Back to 课程
Biology AS CIE
0% Complete
0/0 Steps
-
1-cell-structure10 主题
-
1-2-cells-as-the-basic-units-of-living-organisms AS viruses
-
1-2-cells-as-the-basic-units-of-living-organisms AS prokaryotic-v-eukaryotic-cells
-
1-2-cells-as-the-basic-units-of-living-organisms AS the-vital-role-of-atp
-
1-2-cells-as-the-basic-units-of-living-organisms AS animal-and-plant-cells
-
1-2-cells-as-the-basic-units-of-living-organisms AS eukaryotic-cell-structures-and-functions
-
1-1-the-microscope-in-cell-studies AS calculating-actual-size
-
1-1-the-microscope-in-cell-studies AS resolution-and-magnification
-
1-1-the-microscope-in-cell-studies AS eyepiece-graticules-and-stage-micrometers
-
1-1-the-microscope-in-cell-studies AS magnification-calculations
-
1-1-the-microscope-in-cell-studies AS the-microscope-in-cell-studies
-
1-2-cells-as-the-basic-units-of-living-organisms AS viruses
-
2-biological-molecules19 主题
-
2-4-water AS water-and-the-hydrogen-bond
-
2-4-water AS the-role-of-water-in-living-organisms
-
2-3-proteins AS collagen
-
2-3-proteins AS haemoglobin
-
2-3-proteins AS globular-and-fibrous-proteins
-
2-3-proteins AS protein-shape
-
2-3-proteins AS the-four-levels-of-protein-structure
-
2-3-proteins AS amino-acids-and-the-peptide-bond
-
2-2-carbohydrates-and-lipids AS phospholipids
-
2-2-carbohydrates-and-lipids AS triglycerides
-
2-2-carbohydrates-and-lipids AS cellulose
-
2-2-carbohydrates-and-lipids AS starch-and-glycogen
-
2-2-carbohydrates-and-lipids AS the-glycosidic-bond
-
2-2-carbohydrates-and-lipids AS reducing-and-non-reducing-sugars
-
2-2-carbohydrates-and-lipids AS covalent-bonds-in-polymers
-
2-2-carbohydrates-and-lipids AS biological-molecules-key-terms
-
2-1-testing-for-biological-molecules AS testing-for-non-reducing-sugars
-
2-1-testing-for-biological-molecules AS the-benedicts-test
-
2-1-testing-for-biological-molecules AS biological-molecule-tests
-
2-4-water AS water-and-the-hydrogen-bond
-
3-enzymes13 主题
-
3-2-factors-that-affect-enzyme-action AS enzyme-activity-immobilised-v-free
-
3-2-factors-that-affect-enzyme-action AS enzyme-inhibitors
-
3-2-factors-that-affect-enzyme-action AS vmax-and-the-michaelis-menten-constant
-
3-2-factors-that-affect-enzyme-action AS rate-inhibitor-concentration
-
3-2-factors-that-affect-enzyme-action AS rate-substrate-concentration
-
3-2-factors-that-affect-enzyme-action AS rate-enzyme-concentration
-
3-2-factors-that-affect-enzyme-action AS rate-ph
-
3-2-factors-that-affect-enzyme-action AS rate-temperature
-
3-1-mode-of-action-of-enzymes AS colorimetry
-
3-1-mode-of-action-of-enzymes AS measuring-enzyme-activity
-
3-1-mode-of-action-of-enzymes AS how-enzymes-work
-
3-1-mode-of-action-of-enzymes AS enzyme-action
-
3-1-mode-of-action-of-enzymes AS enzymes
-
3-2-factors-that-affect-enzyme-action AS enzyme-activity-immobilised-v-free
-
4-cell-membranes-and-transport16 主题
-
4-2-movement-into-and-out-of-cells AS comparing-osmosis-in-plants-and-animals
-
4-2-movement-into-and-out-of-cells AS osmosis-in-animals
-
4-2-movement-into-and-out-of-cells AS osmosis-in-plant-cells
-
4-2-movement-into-and-out-of-cells AS estimating-water-potential-in-plants
-
4-2-movement-into-and-out-of-cells AS investigating-surface-area
-
4-2-movement-into-and-out-of-cells AS surface-area-to-volume-ratios
-
4-2-movement-into-and-out-of-cells AS investigating-diffusion
-
4-2-movement-into-and-out-of-cells AS investigating-transport-processes-in-plants
-
4-2-movement-into-and-out-of-cells AS endocytosis-and-exocytosis
-
4-2-movement-into-and-out-of-cells AS active-transport
-
4-2-movement-into-and-out-of-cells AS osmosis
-
4-2-movement-into-and-out-of-cells AS diffusion
-
4-1-fluid-mosaic-membranes AS cell-signalling
-
4-1-fluid-mosaic-membranes AS the-cell-surface-membrane
-
4-1-fluid-mosaic-membranes AS components-of-cell-surface-membranes
-
4-1-fluid-mosaic-membranes AS the-fluid-mosaic-model
-
4-2-movement-into-and-out-of-cells AS comparing-osmosis-in-plants-and-animals
-
5-the-mitotic-cell-cycle8 主题
-
5-2-chromosome-behaviour-in-mitosis AS observing-mitosis
-
5-2-chromosome-behaviour-in-mitosis AS the-stages-of-mitosis
-
5-1-replication-and-division-of-nuclei-and-cells AS how-tumours-form
-
5-1-replication-and-division-of-nuclei-and-cells AS the-role-of-stem-cells
-
5-1-replication-and-division-of-nuclei-and-cells AS the-role-of-telomeres-
-
5-1-replication-and-division-of-nuclei-and-cells AS the-cell-cycle
-
5-1-replication-and-division-of-nuclei-and-cells AS mitosis
-
5-1-replication-and-division-of-nuclei-and-cells AS chromosome-structure
-
5-2-chromosome-behaviour-in-mitosis AS observing-mitosis
-
6-nucleic-acids-and-protein-synthesis9 主题
-
6-2-protein-synthesis AS gene-mutations
-
6-2-protein-synthesis AS transcription
-
6-2-protein-synthesis AS constructing-polypeptides
-
6-2-protein-synthesis AS the-universal-genetic-code
-
6-2-protein-synthesis AS from-gene-to-polypeptide
-
6-1-structure-of-nucleic-acids-and-replication-of-dna AS the-structure-of-rna
-
6-1-structure-of-nucleic-acids-and-replication-of-dna AS semi-conservative-dna-replication
-
6-1-structure-of-nucleic-acids-and-replication-of-dna AS the-structure-of-dna
-
6-1-structure-of-nucleic-acids-and-replication-of-dna AS nucleotides
-
6-2-protein-synthesis AS gene-mutations
-
7-transport-in-plants11 主题
-
7-2-transport-mechanisms AS phloem-mass-flow
-
7-2-transport-mechanisms AS the-sucrose-loading-mechanism
-
7-2-transport-mechanisms AS movement-in-the-phloem
-
7-2-transport-mechanisms AS xerophytic-plant-leaf-adaptations
-
7-2-transport-mechanisms AS water-and-the-transpiration-pull
-
7-2-transport-mechanisms AS transpiration-in-plants
-
7-2-transport-mechanisms AS water-and-mineral-ion-transport-in-plants
-
7-1-structure-of-transport-tissues AS phloem-sieve-tube-elements
-
7-1-structure-of-transport-tissues AS xylem-vessels-elements
-
7-1-structure-of-transport-tissues AS xylem-and-phloem-distribution
-
7-1-structure-of-transport-tissues AS plant-transverse-sections
-
7-2-transport-mechanisms AS phloem-mass-flow
-
8-transport-in-mammals16 主题
-
8-3-the-heart AS heart-action
-
8-3-the-heart AS the-cardiac-cycle
-
8-3-the-heart AS the-walls-of-the-heart
-
8-3-the-heart AS structure-of-the-heart
-
8-2-transport-of-oxygen-and-carbon-dioxide AS the-bohr-shift
-
8-2-transport-of-oxygen-and-carbon-dioxide AS the-oxygen-dissociation-curve
-
8-2-transport-of-oxygen-and-carbon-dioxide AS plasma-and-carbon-dioxide
-
8-2-transport-of-oxygen-and-carbon-dioxide AS the-chloride-shift
-
8-2-transport-of-oxygen-and-carbon-dioxide AS red-blood-cells-haemoglobin-and-oxygen
-
8-1-the-circulatory-system AS blood-tissue-fluid-and-lymph
-
8-1-the-circulatory-system AS the-role-of-water-in-circulation
-
8-1-the-circulatory-system AS cells-of-the-blood
-
8-1-the-circulatory-system AS blood-vessels-structures-and-functions
-
8-1-the-circulatory-system AS observing-and-drawing-blood-vessels
-
8-1-the-circulatory-system AS the-main-blood-vessels
-
8-1-the-circulatory-system AS circulatory-systems
-
8-3-the-heart AS heart-action
-
9-gas-exchange6 主题
-
9-1-the-gas-exchange-system AS gas-exchange-processes
-
9-1-the-gas-exchange-system AS structures-and-functions-of-the-gas-exchange-system
-
9-1-the-gas-exchange-system AS recognising-structures
-
9-1-the-gas-exchange-system AS recognising-tissues
-
9-1-the-gas-exchange-system AS distribution-of-tissues
-
9-1-the-gas-exchange-system AS the-human-gas-exchange-system
-
9-1-the-gas-exchange-system AS gas-exchange-processes
-
10-infectious-diseases6 主题
-
11-immunity10 主题
-
11-2-antibodies-and-vaccination AS vaccination-to-control-disease
-
11-2-antibodies-and-vaccination AS how-vaccines-work
-
11-2-antibodies-and-vaccination AS types-of-immunity
-
11-2-antibodies-and-vaccination AS uses-of-monoclonal-antibodies
-
11-2-antibodies-and-vaccination AS making-monoclonal-antibodies
-
11-2-antibodies-and-vaccination AS antibodies
-
11-1-the-immune-system AS memory-cells-and-immunity
-
11-1-the-immune-system AS primary-immune-response
-
11-1-the-immune-system AS antigens
-
11-1-the-immune-system AS phagocytes
-
11-2-antibodies-and-vaccination AS vaccination-to-control-disease
课 8,
主题 3
In Progress
8-3-the-heart AS the-walls-of-the-heart
课 Progress
0% Complete
Exam code:9700
The walls of the heart
-
The muscular walls of the atria are thinner than those of the ventricles
-
When the atria contract, the thin muscular walls do not generate much pressure, but enough to force blood down into the ventricles, through the atrioventricular valves
-
In contrast, the walls of the ventricles are thicker and more muscular
-
Following contraction of the atria, the ventricles contract and squeeze blood inwards, increasing its pressure and pushing it out of the heart through right and left semilunar valves
Left and right ventricle
-
The muscle of the left ventricle is significantly thicker than the right ventricle
-
This is because the blood leaving the right ventricle travels less distance than blood leaving the left ventricle
-
-
The blood pumped out from the right ventricle travels to the lungs, whereas blood pumped out from the left ventricle has to travel to the rest of the body to deliver oxygen for respiration
-
To reach the rest of the body, the blood leaving the left ventricle must be under high pressure
-
This is generated by the contraction of the muscular walls of the left ventricle
-
-
The right ventricle generates less pressure from the contraction of its thinner walls, as blood only has to reach the lungs
Worked Example
A graph showing pressures changes in the heart is shown below:
Explain the differences in pressure between left atrium and ventricle in the graph.
The walls of the left atrium are thin, so the pressure generated by their contraction is low. Low pressure is sufficient because blood is forced only a short distance; from the left atrium down to the left ventricle. The muscular walls of the left ventricle are much thicker and generate much higher pressure, as shown on the graph. This is because much more pressure is generated when this thick muscle contracts and squeezes blood with enough force to reach the rest of the body.
Responses