Question

AC (NT) fruments d A deponen te de vista AChcete reco mma Som de intercom Pom diffuses Charge differencec end plate potential Ach is a derby acetylcholine 18 Describe the cross bridge cycle and its com Why is calcium important b. What is the function of ATP on the myosin had! 19. Define a motor unit 20. Define muscle tone, Isotonic, isometric, concentric and eccentric 21. Describe the characteristics of slow and fast twitch muscle fibers CHAPTER 11: 1. List the 4 patterns of fascicles. Provide an example for each NOI Most of this chapters you will have to identify them and know their origin, insertion and actions for lab 2. What is the most common type of lover" in the body, provide an example, 3. Describe the relationship between an agonist and an antagonist muscle. 4. How many skeletal muscles do most people have?

Answer 1

QUESTION :1

Ans :The 4 patterns of fascicles are as follows:

1)Circular- fascicles are arranged in concentric rings .

eg: Orbicularis muscles surround the mouth and eyes.

2)Convergent- has a broad origin and its fascicles converge towards a single tendon of insertion ,they appear as triangular or fan shaped.

eg ;Pectoralis major muscle of anterior thorax.

3)Parallel : The length of the fascicles runs parallel to the long axis of the muscles,such muscles can be either strap shaped or spindle shaped.

eg : Sartorius muscle of the thigh (strap shaped) , biceps brachii muscle of the arm(spindle shaped)

4)Pennate - fascicles are short and they attach obliquely to a central tendon that runs the length of the muscle.

There are 3 forms of Pennate muscles

a)Unipennate ; in which the fascicles insert into only one side of the tendon,as in the extensor digitorum longus muscle of the leg.

b)Bipennate;in which the fascicles insert into the tendon from opposite sides so the muscle grain resembles a feather ,eg:the rectus femoris of the thigh is bipennate.

c)Multipennate ,which looks like many feathers side by side ,with all their quills inserted into one large tendon.The deltoid muscle ,which forms the roundness of the shoulder is multipennate.

QUESTION 2:

Ans : The most common type of the lever is the third class lever.

In the third class lever,the force is applied between Resistance (weight)and Axis (fulcrum)

Examples:a)while lifting a dumbbell,the elbow joint acts as an axis with force applied on our hands by the weight we are lifting.

b) using a shovel to pick an object

c)in paddling a canoe

QUESTION 3

Ans :Relationship between agonist and antagonist muscles:

Antagonist and Agonist muscles often occur in pairs called Antagonistic pairs.

Agonist is a muscle that contracts to cause the movement,the Antagonist is an opposing muscle that relaxes relatively to stretch .

These two roles ,agonist and antagonist can be exchanged back and forth depending on the type of muscular movement,For example;while bending the elbow, the biceps act as an agonist(because it does that movement)and triceps act as an antagonist (because it does the opposite ),whereas while straightening the elbow the triceps act as an agonist and biceps act as an antagonist.

QUESTION 4:

Ans : Most of the people have about 650 skeletal muscles in their body,but the estimations can range from 639 to 850,since some of the muscles consist of multiple parts and these can be divided further,we cannot say the exact number of muscles present in the human body because there is always some variability in muscular structure between the individuals .