Exam 4 terms Flashcards
Hemodynamics
Are the 2 principles that describe the movement of blood in the circulatory system.
Resistance
is the tendency of the cardiovascular system to oppose blood flow.
Laminar flow
When blood flows in a long smooth vessel it streamlines into layers with the contents of each layer staying the same distance from the vessel wall. the innermost layer has the least resistance; the outermost has the most
Velocity of flow
is the distance that a fixed volume of bloodtravels in a given period of time (cm/sec or cm/min).v = Q/A
Mean arterial pressure (MAP)
s blood pressure in the large arteries averaged over time MAP= DBP+ (SBP–DBP)/3
Diastolic arterial pressure
the lowest arterial blood pressure of a cardiac cycle occurring during diastole of the heart
Systolic blood pressure
the highest arterial blood pressure of a cardiac cycle occurring immediately after systole of the left ventricle of the heart
Sphygmomanometer
Arterial blood pressure is commonly measured in the brachial artery using this
Total peripheral resistance (TPR)
he resistance to blood flow imposed by friction between the flowing blood and the walls of all of the vessels within the systemic circulatory route. TPR= Rarteries+ Rarterioles+ Rcapillaries+ Rvenules+ Rveins
cardiac output (CO)
The amount of blood ejected by the left (or right) ventricle into the aorta (or pulmonary trunk) per minute.
Stroke volume
(volume per beat) ×Heart Rate (HR; beats/min)
heart rate
beats/min
Frank-Starling law
The volume of blood ejected by the ventricle (SV) depends on the volume present in the ventricle at the end of ventricular diastole
End diastolic volume (EDV)
Same as Frank-Starling law
Preload
Same as Frank-Starling law
skeletal muscle pumping (milking)
Contraction of skeletal muscles pumps blood in the veins back to the heart. Valves in the veins keep the blood moving toward the heart.
Respiratory pump
caused by movements of the diaphragm during breathing
Cardiovascular center (CVC)
ANS control of CO comes primarily from here (CVC) located in medulla oblongata (and pons) of the brainstem.
Cardiac accelerator nerves
Sympathetic neurons extend from the CVC down the spinal cord and emerge out of sympathetic trunk ganglia) as the cardiac accelerator nerves that innervate the SA and AV nodes, and most portions of the ventricular myocardium
baroreceptors
pressure receptors in the aorta and carotid arteries
chemoreceptors
in the aorta and carotid arteries monitor chemical changes in blood (pH, CO2, O2) and under certain conditions can initiate neural reflex pathways that control HR
capillary bed
extensive branched network of capillaries where exchange occurs
Capillary filtration (bulk flow)
s the mass movement of fluids (and solutes) between the blood and IF as a result of the hydrostatic and osmotic pressure gradients that exist across the walls of the capillaries
Starling forces
the 4 fources that drive bulk flow: -Capillary hydrostatic pressure (P_c) -Interstitial fluid hydrostatic pressure (P_if) -Plasma colloid osmotic pressure(or oncotic pressure)(pi_p) -Interstitial fluid colloid osmotic pressure (pi_if)
capillary hydrostatic pressure (P_c)
is the blood pressure in the capillary bed. It varies depending on arterial pressure, venous pressure, precapillary and post-capillary resistance. (37-17mm Hg)
Interstitial fluid hydrostatic pressure (P_if)
is extremely low (≈1 mm Hg)throughout the capillary bed under normal conditions.
Plasma colloid osmotic pressure (pi_p)
Osmotic pressure created by the presence of non-filterable proteins in the plasma. (25mm Hg)
Interstitial fluid colloid osmotic pressure (pi_f)
Osmotic pressure created by the presence of non-filterable proteinsin the plasma. (0mm Hg)
Ultrafiltration
Net exchange pressure= (37 +0) –(1+ 25)= 11 mm Hg which means ultrafiltration occurs in the arteriolar end. (usually exceeds reabsorption by 3L/day
Reabsorption
Net exchange pressure= (17 +0) –(1 + 25) = -9 mm Hgwhich means reabsorption occurs on the venular end
Net exchange pressure
= (P_c+ pi_if) –(P_if+ pi_p)
edema
Excessive accumulation of interstitial fluid in a tissue
lymphatic capillaries
are closed-ended vessels found widely dispersed in the capillary beds of most tissues.
lymph
Once interstitial fluid (containing its solutes and particulates)enters the lymphatic capillaries, it is referred to as lymph
lymphatics
contain a system of one-way valves and movement of lymph is driven by skeletal muscle contractions, lymphatic vessel contraction, andtissue pressure. There is no dedicated pumpfor lymph circulation
lymph nodes
act as lymph filters to remove foreign particles like bacteria and viruses and to help orchestrate immune responses to pathogens.
pathogens
disease causing microorganisms
bacteria
unicellular prokaryotic organisms that are capable of living outside of a host, or within the tissues (extracellular) and cells (intracellular) of a host (e.g. E. coli, Salmonella).
viruses
obligate intracellular pathogens consisting of a nucleic acid core(DNA or RNA)surrounded by a protein coat (e.g. Influenza virus is an RNA virus, Herpes virus is a DNA virus).
parasites
both unicellular and multicellular eukaryotic organisms that are capable of living outside of a host, or within tissues (extracellular) and cells (intracellular) of a host (e.g. protozoa like amoeba(dysentery) or plasmodium (malaria);worms like tape worms and roundworms)
innate immune system
(Nonspecific defenses): Inherited defense mechanisms thatd o not distinguish between specific pathogens
adaptive (or acquired) immune system
(Specific defenses or Immunity): Defenses against specific types of pathogens.
Cytokines
Low molecular weight proteins(over 100 have been identified)that usually act in a paracrine or autocrine fashion to regulate the intensity and duration of immune defenses.
infection
When the physical barriers that protect the surfaces of the animal are breached by a pathogen, infection of the underlying tissues takes place. Infection leads to activation of both innate and adaptive immune systems.
Inflammation or inflammatory response
An orchestrated host response that occurs at the site of pathogenic infection.This response is usually strongest for bacterial infections.
phagocytes
Cells that engulf (eat) and destroy pathogens or other cellular debris.
diapedesis (extravasation)
Some phagocytes, like neutrophils and monocytes, along with lymphocytes are attracted to sites of inflammation by chemotaxis (movement of cells toward chemical attractants).
opsonization
is the process of targeting cells for phagocytic destruction by tagging the pathogen’s cell surface with eitherbound: 1)Antibodies (Ab)released as part of the specificimmune response or 2)Complement proteins
phagocytosis
ll eating”is the process by which phagocytes engulf (eat) and then destroy pathogens (and other particles).