Circulatory System Chapter 35 Test : Thursday April 14 th !!

Circulation Exchanging with the environment. It may appear that you breath in and out but there is more that happens. Is present to transport nutrients, fight disease, move waste, keep temperature steady

Gas Exchange In mammals oxygen is inhaled and diffuses across epithelial tissue to blood and Carbon dioxide DIFFUSES out and goes in the opposite direction

There are other animals!! They breathe too!! Invertebrates (no spine) have a neurogenic heart (which means the nerves are outside the heart) and 2 types of exchange 1. Gastrovascular Cavity 2. Open/closed circulation

Invertebrate Gastrovascular cavities A thin body wall encases a gastrovascular cavity meaning that both digestion and gas exchange happen in the cavity. Only the cells that are in the inner layer of this incases then have access to nutrients from the outside Examples: ◦ Jellyfish ◦ Flatworms

Open/Closed Circulation 3 basic parts 1.Circulatory fluid (BLOOOOOOODDD) 2.Tubes (blood vessels) 3.Pump (heart) The heart powers the movement using cell energy in insects, there is open circulation where organs are drenched in blood thus blood and interstitial fluid is mixed and called hemolymph Example: cricket

Closed Circulatory System: Blood stays in vessels and is kept separated from interstitial fluid. Materials are exchanged by diffusion between blood and organs Example: Earthworms

Vertebrate( have a spine) Cardiovascular Systems Closed circulatory system Heart (myogenic heart - muscles within the heart) ◦ 1 or 2 atria (receive the blood) ◦ 1 or 2 ventricles (pump blood out) Blood Vessels – Humans have 3 kinds ◦ Arteries (blood from heart to organs) ◦ Veins (blood from organs to heart) ◦ Capillaries (allow gas exchange and come together to create venules which create the veins

Fish Heart – 2 main champers (1 ventricle 1 atrium) 1 circuit Blood travels: Ventricle  gill (get oxygen leave carbon dioxide)  capillary  vein  atrium

Amphibians Heart – 3 chambers (2 atria 1 ventricle) Blood Travels  pulmocutaneous – capilary  left atrium Ventricle  artery  systemic  organs  right atrium Double circulation

Reptiles (NO BIRDS) Double Circulation ◦ Pulmonary circuit (lungs) ◦ Systemic circuit Different reptiles have different hearts

Mammals and Birds 4 chamber heat which supports endothermic (warm blooded) life 2 circuit system Use 10x as much energy as cold blooded organisms

Mammalian Circulation and Heart How does it work (11 step process) 1. Right ventricle pumps blood to lungs 2. Pulmonary arteries carry the blood to lungs 3. Capillary beds allow oxygen and carbon dioxide to exchange in lungs. This oxygen rich blood is in pulmonary veins 4. The left atrium takes the blood from the pulmonary veins

5. From left atrium blood rich in oxygen moves to left ventricle 6. The left ventricle pumps to the aorta which connect to arteries 7. Arteries connect to capillaries in head and arms 8. Which lead to arterioles and capillaries in abdomen and legs exchanging oxygen and carbon dioxide

9. Oxygen poor blood goes to anterior vena cavity 10. Posterior vena cava drains blood from trunk and hind limbs 11. Vena cava empties to right atrium REPEAT

Mammal heart: The heart contracts (which is when pressure is greatest in ventricles) and relaxes in a rhythmic cycle. The contracting causes pulse and pumps blood (systole) when it relaxes it fills the heart with blood (diastole) so your valves keep blood moving Cardiac output depends on: 1. heart rate (beats/minute) 2. stroke volume (amount of blood pumped)

How you keep your pulse/why it is important Recall brain cells die within a few minutes without oxygen Sinoatrial (SA) node (the pacemaker) sets the rate and timing of the heart SA creates electrical impulses like nerve cells and this causes the right atria muscles to contract in unison. The impulse also passes to another region of specialized cardiac muscle tissue the atrioventricular node (AV) the impuslese are read in an electrocardiogram

Blood Circulation What does it do? * Deliver nutrients * Remove waste How? Think of blood vessels being like sewer pipes

Blood Vessels – Arteries and Veins 3 layers of tissue from the outside in 1. Connective tissue with elastic fibers 2. Smooth muscle with elastic fibers 3. Endothelium – flat cells with smooth surface Capillaries are only endothelium Arteries have thicker outer layers Veins have thinner walls

Blood Flow Faster in the aorta than in capillaries

Blood Pressure Fluid flows from high pressure to low pressure blood pressure is the pressure placed against the walls of veins and arteries Systolic Pressure (the top number) is the heart contracting and blood going to arteries Diastolic Pressure (the bottom number) is blood pushing back and relieving pressure

Capillary Function Gives blood to every part of the body at all times. It is not however in even amounts. To regulate this: 1. Smooth Muscle contracts on the arteriole reducing diameter and decreasing blood flow 2. Pre-capillary sphincters control the flow of blood between arterioles and venules

You lose up to 4L of fluid / day which is returned to the blood via the lymphatic system. Lymph moves because of the contraction in body muscles need lymph vessels thus pushing in the correct direction.

Blood is a connective tissue Has cells suspended in plasma Blood Composition 1. Plasma (55% of all blood) : is 90% water, the rest inorganic salts (electrolytes) keeps your pH at Cellular elements (45% of all blood) a. erythrocytes b. leukocytes c. platelets

Erythrocytes – Red blood cells ◦ Transport oxygen and contain hemoglobin Leukocytes – White blood cells (5 types) ◦ Monocytes ◦ Neutrophils ◦ Basophils ◦ Eosinophils ◦ Lymphocytes ◦ Fight infection, engulf bacteria and viruses, scavenge dead cells, create antibodies Platelets ◦ Used for blood clotting

Cardiovascular disease Disorders of the heart and blood vessels increased by ◦ Smoking, lack of exercise, lost of animal fat, high cholesterol Hypertension – high blood pressure increases the risk of heart attack/stroke Heart attack – death of cardiac muscle caused by blood clot that lodges in the blood vessel leading to the heart Stroke – death of nervous tissue

Gas Exchange Lungs are restricted to one location the gap between lungs and rest of the body is bridged by the circulatory system

Mammal Respiratory System Lungs in chest have a sponge texture Breathing is a 9 step process 1. Air enters nostril (filtered by hair, warmed, humidified) this air has the highest amount of oxygen then any other step of breathing 2. Air goes to pharynx 3. Passes through larynx

4. Passes through trachea 5. Then forks at the bronchi 6. Air then enters the lung 7. From lung to bronchi 8. From bronchi to bronchioles 9. Air dead ends at alveoli – no cilli are present Diffusion allows the carbon dioxide and oxygen to exchange

Breathing Alternate inhalation and exhalation of air Amphibians have positive pressure breathing Mammals have negative pressure breathing which pulls air in

Controlled Breathing in Humans Although we can manipulate our breathing patterns ( you can hold your breath until the carbon dioxide is to high) the actual control of our breathing is natural and controlled in 2 places 1. Medulla Oblongata – sets basic breathing rhythm 2. Pons The breathing center responds to a variety of nervous and chemical systems and adjusts breathing accordingly

Respiratory Pigments Proteins that carry oxygen to necessary places they circulate with blood Hemoglobin – respiratory pigment of vertebrates found in erythrocytes carry oxygen to necessary places it also helps discard carbon dioxide The oxygen attaches to the hemoglobin and carbon dioxide is carried out as a bicarbonate