Circulatory System Flashcards
Function of a transportation system
Keeps the body in a state of general physical well being by:
1. Delivering oxygen and nutrients to every cell of the body and removing waste carbon dioxide
2. Serving as a pathway from one part of the body to another for disease fighting agents, hormones, and other chemical messengers
3. Controlling body temperature in warm blooded animals
4. Being an essential link among the cells and organs within the body and between individual cells and the environment
Vascular System
A system of fluid tissue that plays a role in transporting nutrients and other materials to the cells of the organism
Circulatory System
A vascular system in which the progress of fluid is controlled by muscle movements so that it follows a specific pattern.
In higher animals, vascular fluid is pumped by the action of a heart.
Open Circulatory System
Blood is pumped into body cavities (not vessels), where it directly bathes the cells.
It is taken back to the heart through open-ended pores.
Closed Circulatory System
Blood is pumped through vessels that are separate from the intestitial fluid (fluid between parts of tissue) of the body
Amoeba
Self-sufficient
Uses cell surface as a point of exchange - diffusion/active transport across cell membrane
Distributed to organelles by streaming/flowing of cytoplasm
Paramecium
Single-celled protozoan
Digests nutrients that pass through a vacuole to reach all parts of the cell
Sponges (Porifera) and Rotifers (Rotifera)
Simplest animals
Diffusion, no circulatory system
Planarian (flatworm)
Diffusion through body wall
Digestive/waste cavities branch to reach cells
Hydra
Tubular
Diffusion
Grasshopper
Open circulatory system
Tubular heart-like structure pumps fluid (haemolymph) through aorta (only vessel) to body cavity (subdivided into sinuses)
Earthworm
Closed circulatory system
Dorsal (carry blood to front) and ventrical (carry blood to back) vessels connected by aortic arches that pump blood to tissues
Fish
Closed circulatory system
Gill circulation: atrium gets blood from body, ventricle pumps to gills for re-oxygenation
Blood continues to the rest of the body, then back to atrium: systemic circulation
Unidirectional oxygenated flow through two-chenbered heart
Limited rate of O2 delivery and lower metabolic capacity, as blood pressure is lost in capillaries
Frog
Closed circulatory system
Incomplete double circulation: right atrium - blood from body, left atrium - blood from lungs, mix in ventricle and are pumped to the body and lungs
Bidirectional flow of oxygenated and deoxygenated blood through a three-chambered heart
Chicken (and Human)
Closed circulatory system
Complete double circulation
Bidirectional blood flow of oxygenated and deoxygenated blood through a four-chambered heart
Arteries
Thick, elastic, and muscular tissue
Under high pressure
Carry oxygenated blood away from the heart
(Exception - pulmonary artery)
Arterioles
Smaller arteries (branching)
Carry oxygenated blood
Capillaries
Smallest blood vessels
Large in number - division of pressure
Small diameter, single layer of epithelial cells
Site of gas exchange
Veins
Thinner, less elastic, muscular
Slower circulation
Contain valves to prevent backflow of blood
Carry deoxygenated blood to the heart
(Exception - pulmonary vein)
Venules
Smaller veins
Carry deoxygenated blood
Subsystems
1) Pulmonary circuit
2) Systemic circulation
3) Cardiac circuit
Pulmonary circuit
The system of vessels that carries waste carbon dioxide to the lungs and picks up fresh oxygen
Systemic circuit
The system of vessels that carries the blood from the heart to all other body systems and organs
Cardiac circuit
The system of specialized coronary vessels that meet the energy and nutrient needs of the system
Lymphatic
Fine thin-walled tubes leading to larger ducts responsible for collecting fluids that are lost or diffused during passage so that homeostasis (steady state) can be maintained
How much blood does an average human have?
5 litres
male - 80 mLfor every kg of body mass
female - 65 mL for every kg of body mass
Centrifugation
Separates blood into (top to bottom): plasma, buffy coat (leukocytes and platelets), erythrocytes
Plasma
55% of blood
92% water
Globulin, fibrinogen, albumin - proteins
Salts, enzymes, other organic/inorganic substances
No lifespan (not cells)
Pale yellow fluid medium, in which cells are suspended
Carries dissolved nutrients and wastes, blood clotting (fibrinogen), albumin regulates water and binds fatty acids, globulin transports chemicals, disables harmful enzymes, defense against invaders
Fibrinogen
Plays a role in blood clotting
Serum Albumin
Regulates water for bloodflow and binds fatty acids for transport
Serum Globulin
Transports body chemicals, disables harmful enzymes, and is defense against invaders
Red Blood Cells
Erythrocytes
44% of blood
Packed with haemoglobin (protein), which contains iron that binds to oxygen and makes blood red
120 day lifespan
Small - 8 um in diameter
Donut or disk orbiconcave shape (maximum surface area - gas exchange) with no nucleus (maximum space for haemoglobin)
Originate in the stem cells of the red bone marrow and mature when they enter the bloodstream
Carry O2 and CO2 to and from cells - cellular respiration
Make deliveries to cells
White Blood Cells
Leukocytes
1% of blood (increase in number when sick)
Much larger and irregular in shape
Live in the lymph system
Have a nucleus and are colourless
Types: Granular and Non-granular
Help the body fight infection and other diseases
Granular
1) Neutrophil (65%): immune defense
2) Eosinophil (2-4%): allergic responses, phagocytic response
3) Basophil (0.05%): inflammatory response
18 hour lifespan
Largest up to 25 um
Originate in the red bone marrow
Defend the body against foreign bacteria viruses and other pathogens
Neutrophils engulf bacteria and other parasites
Non-granular
1) Lymphocytes (20-25%): unknown life span, specific immune response, T-cells and B-cells (antibodies)
2) Macrophages (3-8%): phagocytic role
3) Monocytes: phagocyte
Lifespan lasts years
Up to 10 um
Originate in the spleen, lymph, and glands
Lymphocytes fight infections caused by bacteria and viruses
Phagocytes swallow and destroy microorganisms and debris in the blood
Platelets
7-10 day lifespan
Cell fragments that are irregularly shaped
Smallest component - 2 um
Do not contain nuclei
Originate in the red bone marrow
Function in blood clotting
Blood clotting
- Platelet membranes rupture during an injury
- Released thromboplastin reacts with firbrinogen catalyzed by Ca2+ ions
- Fribrin forms a mesh of fibres that traps blood cells and forms a clot that prevents blood flow
- Fibres contract and the wound closes
Blood types
A, B, AB, O
Determined by the presence of absense of antigens
Group A
Red blood cell type A
Anti-B antibodies
A antigens
Group B
Red blood cell type B
Anti-A antibodies
B antigens
Group AB
Red blood cell type AB
No antibodies
A and B antigens
Group O
Red blood cell type O
Anti-A and Anti-B antibodies
No antigens
Blood Donors/Receivers
AB - AB (universal receiver)
A - AB, A
B - AB, B
O (universal donor) - AB, A, B, O
Rh factor
Protein on red blood cells
If present - Rh+, absent - Rh-
Rh incompatibility
A condition that occurs during pregnancy if a woman has Rh-negative blood and her baby has Rh-positive blood
Rh-antibodies start attacking the baby’s cells, since they carry Rh
Immunity
Bodies ability to prevent invasion of pathogens
Antigens
Attached to the surface of pathogens and stimulate an immune response in the body
Active Immunity
1) Natural - exposure to infection
2) Artificial - vaccine
Passive Immunity
Acquired from someone or something else
1) Natural - from mother to baby
2) Artificial - immune serum medicine
Pulmonary loop
Deoxygenated blood from the heart ot the lungs and back to the heart
Systemic loop
Oxygenated blood from the heart to the body and back to the heart
Heart structure
Two atria and two ventricles
Right atria and ventricle - deoxygenated blood
Left atria and ventricle - oxygenated blood
Septum - muscle separating the two sides
Right atrium and ventricle separated by:
Left atrium and ventricle separated by:
Arteries leading away from ventricles (aorta and pulmonary):
Tricuspid atrioventricular valve (AV)
Bicuspid AV valve (mitral)
Semi-lunar vales (aortic and pulmonary)
Bring blood to right atrium
Superior and inferior vena cava
Take blood to lungs
Right and left pulmonary arteries
Bring oxygenated blood back to the left atrium
4 right and left pulmonary veins
Aorta
Largest artery with highest pressure
Takes oxygenated blood from the heart to the body
Coordination of the Heartbeat
Heart is made out of cardiac muscle
Electrical impulses from the brain cause the atria then the ventricles to contract and rest (cycle is a heartbeat)
“Lub-dub” sound
Heart valves (tricuspid and bicuspid) closing
Contraction of atria then ventricles
Phases of a Heartbeat
- Atrial Systole: sino-atrial (SA) node causes the atria to contract
- Ventricular systole: atrio-ventricular (AV) node causes the ventricles to contract
- Diastole: chambers relax
Blood pressure
Pressure exerted on the walls of the arteries
1. Systolic: blood pressure on the aorta when blood leaves the heart during systole
2. Diastolic: blood pressure on the aorta when the heart rests in between beats
Normal: systolic/diastolic = 120/80 mm Hg
Atherosclerosis
Hardening of arteries: walls of arteries lose elasticity
Varicose Veins
Dysfunction of valves in veins
Causes blood to pool and veins to swell
Aneurysm
Bulge in an artery due to a weakened area of arterial wall
Risk of burst leading to death
Stroke
Arteries supplying blood to brain are damaged
Damaged tissue and lack of oxygen can damage brain
