Lab 4

P wave

Atrial depolarization

PR interval

Time from depolarization of the SA node to the onset of ventricular depolarization (normal <0.2s). A prolonged PR interval indicates a slowing of conduction between the atria and ventricles, usually due to slow conduction through the AV node.

PR segment

Isoelectric time between atrial depolarization and ventricular depolarization. Includes the atrial contract and delay of signal conduction at AV node.

QRS complex

Ventricular depolarization, atrial repolarization hidden in this complex.

QT interval

Time from ventricular depolarization to ventricular repolarization. Prolongation of the QT interval can result from multiple medications, electrolyte abnormalities, and certain disease states.

ST segment

Isoelectric time between ventricular depolarization and repolarization.

T wave

Ventricular repolarization

Blood Flow

The volume of blood moving past a specific point (or through a vessel

organ

heart); usually measured in ml

min

Tunica intima (interna)

Innermost layer (closest to blood); Made of simple squamous epithelium, present in all vessel types; smooth, continuous to prevent sticking of cells

blood

Tunica media

Middle tunic, contains smooth muscle to create constriction or dilation; thicker in arteries, thinner in veins; absent in capillaries

Tunica externa (externata) also called adventia

Outermost tunic; made of loose & dense connective tissues to anchor vessels to other structures

Arteries, arterioles

Vessels that carry blood away from heart; thickest of all vessels, do not contain valves; contains all three tunics

Veins, venules

Vessels that carry blood back to heart; thin walled, big lumen, contain valves b

c low pressure to keep blood moving back towards heart; contains all three tunics

Capillaries

Exchange vessels, contains slits between cell of tunica intima; lacks tunica media & well-defined tunica externa

Cardiac Output (CO)

The amount of blood (ml

min) pumped by the heart per minute (this equals blood flow through the entire body). Calculated by: heart rate X stroke volume. CO = HR x SV

Stroke volume (SV)

The volume of blood ejected by the left (or right) ventricle per beat (ml

beat)

Heart Rate (HR)

The number of times the heart contracts per minute (beats

min)

Blood Pressure

The force exerted on a vessel wall by the enclosed blood (mm Hg); unless otherwise stated, “blood pressure” usually refers to pressure in large systemic arteries near heart; blood pressure gradients create the driving force for blood flow

Total Peripheral Resistance

The amount friction encountered by blood as it flows through all of the blood vessels in the body; affected mostly by vessel diameter; the higher the resistance, the more difficult it is to move blood through the vessel

Systole

Contraction of the heart; can be used to describe atria or ventricles

Diastole

Relaxation of the heart; can be used to describe atria or ventricles

Systolic pressure

Maximum pressure in the arteries during a heart cycle; occurs during ventricular systole (mmHg)

Diastolic pressure

Minimum pressure in the arteries; occurs just before aortic semi-lunar valve opens (mmHg)

Pulse

The throbbing caused by the regular expansion and recoil of the arteries as the ventricles eject blood (or not) into the arteries. Can be felt through the skin in several places on the body. Counting the number of pulses

minute is a non-invasive way of determining heart rate.

Pulse pressure

The difference in blood pressure between systolic and diastolic pressure

Mean arterial pressure

The mean diastolic pressure plus one third of the pulse pressure; the mean force driving blood flow

Baroreceptors

Special cells that monitor pressure in the walls of the carotid arteries and aorta; associated with afferent neuron; respond to changes in mean arterial pressure

Baroreceptor reflex

A reflex initiated by stimulation of baroreceptors which has the purpose of maintaining a stable level of mean arterial pressure

Vascular Tone

The degree of blood vessel constriction that occurs during resting body states, is relative to vessel’s maximal dilated state.

abdominal aorta

Before: thoracic aorta; After: common iliac arteries

anterior tibial artery (L&R)

Before: popliteal artery; After: capillary beds of anterior leg and foot

aortic arch

Before: ascending aorta; After: thoracic aorta

ascending aorta

Before: left ventricle; After: aortic arch

axillary artery (L&R)

Before: subclavian artery; After: brachial artery

axillary veins (L&R)

Before: basilic vein and cephalic vein; After: subclavian vein

basilic vein (L&R)

Before: capillary beds of upper limb; After: axillary vein

brachial artery (L&R)

Before: axillary artery; After: radial and ulnar arteries

brachiocephalic trunk

Before: aortic arch; After: right common carotid artery and right subclavian artery

brachiocephalic veins (L&R)

Before: subclavian vein and internal jugular vein; After: superior vena cava

bronchial arteries

Before: thoracic aorta; After: capillary beds of bronchi and lung tissue

celiac trunk

Before: abdominal aorta; After: left gastric artery, splenic artery, and common hepatic artery

cephalic veins (L&R)

Before: capillary beds of upper limb; After: axillary vein

common carotid artery (L)

Before: aortic arch; After: internal carotid artery and external carotid artery

common carotid artery (R)

Before: brachiocephalic trunk; After: internal carotid artery and external carotid artery

common hepatic artery

Before: celiac trunk; After: hepatic artery branches within liver

common iliac artery

Before: abdominal aorta; After: external iliac artery and internal iliac artery

common iliac veins (L&R)

Before: external iliac vein and internal iliac vein; After: inferior vena cava

coronary arteries

Before: ascending aorta; After: capillary beds of myocardium

external carotid artery (L&R)

Before: common carotid artery; After: capillary beds of face, scalp, and neck

external iliac artery (L&R)

Before: common iliac artery; After: femoral artery

external iliac veins (L&R)

Before: femoral vein; After: common iliac vein

external jugular veins (L&R)

Before: capillary beds of scalp and superficial face; After: subclavian vein

femoral arteries (L&R)

Before: external iliac artery; After: popliteal artery

femoral veins (L&R)

Before: popliteal vein; After: external iliac vein

fibular artery (L&R)

Before: posterior tibial artery; After: capillary beds of lateral leg

gonadal artery (L&R)

Before: abdominal aorta; After: capillary beds of ovaries or testes

great saphenous veins (L&R)

Before: capillary beds of lower limb; After: femoral vein

hepatic portal vein

Before: capillary beds of digestive organs; After: liver sinusoids

hepatic veins (L&R)

Before: liver sinusoids; After: inferior vena cava

inferior mesenteric artery

Before: abdominal aorta; After: capillary beds of distal large intestine

inferior mesenteric vein

Before: capillary beds of distal large intestine; After: splenic vein

inferior vena cava

Before: common iliac veins and hepatic veins; After: right atrium

intercostal arteries

Before: thoracic aorta; After: capillary beds of thoracic wall

internal carotid artery (L&R)

Before: common carotid artery; After: cerebral arteries and capillary beds of brain

internal iliac veins (L&R)

Before: pelvic capillary beds; After: common iliac vein

internal jugular veins (L&R)

Before: capillary beds of brain; After: brachiocephalic vein

left gastric artery

Before: celiac trunk; After: capillary beds of stomach

lumbar arteries

Before: abdominal aorta; After: capillary beds of posterior abdominal wall

lumbar veins

Before: capillary beds of posterior abdominal wall; After: inferior vena cava

median cubital vein (L&R)

Before: cephalic vein; After: basilic vein

popliteal artery (L&R)

Before: femoral artery; After: anterior tibial artery and posterior tibial artery

popliteal vein (L&R)

Before: anterior tibial veins and posterior tibial veins; After: femoral vein

posterior tibial artery (L&R)

Before: popliteal artery; After: fibular artery and capillary beds of posterior leg

pulmonary arteries (L&R)

Before: pulmonary trunk; After: pulmonary capillaries of lungs

pulmonary trunk

Before: right ventricle; After: right and left pulmonary arteries

pulmonary veins (L&R)

Before: pulmonary capillaries of lungs; After: left atrium

radial artery (L&R)

Before: brachial artery; After: capillary beds of lateral forearm and hand

renal artery (L&R)

Before: abdominal aorta; After: kidney capillary beds

renal veins (L&R)

Before: kidney capillary beds; After: inferior vena cava

small saphenous vein (L&R)

Before: capillary beds of lower limb; After: popliteal vein

splenic artery

Before: celiac trunk; After: capillary beds of spleen

subclavian artery (L)

Before: aortic arch; After: axillary artery

subclavian artery (R)

Before: brachiocephalic trunk; After: axillary artery

subclavian veins (L&R)

Before: axillary vein; After: brachiocephalic vein

superior mesenteric artery

Before: abdominal aorta; After: capillary beds of small intestine and proximal large intestine

superior mesenteric vein

Before: capillary beds of small intestine and proximal large intestine; After: hepatic portal vein

superior vena cava

Before: brachiocephalic veins; After: right atrium

thoracic aorta

Before: aortic arch; After: abdominal aorta

ulnar artery (L&R)

Before: brachial artery; After: capillary beds of medial forearm and hand

vertebral artery (L)

Before: subclavian artery; After: basilar artery and cerebral circulation

vertebral artery (R)

Before: subclavian artery; After: basilar artery and cerebral circulation