Ch. 23 Circulation Flashcards
Circulatory System
The organ system that transports materials such as nutrients, O2, and hormones to body cells and transports CO2 and other wastes from body cells
Capillaries
A microscopic blood vessel that conveys blood between an artery and a vein or between an arteriole and venule; enables the exchange of nutrients and dissolved gases between the blood and interstitial fluid
- enables diffusion via intricate network
What is the function of the circulatory system?
Transport O2 and nutrients
Convey metabolic wastes to waste disposal organs (lungs, kidney)
What is the circulatory system’s 2 key roles in homeostasis?
1) Exchanged molecules cia interstitial fluid -> control makeup of environment cell lives in
2) Control makeup of blood by continuously moving it through organs
Blood
A type of connective tissue w/ a fluid matrix called plasma which blood cells are suspended
What are the 2 basic types of circulatory system?
- Open Circulatory System
2. Closed Circulatory System (Cardiovascular System)
Open Circulatory System
A circulatory system in which blood is pumped through open ended vessels and out among the body cells.
- blood and interstitial fluid are one and the same
- invertebrate (mollusks + arthropods)
Closed Circulatory System (Cardiovascular System)
A closed circulatory system w/ a heart and branching network of arteries, veins, and capillaries
- blood is confined to blood vessels
- interstitial fluid is separate
- vertebrates
What are the 3 kinds of blood vessels?
Arteries, veins, capillaries
Arteries
A vessel that carries blood away from the heart to other parts of the body
- O2 rich
- branch/subdivide for more surface area to reach more cells
- arteriole
Veins
A vessel that returns blood to the heart
- O2 depleted and wastes
- converge (get bigger) closer to heart
- veiniole
Capillaries
A vessel that conveys blood b/w arteries and veins
- sit of exchange b/w blood and cells (diffusion)
- small and thin (single file blood cells for maximized diffusion)
What are the 2 chambers of the heart?
Atrium and Ventricle
Atrium
A heart chamber that receives blood via veins
- thin walled
Ventricle
A heart chamber that pumps blood out of heart
- thick walled
Arterioles
A vessel that conveys blood b/w an artery and capillary bed
- smallest division of artery
Capillary beds
Network of capillaries that infiltrate every organ and tissue in the body
Venules
A vessel that conveys blood b/w a capillary bed and a vein
What are the 2 blood circuits of vertebrates?
- Pulmonary Circuit
2. Systemic Circuit
Pulmonary Circuit
Consists of all blood vessels that carry the blood from the heart to the lungs and back
- dumps off CO2, reloads O2
Systemic Circuit
All blood vessels that carry the blood from the heart to the body and back
- delivers oxygen and materials to all cells
What is the trip of blood in the cardiovascular system?
1) Right ventricle pumps blood to lungs
2) Pulmonary arteries
3) Blood in lungs unloads CO2, load O2 and flow to left atriumn via pulmonary veins
4) O2 flows into left atrium
5) O2 flows to left ventricle
6) Aorta
7) Upper body
8) Abdominal organs and lower body
9) Superior Vena Cava
10) Inferior Vena Cava
11) Venae cavae to right atrium to right ventricle
Pulmonary Arteries
A large blood vessel that conveys blood from the heart to a lung
- only artery with deoxygenated blood
Pulmonary Vein
A blood vessel that conveys blood from a lung to the heart
- oxygenated blood
Aorta
An artery that conveys blood directly from the heart to other arteries
- biggest
Superior Vena Cava
A large vein that returns O2 poor blood to the heart from the upper body and head
Inferior Vena Cava
A large vein that returns O2 poor blood to the heart from the lower, or posterior, part of the body
Cardiac Cycle
The alternating contractions and relaxations of the heart
1) Diastole
2) Systole
Diastole
The stage of the heart cycle in which the heart muscle is relaxed, allowing the chambers to fill w/ blood
- blood enters left and right atrium
- valves b/w atria and ventricles are open -> blood flow
- 0.4 sec
Systole
The contraction stage of the heart cycle, when the heart chambers actively pump blood
- 0.1 sec atria fill w/ blood
- 0.3 sec ventricle contract
Cardiac Output
The volume of blood per minute the left ventricle pumps into the aorta
Pacemakers
SA (sinoatrial node)
A specialized region of cardiac muscle that maintains the heart’s pumping rhythm (heartbeat) by setting the rate at which the heart contracts
- wall of the right atrium
AV (atrioventricular) Node
Relay point b/w right atrium and ventricle w/ delay of 0.1 sec for atria to contract/empty before ventricles contract
Artificial Pacemaker
Tiny electronic device surgically implanted near AV node
Heart Attack
Death of cardiac muscle cells and the resulting failures of the heart to deliver enough blood to the body
Coronary Arteries
The large blood vessel that conveys blood from the aorta to the tissues of the heart
Blood Pressure
The force that blood exerts against the walls of blood vessels
- created by beating of heart
- main force driving blood
- depends on cardiac output and resistance to blood flow
Pulse
The rhythmic stretching of the arteries caused by the pressure of blood forced thru the arteries by contractions of the ventricles during systole
What is the typical blood pressure?
110 - 140 / 70 - 90
Low Blood Pressure
Person w/ systolic blood pressure below 100 mm Hg
What is blood pressure measured with?
Sphygmomanometer and stethoscope
Hypertension
Abnormally high blood pressure; a persistent blood pressure of 140/90 or higher
- caused by reduced flexibility or partial blockage of arteries
- contribute to heart muscle wear out and arterial blockage
- controlled by diet, exercise, medication
What percent of body capillaries have blood flowing thru them?
5 - 10 %
What are 2 mechanisms that control distribution of blood to capillaries?
Depend on smooth muscle tissue.
- contraction/relaxation fo smooth muscle layer of arteriole wall
- sphincters relaxed/contracted
Plasma
The liquid matrix of the blood in which the blood cells are suspended
- 90% water, 10% dissolved substances
- proteins, mineral salts, organic nutrients, nitrogenous wastes, hormones, dissolved salts
Platelets (thrombocytes)
A piece of membrane-enclosed cytoplasm from a large cell in the bone marrow of a mammal; a blood clotting element
Red Blood Cells (erythrocytes)
A blood cell containing hemoglobin, which transports O2
- 25 trillion
- lack nuclei and mitochondria
- biconcave disk w/ surface area for gas exchange
- formed in bone marrow
- 3 to 4 months circulation
What hormone stimulates the production of red blood cells in bone marrow?
Erythropoietin
Anemia
A condition in which an abnormally low amount of hemoglobin or a low # of red blood cells results in the body cells not receiving enough oxygen
- excessive blood loss, vitamin/mineral deficiencies, bone marrow cancer
White Blood Cells (leukocytes)
A blood cell that functions in defending the body against infections and cancer cells
- distinguished by staining properties and shape of nuclei
- irregular size/shape, largest cell, live outside vessel, number varies
- multi-nuclei
Phagocytes
A white blood cell that engulfs bacteria, foreign proteins, and the remains of dead body cells
Fibrinogen
The plasma protein that is activated to form a blot when a blood vessel is injured
Fibrin
Activated form of the blood clotting protein fibrinogen which aggravates into threads that form the fabric of a blood clot
Stem Cells
In the bone marrow, a type of cell that gives rise to all the types of blood cells
Leukemia
A type of cancer of the blood forming tissues, characterized by an excessive production of white blood cells and an abnormally high # of them in the blood; cancer of the bone marrow cells that produces leukocytes
How do different organisms exchange nutrients?
Unicellular use diffusion.
Simple multicellular use gastrovascular.
Complex multicellular use circulatory system.
What are the parts of the circulatory system? All of which assist in maintaining homeostasis.
- Muscular pump (heart)
- Fluid (blood)
- Transport tubes (blood vessels)
What is the structure of an artery wall?
3 layers…
1) Epithelium - innermost layer, smooth
2) Smooth muscle - thickest layer, elastic
3) Connective tissue - outermost, support
What is the structure of vein walls?
Same 3 walls as artery wall but smooth muscle is thinner
- valves
What is the structure of capillaries?
1 cell layer of epithelium
How is blood allowed to go back up veins?
Muscle contractions and activity.
- muscle pushes blood up and when relaxed, blood doesn’t flow back due to veins
What are the main arteries?
1) Aorta
2) Carotid
3) Coronary
4) Pulmonary
Carotid
Artery located on neck and carries blood to the brain
Coronary
Artery that is located on top of heart and provides blood to the heart.
What are the major veins?
1) Pulmonary
2) Jugular
3) Superior + Inferior Vena Cava
- Portal
Jugular
Blood high in waste (de-O2) from brain to heart
Portal
Carries blood from small intestine (w/ nutrients) to liver and branches/subdivides then to the heart
Heart
Muscular pump that drives blood circulation.
- located in thoracic cavity
- endocardium, myocardium, pericardium
- cardiac septum w/ 4 chambers
What is the structure of the heart?
- Endocardium - inner, thinnest, smooth
- Myocardium - middle and thick
- Pericardium - outermost
Right atrium
Receives blood from body
Right ventricle
Blood from right atrium to pulmonary artery
Left atrium
Receives blood from the lungs
Left ventricle
Thickest chamber and pumps blood to aorta
What are the 4 heart valves?
1) Tricuspid / Right Atrioventricular
2) Pulmonary Semilunar
3) Mitrovalve / Bicuspid Valve / Left Ventricular Valve
4) Aortic Semilunar
What is “lubb dupp”?
Sound of blood against valves
- lubb = contraction of ventricles
- dupp = discharge of blood against semi-lunar valves
What are the 2 elements of blood?
Plasma (liquid element) 55%
Corpuscles (blood cells) 45%
What are the five varieties of leukocytes (WBC)?
Basophils Nuetrophils Monocytes Esinophil Lymphocytes
