afterload 

the tension produced by a chamber of the heart in order to contract

ADH 

Antidiuretic hormone

A relatively small (peptide) molecule that is released by the pituitary gland at the base of the brain after being made nearby (in the hypothalamus). ADH has an antidiuretic action that prevents the production of dilute urine (and so is antidiuretic).

Arteries and Aterioles 

Carry blood to the tissues-

coronary arteries nourish the heart muscle 

atria 

1. collection chamber for blood returning to heart

2.  assists in filling ventricles 

atrioventriclular valves 

• control blood flow from atria to ventricles

tricuspid- betweent right atrium and ventricle

mitral/bicuspid- between left atrium and ventricle 

blood pressure 

provides driving force for blood flow

BP= CO x TPR 

BP= CO x TPR 

Blood pressure is equal to cardiac output times the total peripheral resistance. 

capillaries 

provides a site for transfer of gases, nutrients, and wastes

structure: 

• thin walls (only single layer of endotheial cells thick)
• small size, but large surface area to ensure adequate exchange between tissues and blood

cardiac contractility 

the force with which ventricles pump, independent of effects of preload and afterload. 

cardiac output 

the amount of blood the heart pumps each minute

CO= HR X SV 

cardiac tamponade 

compressed heart chambers 

cardioinhibitory center 

parasympathetic-mediated decrease in heart rate 

cardiomyopathy 

group of disorders that affect the myocardium 

CO= HR x SV 

Cardiac Output is equal to heart rate times stroke volume 

collateral circulation 

a process in which small (normally closed) arteries open up and connect two larger arteries or different parts of the same artery. They can serve as alternate routes of blood supply.

diastole 

period during which ventricles relax and fill 

systole 

period during which ventricles contract 

Endocardium 

lines the heart wall 

endothelium 

s the thin layer of cells that line the interior surface of blood vessels

infarction 

tissue death 

infective endocarditis 

the surface of heart is infected by pathogens causing vegetative lesions.   

ischemia 

a restriction in blood supply 

myocardium 

heart muscle 

pericardial effusion 

an abnormal amount of fluid in the pericardial space

can compress the heart chambers and lead to cardiac tamponade 

preload 

1.  the size of the load that the heart muscle must move, determined primarily by amount of venous blood return to the ventricles prior to contraction.

2.  within limits, the bigger load/ventricular volume leads to an increase force of contraction and an increased stroke volume (starlings law)

3.  max force of contraction occurs when muscle fibers are stretched about 2 1/2 times normal resting length. 

pericardium 

two layer structure that maintains heart's position in thorax, provides physical protection from friction and other stresses, barrier to infection, and prevents overfilling of the heart.  Two layers include a tough outer layer that resists distension and a serous inner layer that lines the heart/outer layer of pericardium, forming cavity that contains small amount of serous fluid. 

primary/ essential hypertension 

a chronically elevated BP over 140/90 that is not caused by any specific dz 

pulmonary circulation 

blood moves through lungs so it becomes oxygenated, is maintained by the right ventricle 

RAAS 

renin-angiotension-aldosterone system

renin released from juxtaglomerular cells of kidneys in response to fall in BP, converts angiotensinogen to angiotensin I and ACE in blood vessels of lung converts angiotensin I to II which causes vasoconstriction and an increase in aldosterone from adrenal cortex causeing Na and water retention. 

secondary hypertension 

hypertension with an identifiable and usually treatable cause 

semilunar valves 

control blood flow from ventricles to pulmonary or system circulation

pulmonic controls flow to pulmonary artery

aortic controls flow to aorta 

Starling's law of the heart 

aka Frank Starling mechanism

the bigger the ventricular volume, the greater increase in force of contraction and the greater increase in stroke volume. 

stroke volume 

the amount of blood pumped out with each beat/contraction 

systemic circulation 

maintains systemic circulation- controlled by the left ventricle 

TPR 

total peripheral resistance

resistance blood encounters as it is pumped through vessels.  Determined mainly by degree of arterial constriction and elasticity. 

valvular stenosis 

narrowing of the valves causing the heart to work harder and decreasing CO 

vasomotor center 

sympathetic- mediated  increase in HR and contractility and changes in blood vessel tone

Part of the medullary control centers 

pump blood out of the heart 

veins and venules 

Function: 

return blood to the heart (assisted by venous valves and "milking" action of skeletal muscles)

Also serves as storage vessels

Structure: thin walls, distensible so can serve as reservoir

much lower pressure than in arteries 

conducting airways 

zero gas exchange occurs here

includes upper airways:  nasal passages, mouth, pharynx, and larynx

and lower airways:  trachea, bronchi, terminal bronchioles 

Functions: to warm, moisten, filter air

surface tension 

cohesive property of molecules on the surface of a liquid that cause them to assume the shape with the smallest surface area 

alveoli 

 contains pulmonary cavities and a large surface area for gas exchange 

Type I alveolar cells:  site of gas exchange

Type II alveolar cells:  produces surfactant that decreases surface tension with alveoli to facilitate lung inflation (so they don't collapse on themselves)

Alveolar macrophages:  protect against foreign substances 

atelectasis 

aveolar collapse 

surfactant 

produced by type II alveolar cells, it decrease surface tension with the alveoli, preventing collapse 

Type I alveolar cells 

site of gas exchange 

Type II alveolar cells 

produces surfactant to decrease the surface tension within alveoli, facilitate lung inflation 

pleura 

pleural space 

considered a potential space (contains a small amt of serous fluid). 

pleuritis 

inflammation of the pleura

causes sharp chest pain r/t chest movement 

pneumothorax 

lung collapse  r/t air gets into the pleural space

lung compliance 

the ease with which the lungs can be inflated.  Takes increased pressure to move same amount of air into noncompliant lung

Factors that decrease compliance:  scar tissue, fibrosis, fluid in lungs, decrease in surfactant

Factors that increase LC:  emphasema 

airway resistance 

the opposition to flow that air encounters as it moves through airways.  An increase in airway resistance leads to an increased respiratory effort required to maintain same rate of air flow. 

tuberculosis 

airborne infections disease caused by M. tuberculosis

Infection:  implantation of the organism, inflammation, and dev't of tubercle/Ghon's focus to prevent spread or organism, scar tissue forms around tubercle.  Skin test is positive, but no s/s, not contagious

Active Dz:  organisms multiple, lesions enlarge, erodes into bronchus, necrotic tissue and live organism coughed up in sputum causes cavities left behind and more scar tissue formation.  Contagious 

ventilation 

movement of air into and out of alveoli 

perfusion 

move venous blood through pulmonary capillaries adjacent to alveoli 

diffusion 

transport of O2/CO2 across alveolar-capillary membrane 

partial pressure 

the portion of total atomospheric pressure excerted by a single gas in the mixture.  Gases diffuse from areas where partial pressure is higher to areas where it is lower. 

surface area 

the space available for gas exchange (decreased surface area, decreased diffusion) 

shunt 

areas of lungs are perfused but not ventilated

CO2 + H2O<=>H2CO3<=>HCO3 + H+

 carbon dioxide transport: changed into bicarbonate and transported in that form (60%).  Carbon dioxide diffuses into RBC, combines with water, becomes carbonic acid (H2CO3) and readily ionizes to bicarbonate and hydrogen ions, the bicarb diffuses into plasma and can be retained or eliminated as needed by kidneys to maintain acid-base balance.

CO2 narcosis

an increased amount of carbon dioxide in the blood, makes a person sleepy

hypoxia 

a decreased oxygen supply to tissues 

hypercapnia 

an increase of carbon dioxide in the blood, can cause carbon dioxide narcosis 

respiratory failure 

when hypoxia or hypercapnia are severe, lungs fail to adequately oxygenate blood or prevent excessive retention of carbon dioxide, even at rest

(when PO2 50 mm Hg or less and PCO2 > 50 mm Hg)

mucociliary blanket 

removes secretions, microorganisms, and particles from respiratory tract 

pneumonia 

inflammation caused by microorganism, inhalation of irriating gases, aspiration creating exudation of fluid into alveoli and increased mucus production 

typical vs atypical 

pneumonia 

bacterial vs viral

decreases surface areas and lung compliance 

viral s&s are not as severe as bacterial but can predispose to bacterial infections 

community acquired vs hospital acquired 

pneumonia 

hospital acquired is more difficult to treat than community