Chapter 1: General Concepts of Disease | Principles of Diagnosis

Question 1

What is disease?

Answer 1

any disturbance of the structure or function of the body

Question 2

What does congenital mean?

Answer 2

something you are born with

It could not manigest until the body is under stress, or never at all.

Question 3

E.g. You are at the Doctors office for a routine check-up and he finds something wrong with you. What is this finding called?

Answer 3

an incidental finding

Question 4

concept: health is on a [blank].

Answer 4

continuum.
- health flutates from day-day, week-week, etc.
- -health fluctuates with age

Question 5

What is a sign vs a symptom?

Answer 5

sign: physical findings of diease (see)
symptoms: subjective manifestations of disease (feel)

Question 6

What is pathogenesis?

Answer 6

the manner in which disease develops
(the progression)

Question 7

What is etiology?

Answer 7

the cause of the disease

Question 8

Classifications of Disease

Vascular

Answer 8

• blood vessels
• e.g. peripheral artery disease, aortic disease, coronary artery disease

Question 9

Classifications of Disease

Infectious (Inflammatory)

Answer 9

• chronic inflammation is bad and often related to lifestype
• longterm inflammation can lead to diseases
• e.g. asthma, rhematoid arthritis, ulcerative colitis and Crohn’s disease

Question 10

Classifications of Disease

Neoplastic

Answer 10

• tumors
• e.g. myeloid leukemia, myeloproliferative neoplasm, & metastatic malignant neoplasm in the bone marrow

Question 11

Classifications of Disease

Degenerative (Deficiency)

Answer 11

• genetic/congenital issues that lead to deficiency or lack of production of something
• e.g. Alzheimer’s, Parkinson’s, Huntington’s, ALS, spinal muscular atrophy

Question 12

Classifications of Disease

Idiopathic (Iatrogenic)

Answer 12

• we don’t know why it is happening
• e.g. acute idiopathic polyneuritis, diffuse idiopathic skeletal hyperostosis

Question 13

Classifications of Disease

Congenital

Answer 13

• something you are born with
• e.g. heart defets, neural tube defects, Down Syndrome

Question 14

Classifications of Disease

Allergic (Autoimmune)

Answer 14

• immune system reacts to harmless substances, leading to the activation of immune cells
• can sometimes be hard to diagnose
• e.g. Type I Diabetes, Celiac Disease, Hashimoto thyroiditis, Crohn’s, MS, Lupus

Question 15

Classifications of Disease

Endocrine (Environmental)

Answer 15

• sometimes casued by environmental factors or hormonal disruptors
• e.g. insulin resistance, thyroid disease, reproductive abnormalities, cancer

Question 16

Classifications of Disease

Metabolic

Answer 16

• diseases of metabolism
• e.g. Type 1 Diabetes, Gaucher disease, Phenylketonuria (PKU)

Question 17

List and describe the 3 stages of diagnosis.

Answer 17

• clinical history: look at family history, lifestyle etc.
• Physical examination: palpating and visualizing
• Differential diagnosis: list of possible conditions that share the same symptoms described, narrowed down

Question 18

What is prognosis?

Answer 18

the eventual outcome of disease (outlook for recovery)
- e.g. good, poor, guarded

Question 19

What is treatment?

Answer 19

• specific treatment: treats underlying cause
• symptomatic treatment: alleviates symptoms but does not influence course of disease

Question 20

What is the Patient-Centered Approach of taking a clinical history?

List the 5 stages.

Answer 20

1. history of current illness: chief complaint, severity, onset
2. medical history: details of general health, prev. illnesses
3. family history: disease that may run in the family
4. social history: occupation, habits, alcohol/tobacco
5. review of symptoms: symptoms other than disclosed in history of present illness

Question 21

What goes into choosing a diagnostic test?

Answer 21

• cost
• invasive vs non-invasive
• appropriateness for question being asked
• false positive/false negative ratio

Question 22

What is specificity?

Answer 22

the percentage of patients without disease misclassified as having disease
- true negatives (+ false positives)

Question 23

What is sensitivity?

Answer 23

the percentage of patients with the disease misclassified as not having the disease
- true positives (+false negatives)

Question 24

What is a clinical laboratory test?

Answer 24

• a test ot determine the concentration of substances that are frequently altered by disease in blood or urine
• determine concentration or activity of enzymes in blood
• evaluate organ function
• monitor response of certain cancers to treatment
• detect disease-producing organisms in urine, blood, feces
• determine response to antibiotics

Question 25

# Diagnostic tests: Imaging What is an X-Ray?

Answer 25

* the use of high-energy radiation waves at lower doses to produce images for diagnosing disease * can penetrate through tissues at varying degrees * act on photographic film as the rays leave the body

Question 26

# Diagnostic tests: Imaging What is radiopaque?

Answer 26

(during X-ray) appears white on film; high density tissues (like bone) abosrb most of the rays

Question 27

# Diagnostic tests: Imaging What is radiolucent?

Answer 27

(during X-ray) appears dark on film; low density tissues allow rays to pass through

Question 28

What is a CT scan?

Answer 28

computed tomography * radiation detectors record the amoung of X-rays or ionizing radiation absorbed by the body and feed data onto the computer that reconstruct the image * radiopaque and radiolucent tissues appear white and dark like in X-ray * higher dose of radiation than X-ray * screen for cancer * detect abnormalities in organs that cannot otherwise be identified by X-ray

Question 29

What is MRI?

Answer 29

magnetic resonance imaging * computer-constructed images of body based on response of hydrogen protons in water molecules when placed in a strong magnetic field * protons align in the direction of the magnetic field * protons are temporarily dislodged and wobble when radiofrequency waves are directed at them * protons emit a measurable signal that can be used to construct images

Question 30

What is a PET test?

Answer 30

positron-emission tomography * measures metabolism of biochemical compounds that are labeled with positron-emitting isotopes to measure organ function * evaluate changes in blood flow in heart muscle following heart attack * determine metablic activities of organ or tissue * expensive, not widely available, requires a lot of resources

Question 31

What is a radioisotope study?

Answer 31

radioisotope (radionuclide) studies * evaluate organ funciton by determining rate of uptake and excretion of substances labeled with a radioisotope * anemia, hyperthyroidism, pulmonary blood flow, cancer sprea, heart muscle damage

Question 32

What is a cytology test?

Answer 32

the exam of a single cell type * e.g. Papanicolaou smear: identifies abnormal cells in fluids or secretions for cervical or other cancers

Question 33

What do these electrical activity tests measure: ECG, EEG, and EMG?

Answer 33

ECG: measures changes in electrical activity of **heart** (a.k.a. EKG) EEG: measures electrical activity of **brain** and brain waves EMG: measures electrical activity of **skeletal** **muscle** during contraction and at rest

Question 34

What is an endoscopy?

Answer 34

an examination of the interior of the body using a rigid/flexible tubular instrument equipped with a lens and light source

Question 35

What is an ultrasound?

Answer 35

mapping echoes produced by high-frequency sound waves transmitted into body; echoes reflect change in tissue density to produce images