Circulatory and Respiratory System Biology Powerpoint #4 Unit 8 – Chapter 37

Circulatory System Structures: Heart, Blood vessels, blood Functions: Brings oxygen, nutrients and hormones to cells Fights infection Regulates body temperature.

Heart Made of cardiac muscle Beats on average 65-85 beats per minute Pumps to circulate blood throughout the body

Take your heart Rate

The Heart The human heart has four chambers Left and right ventricle Left and right atrium The left side of the heart pumps oxygenated blood to the body The right side of the heart pumps deoxygenated blood to the lungs

BLUE = Deoxygenated Blood Blood Flow in the Heart RED = Oxygenated Blood BLUE = Deoxygenated Blood

1) After passing through the lungs, oxygenated blood returns to the heart in the pulmonary veins. From lungs

2) The left atrium receives blood from the pulmonary vein.

3) Blood passes through the mitral valve into the left ventricle.

4) The left ventricle pushes blood into the aorta 4) The left ventricle pushes blood into the aorta. Blood travels to all regions of the body To rest of body

5) Deoxygenated blood returns from the rest of the body through the superior and inferior vena cava.

6) The right atrium receives the deoxygenated blood.

7) Blood then enters the right ventricle through the tricuspid valve.

8) The right ventricle pushes blood through the pulmonary valve into the pulmonary arteries to the lungs. To lungs

Blood Pressure Blood pressure is a measure of the force exerted by the blood on the wall of the arteries. An example is 120/80 (systolic pressure/diastolic pressure. Systolic pressure is the result of the contraction of the ventricles (normal 110-140) Diastolic pressure is during the ventricle relaxation (normal 70-90)

Blood Vessels: Arteries Capillaries Veins Carry blood to cells Lined with smooth muscle tissue Three kinds: Arteries Capillaries Veins

Arteries Carry oxygenated blood from the heart to the rest of the body.

Capillaries Branch off of the Arteries The smallest of the blood vessels Takes blood to cells

Veins Takes deoxygenated blood from the capillaries back to the heart

Blood The human body has 4-6 liters of blood Blood: 45% of blood is Cells 55% of blood is plasma

Blood Cells: 3 kinds Red Blood Cells: transports oxygen, contain hemoglobin (gives them color) White Blood Cells (leukocytes): attack foreign substances or organisms. Platelets: stick to broken blood vessels to stop bleeding when you are cut

Plasma 90% water 10% other materials: Dissolved gases Salts Nutrients Enzymes Hormones Waste products

Disorders of the Circulatory System Coronary artery disease – Atherosclerosis Plaque buildup blocks arteries, reducing, or even stopping blood flow. Plaques can break off, causing heart attack or stroke Cause: Damaged arteries are ‘invaded’ by bad LDL cholesterol. White blood cells try to digest the LDL. Ultimately, a jumble of cholesterol and cells is accumulated. Risk Factors: Smoking, high blood pressure, high LDL cholesterol, diabetes

Disorders of the Circulatory System Heart Attack– Myocardial Infarction (MI) Death of cardiac muscle cells Cause: Plaque dislodges, blocking an artery to the heart muscle. Cardiac muscle cells are starved for oxygen and die. After a heart attack, scar tissue forms where the cells had died, this reduces the functionality of the heart. Severity of a heart attack depends on size and area supplied by the artery. Risk Factors: Smoking, high blood pressure, high LDL cholesterol, diabetes

Disorders of the Circulatory System Stroke Death of cells in the brain. Cause: A blood vessel in the brain is blocked, or bursts, starving the cells of oxygen A stroke can have many different symptoms, including: numbness, vision changes, speech changes, or confusion. Risk Factors: Smoking, high blood pressure, high LDL cholesterol, diabetes

Disorders of the Circulatory System Arrhythmia Irregular / skipped heart beat Cause: The heart uses electrical signals created in the SA node in the right atria, to begin a heartbeat. The conduction of these signals, or irregular firing of the SA node, can cause arrhythmias. Atrial arrhythmias are less dangerous than ventricular arrhythmias. Risk Factors: Generally random, but factors are stimulants (such as caffeine), fevers, stress, or genetic disorders.

Disorders of the Circulatory System High blood pressure - Hypertension Diastolic pressure over 90 Why it is dangerous: Excessive pressure can cause the arteries to thicken, and blood vessels to weaken and rupture. This can lead to heart failure, stroke, kidney failure, loss of sight when vessels in eyes burst. Risk Factors: Genetics, overweight, limited physical activity, smoking, alcohol consumption, certain medications

Respiratory System Function: Bringing Oxygen into the body, and removing carbon dioxide and water vapor.

Respiratory System What gases are in our atmosphere? 78% Nitrogen 21% Oxygen 1% Argon

Respiratory System Structures: Nose Pharynx larynx trachea bronchi bronchioles lungs

Nose, pharynx, larynx, trachea, bronchi, bronchioles, lungs

Respiratory System Larynx Generates sound Contains vocal chords Pharynx Part of both respiratory & digestive systems Aids in swallowing Houses the tonsils

Respiratory System What is the job of the nose?: Cilia (small hairs) filter out dirt Moistens and warms the air you breathe

Respiratory System Inhalation: Rib muscles contract Rib cage expands Lung volume increases Air pressure in lungs decreases Air flows into lungs

Respiratory System Exhalation: Rib muscles relax Rib cage becomes smaller Air pressure in lungs increases Air flows out of lungs

Respiratory System Diaphragm: Dome shaped muscle Located at base of rib cage

Smallest Part of Lung= Alveoli Alveoli: air sacks

Oxygen and Carbon Dioxide Exchanged in the lungs though: Diffusion The process by which materials move from an area of: High concentration to an area of low concentration