BIO 202 Exam 1 Objectives and Essay Topic Questions With Complete Solutions Essay Topic Exam 1 will be covering material from Lessons 1-4. The essay topic is *cardiac impulse generation.*
Helpful Hints for Writing the Essay:
1) Make sure that you have completely answered the question. Good examples and definitions always strengthen your answers.2) Sometimes students get stumped when trying to start an essay. Try writing the body paragraph (the paragraph which addresses the essay question first), and then go back and write the introduction and application paragraphs.3) Make sure to include the application paragraph. It is worth 20% of your total essay score!4) The introduction of your essay should include background information on the topic and should help to transition into your supporting paragraphs.5) For help with writing I suggest visiting Rio Salado's online writing lab. Online Writing Laboratory (OWL) - Correct Answers ✅Your heart beats as a result of the generation and conduction of electrical impulses. Cardiac conduction is the rate at which the heart conducts electrical impulses.These impulses cause the heart to contract and then relax.The constant cycle of heart muscle contraction followed by relaxation causes blood to be pumped throughout the body.Cardiac conduction can be influenced by various factors including exercise, temperature, and endocrine system hormones. 1 / 3
BIO 202 Exam 1 Objectives and Essay Topic Questions With Complete Solutions
Step 1: Pacemaker Impulse Generation
The first step of cardiac conduction is impulse generation.The sinoatrial (SA) node (also referred to as the pacemaker of the heart) contracts, generating nerve impulses that travel throughout the heart wall. This causes both atria to contract.The SA node is located in the upper wall of the right atrium. It is composed of nodal tissue that has characteristics of both muscle and nervous tissue.
Step 2: AV Node Impulse Conduction
The atrioventricular (AV) node lies on the right side of the partition that divides the atria, near the bottom of the right atrium. When the impulses from the SA node reach the AV node, they are delayed for about a tenth of a second. This delay allows atria to contract and empty their contents into the ventricles prior to ventricle contraction.
Step 3: AV Bundle Impulse Conduction
The impulses are then sent down the atrioventricular bundle.This bundle of fibers branches off into two bundles and the impulses are carried down the center of the heart to the left and right ventricles.
Step 4: Purkinje Fibers Impulse Conduction 2 / 3
BIO 202 Exam 1 Objectives and Essay Topic Questions With Complete Solutions At the base of the heart, the atrioventricular bundles start to divide further into Purkinje fibers. When the impulses reach these fibers they trigger the muscle fibers in the ventricles to contract. The right ventricle sends blood to the lungs via the pulmonary artery. The left Erythrocytes - Correct Answers ✅transport oxygen and carbon dioxide Leukocytes - Correct Answers ✅ Granulocytes - Correct Answers ✅ Neutrophils - Correct Answers ✅phagocytize bacteria Eosinophils - Correct Answers ✅kill parasitic worms; complex role in allergy and asthma
TWO LOBES
Basophils - Correct Answers ✅release histamine and other mediators of inflammation; contain heparin and anticoagulent Agranulocytes - Correct Answers ✅
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