practice. Recurring themes of women's roles and status, religious (Christian) values, war, societal attitudes, and visionary nursing leadership have influenced nursing practice in the past. Many of these factors still exert their influence today.

Women's Roles
Traditional female roles of wife, mother, daughter, and sister have always included the care and nurturing of other family members. From the beginning of time, women have cared for infants and children; thus, nursing could be said to have, its roots in "the home." Additionally, women, who in general occupied a subservient and dependent role, were called on to care for others in the community who were ill. Generally, the care provided was related to physical maintenance and comfort. Thus, the traditional nursing role has always entailed humanistic caring, nurturing, comforting, and supporting.

Religion
Religion has also played a significant role in the development of nursing. Although many of the world's religions encourage benevolence, it was the Christian value of "love thy neighbor as thyself' and Christ's parable of the Good Samaritan that had a significant impact on the development of Western nursing. During the third and fourth centuries, several wealthy matrons of the Roman Empire, such as Fabiola, converted to Christianity and used their wealth to provide houses of care and healing (the forerunner of hospitals) for the poor, the sick, and the homeless. Women were not, however, the sole providers of nursing services.

The Crusades saw the formation of several orders of knights, including the Knights of Saint John of Jerusalem (also known as the Knights Hospitalers), the Teutonic Knights, and the Knights of Saint Lazarus . These brothers in arms provided nursing care to their sick and injured comrades. These orders also built hospitals, the organization and management of which set a standard for the administration of hospitals throughout Europe at that time. The Knights of Saint Lazarus dedicated themselves to the care of people with leprosy, syphilis, and chronic skin conditions.

The deaconess groups, which had their origins in the Roman Empire of the third and fourth centuries, were suppressed during the Middle Ages by the Western churches. However, these groups of nursing providers resurfaced occasionally throughout the centuries, most notably in 1836 when Theodore Fliedner reinstituted
the Order of Deaconesses and opened a small hospital and training school in Kaiserswerth, Germany. Florence Nightingale received her "training" in nursing at the Kaiserswerth School.

Early religious values, such as self-denial, spiritual calling, and devotion to duty and hard work, have dominated nursing throughout its history. Nurses' commitment to these values often resulted in exploitation and few monetary rewards. For some time, nurses themselves believed it was inappropriate to
expect economic gain from their "calling."

War
Throughout history, wars have accentuated the need for nurses. During the Crimean War (1854-1856), the inadequacy of care given to soldiers led to a public outcry in Great Britain. The role Florence Nightingale played in addressing this problem is well known. She was asked by Sir Sidney Herbert of the British War
Department to recruit a contingent of female nurses to provide care to the sick and injured in the Crimea. Nightingale and her nurses transformed the military hospitals by setting up sanitation practices, such as hand washing and washing clothing regularly. Nightingale is credited with performing miracles; the mortality rate in the Barrack Hospital in Turkey, for example, was reduced from 42% to 2%..

During the American Civil War (1861-1865), several nurses emerged who were notable for their contributions to a country torn by internal strife. Harriet Tubman and Sojourner Truth  provided care and safety to slaves fleeing to the North on the Underground Railroad. Mother Biekerdyke and Clara Barton searched the battlefields and gave care to injured and dying soldiers. Noted authors Walt Whitman and Louisa May Alcott volunteered as nurses to give care to injured soldiers in military hospitals. Another woman leader who provided nursing care during the Civil War was Dorothea Dix . She became the Union's Superintendent of Female Nurses responsible for recruiting nurses and supervising the nursing care of all women nurses working in the army hospitals.

The arrival of World War I resulted in American, British, and French women rushing to volunteer their nursing services. These nurses endured harsh environments and treated injuries not seen before. *A monument, entitled "The Spirit of Nursing," stands in Arlington National Cemetery . It honors the nurses who served in the U.S. Armed Services in World War I, many of whom are buried in Section 21 which is also called the "Nurses Section" (Military District of Washington, n.d.). Progress in health care occurred during World War I, particularly in the field of surgery. For example, there were advancements in the use of
anesthetic agents, infection control, blood typing, and prosthetics.

World War II casualties created an acute shortage of caregivers, and the Cadet Nurse Corps was established in response to a marked shortage of nurses (Figure 1-6 •). Also at that time, auxiliary health care workers became prominent. "Practical" nurses, aides, and technicians provided much of the actual nursing
care under the instruction and supervision of better prepared nurses. Medical specialties also arose at that time to meet the needs of hospitalized clients.

During the Vietnam War, approximately 90% of the 11,000 American military women stationed in Vietnam were nurses. Most of them volunteered to go to Vietnam right after they graduated from nursing school. This made them the youngest group of medical personnel ever to serve in wartime (Vietnam Women's Memorial Foundation, n.d.). Near the Vietnam Veterans Memorial ("The Wall") stands the Vietnam Women's Memorial . This monument was established to "honor the women who served and also for the families who
lost loved ones during the war . . . to let them know about the women who provided comfort, care and a human touch for those who were suffering and dying" (Vietnam Women's Memorial Foundation, n.d.).

Societal Attitudes
Society's attitudes about nurses and nursing have significantly influenced professional nursing.

Before the mid-1800s, nursing was without organization, education, or social status; the prevailing attitude was that a woman's place was in the home and that no respectable woman should have a career. The role for the Victorian middle-class woman was that of wife and mother, and any education she obtained was for the purpose of making her a pleasant companion to her husband and a responsible mother to her children. Nurses in hospitals during this period were poorly educated; some were even incarcerated criminals. Society's attitudes about nursing during this period are reflected in the writings of Charles Dickens. In his book Martin Chuzzlewit (1896), Dickens reflected his attitude toward nurses through his character Sairy Gamp. She "cared" for the sick by neglecting them, stealing from them, and physically abusing them (Donahue, 1996, p. 192). This literary portrayal of nurses greatly influenced the negative image and attitude toward nurses up to contemporary times.

In contrast, the guardian angel or angel of mercy image arose in the latter part of the 19th century, largely because of the work of Florence Nightingale during the Crimean War. After Nightingale brought respectability to the nursing profession, nurses were viewed as noble, compassionate, moral, religious, dedicated, and self-sacrificing.

Another image arising in the early 19th century that has affected subsequent generations of nurses and the public and other professionals working with nurses is the image of doctor's handmaiden. This image evolved when women had yet to obtain the right to vote, when family structures were largely paternalistic, and when the medical profession portrayed increasing use of scientific knowledge that, at that time, was viewed as a male domain. Since that time, several images of nursing have been portrayed. The heroine portrayal evolved
from nurses' acts of bravery in World War II and their contributions in fighting poliomyelitis—in particular, the work of the Australian nurse Elizabeth Kenney. Other, images in the late 1900s include the nurse as sex object, surrogate mother, tyrannical mother, and body expert.

During the past few decades, the nursing profession has taken steps to improve the image of the nurse. In the early 1990s, the Tri-Council for Nursing (the American Association of Colleges of Nursing, the American Nurses Association, the American Organization of Nurse Executives, and the National League for Nursing) initiated a national effort (titled "Nurses of America") to improve the image of nursing. More recently, the
Johnson & Johnson corporation contributed $20 million in 2002 to launch a "Campaign for Nursing's Future" to promote nursing as a positive career choice (Anonymous, 2003; Fitzpatrick, 2002). In addition, nursing schools and hospitals are targeting men in their recruitment efforts (Meyers, 2003).


Success is most often achieved by those who don't know that failure is inevitable. 
- Coco Chanel