Fluid mosaic model
Proposed by “Singer & Nicolson” in 1972
→ Describes membrane as in “state of fluidity like a gel”.
→ Compared with “Icebergs” (Membrane proteins) floating in sea (phospholipid molecules).
Tag: AIIMS PG
Fluid compartment of CNS
Main fluid components – Cerebrospinal Fluid & Cerebral blood flow
Functionality:
• Lubrication by CSF
• Nutrition by cerebral blood flow
Cerebrospinal Fluid:
→ Normal Volume = 150 mL; Normal CSF pressure = 70 -180 mm H2O.
→ Rate of CSF production = 550 mL/day; Recycling rate = 3.7 times/day
→ Site of production = CHOROID PLEXUS; Absorption site = ARACHNOID VILLI
→ Regulation occurs at level of absorption.
Fetal surveillance
→ It should begin b/w 32-34 weeks in stable diabetes & @ 28 weeks for growth restricted fetuses.
→ Overt diabetics and GDM patients on insulin are admitted at 34 weeks and antepartum monitoring done.
→ USG for fetal growth – starts at 28 wk. and is done every 4 weekly.
→ Fetal surveillance methods are = kick count, weekly BPP and biweekly NST.
Extramniotic Ethacridine
Mechanism behind is as it separates the uterus from membranes, membranes will start producing progesterone which will bring about contractions of the uterus and ultimately expelling of the fetus or conception product.
The steps in the mechanism consists of:
- Foleys catheter
- Place between uterus & membranes
- Pass Ethacridine
- %, dose 10ml x weeks of gestation
→ Maximum -150ml, and Foleys is allowed to be there for 4-6 hours.
→ Abortion begins by 12-48hours.
Endocytosis-Types
Phagocytosis / CeIl Eating:
→ Endocytosis of solid particle (bacterium / dead cells)
→ Ex. As in WBCs & tissue macrophages.
Pinocytosis / Cell Drinking
→ Endocytosis of liquid.
→ Occurs in most of our body cells.
Endocytosis & Exocytosis
1. Endocytosis
Cell takes contents in (i.e.., from ECF to cytoplasm).
Steps:
On contact with large molecule, cell membrane invaginates forming vesicle, including macromolecule.
Vesicle is pinched within cell & restoring cell membrane.
Requires energy, Ca++ & contractile elements in cell.
2. Exocytosis/endocytosis/reverse pinocytosis:
Reverse of endocytosis.
Process of extrusion of secretory granules from cell.
On contact of secretory vesicle with cell membrane, vesicular fusing & subsequent vesicular content extrusion takes place à Extruded as secretory granules.
Requires energy, Ca+.
Ear-Functions
The functions of ear are:
1.Hearing-Controlled by cochlea
2.Balance-Controlled by vestibular apparatus
Both the functions are taken care by Cranial nerve 8-Vestibulocochlear nerve
Drugs to prevent Pregnancy Induced hypertension
- Best- Aspirin (↓ Thromboxane A2)
-
Dose of Asprin-50-150 mg/day @ 12-28 weeks (if pt. develops PIH then continue throughout pregnancy
-
Heparin & Aspirin
-
Ca2+ supplementation if it is ↓
-
Regular exercise
→ Following has No role in preventing PIH: –
-
Bed Rest
-
Diet Salt restriction
-
Supplementation of Fish oil
-
Supplementation of antioxidants
-
Low dose Heparin alone
-
Supplementation of Vitamin C, D and E
Initial factors considered to diagnose intrauterine growth restriction
1. Identify mothers at risk: –
→ PIH
→ Chronic Renal Disease
→ BMI↓ & Less wt. gain
→ Infections
2. Sure about gestational age
Confirmed causes of recurrent abortion
• Recurrent abortion: RPL- (recurrent pregnancy loss): – It is defined as a sequence of three or more consecutive spontaneous abortions before 20 weeks. American society for reproductive medicine (2013) defines RPL as 2 or more failed pregnancies confirmed by USG or histologically.
• Uterine causes account for 10-50 %.
• M/c cause of RPL is cervical incompetence followed by uterine malformations.
• Uterine causes lead to 2nd trimester abortions/
• Most common uterine cause is cervical incompetence >uterine malformation.
1.Uterine causes:
Congenital causes-
o Uterine malformations
o Septate uterus
Acquired causes-
o Cervical incompetence
o Fibroid
o Endometrial polyp
2.Hypothyroidism
3.Chromosomal Abnormality-Balanced translocation
4. Antiphospholipid antibody syndrome-5-15%
