Chapter 8: Excitation and Contraction of Smooth Muscle

Question 1

The smooth muscle of each organ is distinctive from that of most other organs in several ways;

Answer 1

• physical dimensions
• organization into bundles or sheets
• response to different types of stimuli
• characteristics of innervation
• function

Question 2

Smooth muscle can generally be divided into two major types

Answer 2

• multi-unit smooth muscle
• unitary (or single-unit) smooth muscle

Question 3

this type of smooth muscle is composed of discrete, separate smooth muscle fibers

Answer 3

Multi-unit Smooth Muscle

Question 4

Covered by a thin layer of basement membrane-like substance, a mixture of fine collagen and glycoprotein that helps insulate the separate fibers from one another

Answer 4

Multi-unit Smooth muscle

Question 5

the most important characteristic of multi-unit smooth muscle fibers

Answer 5

• each fiber can contract independently of the others and their control is exerted mainly by nerve signals

Question 6

a major share of control of unitary smooth muscle is exerted by?

Answer 6

non-nervous stimuli

Question 7

Example of multi-unit smooth muscles

Answer 7

• ciliary muscle of the eye
• iris muscle of the eye
• piloerector muscle that cause erection of the hairs when stimulated by the sympathetic nervous system

Question 8

unitary smooth muscle also called?

Answer 8

syncytial smooth muscle or visceral smooth muscle

Question 9

unitary smooth muscle also called visceral smooth muscle because it is found in the walls of most viscera of the body, including?

Answer 9

gastrointestinal tract, bile ducts, ureters, uterus, and many blood vessels