17 - diploic veins and diploic bones

Recently a question was asked in the DNB june 2008 exam about the diploic bones , which was like this :

q. which of the following is a diploic bone ?

a.zygomatic

b.ethmoid

c. maxilla

d. frontal

answer : d . frontal bone.

The diploic veins are found in the skull, and drain the diploic space. This is found in the bones of the vault of the skull, and is the marrow-containing area of cancellous bone between the inner and outer layers of compact bone.

The diploic veins drain this area to the outside of the skull.

Specific diploic veins

They are usually four in number: one frontal, two parietal, and one occipital. These bones are also called the diploic bones.

• (1) the frontal, which opens into the supraorbital vein and the superior sagittal sinus.

• (2) the anterior temporal, which is confined chiefly to the frontal bone, and opens into the sphenoparietal sinus and into one of the deep temporal veins, through an aperture in the great wing of the sphenoid.

• (3) the posterior temporal, which is situated in the parietal bone, and ends in the transverse sinus, through an aperture at the mastoid angle of the parietal bone or through the mastoid foramen.

• (4) the occipital, the largest of the four, which is confined to the occipital bone, and opens either externally into the occipital vein, or internally into the transverse sinus or into the confluence of the sinuses (torcular Herophili).

16 - Intrinsic Muscles of Larynx

1q : What are the abductors of the vocal cords ?

answer : posterior cricoarytenoids.

2q: What are the adductors of the vocal cords ?

answer : Lateral cricoarytenoids,transverse arytenoid(Inter-arytenoid),cricothyroids,thyroarytenoids (external part)

3q: What are the tensors of the vocal cords ?

answer : cricothyroids and Vocalis (Thyro-arytenoid's internal part).

4q: what are the relaxers of the vocal cords ?

answer : ??????

5q: what are the muscles of the larynx that close the laryngeal inlet ?

answer : oblique arytenoids and aryepiglotticus.

6q: what are the muscles of the larynx that open the laryngeal inlet ?

answer : thyroepiglotticus.

7q: which is the laryngeal muscle that helps in adduction of the vocal cords and tensors of the vocal cords ?

answer : cricothyroid .

8q: what is the laryngeal muscle that helps in the adduction of the vocal cords and relaxes them as well ?

answer : thyroarytenoids .

9q: what is the only unpaired laryngeal muscle ?

answer: transverse arytenoid .

10q: what is the nerve supply of cricothyroid ?

answer : external laryngeal nerve.

11q: what is the nerve supply of all the intrinsic muscles of the larynx except cricothyroid ?

answer : recurrent laryngeal nerve .

15 - plantar flexion and dorsiflexion - muscles

you ought to have an idea about the principal and accesory muscles which cause plantar flexion and dorsiflexion , both for the sake of knowledge and post graduation entrance purposes . lets go into it.

The principal or main muscles which are responsible for plantar flexion are :

1. gastrocnemius
2. soleus

The prinicipal or main muscles which are responsible for dorsiflexion are :

1. tibialis anterior

( now lets look into the accesory muscles of plantar flexion and dorsiflexion )

The accesory muscles of plantar flexion are :

a. flexor hallucis longus
b. flexor digitorum longus
c. tibialis posterior and
d. plantaris

The accesory muscles of dorsiflexion are :

a. extensor hallucis longus
b. extensor digitorum longus
c. peroneus tertius

14 - superficial and deep perineal muscles

several questions are asked in this topic, so u gotta be thorough with them. recently a question was asked in the DNB CET june 2008 related to this topic and the question was as follows ;

question : which of the following is not a superficial perineal muscle ?

a. superficial transverse perinei
b. ischiocavernous
c. bulbospongiosus
d. sphincter urethrae

answer : d . sphincter urethrae .

so lets study the perineal muscles .

The superficial perineal muscles are three in number , they are :

1. superficial transverse perinei
2. bulbospongiosus
3. ischiocavernosus

The deep perineal muscles are two in number , they are ;

1. deep transverse perinei
2. sphincter urethrae

( there is an important point which u have to remember when u are answering questions related to this particular topic. most of these questions have ILIOCOCCYGEUS and PUBOCOCCYGEUS in them, these two are together called the LEVATOR ANI , which is a pelvic muscle and not a perineal muslce. it constitutes the pelvic diaphragm. so remember that iliococcygeus or pubococcygeus or levator ani , any of these are neither superficial nor deep perineal muscles ).

if u wanna have a look at the other anatomy mcqs asked in DNB june 2008 session. click here . the same site provides DNB JUNE 2008 session mcqs of other subjects too.