intro to clinical med unit 1

Diseases were originally believed to come from?

Bad spirits, worms, decay and punishment from the Gods

The cradle of modern western medicine

Greece

Greek medicine revolved around?

The four “humors”

What were the four “humors”?

Blood, phlegm, yellow bile and black bile

Who was Imhotep?

He was “the one who came in peace”, a pyramid builder, physician to the pharoah known as the “shepherd of the royal anus”. Lived around 2650 BC

Who was Hippocrates?

He founded a school of physicians whose writings have been preserved, known for the hippocratic oath and his school taught careful observation

What is the Edwin Smith Papyrus?

It’s the earliest writing of medicine, which was purchased in 1862 by Edwin Smith, an American Egyptologist from Mustafa.

Who was Celsus (Greek Medicine)?

He discovered the cardinal signs of inflammation, these signs were described in his books “De Medicina”, a book on surgery, diet, pharmacy, etc. which still exists in present day

Who was Galen (Greek Medicine)

He is considered one of the most influential physicians in history, his writings dominated medical teachings in Europe and the Middle East for more than 1000 years, he was among the first to note that arteries contain blood, instead of air which was previously believed

Medicine did not advance beyond the teachings of Galen until?

The Renaissance, during the 13-14th century

Who was Edward Jenner?

He introduced the first systematic vaccination and discovered that cowpox could protect against smallpox after realizing that milkmaids in contact with cowpox did not contract smallpox

Who was Ignaz Semmelweis (1818-1865)?

He worked in a maternity ward as a physician in Hungary, established that sanitary conditions were necessary during surgery after noting how babies had a higher survival rate when they were delivered by nuns who had sanitary conditions, when compared to doctors who did not sanitize their areas.

Who was Robert Koch?

The founder of modern bacteriology

Who was Louis Pasteur?

Discovered the principles of vaccination and fermentation

Who was Sir Joseph Lister?

Discovered that after doing surgery it is necessary to disinfect the wound to prevent wound infections, he used carbolic acid to disinfect the wounds

Who was George Papanicolau?

He developed the pap smear, decreased the fatality rate of cervical cancer, he used swabs of the cervix to check for cancerous cells, he was a pioneer in early cancer detection

Who was Rudolf Virchow?

He was the first cellular pathologist, credited with first recognizing leukemia, known for Virchow’s node which is an enlarged left supra-clavicular lymph node as an early sign of gastric cancer

What are human diseases?

In the broadest sense, they are undesired deviations from the norm

How are diseases usually detected?

They are detected through signs and symptoms

What are signs of disease?

They can be seen by the doctor and detected by clinical tests such as fever, high blood pressure, bleeding, etc.

What are symptoms of disease?

These are reported by the patient and cannot be measured, such as pain, drowsiness, vertigo, etc.

Basic Principles of Human Disease:

They can be acquired (ex. infection), they can have a genetic basis (ex. gene mutations), they can be see by eye (ex. bleeding, jaundice), and some are only visible with medical tests/imaging (pigment or inclusions visible in cells, urine exams, nose swabs)

What are the four pillars to understanding disease?

Disease etiology, pathogenesis, lesion, and functional changes.

What is disease etiology?

The cause of a disease, infection, injury, genetic defects. (ex. streptococcus pneumonia infection of the lungs)

What is pathogenesis?

The disease process (ex. streptococcus infection of the lung leads to lung damage, inflammation, fluid accumulation)

What is lesion?

Morphological changes/ultrastructural, structural changes in the affected tissues (ex. bacterial pneumonia leads to lobar consolidation, inflammatory infiltrates, lung edema)

What are functional changes?

Impaired function of an organ system = clinical manifestation (ex. lobar bronchopneumonia, fever, pain, malaise, possibly death)

How to recognize diseases

Reported by the patient, gross examination, histologic examination, laboratory examination and specialized examination

What is gross examination?

The alteration (lesion) is visible by naked eye (ex. physical examination, autopsy)

What is histologic examination?

Alterations that are visible by microscope

What is laboratory examination?

Ex. blood tests, urine samples, DNA tests

What are specialized examinations?

X-ray, ultrasound, endoscopy, magnetic resonance imaging

What are Aulus Celsus’ four cardinal signs of inflammation?

Rubor (redness), tumor (swelling), dolor (pain), and calor (heat/warmth)

Cardinal signs of acute inflammation between 0-4 hours:

Preformed factors: antibodies, complement, serum, factors, vasoactive factors

CS: rubor, calor

Cardinal signs of acute inflammation between 4-48 hours:

influx of neutrophils

CS:  rubor, calor dolor tumor 

Cardinal signs of acute inflammation between 24-96 hours:

influx of macrophages

CS:  rubor, calor, dolor, tumor, functio laesa 

Cardinal signs of acute inflammation after 0-4 hours:

adaptive immunity T lymphocytes are activated and migrate to inflammatory site CS: dolor, tumor, functio laesa

Galen Virchow’s fifth sign of acute inflammation

Functio laesa (impaired function)

Patient history

• When did the signs/symptoms start? Circumstances?

• Is this the first time the patient had these symptoms?

• Are the symptoms getting worse, better, or remain stable 

• What steps did the patient take? Did anything help or change?

• If the patient had this in the past, was there a significant change?4

• Current and past medical history 

• Are there other concurrent medical problems?

• Other patient issues that could be relevant are smoking, alcohol, drugs, social issues, job loss

• Family history 

• Any other information that might help with the case

What are the diagnostic tests?

Invasive and non-invasive procedures

The Physical Examination

• Cultivate the art of observation 

• Be systematic in your examination

• Develop a routine that you follow 

• Know your tools (ex. stethoscopes)

• The future: mobile ultrasound devices 

Non invasive procedures

• eye/ear/throat inspection, neurological test of reflexes

• Urine test, throat swab

• X-ray, ultrasound, MRI, CT, ECG

• Note: if it does not break the skin it is considered non-invasive

Invasive procedures

Invasive procedures

• Blood draw, spinal tap, biopsy, endoscopy

• Note: if it breaks the skin it is considered invasive 

Common lab tests

Blood, urine, stool, cerebrospinal fluid, cells, proteins, microorganisms

CBC

Complete blood count

CMP

Comprehensive metabolic panel (electrolytes (such as Na, K, Cl, Ca), glucose

BUN

Blood Urea Nitrogen

Plasma proteins

albumin, enzymes, immunoglobins

Antibodies

serologic tests

Disease biomarkers

ex. myocardial infarct, pancreatitis, liver diseases, renal diseases

ESR

Erythrocyte sedimentation rate, not very common anymore but used for myeloma, temporal arteritis, polymyalgia rheumatica

WBC

White blood cells

White blood cells range from

4000 to 10,500

If there is an infection, the number of WBC goes above

10,000

NE

Neutrophils, which can be indicators of acute infection, contain multiple nuclei (3-4), most prominent about 60-70%

Lymphocytes are cells that

Can make antibodies, they also make them against vaccines, possess one nucleus, bigger than a red blood cell 20-30% of CBC

What are monocytes?

immune cells that go to sites of infection to combat, and have lower percentage amount of CBC

Basophils have

dark bluish granulosum 

What does plasma carry

Antibodies and other proteins

What are platelets and what do they do?

They are critical for blood coagulation, they are the first blood cells to arrive at injuries to coagulate blood and stop blood leakage, 140k-400k is the average amount 

Some disease conditions cause platelets to

Decrease in amount and cause patients to bleed more 

Red blood cell increase

 erythrocytosis or polycythemia

Red blood cell decrease

anemia or erythroblastopenia 

White blood cells increase

leukocytosis

White blood cells decrease

leukopenia

Lymphocytes increase

lymphocytosis

Lymphocytes decrease

lymphocytopenia

Granulocytes increase

granulocytosis

Granulocytes decrease

granulocytopenia or agranulocytosis 

Neutrophils increase

neutrophilia

Neutrophils decrease

neutropenia

Eosinophils increase

eosinophilia

Eosinophils decrease

eosinopenia

Platelets increase

thrombocytosis

Platelets decrease

thrombocytopenia

Ways of Measuring Electrical Activity for Diagnostic Purposes

Electrocardiogram (ECG/EKG), Electroencephalogram (EEG), Electromyogram (EMG)

What does an Electrocardiogram (ECG/EKG) do?

measures electrical activity of the heart

What does an Electroencephalogram (EEG) do?

measures the electrical activity of the brain

What does an Electromyogram (EMG) do?

measures the electrical activity of muscle

Parts of Typical ECG Strip

• P wave: atrial depolarization

• QRS complex: ventricular depolarization

• T wave: repolarization of the ventricle 

• Mnemonic: dog and the cookie 

Bad lookout of measuring electrical activity

• Ventricular flutter 

• 250-300 beats per min 

• Sinusoidal waves 

Worse lookout of measuring electrical activity

• Ventricular fibrillation, no clear electrical activity