Human Anatomy Vol 1

THORAX

During 'pranayama', deep regulated and smooth

breathing occurs.

. \Alhich diameters increase during deep breathing?
Ans: The anteroposterior diameter increases by

The t sverse diameter increases by the "bucket

handie movement" of the 7-10 ribs

The vertical diameter increases by "piston

mov ent" of the thoracoabdominal diaphragm.

During inspiratiory the vertical diameter is increases

by 3-5 cm and during expiration, the vertical

dia ter decreases.

Principles of mooements

of ich lies just lateral to the tubercle. Because

of the disproportion in the length of the tw'o arms

of the l,ever, the slight movements at the vertebral

end of the rib are greatly magnified at the anterior

end (Fig. 13.28).

2 The anterior end of the rib is lower than the

posterior end. erefore, during elerration of the

occurs mostly in the vertebrosternal ribs.

In this way, the anteroposterior diameter

thorax is increased. Along with the up and

movements of the second to sixth ribs,

of the sternum also moves up and down

'pump-handle mov ents' (Fig. 1,3.29),

The middtre of the shaft of the rib lies at a lower

level tharr the plane passing through the twri e s.

Therefore, during elevation of the rib, shaft

also moves outr,vards. This causes increase in the

transverse diameter of the thorax.

Such movements occur in the vertebrochondral

ribs, and are called'bucket-handle movements'.

As a result each rib is longer than the next higher

rib. On elevation the larger lower rib c es to

occupy the position of the smaller upper rib. s

(Fig. 13.30).

Contraction of diaphragm with relaxation of

anterior abdominal wall muscles inereases the

vertical diameter. Up and down move nts as a

result of contraction and relaxation of thoraco-

abdominal diaphragm can alter the vertical

diameter of the thoracic cavity. is movement is

called "piston movement".

L.

MULTIPLE CHOICE

Transverse diameter of thoracic cage increases by:

a. Pump handle movements of ribs

b. Bucket handle movement of ribs

c. Caliper movement of ribs

d. Contraction of diaphragm

Anteroposterior diameter of thorax increases by:

a. Pump handle movement of ribs

b. Bucket handle movement of ribs

c. Contraction of diaphragm

d. Relaxation of diaphragm

Which one out of the following is a primary

cartilaginous joint?

a. Costovertebral b. Costotransverse 8.

c. First costochondral d. Manubriosternal

4. Which of the following ribs articulates with one
   vertebra only?
   a. First
   c. Third


5. The tubercle of a typical rib articulates with the facet
   on the transverse process of:

ANSWERS

AUESIIONS

a. Vertebra above b. Vertebra below

c. Its own vertebra d. All of the above

6. Which of the following ribs articulates with
   transverse process of a thoracic vertebra?
   a. Eleventh
   c. First

b. Twelfth

d. None of the above

b. Second

d. Fourth

7. The most characteristic feature of the thoracic
   vertebrae is:
   a. The body is heart shaped
   b. The spine is oblique
   c. The body has costal facets
   d. Vertebral foramen is small and circular
   The lower larger facet on the head of a typical rib
   articulates with the demifacet on:
   a. Inferior part of corresponding vertebrae
   b. Superior part of corresponding vertebrae
   c. Inferior part of vertebra above the corresponding
   vertebrae
   d. Superior part of vertebra below the corres-
   ponding vertebrae

1.b 2.a 3.c 4.a 5.c 6. c 7.c 8.b