Circulatory

• elastic
• muscly
• thick
• expands 
• snaps back (pulse)

• thin
• non-elastic
• cannot contract to move blood
• surrounded by skeletal muscles to move the blood
• have one way valves to prevent blood from going backwards
• regulated by heart pressure

• exchange gases, nutrients, pretty much everything
• one cell thick
• no epithelial or endothelial layer
• blood flow is extremely slow to allow for diffusion of nutrients

• reducing the amount of blood in an area
• controlled by nervous system signals originating from brain

• increasing the amount of blood in an area
• controlled by nervous system signals originating from brain

• "normal state"
• normal diameter of arteries
• vasodilation and vasoconstriction at the same time

• two top chambers
• fill with blood returning to heart
• first place where returning blood goes

• bottom two chambers
• receive blood from atria
• send blood away from heart

• thick muscular wall
• divides heart into two parts vertically

• two one-way valves in heart
• separate atria from ventricles

• on the right side
• separates right atrium, ventricle
• has 3 flaps

• also called "mitral valve"
• on the left side
• separates left atrium, ventricle
• has 2 flaps

two one-way valves in heart

separating right ventricle from pulmonary arteries

separating left ventricle from aorta

• EXCLUSIVELY deoxygenated blood
• will go to the lungs to get oxygen

• EXCLUSIVELY oxygenated blood
• will travel throughout the body

• where oxygen-poor blood enters into right atrium
• superior takes blood from top half of body
• inferior takes blood from lower half of body

brings deoxygenated blood toward the blood

where oxygen-rich blood enters the left atrium

associated with lungs

• 1. blood moves in through superior, inferior vena cava into the atrium
• 2. atrium contracts, blood moves via tricuspid valve
• 3. ventricle contracts, blood moves to pulmonary artery via pulmonary valve
• 4. blood goes to lungs to get oxygen

• 1. blood moves in through pulmonary vein into the atrium
• 2. blood moves to left ventricle via bicuspid valve (aorta contracts)
• 3. blood moves to aorta via aortic valve (ventricle contracts)
• 4. oxygenated blood disperses through body

• blood going toward lungs
• exits through right ventricle
• enters through left atrium

• blood dispersing throughout body
• exits through left ventricle
• enters through right atrium

dedicating to providing blood to the muscle tissues of the heart itself via the right and left coronary arteries

• main artery that transports oxygenated blood throughout the body
• ALL blood goes through the aorta

• Sinoatrial node
• controls heartbeat
• stimulates heart muscle cells to contract and relax rhythmically 
• makes left, right atria contract simultaneously
• this is the stimulus that stimulates the heartbeat
• the heartbeat's electrical signals are sent from within the heart itself

• atrioventricular node
• as the atria contract, the electrical signal passes to AV node to the bundle of His (specialized fibre group)
• reaches Purkinje fibres, which initiates almost simultaneous contraction of right/left ventricle

• electrocardiogram
• measures change in voltage produced by electrical signal from SA node

atria contracting

atria relaxing

ventricle contracting

ventricle relaxing

• systolic pressure: contraction, highest blood pressure
• diastolic pressure: relaxing, lowest blood pressure

• filled ventricles contracting
• shuts AV valves
• opens semilunar valves, pushing blood into pulmonary arteries/aorta
• "lubb"
• loudest sound

• ventricles relaxing
• atria contracting
• "dubb"

valves shutting, opening

• blood pressure cuff
• measures blood pressure in millimetres of mercury (mmHg)
• systolic pressure/diastolic pressure
• normal blood pressure is 120/80
• somewhat low blood pressure is normal

• salt levels in blood increase
• water levels in blood increase as a result

• arterial walls thicken
• backflow occurs

• type of arteriosclerosis
• LDL fills in arteries
• pressure increases

blood clot

• after an angioplasty
• prevents blood vessel from collapsing

grafting another artery/vein to bypass the blockage

two parts: 55% plasma, 45% formed parts

• red blood cells (44%)
• platelets, white blood cells (1%)

• watery part of blood
• where red blood cells, white blood cells, platelets are suspended

• erythrocytes
• sole purpose is to carry oxygen
• 280 million molecules of iron per cell
• no nucleus
• biconcave shape increases surface area for oxygen binding
• produced in red bone marrow
• average life span of 120 days
• higher oxygen levels = brighter red than lower oxygen levels = darker red

• too little oxygen
• can be caused by sickle cells, iron deficiency, too few RBC, etc

• leucocytes
• immune response
• have a nucleus
• colourless
• make up 1% of blood, can double when fighting infection (2%)

• fragments of cells
• they form when larger cells in bone marrow break apart
• contain no nucleus, break down quickly
• blood clotting