Laboratory Manual For Human Anatomy & Physiology
Laboratory Manual For Human Anatomy & Physiology
4th Edition
ISBN: 9781260159363
Author: Martin, Terry R., Prentice-craver, Cynthia
Publisher: McGraw-Hill Publishing Co.
bartleby

Videos

Textbook Question
Book Icon
Chapter 36, Problem 1PL

As a person ages, the elasticity of the lens

a. decreases.

b. creases.

c. remains unchanged

d. improves.

Expert Solution & Answer
Check Mark
Summary Introduction

Introduction:

The eye is a three-layered, fluid filled ball divided into two chambers. The sclera forms a white capsule around the eye, except at its anterior surface where it is specialized into clear cornea. The tough, fibrous sclera serves as the insertion point for external muscles that more the eyeballs within their sockets. A portion of the underlying choroid layer is darkly pigmented to absorb light rays at the back of the eyeball. In the front, the choroid layer is specialized into the iris (the structure that gives your eyes their color), the ciliary muscle, and the zonular fibers. Circular and radial smooth muscle fibers of the iris determine the diameter of the pupil, the anterior opening that allows light into the eye. The ciliary muscles determine the shape and focusing power of the crystalline lens just behind the iris. The retina is formed from an extension of the developing brain in fetal life on which the real and inverted image is formed. The eye is divided into two fluid-filled spaces- the aqueous humor between the iris and cornea and vitreous humor between lens and the retina.

Answer to Problem 1PL

Correct answer:

The correct answer is option (a) decreases.

Explanation of Solution

Explanation/justification for the correct answer:

Option (a) decreases. When the eye needs to focus on closely placed objects, the lens needs to change its shape and increase its curvature. This activity is mediated by the ciliary muscles. With the advancement of age, the lens become tough and it becomes difficult to change the shape of the lens. This means that elasticity of the lens decreases. So, the correct answer is option (a).

Explanation for incorrect answer:

Option (b) increases. As the lens becomes tough, it will naturally become less elastic. Therefore, elasticity decreases and does not increase. So, this is an incorrect option.

Option (c) remains unchanged. With the advancement of age, the ciliary muscles become weak and lens becomes tough. Therefore, slowly the condition of the eye starts to deteriorate. So, this is an incorrect answer.

Option (d) improves. As the lens becomes tough, it will naturally become less elastic. Therefore, elasticity decreases and does not improve. So, this is an incorrect option.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
Which of the structural components listed in the Essential terms of section 1.3 (Cell components) could occur in a plant cell? Paragraph く BIUA 川く く 80 + кл K
Which of the following statements refer(s) directly to the cell theory? (Note that one or more correct answers are possible.) Select 2 correct answer(s) a) There are major differences between plant and animal cells. b) There are major differences between prokaryote and eukaryote cells. c) All cells have a cell wall. d) All cells have a cell membrane. e) Animals are composed of cells. f) When a bacterial cell divides, it produces two daughter cells.
Preoperative Diagnosis: Torn medial meniscus, left knee Postoperative Diagnosis: Combination horizontal cleavage tear/flap tear, posterior horn, medial meniscus, left knee. Operation: Arthroscopic subtotal medial meniscectomy, left knee Anesthetic: General endotracheal Description of Procedure: The patient was placed on the operating table in the supine position and general endotracheal anesthesia was administered. After an adequate level of anesthesia was achieved, the patient's left lower extremity was prepped with Betadine scrubbing solution, then draped in a sterile manner. Several sites were then infiltrated with 1% Xylocaine solution with Epinephrine to help control bleeding from stab wounds to be made at these sites. These stab wounds were made anterolaterally at the level of the superior pole of the patella for insertion of an irrigation catheter into the suprapatellar pouch area, anterolaterally at the level of the joint line for insertion of the scope and anteromedially at…
Knowledge Booster
Background pattern image
Biology
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Body Structures & Functions Updated
Biology
ISBN:9780357191606
Author:Scott
Publisher:Cengage
Text book image
Medical Terminology for Health Professions, Spira...
Health & Nutrition
ISBN:9781305634350
Author:Ann Ehrlich, Carol L. Schroeder, Laura Ehrlich, Katrina A. Schroeder
Publisher:Cengage Learning
Text book image
Body Structures & Functions
Biology
ISBN:9781285695495
Author:Scott
Publisher:Cengage
Text book image
An Illustrated Guide To Vet Med Term
Biology
ISBN:9781305465763
Author:ROMICH
Publisher:Cengage
Text book image
Comprehensive Medical Assisting: Administrative a...
Nursing
ISBN:9781305964792
Author:Wilburta Q. Lindh, Carol D. Tamparo, Barbara M. Dahl, Julie Morris, Cindy Correa
Publisher:Cengage Learning
Text book image
Essentials of Pharmacology for Health Professions
Nursing
ISBN:9781305441620
Author:WOODROW
Publisher:Cengage
Visual Perception – How It Works; Author: simpleshow foundation;https://www.youtube.com/watch?v=DU3IiqUWGcU;License: Standard youtube license