Decompression sickness - Caisson's disease

 

Caisson's disease.. key-suh n.. :D

Occurs when you return to normal pressure from area of high pressure. 

Do you know that even at about 10 m below the surface the water exerts twice the pressure?
So when you go underwater, the pressure increases.. That's how your lungs end up taking more nitrogen than usual! :O

How?
Water pressure increases.
Pressure of nitrogen increases in compressed air.
Gas density increases.
So you are taking more nitrogen than you'd take on sea level. 
Get it?

You know O2 and CO2 are metabolized... so they get their way out! ;)

BUT instead of being exhaled, however, the extra nitrogen safely dissolves into the tissues, where it remains until the diver begins his or her return to the surface!

On the way up, decompression occurs (in other words, the water pressure drops)
and with the change in pressure, the extra nitrogen gradually diffuses out of the tissues and is delivered by the bloodstream to the lungs, which expel it from the body.

If the diver surfaces too quickly, however, potentially dangerous nitrogen bubbles can form in the tissues. 
The precise reasons for bubble formation remain unclear.

These bubbles can compress nerves, obstruct arteries, veins, and lymphatic vessels, and trigger harmful chemical reactions in the blood.

Treatment: Decompress again and recompress slowly in a recompression chamber.
Also give hyperbarric oxygen therapy.

So next time you go underwater, beware! :P
Come up slowly.

That's all! :)

Thank you so much for reading ^_^

-IkaN 

Ondine's curse

̉Do you know that the voluntary and automatic control of respiration is seprate?

Sometimes the automatic control of respiration is disrupted without loss of voluntary control :O
And this clinical condition is know as Ondine's curse!

Lemme tell you a German legend.. Once upon a time, a water nymph, Ondine, fell in love with a human being (aww!)

Nymphs are immortal and they never age, unless they have a child with a mortal. Ondine gave up her immortality for this guy (Lawrence, his name.)

She starts to age and loses her beauty. Lawrence is no longer in love with her.
Ondine finds out Lawrence cheated on her! She sees him in the arms of another woman! :O (That bastard, I know!)

Just like the women of twenty first century.. Ondine was a vindictive one!

She curses Lawrence saying "You swore faithfulness to me with every waking breath, and I accepted your oath. So be it. As long as you are awake, you shall have your breath, but should you ever fall asleep, then that breath will be taken from you and you will die!"

To make it simple for all my medico friends.. It translates to the curse took away all his automatic functions and in this state, he could stay alive only by staying awake and remembering how to breathe.

To all those who are still wondering how this sad love story ends.. He eventually fell asleep from sheer exhaustion, and his respiration stopped.

Patients with this intriguing condition generally has bulbar poliomyelitis or disease processes that compress the medulla. Or it may be genetic.

Remember: The pathways for voluntary control pass from the neocortex to the motor neurons innervating the respiratory muscles, bypassing the medullary neurons!

That's all about Ondine's curse ^_^
Thank you so much for reading :)

-IkaN 

Supination and Pronation of Forearm

Hello lovely folks!

Lets learn something from superior extremity.. supination and pronation!
They occur at the superior and inferior radioulnar joints
They are pivot type of synovial joints
It is the rotatory movement of forearm around a vertical axis
The axis passes from the head of the radius above to the ulnar attachment of articular disc below
The axis is not stationary because the lower end of ulna moves backwards and laterally during pronation & forwards and medially during supination

Let's consider pronation
In the movement of pronation, the head of the radius rotates within the annular ligament
Whereas the distal end of the radius with the hand moves bodily forward [pronate your hand and see]
The ulnar notch of the radius moves around the circumference of the head of ulna
In addition, the distal end of ulna moves laterally
If it didn't your hand wouldn't stay in line with the upper limb and would probably displace medially [You dont want that, trust me! :P]
Supination is the reversal of this process

We have two pronators and two supinators
Pronator teres and pronator quadratus, as the name suggests, for pronation
Supinator and Biceps Brachi for supination
[People usually forget to mention biceps brachi, which is really lame, its an important and awesome muscle!]

That's all for today
Thank you so much for reading! :)


-IkaN

Peritoneal ligaments of liver

Hey guys.. Wanna learn about the peritoneal ligaments of liver?

Alrighty!

They support our liver.. Along with the hepatic veins draining into the Inferior Vena Cava and tone of the abdominal muscles.

My handwriting is really sucky.. So lemme just help you read =D

 

The falciform ligament ascends from the umbilicus to the liver.

It has a free margin that contains ligamentum teres.

It passes to the anterior and superior surface

and splits into anterior coronary ligament and left triangular ligament.

The right extremity of the coronary ligament is known as the right triangular ligament.

The pertioneal layers of the coronary ligament are widely separated and leaves an area devoid of peritoneum - bare area of the liver.

The lesser omentum arises from the edges of porta hepatis and fissure for ligamentum venosum

and passes into the lesser curvature of the stomach.

These are from my notes.. They are really bad.. *embarrassed*
I uploaded them anyway..

Thank you so much for reading =]

-IkaN

Lymphatic drainage of the tongue

Remember:
The anterior part of the tongue tends to drain into the nodes farthest down the deep cervical chain (See diagram) ^_^
Anterior two thirds drain unilaterally
Posterior one third bilaterally
That's all you need to know! :)

-ikaN

Extrinsic muscles of the tongue

Extrinsic muscles of the tongue

This is a really cool diagram to explain the tongue..
You can see three out of the four extrinsic muscles here..
Lemme tell you about them! ^_^

Styloglossus
Origin: From tip and anterior surface of the styloid process
Insertion: Into the side of the tongue
Action: So what'll be its action? Its pulling the tongue to its origin.. ie behind
Hence action will be retraction of tongue

Hyoglossus
Origin: Greater cornua and lateral part of hyoid bone
Insertion: Side of the tongue
Action: Think.. Pulling the tongue downward, towards the origin.. Hence, depression of tongue

Genioglossus
Origin: Upper genial tubercle of the mandible
Insertion: Forms bulk of the tongue
Action: Protrudes the tongue.. [Pulling towards origin, remember?]

Palatoglossus
Sorry guys.. I don't have a diagram for this muscle.. Will upload soon!
Origin: Oral surface of palatine aponeurosis
Insertion: Descends into the palatoglossal arch to side of tongue at junction between oral and pharyngeal parts
Action: Elevation of tongue

Nerve supply
I have shown the nerve supply.. Its hyoglossal nerve.
Except for palatoglossus.. which is supplied by the vagus and cranial part of the accessory nerve (CN XI) that travel via the pharyngeal plexus

I just love this diagram.. Shows the muscles properly with the nerve supply.. and it's really cute.. So do make the diagram in your exam, it's really easy! :)
So basically you can remember the origin and insertion through the diagram.. I'll elaborate on palatoglossus with the muscles of the palate.. That's all for the extrinsic muscles!
Thank you so much for reading!

Pray that I do well in my exams =)

-IkaN

Related topic: Innervation of the tongue, palate, pharynx & larynx with mnemonic