Section 5

Plasma: the liquid containing RBC, WBC, platelets, digested food producs, CO2,urea, hormones
Platelets: clump together to clot blood stops you from losing blood, and prevent microorganisms from entering
RBC: biconcave shape- large SA for absorbingeleasing O2. Contains haemoglobin, iron, no nucleus, a lot of space
WBC

Phagocytes: detect foreign thing in the body and engulf and digest them - non specific
Lymphocutes: come across foreign antigen, produce antibodies, antibodies invade the pathogen, antibodies are specific. Antibodies produced rapidly around the body to mark all the similar patogens, Memory cell roduced to remember the foreign antigen and if it enters again, antibodies will be produced much rapidly

Arteries: carry blood away from the heart, strong and elastic, thick wallls - high pressure. Elastic fibres - allows to expand.
Veins: Low pressure, no thick walls, big lumen. Valves to keep the blood flowing in 1 direction
Capillaries: close to cells for exchange of materials, permeable walls/one cell thick short diffusion pathway, supply food, O2 and CO2

Deoxygentated lood enters vena cava - right atrium - right ventricle - pulmonary artery - into the lungs
From lungs - pulmonary vein - left atrium - left ventricle - aorta

During excercise - more enrgy needed, resire more, CO2 level in blood increases, receptors in Aorta and carotid artery detect, send signals to branm heart pumps more
Hormonal system: adrenal glands release adrenaline, this binds to receptors of the heart cusing it to contract more, heart rate increases

supply of blood blocked becayse of layers of fatty materials building up, making arteries more narrow - lack of oxygen heart attck
Risk factors: high saturated diet, smoking increasing bp damage to artery walls, being inactive high bp

Ultrafiltration: blood enters renal artery at high pressure into the glomerulus. Water, urea, ions, glucose squeezed into the bowman's capsule. proteins and blood cells don't squeeze.

Reabsorbption: Glucose reabsorbed (active transport) from the proximal convuluted tubule to be used in respiration. Sufficinet ions aborbed excess is not. Sufficient water absorbed from collecting duct (osmosis
Release of waste: Remaning forms urine. out of the nephron, through the ureter in the bladder, released from urethre. The reabsorbed substances go to the renal vein

ADH - antidiruteic hormone makes the wall of nephron more permeable so more water is reabsorbed from the collecting duct
Hydrated - brain detect high water conc- pituitary gland releases less ADH - kidneys reabsorb less water
Dehydrated: brain detects low water conc - pituitary gland releases more ADH - kidneys reabsorb more water