3 Week Assessment🩺 Flashcards
Veins
Carries blood to the heart
Big lumen
Thin muscular / elastic walls
Arteries
Carries blood away from the heart
Thick muscular / elastic tissue
Small lumen
Capillaries
Diffusion and exchanging of substances
1 cell thick walls
Very small
Erythrocytes
Red blood cells
Biconcave shape
Large surface area
Carries oxygen
Absorbs oxygen in lungs + releases in the rest of the body
Leukocytes
White blood cells
Fights infection
Long term immunity
Has a nucleus
Thrombocytes
Platelets
Small fragments of cell
No nucleus
Sticky
Forms clot at wound surface
Monocyte
Removes dead cells and bacteria
Lymphocyte
T-cells
Destroys viruses and cancer cells
Neutrophils
B-cells
Produces auntibodies
Blood clotting
Platelets stick together
Fibrin (strands of protein) form net at damaged site
Forms scab
Temperature regulation
Hypothalamus in the brain detects temperature and sets off change
-sweat glands release
-capillaries widen / dilate
-hair stands up
-shiver (respiration)
Double circulatory system advantages
Keeps oxygenated and deoxygenated blood separate
Efficient
Makes sure deoxygenated blood goes into the pulmonary loop to pick up oxygen
Makes sure oxygenated blood travels to organs so cells can respire
Systole
Ventricles contract
Blood ejected out of
Diastole
Ventricles relax
Refills with blood
Atrio- ventricular valves
Bi + tricuspid valves
Open in one direction to create one way system
Prevents back blow of blood
Semi lunar valves
Open in one direction to create one way system
Prevents back blow of blood
Sino-atrial node (SAN)
Passes a wave of electrical current through the atria making them contract
Atrial - ventricular node (AVN)
Slows down the passage of current down to ventricle to allow them to fill with blood
Purkyne fibre
Carries current down the middle of the ventricles to the APEX of the heart
Electrocardiograph (ECG)
Monitors hearts electrical activity
Electrodes attached to chest + limbs
Detects changed in polarisation by measuring current at skin surface
Leads connected to machine - draws an ECG
Tachycardia
Faster heart rate
Lots of QRS peaks
Bradycardia
Slower heart rate
Fewer peaks of QRS
Arrhythmia
Irregular heart beat
PQRST waves each different height and times
