Vidyapath Batch Code-61-An202Ea 2024 Zoology Lecture Notes PDF

# VIDYAPEETH ## BATCH CODE-61-AN202EA 2024 ### Subject Name - Zoology ### Chapter Name - Body Fluids and Circulation ### Lecture No.- 07 ## By- Dr. Archana Ma'am ## Today's Goal ### Topic - ECG ### Topic - Regulation of cardiac activity ### Topic - Disorders of Circulatory system ## Quick Last lectu...

# VIDYAPEETH ## BATCH CODE-61-AN202EA 2024 ### Subject Name - Zoology ### Chapter Name - Body Fluids and Circulation ### Lecture No.- 07 ## By- Dr. Archana Ma'am ## Today's Goal ### Topic - ECG ### Topic - Regulation of cardiac activity ### Topic - Disorders of Circulatory system ## Quick Last lecture Revision - Conducting system of heart - Cardiac cycle ## Electrocardiograph (ECG) - ECG is a graphical representation of the electrical activity of the heart during a cardiac cycle. - A patient is connected to the machine with 3 electrical leads (one to each wrist & to the left ankle). - For detailed evaluation of heart's function (Heart activity) - multiple leads are attached to the chest region. ## ECG - Electrocardiogram -> Graphical representation of electrical activity of heart - Electrocardiograph -> ECG Machine (Instrument) ## Standard ECG Graph - Atrial depolarisation (excitation of Atria) leads to contraction of both the atria (Atrial Systole). - Depolarisation of Ventricles leads to contraction of ventricle (Ventricular Systole). - Repolarisation of Ventricle relaxation of ventricles (ventricular diastole). - Depolarisation -> excitation. - Repolarisation -> relaxation. ## Electrocardiograph (ECG) - P-wave: electrical excitation (depolarisation) of the atria leads to the contraction of both the atria. - QRS complex: depolarisation of the ventricles initiates the ventricular contraction. Contraction starts shortly after Q & marks the beginning of systole. - T-wave: return of ventricles from excited to normal state (repolarisation) End of T-wave marks the end of systole. - Diagrammatic presentation of a standard ECG: Shows P wave, QRS complex and T wave, with atrial systole, ventricular systole and ventricular diastole marked. ## ECG - Different individuals have roughly the same ECG. - Any deviation from this shape indicates abnormality or disease. - Hence, it is of a great clinical significance. - ECGs can be used to diagnose various cardiovascular diseases like tachycardia, bradycardia, and heart attacks. ## ECG - Tachycardia : heart rate exceeds 90/min. - Bradycardia: heart rate falls below 60/min. ## Regulation of Cardiac Activity - Normal activities of the heart are regulated intrinsically, i.e. auto regulated by specialised muscles (nodal tissue) hence the heart is called myogenic.. - Nervous Regulation: A special neural centre (cardiac centre) in the medulla oblongata can moderate the cardiac function through ANS (Autonomic Nervous System) - Neural signals through the sympathetic nerves can increase the rate of heart beat, the strength of ventricular contraction and thereby the cardiac output. - On the other hand, parasympathetic neural signals decrease the rate of heart beat, speed of conduction of action potential and thereby the cardiac output. - Hormonal Regulation: Adrenal medullary hormones (adrenaline and nor-adrenaline) and Thyroxine hormone of thyroid gland can increase the heart rate and the cardiac output. ## Portal system - Venous connection - Renal portal system - Hepatic portal system - Hypophysial portal system ## Renal Portal system - Veins which collect blood from posterior part of the body and legs combine to form a renal portal vein. - This vein goes into kidney and divide into capillaries. - Kidneys separate nitrogenous waste from this blood. - In mammals, Renal portal system is absent. - In frogs: renal and hepatic portal system is present. ## Hepatic Portal System - Unique vascular connection exists between the digestive tract and liver - The hepatic portal vein carries blood from intestine to liver before it is delivered to the systemic circulation. ## Hypophysial Portal system - Formed by a vein from hypothalamus which breaks up into capillaries in anterior lobe of pituitary gland (Adenohypophysis) - Hypothalamus produces no of hormones for controlling endocrine activity of adenohypophysis. - *A special coronary system of blood vessels is present in our body exclusively for the circulation of blood to and from the cardiac musculature.* ## Blood Pressure - Systolic pressure: state of heart contraction 120 mm Hg - Diastolic pressure: state of heart relaxation 80 mm Hg - Normal Bp: 120/80 - High BP 140/90 -> Hypertension - Low BP 110/70 -> Hypotension - Instrument to measure Bp: Sphygmomanometer ## Disorders of Circulatory System ### High Blood Pressure (Hypertension) - Blood pressure is higher than normal. - If repeated checks of blood pressure of an individual is 140/90 (140 over 90) or higher. - High blood pressure leads to heart diseases. - Affects vital organs like brain and kidney. ### Coronary Artery Disease (CAD) - Often referred to as atherosclerosis. - Affects the vessels that supply blood to the heart muscle. - Caused by deposits of calcium, fat, cholesterol and fibrous tissues, which makes the lumen of arteries narrower. ### Angina (angina pectoris) - A symptom of acute chest pain appears when no enough oxygen is reaching the heart muscle. - Can occur in men and women of any age but more common among the middle-aged and elderly. - Occurs due to conditions that affect the blood flow. ### Heart Failure - Heart is not pumping blood effectively enough to meet the needs of the body. - Called congestive heart failure because congestion of the lungs is one of the main symptom. - Cardiac arrest: when the heart stops beating. - Heart attack: Heart muscle is suddenly damaged by an inadequate blood supply ## Question 1 The QRS complex in ECG represents - A Repolarisation of Atria - B Depolarisation of atria - C Repolarization of ventricles - **D Depolarisation of ventricles** ## Question 2 Centre for heart beat regulation is located in - **A Medulla oblongata** - B Pons varoli - C Cerebrum - D Cerebellum ## Question 3 Which instrument is used for measurement of blood pressure? - **A Sphygmomanometer** - B Stethoscope - C Thermometer - D Spirometer ## Question 4 Which of the following hormone can increase the heart rate and cardiac output ? - **A Adrenaline** - B Nor-adrenaline - **C Thyroxine** - **D All of these** ## Question 5 Identify the correct statement from the following - **A High blood pressure leads to heart diseases** - **B Coronary Artery Disease is referred to as atherosclerosis** - **C In frogs, renal and hepatic portal system is present** - **D All of these** ## Question 6 The Hepatic portal vein carries blood from - A Intestine to kidney - B Kidney to liver - C Heart to kidney - **D Intestine to liver** ## Homework - DPP - DPP NO DPP-7, Question No 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 - MODULE EXERCISE QUESTIONS ## Next Lecture's Goal - **Topic - Revision and Dangal of Body fluids and Circulation.** **Rate your today's class in the Batch** **Solve the DPP and check Solution** **Thank You!!! 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