2ND YR HISTO QUICK RECAP.pdf

AIMC ACADEMIA 2020
Allama Iqbal Medical College Lahore
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SECOND YEAR HISTOLOGY QUICK RECAP
You need to do all the Histology past-paper questions and these points only along with the diagrams
from your practical copy and you are done. These points are extremely important to cover the 6-7 MCQs
from the histology portion that you normally skip.
Laiq Hussain Histology:
Chapters included in syllabus: 12,16,18,19,20,21,22,23. (Most Important: 18,19,20,21).
Do read or memorize these important points assembled, chapter wise.
CHAPTER12:
Old type of cortex is known as ‘’allocortex’’
New cortex is called ‘’neocortex’’
In the internal pyramidal layer of primary motor area giant pyramidal cells, called Betz cells are found.
There are six layers of cerebral cortex:
1. Molecular layer
2. External Granular layer
3. External pyramidal layer
4. Internal Granular area
5. Internal Pyramidal layer
6. Multiform layer
The cerebellum consists of two hemispheres and a central vermis.
Cerebellar cortex has three layers:
1. Molecular layer: Basket & stellate cells.
2. Purkinje cell layer: Purkinje cells
3. Granular layer: Granule cells.
Afferent fibers of cerebellum include:
1. climbing fibers that originate from inferior olivary nucleus.
2. Mossy fibers that originate in spinal cord or brain stem.
Spinal cord has a ‘H-shaped’ appearance of the grey matter with anterior, posterior & lateral horns.
Outer to the grey matter there is white matter of the spinal cord divided into dorsal & ventrolateral white
columns.
CHAPTER16: ENDOCRINE SYSTEM
The hypophysis or the pituitary gland is the master endocrine gland producing several hormones.
Hypophysis divided into
(i) adenohypophysis
(ii) neurohypophysis.
Neurohypophysis derived from the neuroectoderm (diencephalon) forms posterior pituitary.
Adenohypophysis derived from the Rathke’s pouch (oral ectoderm) forms anterior pituitary.
The adenohypophysis divided into: pars distalis & pars intermedia.
An extension of pars distalis is known as pars tuberalis.
The neurohypophysis is divided into two parts: pars nervosa and infundibulum.
Chromophobes and chromophils are the cells of pars distalis based upon the old classification.
On basis of their hormonal secretory activity there are five cell types:
1) Somatotropes (acidophilic)
2) Mammotropes (acidophilic)
3) Corticotropes (basophilic)
4) Gonadotropes (basophilic)

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5) Thryotropes (basophilic)
The adrenal gland is divided into outer cortex and inner medulla. The cortex further divided into three
zones:
1) zona glomerulosa
2) zona fasciculata consists of cells known as spongiocytes.
3) zona reticularis
The adrenal medulla consists of mainly chromaffin cells on their strong ability to chromium salts.
The medullary cells contain a variety of soluble proteins called chromogranin.
The parenchyma of thyroid gland consists of thyroid follicles surrounding a colloid.
There are two types of cells in thyroid gland called:
(1) follicular cells
(2) parafollicular cells.
The follicular cells in inactive state are low cuboidal but in hyperactive state assume columnar shape.
Parafollicular cells also called ‘’C-cells’’ secrete hormone calcitonin which lowers the plasma calcium
level acting as an antagonist to Parathyroid hormone.
The parathyroid gland consists of
(1) chief cells
(2) oxyphill cells.
Pineal gland consists of
(1) pinealocytes
(2) interstitial cells.
Pinealocytes secrete melatonin.
Calcified concretions appear in pineal ECM, these mulberry shaped structures are titled as ‘’CORPORA
ARENACEA’’.
CHAPTER 18: DIGESTIVE SYSTEM
TONGUE:
The epithelium is of stratified squamous type, being non-keratinized on the ventral (lower surface) and
partially keratinized on the dorsal (upper) surface of the tongue.
The dorsal surface of tongue divided into anterior 2/3rd & posterior 1/3rd by a V-shaped sulcus
terminalis.
There are lingual papillae on the dorsal surface of tongue & of four types:
(a) Filiform
(b) Fungiform
(c) Circumvallate
(d) Foliate
Filiform papillae are the most numerous of lingual papillae.
Fungiform papillae are the most abundant at the tip of the tongue.
Numerous taste buds are present on circumvallate papillae.
There are Von Ebner’s glands, anterior lingual glands & mucous glands present in the tongue.
Foliate papillae are less in number and present on the sides of the tongue.
Tubular digestive tract wall has the following four concentric layers or coats:
(a) Mucosa
(b) Submucosa
(c) Muscularis externa
(d) Serosa
ESOPHAGUS:
Mucosa further divided into:
(1) Epithelium: Stratified squamous non-keratinized epithelium.

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(2) Lamina Propria: CT and lymphatic nodules.
(3) Muscularis mucosa: Smooth muscles running mainly in longitudinal direction.
(4) Submucosa: Has esophageal glands proper.
Muscularis externa: Esophagus consists of inner circular & outer longitudinal layers but differ in the
way that it has both skeletal and smooth muscles in following arrangement.
(1) UPPER 1/3RD: ONLY SKELETAL
(2) MIDDLE 1/3RD: MIXTURE OF SMOOTH & SKELETAL
(3) LOWER 1/3RD: ONLY SMOOTH.
Abdominal part of esophagus is serosa, whereas thoracic & cervical part is adventitia.
STOMACH:
Mucosa of empty stomach thrown into longitudinal folds called ‘rugae’
No glands present in the submucosa of the stomach.
Muscularis externa composed of three layers of smooth muscle:
(1) inner oblique
(2) middle circular (thickened at pylorus to form the pyloric sphincter)
(3) outer longitudinal.
Lamina propria consists of three types of glands:
(1) Fundic glands
(2) Cardiac glands
(3) Pyloric glands.
Cells of the fundic gland:
(1) Mucous neck cells
(2) Parietal cells (most imp)
(3) Chief cells a.k.a (zymogenic cells or peptic cells) secretes pepsinogen.
(4) Endocrine cells
(5) Stem cells.
Parietal cells:
Secrete HCL & intrinsic factor and are also called oxyntic cells.
Large round to pyramidal cells
Centrally located nucleus, large Golgi apparatus, eosinophilic stain.
EM study reveals presence of intracellular canaliculus.
There are microtubules and vesicles.
SMALL INTESTINE:
Several features that increase the surface area for absorption includes:
1) Plicae Circularis (a.k.a) Valves of Kerckering: Most pronounced in jejunum and absent in the
proximal part of duodenum and distal half of ileum.
2) Villi: Ten-fold increase in surface area. Difference in the shape of villi in different parts of
small intestine: mixture of leaf-shaped & finger like villi in duodenum. Ileum entirely has
finger shaped villi.
3) Microvilli: Enterocytes have microvilli on their apical surfaces. Increase surface area by a
factor of 20 (MOST).
4) Crypts of Lieberkühn
The mucosa of the small intestine is lined by simple columnar epithelium.
This epithelium consists of 5 types of cells:
1) Enterocytes
2) Goblet cells
3) Enteroendocrine cells

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4) Paneth cells
5) M cells.
FEATURES
ENTEROCYTES:
• Tall columnar cells, oval nucleus.
• apical surface has thousands of microvilli.
• Hence a striated brush border.
• EM reveals a glycocalyx coat on tip of microvilli.
• Bind to each other by junctional complexes.
GOBLET CELLS:
• Mucus secreting
• unicellular.
• few microvilli
ENTEROENDOCRINE CELLS: (remember just the name)
PANETH CELLS:
• exclusively in the bottom of crypts of Lieberkühn.
• Secretory product has the ability to kill certain bacteria and protozoa, hence regulate intestinal
flora.
M-cells:
• These are antigen-transporting cells.
• Play a very important role in the immunological surveillance of the intestinal luminal regions.
• The submucosa of the small intestine there are glands called Brunner’s gland of the duodenum
• The muscularis externa consists of inner circular & outer longitudinal layers of smooth muscles
in between which they consist of Myenteric plexus.
• Only the posterior surface of duodenum has adventitia, the rest of small intestine has serosa.
COLON:
• The muscularis externa of colon consists of inner circular & outer longitudinal layer of smooth
muscle.
• The outer longitudinal are gathered into three, flat bands called taeniae coli.
• The serosa of colon is characterized by presence of numerous small protuberances called
appendices epiploic composed of adipose tissue.
APPENDIX:
• The lamina propria of the appendix is heavily infiltrated with lymphocytes and contains
numerous lymphoid nodules
• Taeniae coli are absent
RECTUM & ANAL CANAL: (imp)
• Rectum is mostly like the colon.
• The anal canal mucosa shows a number of longitudinal folds called anal columns.
• The depressions between anal columns are called anal sinuses.
• The lower ends of the columns are joined to one another by mucosal folds known as anal valves
• Above the level of anal valves, mucosa is lined by simple columnar epithelium.
• Below the level of anal valves, mucosa is lined by stratified squamous non keratinized type.
• There are anal glands in the submucosa.
• The muscularis externa consists of inner circular & outer longitudinal layers of smooth muscle
• At level of anal columns, the inner circular layer becomes thickened to form the internal anal
sphincter.
• -The external anal sphincter consists of skeletal muscle belongs to pelvic floor musculature.

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SALIVARY GLANDS:
The salivary glands are compounds having a highly branched duct system.
Ducts classified into generally three types:
(i) intercalated
(ii) striated
(iii)excretory
• INTERCALATED DUCTS: SIMPLE CUBOID EPITHELIUM
• STRIATED DUCTS: LOW COLUMNAR EPITHELIUM
• INTRALOBULAR DUCTS = INTERCALATED + STRIATED DUCTS
• EXCRETORY DUCTS = INTERLOBULAR + INTRALOBULAR + MAIN DUCTS
The main duct is lined by stratified columnar epithelium that changes to stratified squamous non
keratinized near its opening to oral cavity
• PAROTID = SEROUS IN NATURE
• SUBMANDIBULAR = MIXED
• SUBLINGUAL = MUCOUS IN NATURE
PANCREAS:
Major part of the organ is made up of exocrine portion.
The endocrine consists of islets of Langerhans.
There are serious cells in the pancreatic acini, apical region contains acidophilic zymogen granules.
Some secretions of the pancreatic acini also exhibit low cuboidal epithelial cells known as ‘’Centro-
acinar cells’’
(i) Alpha cells secrete glucagon.
(ii) Beta cells secrete insulin.
(iii)Delta cells secrete somatostatin.
LIVER: (VERY IMPORTANT)
The liver is covered by a thin connective tissue capsule called ‘’Glisson’s capsule’’.
FIG 18-15 OF LAIQ HUSSAIN HISTOLOGY IS A MUST!!
The parenchyma consists of epithelial cells called hepatocytes arranged as anastomotic plates.
Between the plates are present blood sinusoids called hepatic sinusoids.
Three types of lobules in liver structure:
1) Classic Hepatic Lobule.
2) Portal Lobule.
3) Hepatic acinus.
There’s a relatively large venule called ‘central vein” in the classic lobule.
At the angles of the hexagonal hepatic lobules are present roughly triangle areas called portal areas.
Bile flows in narrow channels called Bile canaliculi.
Features of hepatocytes: (imp)
(1) polygonal cells with six or more surfaces.
(2) packed closely, arranged as anastomotic plates arranged radially around the central vein.
(3) most have single spherical nucleus.
(4) They have the usual cell organelles e.g., Golgi & mitochondria
(5) Presence of intracellular channels called bile canaliculi.
(6) The surface of the hepatocyte is separated from the wall of the sinusoid by a narrow space
that contains type III collaged called the ‘’perisinusoidal space’’ or space of DISSE.
The perisinusoidal space consists of star shaped cells called hepatic stellate cells (or Ito cells).
Hepatic sinusoids have two types of cells:
(1) ENDOTHELIAL CELLS

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(2) KUPFFER CELLS
CHAPTER 19: URINARY SYSTEM
The human kidney has two main regions called – ‘’medulla’’ & ‘’cortex.’’
The uriniferous tubule has two parts – ‘’a nephron’’ & ‘’a collecting tubule.’’
There are three types of nephrons:
1) ‘’superficial’’ cortical
2) Mid-cortical or intermediate cortical
3) juxtamedullary nephrons.
Differences among these three nephrons include:
• having their renal corpuscles in outer part of renal cortex & consist short loop of Henle.
• having their corpuscles in mid-region of cortex and loop of Henle of intermediate length.
• having their corpuscles in deepest part of cortex and long loop of Henle’s.
Renal corpuscle has a Bowman’s capsule & glomerulus.
The podocytes are large, irregularly star-shaped cells which share a common basal lamina with the
endothelial cells of the glomerular capillaries.
Numerous secondary processes, known as PEDICELS make direct contact with the capsular surface of
the common basal lamina.
The Foot processes (pedicels) of each podocyte interdigitate with those of the neighboring podocytes.
The elongated spaces between the interdigitating pedicels are called ‘’filtration slits.’’
The filtration barrier constituted by structures that intervene between the blood in the glomerular
capillaries & the filtrate in the capsular space.
Barrier consists of 3 components:
(1) The fenestrated capillary endothelium.
(2) The glomerular basement membrane.
(3) The filtration slits with slits diaphragms.
The PCT (proximal convoluted tubule) is the tortuous and the longest part of nephron.
Examination of a cross section of the proximal convoluted tubule under LM reveals that this part of the
nephron is lined by a simple cuboidal epithelium.
Each lining cell contains a centrally located spherical nucleus, luminal surface of cells shows a ‘’brush-
border.’’
The neighboring cells of PCT are bound to each other by junctional complexes consisting of tight
junctions & zonulae adherents.
Principal function of PCT is to actively absorb sodium from the glomerular filtrate & to pump it into
the intercellular space.
The Loop of Henle consists of four parts:
1. a thick descending segment
2. a thin descending segment
3. thin ascending segment
4. thick ascending segment
The distal tubule of the nephron comprises of two parts – pars recta (distal straight tubule) & pars
convulata (distal convoluted tubule).
Distal straight tubule lined by cuboidal cells.
Distal convoluted tubule has no brush border unlike PCT and have very small microvilli unlike PCT as
well.
In other differences from PCT, the Distal Convoluted tubule has is smaller in diameter & begins at the
vascular pole.
Principal function of DCT is the resorption of sodium from the glomerular filtrate.

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Collecting tubules & collecting ducts:
Collecting tubules have an average diameter of 40 micrometers and have simple cuboidal epithelium.
Collecting ducts are lined by simple columnar epithelium.
Collecting ducts contain two types of cells called the light cells & the dark cells.
The light cells are also called the principal cells pale staining, oval, centrally placed nuclei.
The dark cells are also called intercalated cells, are fewer and contain central round nuclei.
JG APPARATUS:
• comprises of three components (i) Macula Densa (ii) JG cells (iii) Extraglomerular mesangial
cells.
• Features of Macula Densa cells:
• Simple cuboidal epithelium.
• Cells are tall columnar in shape; Golgi apparatus is located in subnuclear position. Darker,
denser appearance.
• JG CELLS Features:
• Large size and their nuclei are spherical. Cytoplasm full of granules, which do not stain, secrete
rennin.
• Extraglomerular mesangial cells are also called lacis cells.
URETER:
• THREE COATS: (i) Mucosa (ii) Muscularis (iii) Adventitia.
• Mucosa: into folds, star shaped lumen. transitional epithelium with 3-5 cell layers. lamina
propria has CT.
• Muscularis: thick with two layers of smooth muscle not clearly demarcated. Inner longitudinal,
outer circular layer whereas a third layer of longitudinally running muscle fibers is added outer
to the circular layer.
• The adventitia outermost layer, with loose CT, blood vessels, lymphatics.
URINARY BLADDER:
• MUCOSA: numerous folds that disappear when bladder is distended with urine. Epithelium:
transitional epithelium, layers change with state of distention. In empty transitional epithelium
shows 6-8 layers whereas in distended it shows 2-3 layers.
• PLAQUES region is present on the epithelium of the urinary bladder.
• MUSCULARIS: Consists of interlacing bundles of smooth muscle fibers and distinction into
layers is not possible except in the neck region of the bladder.
• In this region, thin inner longitudinal, thick middle circular, thin outer longitudinal.
• Adventitia/Serosa Most covered by adventitia, superior surface covered by serosa.
URETHRA:
• FEMALE URETHRA: Initial part of urethra lined by transitional epithelium whereas
remaining part lined by stratified squamous non keratinized epithelium. Numerous mucous
secreting simple acinar glands called urethral glands or glands of Littre.
• MALE URETHRA: Prostatic urethra > Transitional epithelium.
• Membranous urethra = Stratified columnar epithelium interspersed with patches of
pseudostratified columnar epithelium.
• Penile Urethra = Pseudostratified epithelium except at its distal part where it is lined by
stratified squamous non keratinized epithelium.
CHAPTER 20: MALE REPRODUCTIVE SYSTEM
• Each testis is covered by a thick capsule of dense irregular CT called tunica albuginea.

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• Thin and incomplete CT septa called septula testis radiate from the mediastinum testis to the
capsule and divide further the interior of organ to 250 pyramidal intercommunicating
compartments called testicular lobules.
• Beneath tunica albuginea a layer called tunica vasculosa lining septula testis.
• Each testicular lobe contains one to four highly convoluted seminiferous tubules.
• Seminiferous tubules are 0.2 mm in diameter.
• Tubuli recti constitute the initial part of the male genital duct system.
• The tubuli recti pass into mediastinum testis to join a network of anastomosing channels called
rete testis.
SEMINIFEROUS TUBULES:
• ARE LINED BY A COMPLEX SEMINIFEROUS EPITHELIUM WHICH IS MODIFIED
STRATIFIED CUBOIDAL EPITHELIUM.
• Spermatogonia are the cells of seminiferous epithelium and are divided into TYPE A DARK
& TYPE A PALE spermatogonia along with TYPE B spermatogonia depending on the nuclear
structure.
• Sertoli cells also called the sustentacular cells, tall columnar cells extend from basal lamina to
the lumen of seminiferous tubules.
• Sertoli cell has nucleus that exhibits distinctive features like (folding in nuclear envelope) or
(nucleolus being prominent).
• Has lipid droplets, glycogen granules, spindle shaped crystalloid. ER, GOLGI, mitochondria
under EM.
• Cells of lateral wall bound by occluding junction.
• Basal compartment has spermatogonia and primary spermatocytes.
• Adluminal compartment has secondary spermatocytes, spermatids, spermatozoa.
• Functions:
• Physical and nutritional support to developing germ cells, important blood-testis barrier
formation, phagocytosis, secretion of AMH (antimullerian hormone), antigen binding protein
production, secretion of inhibin.
• Occluding junctions between the adjacent Sertoli cells establish a blood-testis barrier between
the basal and Adluminal compartments of seminiferous tubules.
• Role in isolating the haploid germ cells in a compartment to prevent any kind of immune
response against the cells.
• Interstitial cells of Leydig arranged as groups in close association to blood capillaries have
following features: large ovoid cells, central dark staining nucleus, eosinophilic cytoplasm rich
in lipid droplets. Rod shaped crystalloids of Reinke are commonly seen in the cytoplasm of
interstitial cells. They secrete the male sex hormone testosterone.
• Tubuli recti or vasa recta proximal part lined by Sertoli cells whereas distal part lined by
simple cuboidal epithelium.
• Rete testis have simple cuboidal epithelium.
• Ductuli efferentes has columnar epithelium.
EPIDIDYMIS:
• Coma shaped body that overlies the posterior superior surface of tests
• Cross section reveals that the duct of epididymis is lined by a pseudostratified columnar
epithelium.
• Functions include the storage of spermatozoa, its transport to the ductus deferens, reabsorption
of most of the fluid leaving testes.
DUCTUS DEFERENS (VAS DEFERENS):

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Three coats (Mucosa, Muscularis, Adventitia).
1. Mucosa: lumen star shaped, pseudostratified columnar epithelium in which tall columnar cells
bear stereocilia.
2. -Muscularis: Composed of three layers of smooth muscle: thin inner longitudinal, thick middle
circular, thick outer longitudinal.
3. Adventitia
The distal end of the ductus deferens is dilated to form the ampulla.
SEMINAL VESICLES:
• Mucosa thrown into longitudinal folds. Lining epithelium of pseudostratified columnar variety.
• Principal cells tall columnar and bear short microvilli on apical surface. Short basal cells rest
on basal lamina.
• Muscularis: Consists of inner circular & outer longitudinal layers of smooth muscle.
• Seminal vesicles functions as glands which secrete a yellow viscous fluid that constitutes about
70 % of the volume of semen.
• The secretion also contains the yellowish pigment called ‘’FLAVIN’’.
PROSTRATE GLAND:
• Largest accessory sex gland of male.
• Covered by a thin capsule of dense irregular CT.
• Stroma of the prostrate is fibromuscular consisting of collagen, elastic & smooth muscle fibers.
• Parenchyma has 30-50 tubuloacinar glands.
• Mucosal glands, submucosal glands & main prostatic glands.
• Small spherical bodies known as prostatic concentrations or CORPORA AMYLACEA are
observed in the lumina of some of the prostatic alveoli.
• The parenchyma of the gland is divided into three zones:
• peripheral zone = contains the main prostatic glands about 70% of glandular mass. major site
of prostatic cancer.
• transitional zone = contains the submucosal glands, site of BPH (BENIGN PROSTATIC
HYPERPLASIA).
• Central Zone = mucosal glands, resistant to hyperplasia as well as malignancy.
CHAPTER 21: FEMALE REPRODUCTIVE SYSTEM
• The surface of ovary is covered by a simple cuboidal epithelium (also called germinal
epithelium).
• Ovary consists of two zones (central deep zone of medulla & outer zone of cortex).
• The ovarian cortex has scattered spherical bodies called ovarian follicles.
• A layer of dense CT, known as tunica albuginea lies between germinal epithelium &
underlying cortex.
• The ovaries of a female child contain only one type of ovarian follicles called primordial
follicles.
• Ovary of an adult female has three varieties of ovarian follicles.
• Primordial follicle under the influence of gonadotropic hormones secreted by
adenohypophysis is called the growing follicles.
• Only one growing follicle mature while others undergo atresia.
• Remains of the ovulated follicle are converted into temporary glandular structure called
corpus luteum.

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• Primordial follicle has an immature ovum arrested in prophase of meiosis I.
• The oocyte of primordial follicle contains a large, eccentric situated, vesicular nucleus with
prominent nucleolus.
• The follicular cells also called granulose cells are squamous epithelial cells that surround the
oocyte and attached to each other by desmosomes.
• Primordial follicle grows into > Unilaminar primary follicle > Multilaminar primary follicle >
Secondar follicle > Mature Graafian follicle.
• At Unilaminar primary follicle stage, a layer of amorphous, homogeneous material appears
between the oocyte and the granulose cells called ‘’zona pellucida.’’
• Layers of theca interna & theca externa are formed during the Multilaminar follicle stage.
• The inner layer theca interna consists mainly of cuboidal secretory cells. Synthesize and
secrete the androgen androstenedione, which passes to the granulose cells where it is
converted into estrogen called estradiol.
• Theca externa outer layer of theca folliculi consist of fibroblasts, collagen fibers & smooth
muscle fibers.
• Secondary follicle stage is characterized by the presence of a cavity called the antrum
folliculi.
• The liquor folliculi is an exudate of plasma that appear in the clefts between the stratum
granalosum.
• Most secondary follicles undergo atresia, one of them matures and becomes a Graafian
follicle or a tertiary follicle.
• Ruptured follicle does not disintegrate but once is transformed into a temporary endocrine
organ called corpus luteum.
• The granulose lutein cells are pale staining, large cells, cytoplasm yellowish with the lutein
pigment, principal function to secrete progesterone.
• The theca lutein cells have fat droplets in cytoplasm, mitochondria with tubular cristae, SER.
Secretes estrogens as well as progesterones.
• Degeneration of the corpus luteum results in autolysis of the lutein cells and increase in CT,
finally the whole mass is transformed into a whitish scar called corpus albicans.
UTERINE TUBES:
• Mucosa: longitudinal folds throughout the length, epithelium lining the oviducts is of simple
columnar variety and contains either ciliated or non-ciliated cells. Lamina propria of uterine
tubes has loose CT, reticular & collagen fibers.
• Muscularis: thick inner circular & a thin outer longitudinal layer of smooth muscle fibers.
• Outermost covering of the uterine tube is called ‘’serosa.’’
UTERUS:
• OUTER LAYER: PERIMETRIUM
• MIDDLE LAYER: MYOMETRIUM
• INNER LAYER: ENDOMETRIUM.
• Perimetrium is either serosa or adventitia depending on the surface of uterus being examined.

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• Myometrium is the thickest coat with three layers of smooth muscles. (i) thin outer layer of
longitudinally arranged muscles. (ii) middle layer of circularly disposed muscle fibers. (iii)
inner layer of longitudinal muscles.
• Endometrium = lining epithelium is of simple columnar variety with two types of cells (i)
ciliated (ii) secretory.
• The functionalis also called the stratum functonale is the thick superficial zone which is
sloughed off at the beginning of each menstrual cycle.
• The basalis or stratum basale is the deeper, narrower zone of the endometrium.
• 4 phases of menstrual cycle (i) proliferative (ii) secretory (iii) premenstrual (iv) menstrual.
VAGINA:
• THREE COATS (MUCOSA, MUSCULARIS, ADVENTITIA).
• MUCOSA transverse folds or rugae, two layers = epithelium & lamina propria.
• Epithelium of the stratified squamous non keratinized variety although some of the superficial
cells of the epithelium contains keratohyalin granules.
• Lamina propria with layer of loose CT, containing a number of elastic fibers.
• Muscularis Consists of smooth muscle fibers which are arranged into two intermingling
layers, the inner layer is composed mainly of the circularly arranged muscle fibers. The thick
outer layer is composed of bundles of longitudinally running smooth muscle fibers.
• Adventitia > layer of dense CT that binds the vagina to the surrounding structures.
• The vaginal wall has no glands.
CHAPTER 22: EAR
• Auricle is composed of ‘’ELASTIC CARTILAGE.’’
• The cartilaginous part of meatus contains ‘’ceruminous glands.’’
• Secretory product of sebaceous & ceruminous glands mixes to form the ear wax.
• Auditory tube is lined by pseudo-stratified columnar ciliated epithelium.
• Membranous labyrinth is filled with fluid called ‘’endolymph.’’
• Osseous labyrinth consists of central cavity called ‘’vestibule.’’
• Cristae ampullaris are 3 in number whereas macula is two in number.
• Stereocilia of Hair cells are embedded in a thick glycoprotein material called ‘’cupula.’’
• Otoliths are composed of calcium carbonate.
• Tectorial membrane overlies the organ of corti.
CHAPTER 23: EYE
• Middle layer of eyeball is also called ‘’uveal region.’’
• Corneoscleral junction is called corneal limbus.
• Corneal epithelium = Stratified squamous non-keratinized.
• Bowman’s membrane of cornea contains type-1 collagen fibers.
• Retina develops as invagination of forebrain called the ‘’optic vesicle.’’
• Dilated fibers radiating from the ciliary processes are called ‘’zonular fibers.’’
• Contraction of longitudinal fibers of ciliary muscles Facilitates the drainage of Aqueous
Humor.
• Contraction of radial fibers of ciliary muscle cause the lens to flatten for the distant vision.

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• Retinal pigment epithelium is a single layer of low columnar cells.
• Lens capsule contain collagen type IV.

2ND YR HISTO QUICK RECAP.pdf

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