Anatomy

Except rich blood supply all are the criteria of white fibers

(Ref: medical examination review anatomy P:42)

[Ref. Snell's Cilinical Neuroanatomy] 

Function:
 Sensory relay station
A vast amount of sensory information of all types (except smell) converges on the thalamus and presumably is integrated through the interconnections between the nuclei. The resulting information pattern is distributed to other parts of the central nervous system.

Foramen of Monro connects Lateral ventricle to third ventricle

The blood supply to the brain has continuous capillaries (in the blood-brain barrier), the SI has fenestrated capillaries (to facilitate absorption of digestion products), the liver has sinusoids.

Smooth ER is the site of Lipid synthesis

Refractive Media of the Eye:
From before backwards, these are
1. Cornea
2. Aqueous humour
3. Lens
4. Vitreous body

Myofibrils are the structural and functional subunits of muscle fiber. Myofibrils are arranged longitudinally in the muscle fiber and runs in the entire length of muscle fiber.

Sarcomere is the structural & functional unit of myofibrils. 

Primary oocyte is produced during prenatal period.

Explanation-
Lesser omentum, Falciform ligament, Coronary ligament from ventral mesogastrium.

Reference: Langman’s 13th; P-47

Septum transversum gives rise to central tendon of the diaphragm & fibrous pericardium.

Transitional epithelium prevents urine from leaking of the bladder due to Tight junction

Thyroxine is not teratogenic. Thyroxine replacement is given during pregnancy if there is hypothyroidism.

Nestin is found in some stem and embryonic cells. Rests of them are true.

*** The corpus callosum is the largest commissure of the brain. It connects the two cerebral hemispheres. It is 10 cm in length in man.

45XO- Turner's syndrome
47 XXY- Klinefelter's syndrome
47 XX/XY+18- Edward's syndrome (Trisomy 18)
47 XX/XY+13- Patau's syndrome (Trisomy 13)

Down's syndrome:
Also known as Trisomy 21 is the most common numerical chromosomal abnormality.

Cause :
- Non disjunction (94%)- 47 XX/XY+21 (Trisomy 21)
- Mosaicism (2%)
- Transloation (4%)

Microtubule, microfilament & intermediate tubule are cytoskeleton of cell

The centromeres also move away from the centre, pulling along the remainder of the chromosome during Anaphase.

* The basic structural unit of chromatin is the nucleosome.
Nucleosomes are composed of  DNA wrapped around a set of eight histone proteins. 

* Gene, the functional unit of DNA, is the unit of inheritance.

* The nucleotides are the basic structural units of the DNA.
• Nitrogen base + sugar = Nucleoside
• Nucleoside + phosphate group = Nucleotide
• Nucleotide polymer = Nucleic acid (DNA/RNA)

The fibrous skeleton is a dense framework of collagen within the heart that keeps the orifices of the atrioventricular (AV) valves and semilunar valve patent, provides an attachment site of the valve leaflets and cusps, serves as the origin and insertion sites of cardiac myocytes, and forms an electrical “barrier” between the atria and ventricles so that they contract independently.

Criteria of ovum at the time of ovulation:
• Ovum at the stage of secondary oocyte arrested at Metaphase of Meiosis-II 
• 120-150um in diameter
• Surrounded by cumulous oophorus/granulosa cell
• Completes 1st meiotic division 3 hours before ovulation
• Expulsion of 1st polar body just occurred
• Completes 2nd meiotic division after fertilization
• Ovulation process may last 12-48 hours
• Ovulation occurs after 36 hours of LH peak
• Inj. HCG causes ovulation after 38-40 hours

Abnormal sites of implantation:
1. Ampullary region of the tube (80%, most common site of ectopic pregnancy)
2. Tubal implantation (12%)
3. Abdominal cavity (commonly in pouch of Douglas)
4. Internal os of uterus
5. Ovary
6. Mesentary

Explanation-
Spleen - intraperitoneal

Ovarian cortex is covered by the germinal epithelium which is made up of a single layer of cuboidal cells in younger age. 

Renal angle is Angle between 12th rib and edge of erector spinae muscle

Reference: Junqueira’s Basic Histology; 14th Edition; Page-236

Normal site of Implantation- Anterior or posterior wall of body of uterus

Chromatid is formed during Prophase

Valves prevent blood in veins from flowing away from the heart, while contracting skeletal muscle compresses the veins and this pushes blood through them towards the heart (as the valves prevent blood from being pushed in the other direction.

Cytoplasmic organelles Involved in Protein Synthesis (Translation):
1. Ribosome
2. RER
3. Mitochondria

Post-translational Modification of Protein Occurs in:
1. Golgi apparatus
2. Ribosome
3. RER

Filum terminale is a thin fibrous cord form by pia mater

Osteoclast helps in bone remodelling by bone resorption activity.

It drains all the body except right upper limb and right half of the body above the diaphragm which is drained by right lymphatic duct.

Ito cell present in Space of Disse

Reference: Langman’s 13th; P-39

The cribriform plate of the ethmoid bone has many foramina through which pass olfactory nerves that transmit sensory information from inhaled air to the olfactory bulbs.