Circulatory System Flashcards
What is the role of the cardiovascular system?
Delivers oxygen and nutrients to cells; removes wastes from cells (like CO2)
Right side of heart
body (atria) -> lungs (ventricle)
Left side of heart
lungs (atria) -> body (ventricle)
Tricuspid valve
On the right
Prevents backflow between the right atrium and ventricle
Bicuspid valve
Prevents backflow between the left atrium and ventricle
Chordae Tendinae
Heart strings that attach to valves
Papillary muscles
Contract to pull on the heartstrings to open the valves
Cardiac cycle
Sequence of events that occurs in one complete beat of the heart
PHASES
Systole - heart muscle contracts -> pump blood
Diastole - heart chambers relax -> fill with blood
Types of Systole
Atrial systole -> atria contract forcing blood into ventricles
Ventricular systole -> ventricles contract forcing blood into aorta or pulmonary arteries
Blood pressure
Pressure of blood in the arteries as it is pumped around the body
Larger number - systolic bp
Smaller number - diastolic bp
Arteries
- Take blood away
- Have thick, muscular and elastic walls
- Inconsistent high blood pressure
- Small lumen
Capillaries
- Connect arteries and veins
- One cell thick
- Site of gas & nutrient exchange
- Blood moves slowly in high pressure
Veins
- Carry blood towards the heart
- Thin in-elastic walls with little muscle
- Consistent relatively low blood pressure
- Large lumen
- Valves
Superior vena cava
upper body -> right atrium
Pulmonary
lungs
Inferior vena cava
lower body -> right atrium
Hepatic
liver
Hepatic portal vein
Intestines -> liver
Renal
kidney
Femoral
legs
Carotid artery
heart -> head
Aorta
left ventricle -> body
Mesenteric
Heart -> intestine
Role of blood
- carries oxygen and nutrients to individual cells
- remove carbon dioxide and other wastes
Blood composition
55% plasma
45% formed elements (blood cells & platelets)
Plasma
main way requirements and wastes are transported around the body
- liquid pale yellow colour part of blood
- mixture of water (90%) and dissolved substances (nutrients & gases)
- carries hormones & antibodies around body
Red blood cells
a.k.a. Erythrocytes
- transport oxygen and co2
- biconcave disc filled with haemoglobin which binds oxygen to carry it around body
- increases surface area to allow more oxygen
- flexible so it can fit through capillaries
- don’t have nucleus -> more room
- live for approx 120 days
White blood cells
a.k.a. leucocytes
- larger than RBC but fewer in number
- has a nucleus that determines the type
- surrounds disease-causing microorganisms (like bacteria) through a cell-eating process called Phagocytosis
- life span 1-2 days
Where are the blood cells produced?
Red bone marrow
Platelets
a.k.a. Thrombocytes
- irregular small cell fragments
- no nucleus
- sticks to damaged blood vessels and clots the blood
- lives about 7 days
Antigen
Marker on the outside of the cell membrane that allows cells to identify each other
Antibody
Proteins made in response to an antigen; it combines with the antigen to neutralise or destroy it
Agglutination
Clumping of microorganisms or blood cells due to an antigen-antibody interaction.
This gets the blood cells stuck in capillaries
Gene
A segment of DNA of the DNA sequence that codes for a specific trait
Genotype
Genetic makeup of an organism, represented by a two letter code
Codominant
When traits are equally dominant, therefore both shown.
