Transport in Animals - Chapter 9 - 2024 PDF

Chapter 9 Transport in Animals  Circulatory system Valves in the heart, blood vessels 🡪 make sure the blood flows in the right direction Liquid Pump Tubes blood heart...

Chapter 9 Transport in Animals  Circulatory system Valves in the heart, blood vessels 🡪 make sure the blood flows in the right direction Liquid Pump Tubes blood heart blood vessel  The heart Function >> to pump blood around the body Cardiac muscle >> special muscle 🡪 the heart 🡪 contracts and relaxes regularly, throughout life 4 chamber : right atrium, left atrium, right ventricle, left ventricle 4 chambers ✔ Right atrium ✔ Left atrium ✔ Right ventricle ✔ Left ventricle The heart ✔ Valve Aortic (semilunare) valve ✔ Pulmonary valve ✔ Tricuspid valve ✔ Bicuspid / mitral valve Double circulatory system The blood passes through the heart twice on one complete circuit of the body >> mammals, birds, reptiles. Single circulatory system The blood passes through the heart only once on a complete circuit >> fish Systemic system >> the blood vessels that take the blood to the rest of the body and back Pulmonary system >> the blood vessels that take the blood to the lungs and back  CO2 CO2 CO2 CO2 “BODY” Vena cava Right atrium Right ventricle Pulmonary artery CO2 CO2 LUNGS O2 AORTA Left ventricle Left atrium Pulmonary vein O2 O2 O2 O2  Pulmonary system Single circulatory system Systemic system Double circulatory system CORONARY ARTERY The muscle of the heart are so thick that the nutrients and oxygen in the blood inside the heart would not be able to diffuse to all the muscle quickly enough The heart muscle needs a constant supply of nutrients and oxygen keep contracting and relaxing 🡪 coronary artery supply this  Pump blood out Receive of the blood 🡪 heart (thicker, more ventricles muscular walls than the atria) Right ventricles >> pumps blood to the lungs (very close to the heart) Left ventricles >> pumps blood all around the body 🡪 farther 🡪 thicker walls of muscle to enable it to do it The blood flowing to the lungs in the pulmonary artery has a much lower pressure than the blood in the aorta The walls of the left ventricles >> thicker than the right ones CORONARY HEART DiSEASE >> a blockage of the coronary arteries A coronary artery gets blocked (ex : blood clot) 🡪 the cardiac muscles run shot of oxygen 🡪 cannot respire 🡪 cannot obtain energy to allow the muscles contract 🡪 the heart stops beating 🡪 a heart attack / cardiac arrest Several factors that increase a person’s risk of getting coronary heart disease ✔ Smoking ✔ Diet ✔ Obesity ✔ Stress ✔ Genes  Preventing CHD ✔ Exercise ✔ Stop smoking ✔ Avoid diets high in animal fats People 🡪 high blood pressure, very over weight 🡪 drug (statin)🡪 helps to reduce cholesterol levels in Treating CHD the blood. ► Drugs to help to lower blood pressure : propanolol ► Drugs to decrease blood clotting: warfarin ► Surgery🡪coronary by pass operation ► Angioplasty ► Heart transplant  ✔ Stethoscope ✔ Pulse rate Heart (caused by the expansion and relaxation of an artery, caused by the heart pushing blood through it) Beat ► Normal 60-75 x/minutes ► 1 heart beat : lup-dub ► ECG  Normal ECG ECG (electrocardiography) >> to record the activity of the heart The sinoatrial node (SA node or the sinus node : 1 & 2) is a group of cells located in the wall of the right atrium of the heart. These cells have the ability to spontaneously produce an electrical impulse (action potential), that travels through the heart via the electrical conduction system causing it to contract. In a healthy heart, the SA node continuously produces action potential, setting the rhythm of the heart and so is known as the heart's natural pacemaker. The rate of action potential production (and therefore the heart rate) is influenced by nerves that supply it.  Valves SYSTOLE The cardiac muscles contract 🡪 the heart becomes smaller 🡪 squeezing blood out DIASTOLE The cardiac muscles relax 🡪 the heart becomes larger 🡪 allowing blood to flow into the atria and ventricles Blood Vessels Differences between artery, vein, and capilarry ARTERIES strong walls 🡪 to withstand the high pressure of the blood flowing through them (the blood has been forced out of the heart) Elastic tissue 🡪 can stretch and recoil with the force of the blood >> pulse in the wrist VEINS The blood is at much lower pressure than it was in the arteries The blood flows more slowly, smoothly Wider lumen than the arteries have No need to have such thick, strong, elastic walls Have valves (to stop the blood flowing backwards) CAPILLARIES ▪ Very small ▪ To take the nutrients, oxygen, take away ‘the waste’ ▪ Very thin Sphygmomanometer To measure the blood pressure ▪ One cell thick in the arteries of the arm Blood ❖ Liquid >> Plasma (mostly water) transport glucose, amino acid, mineral, hormon, CO2 ❖ Solid ▪ RBC ▪ WBC ▪ Platelet made in the bone marrow of some bones (ribs, vertebrae, limb bones) not live for very long , about 4 months ( RBC have made so quickly) RBC contain pigment haemoglobin (protein, contains iron 🡪 carries oxygen) biconcave disc, small size (large surface area compared with its volume) 🡪 speed up the rate at which oxygen can diffuse in and out of the RBC, enabling to squeeze through even the tiniest capillaries no nucleus  WBC Have a nucleus To clear up any dead body cells Often quite large and lobe Taking in, digesting bacteria >> phagocytosis (lobed nuclei) Can squeeze out through the walls of blood capillaries Produce antibodies To fight pathogens  No nucleus Small fragments of cells Made in red bone marrow Involved in blood clotting (blood clotting stops pathogen getting into the body through breaks in the skin) To prevent too much blood loss Platelets Blood clotting