- Acid Reflux.

Acid Reflux

Def:- Acid Reflux is a common irritation of the walls of the esophagus after eating.

Commonly called "Heart Burn" as it give epigastric burning sensation.

causes:-
- Incompetent Lower espohageal sphincter ( LES)which fail to close during digestion.
a properly functioning sphincter, holds food and acid away from the esophagus during the digestion process.

-For acid reflux to occur, the LES relaxes, thereby allowing the food and acid to seep into the esophagus. The acid seepage in turn causes irritation or burning. Secondary peristalsis, or the movement of the esophagus caused by swallowing pushes about 90% of the food and acid back into the stomach. The LES closes again for normal digestion. The remaining 10% of food and acid left in the esophagus is neutralized by saliva.
-While many people experiences with acid reflux is asymptomatic, acid reflux can be part of a larger problem. Acid reflux is lumped into a much larger category called Gastroesophageal Reflux Disease or GERD. According to GERD.com, this is "Any symptomatic clinical condition or change in tissue structure that results from the reflux of stomach or duodenal contents into the esophagus."

GERD is said to be caused by many different factors:-
- transient LES relaxation,
- decreased LES resting tone,
- impaired esophageal clearance,
- delayed gastric emptying,
- decreased salivation,
- impaired tissue resistance.

An individual's lifestyle can also be a factor in causing this condition:-
-Smoking,
- large meals,
- fatty foods,
- caffeine,
- pregnancy,
- obesity,
- body position,
- drugs,
- hormones may all exacerbate GERD.
- hiatal hernia frequently accompanies severe GERD.
- wearing tight clothing
- lying down after a meal
- bending over can help trigger acid reflux.

With my best wishes
Dr-hema

- Lactose Intolerance.

Lactose Intolerance

Def:- lactose intolerance is the inability to digest dairy products containing lactose, most notably milk.

Lactose is a sugar that is broken down in the body by an enzyme called lactase.

Lactase is normally secreted by cells lining the small intestine, and breaks down lactose into glucose& galactose.

Cause of Lactose Intolerance:-

When lactase is deficient, undigested lactose begins to ferment in the lower intestines.

symptoms of Lactose Intolerance:-

This can cause physical discomfort :-
- bloating(إنتفاخ).
- nausea.
- gas.
- cramps.
- diarrhea.

The severity of the physical discomforts will depend on how much lactase a person produces in relation to how much lactose is consumed. For example, one glass of milk may not cause a person any problems, while two glasses could.


N.B:-

While it is rare for children to be born without the ability to produce lactase, after about 2 years of age the body's production of this enzyme diminishes. It's not unusual then that so many adults are affected by lactose intolerance to varying degrees.

Diagnosis:-
1- - A lactose-rich liquid is consumed after a short fast.
- The doctor might then draw several blood samples over a 2-hour period to see how the body is digesting the lactose.
- If digested properly, it should be converted to glucose that will be found the blood.
- Or, if you opt for the hydrogen breath test, your breath will be tested for the presence of hydrogen. Hydrogen is normally not present in the breath except in very small quantities, but fermenting lactose will produce greater amounts of hydrogen that will be detected and measured.

2- - If a very young child or an infant needs to be tested for lactose intolerance, an alternate test is available that checks for acidity in the stool.
- Undigested lactose creates lactic acid and other fatty acids that will be found in the stool sample.

Traetment:-
- Lactose intolerance is controlled through diet. Often a small amount of lactose is fine and it is simply a matter of finding your level of tolerance and limiting foods with lactose content.
- Lactase enzymes are also available over the counter. Taken with lactose food, the enzymes break down the lactose for your body.
- Lactose-reduced dairy products are also an option.

- Lactose intolerant people may be concerned about calcium intake. Many non-dairy foods are high in calcium, such as green vegetables like broccoli and kale. Some types of fish are also high in calcium.


Lactose intolerance can be annoying but it is not a serious concern, nor is it a food allergy. If you do have an allergy to dairy products this can produce more severe effects.

With my best wishes
Dr-hema

- Histology of the cornea.

Histological structure :- is Composed of 5 Layers:-

1- Epithelium:-

• Active mitosis → regeneration within 6- 24 hrs.
• Continue with conjunctiva.

2-Bowman's membrane:-

• Acellular Clear membrane lie under the epithelium.
• Ends abruptly at the limbus. (i.e. end in folded manner)
• Is considered as modified lamella of stroma.
• If destroyed cannot regenerate.

3-Stroma:-

• Represent 90% of corneal thickness .
• Formed of collagen fibrils (Type 1) which has special arrangement which run parallel to each other and parallel to the surface of the cornea making the cornea transparent, unlike sclera in which arrangement is not done in specific way so appear opaque.
• Collagen fibrils lie in mucoid matrix Scattered keratocytes lie between lamellae and are stellate in shape.

4-Descemet's membrane:-

• An elastic membrane which lie ( ) Endothelium and stroma.
• It is resistant to pathology and regenerate easily. 
• This layer is continuous with material of the pectinate ligament or trabecular meshwork of the iris.

5-Endothelium:-
Single layer of flat hexagonal cells with No mitosis.

- Pumps water out → prevent corneal edema → prevent corneal opacification.

(By light microscope)

So Cornea formed of :-

• Epithelium resting on B.M
• Endothelium resting on D.M
• stroma in between

- The Meninges of the Brain.

The Meninges of the Brain

1-The Dura mater.

2-The Arachnoid mater .

3The Pia mater.

1-The Dura mater:


-The dura mater is as two layers:

the endosteal layer and the meningeal layer.

These are closely united except along certain lines,

where they separate to form venous sinuses & folds

which act as septae forming cranial cavity compartments.

- Dural folds :

• Falx cerebri
• Tentorium cerebelli
• Falx cerebelli
  

2-The Arachnoid mater :

-The arachnoid mater is a delicate, impermeable membrane

covering the brain and lying between the pia mater

internally and the dura mater externally.

- It is separated from the dura by a potential space, the subdural space,

- It is separated from the pia by the subarachnoid space,

which is filled with cerebrospinal fluid.


2-The pia mater :

-The pia mater is a vascular membrane that

closely invests the brain,covering the gyri and

descending into the deepest sulci.

See you,

Dr Ibrahim

- The Cranial cavity in brief .

The Cranial cavity in brief

- The cranial cavity, or intracranial space,

is the space formed inside the skull

- The skull or cranium is a bony structure

serves as the general framework for the head....

- Brain : occupies the cranial cavity,

which is lined by the meninges


The meninges are the system of membranes that

envelop the central nervous system and which

contains fluid to cushion blows.

- Cranial cavity is composed by the frontal,

parietal, sphenoid, temporal and occipital bones,

and in part the ethmoid, all covered by

endosteal layer of dura mater.


- The cranial cavity is divided into

three cranial fossae :

1-Anterior cranial fossa which accommodates

the anterior lobe of brain.

2- Middle cranial fossa, much wider than the

anterior cranial fossa contain the 2 temporal lobes of brain.

3- Posterior cranial fossa is much shallower and

wider than the middle cranial fossa and it

accommodates the occipital lobes of the brain.

see you,

Dr Ibrahim