cardiovascular brings o 2 and nutrients to all body cells and remove wastes. chapter 13
TRANSCRIPT
CARDIOVASCULARBrings O2 and nutrients to all body cells and remove
wastes.
CHAPTER 13
HEART• Located in the pericardial/thoracic cavity (contains
serous fluid to reduce friction)
• Lined by a serous membrane called the pericardium
• 3 layers– Epicardium-outer layer that protects heart– Myocardium-thick middle layer of cardiac muscle that
forces blood out the heart chambers– Endocardium-inner layer that contains blood vessels
that attach to the heart
• 4 chambers– Atria: upper 2 chambers that have thin walls and
receive blood returning to heart– Ventricles: lower 2 chambers that have thick walls
and receive blood from atria then contract to force blood out of heart
• Interventricular Septum-solid wall that separates the heart into left and right halves
• Coronary arteries-supply blood to the hearts tissues (the 1st 2 branches of the aorta)
• Cardiac veins& Coronary sinus: blood returns to the right atrium through these
• Atrioventricular valves: tricuspid/bicuspid • Semilunar valves: pulmonary/aortic
PATH OF BLOOD FLOW THROUGH HEART1. Superior & Inferior vena cava2. Right atrium3. Tricuspid valve4. Right ventricle5. Pulmonary valve6. Pulmonary trunk7. Pulmonary arteries8. Lungs9. Pulmonary veins10. Left atrium11. Bicuspid valve12. Left ventricle13. Aortic valve14. Aorta15. Your body
BLOOD VESSELSArtery arteriole capillary venule vein (away from heart) *site of nutrient, (back to
heart) gas, and waste exchange
• Closed system of blood circulation– Pulmonary circuit: sends deoxygenated blood to lungs– Systemic circuit: sends oxygenated blood and nutrients to all
body cells and removes wastes
• The heart pumps 7,000 liters of blood through the body each day, contracting some 2.5 billion times in an average lifetime.
CARDIAC CYCLE• The events of one complete heart beat (1 contraction
& relaxation) that lasts about .8 sec.• Both atria contract while ventricles are relaxing.• Both atria relax while ventricles are contracting. • Pressure within the chambers rises and falls causes the
valves to open and close.• When ventricular pressure exceeds atrial pressure, the
AV valves open.• Papillary muscles contract and pull chordate tendineae
to open and close the valves. They aid in preventing back flow of blood.
• Heart beat sound: lupp-dupp• Lupp occurs when the AV valves are closing• Dupp occurs when the semilunar valves are closing
• Cardiac conduction system coordinates the events of the cardiac cycle.• S-A node (sinoatrial node) or pacemaker
• upper right atrium• generate the hearts rhythmic contractions
• A-V bundle• Purkinje fibers
• Electrocardiogram (ECG): recording of the electrical changes that occur in the myocardium during the cardiac cycle.
ECG cont…• S-A node triggers a cardiac impulse, atrial
fibers depolarize(contraction), producing an electrical charge.
• Ventricle walls are thicker causing a greater electrical charge.
• Adult heart rate 60-100 beats per minute. Well trained athlete 40-60 bpm.
• Heart rate influences• Emotional upset, anxiety• Temperature change• Ion changes (K+, Ca+2)
BLOOD PRESSURE• Force blood exerts against the blood vessel walls.
Specifically, pressure in arteries supplied by branches of the aorta.
• Forces blood throughout the body.• Blood vessels walls are constructed to adequately carry blood
(pg. 358) • Artery arteriole capillary venule vein Highest pressure Lowest
pressure
• Cut an artery, blood squirts out; cut a vein, blood flows out• Contraction of the human heart creates enough pressure to
squirt blood 30 ft.
Blood Pressure cont..• Systolic pressure: maximum pressure in the arteries
during ventricular contraction.• Diastolic pressure: lowest pressure remaining in
the arteries before the next ventricular contraction.• Average blood pressure 120/80 systolic/diastolic
Arterial PulseTemporal femoralFacial poplitealCarotid posterior tibialBrachial dorsalis pedisradial
• Factors that influence blood pressure• Stroke volume: amount of blood discharged from
ventricle with each contraction• Blood volume: sum of all blood components• Peripheral resistance: friction b/w the blood and
blood vessel walls• Viscosity: consistency of blood
CARDIOVASCULAR DISORDERS• Tachycardia- abnormally fast heart beat – above
100 BPM• Bradycardia – slow heart beat – below 60 BPM• Murmur – abnormal heart sound due to incomplete
closure of heart valves• Idiopathic cardiomyopathy – enlarged heart• Congenital defects – defect present at birth• Stenosis – narrowing of an opening• Myocardial infarction – heart attack• Angina pectoris – pain in the chest• Hypertension – high blood pressure (140/90)
• Arrhythmias – abnormal heart rhythms• Atherosclerosis – a build-up of plaque in the arteries• Arteriosclerosis – hardening of the arteries• Coronary bypass – surgery using a vein from the leg or
artery from the chest to correct blocked coronary arteries
• Thrombus – blood clot• Embolus – moving blood clot• Ischemia – lack of blood flow and oxygen to heart• Aneurysm – a permanent weakness in an artery• Angioplasty – a catheter is inserted into an artery in the
leg or arm and fed into a coronary artery• Cardiac output – the amount of blood the heart pumps
each minute