Biology for Engineers Lecture Notes (PDF)

Biology for Engineers 24EN1113 ( I/II Sem) – 2 credits Unit 1- Biomimetics Biomimetics: Biology for Engineers, Body Fluid: Blood- Mechanics of heart, Blood pressure, Life molecules: Water, Carbohydrates, Proteins, Lipids and Nucleic acids, Biomimetics: Bio-processes -enginee...

Biology for Engineers 24EN1113 ( I/II Sem) – 2 credits Unit 1- Biomimetics Biomimetics: Biology for Engineers, Body Fluid: Blood- Mechanics of heart, Blood pressure, Life molecules: Water, Carbohydrates, Proteins, Lipids and Nucleic acids, Biomimetics: Bio-processes -engineering analogies (6 Hrs) Class 2: Body Fluid: Blood- Mechanics of heart Bio-fluids: Blood- Mechanical systems of the heart  Circulatory system System that passes nutrients, gases, hormones and blood cells to and from cells in the body – to help fight diseases, – stabilize body temperature and pH, – to maintain homeostasis. Components  The Heart : Eternal Pump The Heart : Eternal Pump and strongest muscle of our body An giant electro-mechanical system Weighs 11 ounces (size of fist) Pumps 2,000 gallons of blood Beats 100,000 times/day 2.5 billion times in lifetime The muscle of the heart (or more specifically, the heart's muscular middle layer) is called the myocardium. (Myo- refers to muscle.) Heart Chambers and Valves  BLOOD VESSELS There are three main types of blood vessels : – Arteries : the vessels that lead blood AWAY from the heart – Veins : the vessels that lead blood back TOWARD the heart – Capillaries : the microscopic vessels that connect arteries and veins; they serve as the place where gasses (oxygen, carbon dioxide, etc.) and nutrients are exchanged. BLOOD  Blood Body contains approximately 4 to 5 liters of blood, making up about 8% of the body’s weight Functions : – Transporting nutrients, oxygen, and hormones – Removing metabolic wastes and carbon dioxide – Providing immunity through antibodies – Maintaining body temperature and electrolyte balance – Clotting to prevent bleeding from a wound  Platelets (Thrombocytes) Platelets can form a plug to seal small vessels by themselves or start the clotting process Produced in red bone marrow Live about 5 to 9 days  Red Blood Cells (Erythrocytes) Live only for 90 to 120 days Contain hemoglobin and red color is due to hemoglobin. New cells are manufactured by the red marrow or myeloid tissue in bones The liver and spleen remove dead red blood cells RBCs lose their nucleus at maturity. Make up about 99% of the blood’s cellular component.  Hemoglobin Hemoglobin is a complex protein made up of four protein strands, plus iron-rich heme groups. Each hemoglobin molecule can carry four oxygen atoms. The presence of oxygen turns hemoglobin bright red. White Blood Cells (Leukocytes) White blood cells remove foreign particles, fight infection, and help prevent disease White blood cells are larger  Plasma A pale yellow liquid that remains when elements are removed from blood Whole blood is 55% plasma Plasma is 90% water and approximately 10% proteins It contains – nutrients, electrolytes, oxygen, enzymes, hormones, and wastes Helps fight infection and assists in the clotting (coagulation) of blood  Double circulatory system Lungs the right side of the the left side of the system system deals with deals with deoxygenated oxygenated blood. blood. Body cells  Types of circulation Pulmonary circulation: the relatively short part of the loop that starts with deoxygenated blood in the pulmonary artery and ends with oxygenated blood in the pulmonary vein; the part of the loop responsible for "refilling" the blood with oxygen in the lungs Systemic circulation: starts with oxygenated blood in the aorta, ends with deoxygenated blood in the vena cava; the part of the loop that provides most of the body with its blood  Circulation Pulmonary circuit right atrium  right ventricle  pulmonary artery trunk  pulmonary arteries  lungs  pulmonary veins  heart (left atrium) Systemic circuit left atrium  left ventricle  aorta  arteries  arterioles  capillaries  venules  veins  vena cava  heart (right atrium) 27-24  “Dual pump” operation The four-chambered heart acts as two pumps.  The Heart: Heart Sounds One cardiac cycle – two heart sounds (lubb and dubb) when valves in the heart snap shut – Lubb – First sound When the ventricles contract, the tricuspid and bicuspid valves snap shut – Dubb – Second sound When the atria contract and the pulmonary and aortic valves snap shut  Blood Pressure Blood pressure is one of the vital signs, a l o n g w i t h r e s p i ra t o r y r a t e , heart rate, oxygen saturation, and body temperature. The blood pressure of blood vessels is related to the total cross- sectional area  Blood Pressure When blood pressure is taken, the cuff is wrapped around the upper portion of the arm and pumped with air until blood flow in the artery is blocked. As the pressure in the cuff is relaxed, 2 numbers are recorded. – Systolic pressure- the first number taken, is the force felt in the arteries when the ventricles contract. – Diastolic pressure- the second number taken, is the force of the blood on the arteries when the ventricles relax.  Hypertension Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Diagnosis and Treatment A stent is a short, wire mesh tube that acts like a scaffold to help keep artery open.