Anatomy

Anosmia refers to total loss of sensation of smell, i.e. inability to recognize or detect any odor.

Oxytocin stimulates milk ejection by acting on mammary gland

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

[Ref. Junquira 15th, 62]

When the body is at rest, approximately 70% of the blood moves through the systemic circulation, about 18% through the pulmonary circulation, and 12% through the heart.

1. Euchromatin:
- It is a partially condensed and less coiled 
- It is more active and lightly stained
- It is expressed during interphase
- Prominent in metabolically active cells
 
2. Heterochromatin:
- It is a condensed and more coiled 
- It is inactive and darkly stained (intensely basophilic in light microscope)
- It does not express during interphase
- Example: Sex chromatin (Barr body), chromatin in circulating lymphocyte

The most abundant type of cortical neurons are the pyramidal cells. About two thirds of all cortical neurons are pyramidal. Their cell bodies are triangular, with the apex generally directed towards the surface of the cortex.

Central artery of the retina is a true end artery

Events of cell cycle:
1. Mitosis (M phase)
2. Interphase: The long period between two mitosis division (the G1, S, and G2 phases) is  called interphase.
• G1 phase (pre-synthetic phase)
• S phase
• G­­­2 phase (post-synthetic phase)

G1 Phase:
- The period between mitosis and the beginning of DNA replication.
- The G1 phase, usually the longest and most variable part of the cycle.
- It is a period of active RNA and protein synthesis (RNA & regulatory proteins essential for DNA replication)
- Also in G1, the cell volume, reduced by half during mitosis, returns to its previous size.

S Phase:
- The S phase is characterized by DNA replication, histone synthesis, and the beginning of centrosome duplication.
- The cell now contains twice the normal amount of its DNA, that is - the (2n) amount of DNA is doubled (4n) in preparation for cell division.

G2 Phase:
- In the relatively short G2 phase, RNA and proteins essential for cell division are synthesized.

Oesophagus & vagus nerves passes through oesophageal opening.

Other than intervertebral disc all are hyaline cartilage

Anus below the pectinate line develops from proctoderm

Reference: Junqueira’s Basic Histology; 14th Edition; Page-438

Lysosomal enzymes:
The most common lysosomal enzymes are acid hydrolases such as
 Proteases
 Nucleases
 Phosphatase
 Lipase
 Phospholipases
 Sulfatases
 ß-glucuronidase

Enzymes of peroxisomes: Catalase, D-and L-amino oxidases, urate oxidase, hydroxyacid oxidase

Molecular layer (plexiform layer). This is the most superficial layer; It consists mainly of a dense network of tangentially oriented nerve fibres. These fibres are derived from the apical dendrites of the pyramidal cells and fusiform cells, the axons of the stellate cells, and the cells of Martinelli.

Inlet of inguinal canal is an oval gap in fascia transversalis.

Gametes are derived from Primordial germ cells

Valvulae conniventes is present in small intestine

Ref: BD/7th/vol-2/ page 335

Most tissues undergo cell turnover with slow cell division and cell death. Nerve tissue and cardiac muscle are exceptions because their differentiated cells cannot undergo mitosis.

Urethra lies in deep perineal pouch.

Pons, Cerebellum, Medulla oblongata-parts of hind brain.

Reference-BD Chaurasia’s/7th/vol-4/p-139

[Ref. Junquira}

-Nucleus is situated at the periphery in case of yellow fat.
-Yellow fat is unilocular. Brown fat is multilocular.

Sigmoid colon is commonly affected by Hirschsprung disease

Prostatic utricle & appendix of testes are fates of Mullerian duct in male

-Follicular cells are columnar when stimulated
-Parafollicular cells are larger than follicular cells
-Parafollicular cells produce calcitonin, follicular cells produce T3,T4.

***Microvilli has core of microfilaments.

Microtubules:
Microtubules are non-branching hollow tubules made up of tubulin proteins (∝ and ß tubulin) with a diameter of 25 nm.

Locations:
· Cilia
· Flagella
· Centrioles
. Mitotic spindle
· Elongating cell processes and
· Growing axons

Functions:
1. Movement of cilia, flagella (tail of sperm)
2. Intracellular transport of vesicles
3. In cell division, formation of mitotic spindle
4. Maintenance of cell shape

The arterial supply of the uterus is from the uterine arteries, which arise from the internal iliac artery. There is a potential collateral supply from the ovarian arteries.

Reference: Langman’s 13th; P-42

After formation, the spermatozoa are stored within the head of the epididymis. 

Spermatogenesis: The process of maturation of primordial male germ cell to mature sperm.
Onset: At puberty and continues up to old age.
Site: The wall of the convoluted seminiferous tubule 
Temperature required: 32 C.
Storage site: Head of epididymis.
Duration:
In man, the process of spermatogenesis requires 74 days, and passage through the epididymis approximately another 12 days. Therefore, it takes (74 days + 12 days) for a sperm for complete maturation and to be available for ejaculation.

Fibroblasts are the most common cells in connective tissue proper, produce and maintain most of the tissue’s extracellular components. Fibroblasts synthesize and secrete collagen (the most abundant protein of the body) and elastin, which both form large fibers, as well as the GAGs, proteoglycans, and multiadhesive glycoproteins that comprise the ground substance.