Question

In: Anatomy and Physiology

the 11 step for association of sight (vision chemistry)

the 11 step for association of sight (vision chemistry)

Solutions

Expert Solution

Physiology of vision is a complex phenomenon which is still poorly understood. The main mechanisms involved in physiology of vision are:
• Initiationofvision(Phototransduction),afunction
of photoreceptors (rods and cones),
• Processing and transmission of visual sensation,
a function of image processing cells of retina and
visual pathway, and
• Visualperception,afunctionofvisualcortexand
related areas of cerebral cortex.
Phototransduction
The rods and cones serve as sensory nerve endings for visual sensation. light falling upon the retina causes photochemical changes which in turn trigger a cascade of biochemical reactions that result in generation of electrical changes. Photochemical changes occurring in the rods and cones are essentially similar but the changes in rod pigment (rhodopsin or visual purple) have been studied in more detail. This whole phenomenon of conversion of light energy into nerve impulse is known as phototransduction.
Photochemical changes
The photochemical changes include:
Rhodopsin bleaching. Rhodopsin refers to the visual pigment present in the rods—the receptors for night (scotopic) vision. Its maximum absorption spectrum is around 500 nm. Rhodopsin consists of a colourless protein called opsin coupled with a carotenoid called retinine (Vitamin A aldehyde or 11-cis-retinal). light falling on the rods converts 11-cis-retinal component of rhodopsin into 11-cis-retinal through various stages . The all-trans-retinal so formed is soon separated from the opsin . This process of separation is called photodecomposition and the rhodopsin is said to be bleached by the action of light. Rhodopsin regeneration. The 11-cis-retinal is regenerated from the alt-trans-retinal separated from the opsin (as described above) and vitamin-A (retinal) supplied from the blood. The 11-cis- retinal then reunites with opsin in the rod outer segment to form the rhodopsin. This whole process is called rhodopsin regeneration . Thus, the bleaching of the rhodopsin occurs under the influence of light, whereas the regeneration process is independent of light, proceeding equally well in light and darkness.
Visual cycle. In the retina of living animals, under constant light stimulation, a steady state must exist under which the rate at which the photochemicals are bleached is equal to the rate at which they are regenerated. This equilibrium between the photodecomposition and regeneration of visual pigments is referred to as visual cycle.


Related Solutions

step by step physical chemistry, Describe the structures of 1,3-butadiene and 1,3-pentadiene using hybrid orbitals.
step by step physical chemistry, Describe the structures of 1,3-butadiene and 1,3-pentadiene using hybrid orbitals.
Classification and Reg Tress + Association Rules Question 11 The number of association rules increases Additively...
Classification and Reg Tress + Association Rules Question 11 The number of association rules increases Additively with number of items Multiplicatively with number of items Exponentially with number of items Question 12 If there are k items, number of association rules formed is formulated as : 3^k - 2^(k-1) 3^k - 2^(k+1) + 1 3^k - 2^(k+1) - 1 3^k - 2^(k-1) + 1 Question 13 Consider the rules A -> B, B -> A, where A, B are two...
For your company Amazon: (Please answer step by step) (Dont copy/paste information please) State company's vision,...
For your company Amazon: (Please answer step by step) (Dont copy/paste information please) State company's vision, mission, and values. What is your company's strategy? Perform a stockholder's impact analysis for your company. Prepare the PESTEL model for your company. Prepare the Five Forces Model for your company's industry. Prepare the SWOT analysis for your company. What are your company's competitive advantages? Which KPIs does your company use to measure performance? What is your company's business model? What is your company's...
I would like to get the step by step solution for the below question Question 11...
I would like to get the step by step solution for the below question Question 11 pts What is the difference between positive economics and normative economics? Group of answer choices Positive economics deals with dynamic systems, while normative economics focuses on static systems. Normative economics deals with how the world actually works, whereas positive economics focuses on what people ought to do. Positive economics requires making value judgments, while normative economics relies solely on factual statements. Normative economics applies...
please show me step by step? Chapter 11 Exercise 11-8 Volume Trade-Off Decisions [LO11-5, LO11-6] Barlow...
please show me step by step? Chapter 11 Exercise 11-8 Volume Trade-Off Decisions [LO11-5, LO11-6] Barlow Company manufactures three products—A, B, and C. The selling price, variable costs, and contribution margin for one unit of each product follow: Product A B C Selling price $ 180 $ 270 $ 240 Variable expenses: Direct materials 24 80 32 Other variable expenses 102 90 148 Total variable expenses 126 170 180 Contribution margin $ 54 $ 100 $ 60 Contribution margin ratio...
11. If an exposure has no association with a certain outcome, then what value would you...
11. If an exposure has no association with a certain outcome, then what value would you obtain for each of the measures of association listed below? Fill in all the blanks. 4 points. Rate ratio ________________ Odds ratio ________________ Rate difference _____________ D. Attributable proportion in the exposed___________
Sulfanilamide Multi-step Synthesis Discuss the chemistry behind the chemical reactions and experimental techniques (region/stereoselectivity of the...
Sulfanilamide Multi-step Synthesis Discuss the chemistry behind the chemical reactions and experimental techniques (region/stereoselectivity of the reactions, use of LeChatelier’s principle to maximize yields, why some reactions are moisture sensitive, the importance of protecting groups, etc. Include each of the reactions using structures and the complete mechanisms. The mechanism must be NEATLY hand drawn by you and will be graded for completeness and accuracy. Specific details to include: Formation of the arylsulfonyl chloride from acetanilide by reaction with chlorosulfonic acid...
A stick is resting on a concrete step with 2/11 of its length hanging over the...
A stick is resting on a concrete step with 2/11 of its length hanging over the edge. A single ladybug lands on the end of the stick hanging over the edge, and the stick begins to tip. A moment later, a second, identical ladybug lands on the other end of the stick, which results in the stick coming momentarily to rest 56.9° from the horizontal. If the mass of each bug is 2.92 times the mass of the stick and...
Problem 11-54 (Algo) Step Method with Three Service Departments (LO 11-3) Model, Inc., produces model automobiles...
Problem 11-54 (Algo) Step Method with Three Service Departments (LO 11-3) Model, Inc., produces model automobiles made from metal. It operates two production departments, Molding and Painting, and has three service departments, Administration, Accounting, and Maintenance. The accumulated costs in the three service departments were $262,000, $392,000, and $189,000, respectively. Management is concerned that the costs of its service departments are getting too high. In particular, managers would like to keep the costs of service departments under $3.50 per unit...
Exercise 11-29 Cost Allocation: Step Method (LO 11-3) Caro Manufacturing has two production departments, Machining and...
Exercise 11-29 Cost Allocation: Step Method (LO 11-3) Caro Manufacturing has two production departments, Machining and Assembly, and two service departments, Maintenance and Cafeteria. Direct costs for each department and the proportion of service costs used by the various departments for the month of August follow: Proportion of Services Used by Department Direct Costs Maintenance Cafeteria Machining Assembly Machining $ 120,000 Assembly 80,000 Maintenance 53,000 — 0.2 0.5 0.3 Cafeteria 42,000 0.7 — 0.2 0.1 Required: Use the step method...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT