Circulation and Gas Exchange - Flashcards

Flashcards for reviewing lecture notes on Circulation and Gas Exchange, focusing on blood components, circulatory systems, cardiac cycles, blood vessels, and related concepts.

Blood

A connective tissue composed of a fluid matrix, called plasma, within which are found different cells and formed elements.

Functions of Circulating Blood

Transportation of materials, regulation of body functions, and protection from injury and invasion.

Red blood cells (erythrocytes)

Contain hemoglobin, a pigment that binds and transports oxygen; mature mammalian ones lack nuclei.

White blood cells (leukocytes)

Larger than erythrocytes and have nuclei; can also migrate out of capillaries.

Granular leukocytes

Neutrophils, eosinophils, and basophils

Agranular leukocytes

Monocytes and lymphocytes

Platelets

Function in the formation of blood clots.

Hematopoiesis

Occurs in the bone marrow.

Erythropoietin

Kidney produces this hormone, which stimulates the production of erythrocytes

Totipotent

Can give rise to any cell type.

Determination

Process by which a cell or group of cells becomes committed to a particular fate.

Differentiation

Resulting specialization in structure and function

Pluripotent

Can give rise to multiple different cell types.

Open circulatory system

No distinction between circulating and extracellular fluid; the fluid is called hemolymph.

Closed circulatory system

Distinct circulatory fluid enclosed in blood vessels and transported away from and back to the heart.

Hemolymph

Fluid that bathes the organs directly in an open circulatory system.

Pulmonary circulation

Moves blood between the heart and lungs.

Systemic circulation

Moves blood between the heart and the rest of the body.

Four-chambered heart Function

right atrium receives deoxygenated blood from body and delivers it to right ventricle, left atrium receives oxygenated blood from lungs and delivers it to left ventricle.

Three main types of blood vessels

Arteries, veins, and capillaries.

Arteries

Branch into arterioles and carry blood away from the heart to capillaries.

Capillary beds

Networks of capillaries that are the sites of chemical exchange between the blood and interstitial fluid.

Venules

Converge into veins and return blood from capillaries to the heart.

Pulmonary Artery

Contraction of the right ventricle pumps blood to the lungs via the __.

Cardiac Cycle

The heart contracts and relaxes in a rhythmic cycle called the __.

Systole

The contraction, or pumping, phase is called __.

Diastole

The relaxation, or filling, phase is called __.

Atrioventricular (AV) valves

guard the openings between atria and ventricles (Tricuspid valve = On the right; Bicuspid, or mitral valve = On the left).

Semilunar valves

guard the exits from the ventricles to the arterial system (Pulmonary valve = On the right; Aortic valve = On the left).

Systemic Arteries

The aorta and all its branches are __, carrying oxygen-rich blood from the left ventricle to all parts of the body.

Coronary arteries

First branches of aorta that supply the heart muscle itself

Superior vena cava

Drains the upper body

Inferior vena cava

Drains the lower body

Systolic pressure

Peak pressure at which ventricles are contracting.

Diastolic pressure

Minimum pressure between heartbeats at which ventricles are relaxed.

Sinoatrial (SA) node, or pacemaker

Sets the rate and timing at which cardiac muscle cells contract

Electrocardiogram (ECG or EKG)

Impulses that travel during the cardiac cycle can be recorded as an __.

Sympathetic division

Speeds up the pacemaker

Parasympathetic division

Slows down the pacemaker

Sinoatrial (SA) node

acts as a pacemaker for rest of the heart

Heart Electrical Activity Recording

electrical activity can be recorded on an electrocardiogram (ECG or EKG)

Arterioles

finest, microscopic branches of the arterial tree

Capillaries

where blood from arterioles enters

Venules

where blood is collected into, which lead to larger vessels, veins

Central lumen

lined with an epithelial layer that lines blood vessels

Arteries and veins

have an endothelium, smooth muscle, and connective tissue

Veins

contain valves to maintain unidirectional blood flow

Systolic pressure

the pressure in the arteries during ventricular systole; it is the highest pressure in the arteries

Pulse

the rhythmic bulging of artery walls with each heartbeat

Diastolic pressure

the pressure in the arteries during diastole (when the ventricles are relaxed); it is lower than systolic pressure

Vasoconstriction

is the narrowing of arteriole walls; it increases blood pressure

Vasodilation

is the increase in diameter of the arterioles; it causes blood pressure to fall

Lymph nodes

site of lymphocyte activation

Heart attacks (myocardial infarctions)

main cause of cardiovascular deaths in US -Insufficient supply of blood to heart

Stroke

Interference with blood supply to the brain

Atherosclerosis

Accumulation of fatty material within

Arteriosclerosis

Arterial hardening due to calcium deposition

Cardiac output

Increases during exertion because of an increase in both heart rate & stroke volume

Acetylcholine

Decreases heart rate

Norepinephrine

Increases heart rate

Arterial Blood Pressure

baroreceptors detect changes in this