Circulatory System circulatory system circulatory sustem2

Vocabulary Brady- slow Tachy- fast Diastol- dilation -gram- written -syn-together Systol- contraction

Functions To take oxygen and nutrients to all parts of the body To take carbon dioxide and waste products out of the body

2 Pathways Pulmonary- sends oxygen-depleted blood to the lungs to pick up oxygen Systemic- sends oxygenated blood and nutrients to the body and removes waste

Heart Pericardium- the membrane that encloses the heart Parietal Pericardium- inner lining of the pericardium Visceral Pericardium- innermost layer surrounding the heart

Layers of the heart muscle Epicardium- outer layer Protects the heart by reducing friction Myocardium- cardiac muscle- Pumps blood out of the heart Endocardium- inner layer of the heart- Contains blood vessels and purkinje fibers

Chambers of the heart Atria- upper chambers; receive blood returning to the heart Ventricles- lower chambers; receive blood from the atria and force blood out into the arteries

Chambers of the heart Septum- a solid wall-like structure separating the atria and ventricles so that blood from one side never mixes with the other side Atrioventrical valve (AV valve)- ensures one way blood flow between atria and ventricles

Blood supply to the heart Coronary Arteries- supply blood to the heart Cardiac Veins- drain blood from the heart

Pathways Veins and venuoles- bring deoxygenated blood from the body to the heart Arteries and capillaries- bring oxygen-rich blood to body parts

Heart Sounds Valves closing (lubb-dupp) Lubb: ventricular contraction Dubb: ventricular relaxation

Sanode Sinoatrial Node- pacemaker of the heart Nerve cells touch so impulse spreads easily across the heart Average 78 BPM in adults

Purkinje Fibers Purkinje fibers- cardiac muscle fibers that conduct nerve impulses Electrocardiogram (ECG)- a record of the electrical changes in the heart

Heart beat Tachycardia- irregularly fast heart beat 100+ beats per minute Bradycardia- reduced heart rate fewer than 60 BPM

Blood vessels Vasoconstriction- (contract) reduced diameter of blood vessels Vasodilation- (relaxed) increased diameter of blood vessels

Blood Pressure Systolic Pressure- maximum contraction of ventricles Diastolic Pressure- when the ventricles are at their lowest and are about to contract again Sphygmomanometer- instrument used to measure blood pressure

Influence of BP Blood volume- 5 liters is normal Peripheral resistance- friction between blood and blood vessels Blood viscosity- how resistant blood is to flowing High viscosity = slow flow Low viscosity = fast flow * Blood cell count and plasma change blood viscosity

Blood Pressure Hypertension = high blood pressure Consequences- myocardium thickens, enlargement of heart Causes- obesity, diet (salt), heart disease, kidney disease, psychological stress