Premium Essay

Frog Cardio Vascular

In: Science

Submitted By vedpathak
Words 386
Pages 2
The function of the heart is simply to act as a pump that provides pressure to move blood to its ultimate destination – the tissues. Cardiac muscle differs from skeletal muscle both morphologically and functionally. Probably the most striking and fascinating feature of its contractility is its automaticity, that is its ability to initiate its own rhythmic contractions without requiring external stimulation. This automaticity is believed to be due to ‘leaky’ cell membranes, in which the calcium ions slowly leak into the cells. This leaking causes a slow depolarization to threshold, thus firing an action potential and initiating contractions of cardiac muscle. The cells that are most ‘leaky’ to calcium and that depolarize fastest control the rate of contraction of all other cardiac cells, thus they act as pacemakers for the rest of the heart. In the mammalian heart, the pacemaker is the sinoatrial (SA) node, a group of specialized cells near the junction of the vena cava and the right atrium. In the frog heart, the pacemaker is the sinus venosus, an enlarged region between the vena cava and the right atrium. (The mammalian SA node is believed to be an evolutionary remnant of the sinus venosus). Each region of the heart has its intrinsic rate of beating: for example SA node 72 beats/min; atrium 60 beats/mind; ventricle 25 beats/min. Only when the faster pacemaker region is blocked is it possible to observe the intrinsic rate of the slower regions.

In this series of experiments you will use a frog heart because it functions well at room temperature and will continue to beat even when excised from the body. Mammalian hearts have the same contractile characteristics but must be supplied with a constant flow of warm oxygenated blood to maintain their contractility.

The frog heart differs from the mammalian heart anatomically in that they are three

Similar Documents

Free Essay

Essay of Today

...1. Which of the following is the characteristic of the living thing? A. have specific shape B. have regular shape C. have organized body D. none of the above 2. Which of the followings includes in homeostasis? a. To maintain the shaped of the body b. To maintain the balance of the body c. To maintain the temperature of the body d. To keep the animal away from the body 3. Your hearts starts beating before seven month of your birth. The study of your body at this stage comes within: (a) Morphology (b) Embryology (c) Anatomy (d) Histology 4. A doctor is studying the contraction and relaxation of a heart. He is studying: (a) Morphology (b) Embryology (c) Anatomy (d) Histology 5. Study of different parts of eye is called (a) Histology (b) Anatomy (c) Physiology (d) None of these 6. A biologist removes some bones of dinosaurs from a rock. He is studying: (a) Morphology (b) Paleontology (c) Ecology (d) None of these 7. Darwin sys, “man has formed from monkey”. He talked about (a) Fossil (b) Evolution (c) Taxonomy (d) None of these 8. Kangaroo lives in Australia but buffaloes lives in Pakistan. The study of this distribution of animals is called (a) Ecology (b) Environmental biology (c) Taxonomy (d) Zoogeography 9. The study of structure of molecule of starch is called: (a) Molecular biology (b) Biochemistry (c) Morphology (d) None 10. The study of Amoeba comes with in the branch of biology: (a) Taxonomy (b) Ecology (c) Microbiology (d) None 11. The study...

Words: 18276 - Pages: 74

Premium Essay

Lalalal

...1 UNIT 1 Living Things and Their Environment DRAFT April 29, 2014 Photo Credit: http://www.flyingfourchette.com/2013/05/25/around-ubud/ 2 UNIT 1: Living Things and Their Environment Introduction At this point, students have already learned in Grade 8 how the body breaks down food into forms that can be absorbed through the digestive system and then transported to each cell, which was on the other hand discussed in Grade 7 to be the basic unit of life. The learners have also discovered that cells divide to produce new cells by mitosis and meiosis. They have understood that meiosis is an early step in sexual reproduction that leads to variation. Students have been introduced to genetics to be able to appreciate evolutionary differences among species. Learners have also found out that biodiversity is the collective variety of species living in an ecosystem, and by studying the ecosystem; they have come across the various cycling of materials and energy transformation. DRAFT April 29, 2014 All modules in Grade 9 Unit 1-Living Things and Their Environment present student-centered activities that will allow the learners to discover and develop concepts that they may consider useful to their everyday life. At the end of each lesson, key concepts are provided for the students to grasp ideas and information that they will remember even after they have left school. Instructional activities are designed to build up the students’ knowledge, understanding, skills, and ability to transfer...

Words: 68324 - Pages: 274

Free Essay

Swn Jdkjkjje Jne

...Employment News 31 May - 6 June 2014 www.employmentnews.gov.in 21 UNION PUBLIC SERVICE COMMISSION EXAMINATION NOTICE NO. 09/2014-CSP (LAST DATE FOR RECEIPT OF APPLICATIONS : 30/06/2014) DATE :31.05.2014 CIVIL SERVICES EXAMINATION, 2014 (Commission’s website-http://upsc.gov.in) F. No. 1/5/2013-E.I(B) : Preliminary Examination of the Civil Services Examination for recruitment to the Services and Posts mentioned below will be held by the Union Public Service Commission on 24th Aug., 2014 in accordance with the Rules published by the Department of Personnel & Training in the Gazette of India Extraordinary dated 31st May, 2014. (i) Indian Administrative Service. (ii) Indian Foreign Service. (iii) Indian Police Service. (iv) Indian P & T Accounts & Finance Service, Group ‘A’. (v) Indian Audit and Accounts Service, Group ‘A’. (vi) Indian Revenue Service (Customs and Central Excise), Group ‘A’. (vii) Indian Defence Accounts Service, Group ‘A’. (viii) Indian Revenue Service (I.T.), Group ‘A’. (ix) Indian Ordnance Factories Service, Group ‘A’ (Assistant Works Manager, Administration). (x) Indian Postal Service, Group ‘A’. (xi) Indian Civil Accounts Service, Group ‘A’. (xii) Indian Railway Traffic Service, Group ‘A’. (xiii) Indian Railway Accounts Service, Group 'A'. (xiv) Indian Railway Personnel Service, Group ‘A’. (xv) Post of Assistant Security Commissioner in Railway Protection Force, Group ‘A’ (xvi) Indian Defence Estates Service, Group...

Words: 47693 - Pages: 191

Free Essay

Whirlpool

...Employment News 11 - 17 February 2012 www.employmentnews.gov.in 21 Union Public Service Commission EXAMINATION NOTICE NO. 04/2012-CSP DATED 11.02.2012 (LAST DATE FOR RECEIPT OF APPLICATIONS : 05.03.2012) CIVIL SERVICES EXAMINATION, 2012 (Commission's website - http://www.upsc.gov.in) F. No. 1/4/2011-E.I(B) : Preliminary Examination of the Civil Services Examination for recruitment to the Services and Posts mentioned below will be held by the Union Public Service Commission on 20th May, 2012 in accordance with the Rules published by the Department of Personnel & Training in the Gazette of India Extraordinary dated 4th February, 2012. (i) Indian Administrative Service. (ii) Indian Foreign Service. (iii) Indian Police Service. (iv) Indian P & T Accounts & Finance Service, Group ‘A’. (v) Indian Audit and Accounts Service, Group ‘A’. (vi) Indian Revenue Service (Customs and Central Excise), Group ‘A’. (vii) Indian Defence Accounts Service, Group ‘A’. (viii) Indian Revenue Service (I.T.), Group ‘A’. (ix) Indian Ordnance Factories Service, Group ‘A’ (Assistant Works Manager, Administration). (x) Indian Postal Service, Group ‘A’. (xi) Indian Civil Accounts Service, Group ‘A’. (xii) Indian Railway Traffic Service, Group ‘A’. (xiii) Indian Railway Accounts Service, Group 'A'. (xiv) Indian Railway Personnel Service, Group ‘A’. (xv) Post of Assistant Security Commissioner in Railway Protection Force, Group ‘A’ (xvi) Indian Defence Estates Service, Group ‘A’. (xvii) Indian Information...

Words: 50586 - Pages: 203