Biology: Chapter 7 Flashcards
Pulmonary circulation
The right side of the heart accepts deoxygenated blood returning from the body and moves it to the lungs through pulmonary arteries
Systemic circulation
The left side of the heart receives oxygenated blood from the lungs by way of the pulmonary veins and forces it out to the body through the aorta
Atria
-thin-walled structures where blood is received from either the venae cava or the pulmonary veins
-The atria contract to push blood into the ventricles
Ventricles
-receive blood from the atria
-After they fill, they contract to send blood to the lungs and to the systemic circulation
-Far more muscular than the atria which allows for more powerful contractions
Atrioventricular valves
separate the atria from the ventricles
Tricuspid valves (AV valves)
valve between the right atrium and the right ventricle
Mitral/Bicuspid valves (AV valves)
valve between the left atrium and the left ventricle
Semilunar valves
separate ventricles from vasculature
Pulmonary valve (semilunar valve)
the valve that separates the right ventricle from pulmonary circulation
Aortic valve (semilunar valve)
the valve that separates the left ventricle from the aorta
SA node (electrical conduction of the heart)
-impulse initiation occurs here
-located in the wall of the right atrium
-As the depolarization wave spreads from the SA node, it causes the two atria to contract simultaneously (atrial systole)
AV node (electrical conduction of the heart)
-signal travels here which sits at the junction of the atria and ventricles
-The signal is delayed here to allow the ventricles to fill completely before they contract
Bundle of His (electrical conduction of the heart)
signal travels down this and its branches which is embedded in the interventricular septum
Purkinje fibers (electrical conduction of the heart)
distribute the electrical signal through the ventricular muscle and allows for ventricular contraction
Systole
ventricular contraction and closure of the AV valves occurs and blood is pumped out of the ventricles
Diastole
the ventricles are relaxed, the semilunar valves are closed, and blood from the atria fills the ventricles
Cardiac output
-the total blood volume pumped by a ventricle in a minute
-Product of heart rate (HR, beats per minute) and stroke volume (SV, volume of blood pumped per beat)
-CO = HR x SV
Endothelial cells (vasculature)
-release chemicals to aid in vasodilation and vasoconstriction
-allow white blood cells to pass through the vessel wall and into the tissues during inflammatory response
Arteries
-Move blood away from the heart to the lungs and other parts of the body
-Most contain oxygenated blood; only pulmonary arteries and umbilical arteries contain deoxygenated
-Highly muscular and elastic
Capillaries
-Vessels with a single endothelial cell layer and are so small that red blood cells must pass through the capillaries in a single-file line
-Thin wall allows for easy diffusion of gases, nutrients, and wastes
-Leaky which aids in the transport of gases and solutes
Veins
-Transport blood to the heart
-Thin-walled and inelastic
-Most contain deoxygenated blood; only pulmonary veins and umbilical veins contain oxygenated
Superior vena cava (SVC)
returns blood from portions of the body above the heart
Inferior vena cava (IVC)
returns blood from the portions of the body below the heart
Hepatic portal system
blood leaving capillary beds in the walls of the gut pass through the hepatic portal vein before reaching capillary beds in the liver
Hypophyseal portal system
blood leaving capillary beds in the hypothalamus travels to a capillary bed in the anterior pituitary to allow for paracrine secretion of releasing hormones
Renal portal system
blood leaving the glomerulu travels through an efferent arteriole before surrounding the nephron in a capillary network called the vasa recta
Plasma
liquid portion of blood. An aqueous mixture of nutrients, salts, respiratory gases, hormones, and blood proteins
Cellular portion of blood
erythrocytes, leukocytes, and platelets
Erythrocytes
-red blood cells
-Specialized cell designed for oxygen transport
-contains molecules of hemoglobin, each of which can bind four molecules of oxygen
-Their shape assists them in traveling through small capillaries and aids in increasing surface area which increases gas exchange
-When they mature, they lose the nuclei, mitochondria, and other organelles in order to make room for hemoglobin
Leukocytes
-white blood cells
-Crucial part of the immune system, acting as our defenders against pathogens, foreign cells, cancer, and other material not recognized
Types of leukocytes
Neutrophils, eosinophils, basophils, lymphocytes, monocytes
Classes of leukocytes
-Granulocytes (neutrophils, eosinophils, basophils)
-Agranulocytes (lymphocytes, monocytes)
Granulocytes
-neutrophils, eosinophils, basophils
-contain cytoplasmic granules which contain a variety of compounds that are toxic to invading microbes
Agranulocytes
-lymphocytes, monocytes
-don’t contain granules
Lymphocytes
act as primary responders against infection or maintain a long-term memory bank of particular pathogens
Monocytes
-phagocytize foreign matter such as bacteria
-Once they leave the bloodstream and enter an organ, monocytes are renamed macrophages
Monocytes
-phagocytize foreign matter such as bacteria
-Once they leave the bloodstream and enter an organ, monocytes are renamed macrophages
Thrombocytes
-Platelets
-Cell fragments or shards released from cells in bone marrow called megakaryocytes
-Assist in blood clotting
Blood types
A, B, AB, O
Universal donor
O
Universal receiver
AB
Rh factor
-Another surface protein expressed on red blood cells
-positivity follows autosomal dominant inheritance; one positive allele is enough for the protein to be expressed
-Can lead to erythroblastosis fetalis where maternal blood cells attack fetal blood cells
Low blood pressure
-promotes aldosterone and ADH to release
-High blood osmolarity also promotes ADH release
High blood pressure
promotes atrial natriuretic peptide (ANP) release
Gas and solute exchange
occurs at the level of capillaries and relies on the existence of concentration gradients to facilitate diffusion across the capillary walls
Partial pressure of oxygen in the lungs
-high
-oxygen is loaded onto hemoglobin
Partial pressure of oxygen in the tissues
-low
-oxygen is unloaded from hemoglobin
Starling forces
hydrostatic pressure and osmotic pressure
Hydrostatic pressure
-the pressure of the fluid within the blood vessel
-forces fluid out at the arteriolar end of a capillary bed
Osmotic pressure
“sucking” pressure drawing water toward solutes
Oncotic pressure
-osmotic pressure due to proteins
-draws fluid back in at the venule end
Bohr effect
a high CO2 partial pressure, high H+ concentration, low pH, high temperature, and high concentration of 2,3-BPG can cause a right shift in the oxyhemoglobin dissociation curve, reflecting a decreased affinity for oxygen
Coagulation
-Results from an activation cascade
-When the endothelial lining of a blood vessel is damaged, the collagen and tissue factor underlying the endothelial cells are exposed which results in a coagulation cascade that forms a clot over the damaged area
-Platelets bind to the collagen and are stabilized by fibrin, which is activated by thrombin
-Clots can be broken down by plasmin
