CLPA Definitions Part 3

Blood Flow

right atrium → right ventricle → left atrium → left ventricle

Cirrhosis (/Advanced liver disease)

increases resistance to venous blood flow in the liver

DVT (deep vein thrombosis)

clot formation in large lower extremity veins

signs: asymmetrical calf size, edema, tenderness to palpation over vessel, Horman’s sign (pain on flexion of knee with dorsiflexion of foot)

Murmur

rushing or whooshing sound

occurs during turbulent blood flow past a malfunctioning cardiac valve

Hematology lab test

assesses cellular components of the blood

CBC (Complete Blood Count)

RBC count and hematocrit, Hemoglobin, RBC indices, platelets, WBC count

3 basic blood cell types: RBCs (erythrocytes), WBCs (leukocytes), platelets (thrombocytes)

Hematocrit (Hct)

% of space occupied by RBCs in whole blood

Hgb

measures g of Hg/dL of blood

Anemia

low RBC count and/or Hgb/Hct

emia

refers to blood or the presence of a substance in the blood

penia

means to lack or to have a deficiency

osis

defined as state, abnormal condition or increase

ex. leukocytosis (very many leukocytes → high WBC count)

MCV

Average volume of a single RBC

1st characteristic used to classify an anemia (normocytic, microcytic, or macrocytic)

MCHC

Average hemoglibn concentration in a single RBC

the 2nd characteristic used in anemia classification (normochromic, hypochromic, or hyperchromic)

RBW (RBC distribution width)

the span of sizes of RBCs in the patient’s blood

Thrombocytopenia

decreased platelet production

Spontaneous bleeding

usually occurs only when platelet count is very low (< 30,000 - 40,000/mm³)

ANC (Absolute neutrophil count)

= neutrophil + band count

Reference range: > 1500

WBC differential

measures populations of WBC subtypes

Pericardium

A double-layered sac surrounding the heart.

Electrical conduction system

SA Node → AV Node → Bundle of His → Purkinje Fibers.

Cardiac cycle

systole (contraction phase) - ventricles contract; AV valves close

diastole (relaxation phase) - ventricles relax and fill with blood; semilunar valves close

T4 (thyroxine)

secreted in the greatest quantity (90%)

Inactive form

T3 (Triiodothyronine)

physiologically active thyroid hormone

TSH (Thyroid Stimulating Hormone)

stimulates the thyroid and produces its hormones

secreted by the anterior pituitary glan

Higher BNP

worse heart failure prognosis

Falling BNP

effective CHF treatment

Transthoracic (Echocardiography method)

Non-invasive, probe placed on chest

Transesophageal (Echocardiography method)

Probe inserted into esophagus for better visualization

Positive D-dimer

Need further testing (e.g., ultrasound or CT angiography)

Negative D-dimer

strong evidence against DVT/PE

Ventilation (breathing)

the movement of air from outside the body into the bronchial tree and alveoli, and back out

Inspiration (inhalation)

Active process requiring muscle contraction

Diaphragm contracts and moves downward, increasing thoracic cavity volume

External intercostal muscles contract, raising ribs and sternum

Expiration (exhalation)

Passive process due to elastic recoil of lung tissues and muscles

Diaphragm relaxes, abdominal organs push it back up

Lung volume decreases, increasing intra-alveolar pressure, forcing air out

Surfactant

A lipoprotein mixture that keeps the alveoli inflated, preventing collapse

Maximal inspiration (a deep breath)

requires the contraction of several other muscles (pectoralis minor, sternocleidomastoid, scalenes), to enlarge the thoracic cavity even more

Spirometry

study of various air volumes that move into and out of the lungs due to different degrees of effort

Right lung

3 lobes, larger than the left lung

Left lung

two lobes, smaller due to heart positioning

Pleura

Visceral pleura covers the lungs

Parietal pleura lines the chest cavity

Alveoli

Gas exchange occurs here (oxygen in, CO2 out)

Respiratory cycle

one inspiration followed by an expiration

4 distinct respiratory volumes:

• tidal volume (enters or leaves the lungs during one respiratory cycle)

• inspiratory reserve volume (inhaled in above the tidal volume)

• expiratory reserve volume (exhaled during maximal forced expiration)

• residual volume (remains in the lungs after maximal expiration)

Ventral respiratory group

Stimulates respiratory muscles, and sets basic breathing rhythm

Dorsal respiratory group

also stimulates respiratory muscles, especially the diaphragm; may be involved in certain cardiopulmonary reflexes that control rate & depth of breathing

Rales (Crackles)

Discontinuous, high-pitched.

Heard in pneumonia, pulmonary edema, CHF.

Wheezes

High-pitched, continuous, musical.

Heard in asthma, COPD, bronchospasm.

Rhonchi

Low-pitched, snoring sound.

Associated with chronic bronchitis.

Stridor

Harsh, high-pitched inspiratory sound.

Indicates upper airway obstruction.