The Heart and Circulatory System Flashcards
Vein
- brings ~deoxygenated~ blood from body to heart
- low pressure
- large lumen
- thin, elastic muscular wall
- has valves
- up to 2.5 cm
(pulmonary vein brings oxygenated blood from lungs to left atrium)
Capillary
Small vessels between artery + vein to exchange O2 , CO2, nutrients, glucose, urea to cells
- low pressure
- red to dark red blood
- very small lumen, RBC travel in single file
- 10 1um (v small)
Artery
- take ~oxygenated~blood from from heart to body
- high blood pressure
- small lumen
- thick, elastic muscular wall (maintain high pressure)
- up to 1.5 cm in diameter
(pulmonary artery is where deoxygenated blood exits the heart and goes to lungs )
Blood plasma
55% : liquid part of blood
- 90% water
- Glucose
- amino acid ps + mineral ions
- CO2 + urea
- proteins : antibodies, hormones
- carries heat around body
White blood cells
~phagocytes~ ingest pathogens
~lymphocytes~produce antibodies
Platelets
- exposure to air stimulates platelets to produce ~fibrin~
- fibrin forms net on wound to trap RBCs
Red blood cells adaptions
45%
Haemoglobin:
-haemoglobin + O2 Oxyhaemoglobin
-transports O2
No nucleus : more haemoglobin in each cell
Biconcave shape : large SA/V ratio + short diffusion distance
Thin membrane : short diffusion distance
Sickle cell anaemia
- Haemoglobin clump together to give RBC a sickle shape
- More vulnerable to infection
Iron deficiency anaemia
Blood doesn’t carry enough O2
- tired and lack energy
- dizziness
Haemophilia
Blood unable to clot
- excessive bleeding
- unexplained bruises
Leukaemia
Too many WBC, not enough RBC
- weight loss
- fatigue
- chills/fever
- repeated infection
Circulatory system
To pump blood around the body
Amoeba have a large SA/V ratio to get O2 from diffusion
Double circulatory system
- Pulmonary circulation* transports blood to/from lungs to exchange O2 + CO2 with air
- Systemic circulation* transports blood to/from body to exchange O2 + CO2 with body cells
Heart rate
Beats per min
Stroke volume
Volume of blood pumped per beat
Describe the flow of blood through the heart
- Deoxygenated blood enters the right atrium by the vena cava from the body.
- It moves down into the right ventricle and blood is pump out the heart through the pulmonary artery to the lungs to pick up O2 and get rid of CO2
- Oxygenated blood enters left atrium by pulmonary verb and moves down to left ventricle
- Blood pumped out to the body via the aorta
Label the heart
check it
Why do veins have valves?
To prevent the back flow of blood
Watch-pocket valves
Why do arteries have muscular walls?
Maintain high blood pressure
Why is injuring an artery more dangerous than a vein?
Blood in artery have higher pressure than veins. Cells won’t be able to respire due to lack of O2
Why is no body cell more than 0.05 mm away from a capillary?
To allow faster diffusion of O2, CO2 and glucose
