MIDTERMS 30% Flashcards
> 15 – 20 layers of flattened non-nucleated keratinized cells
continuously shed
what layer of the skin is described
stratum corneum
> ONLY in THICK SKIN; translucent layer of flattened eosinophilic cells
stratum LUCIDUM
> 3 – 5 layers of flattened polygonal cells
cytoplasm filled with basophilic masses called as
KERATOHYALINE GRANULES
what layer of the skin is described
stratum granulosum
> THICKEST Epidermal layer
polyhedral cells synthesizing KERATIN filaments (form bundles called TONOFIBRILwhich converge and terminate at Desmosomes)
what layer is described
stratum spinosum
> single layer of basophilic columnar or cuboidal cells on the basement membrane;
INTENSE MITOTIC ACTIVITY
stratum basale
> in the basal layer & junctional zone of dermis
contain tyrosinase for melanin synthesis
melanocytes
> dendritic cells containing rod shaped granules
for immunity; antigen-presenting cells
found in the Stratum Spinosum
langerhans cell
> found in the basal layer
touch receptor
what cell is diz
merkel cell
Ø Nature or type of secretion: Serous
Ø Mechanism of release of excretory products: Merocrine
Ø Morphology: Simple coiled tubular
what type of gland is this
sweat gland
specific subtype of papillary layer of the dermis
loose connective tissue
morphology of sebaceous glands
simple branched acinar
Ø Nature or type of secretion: Mucous
Ø Mechanism of release of excretory products:
Holocrine
sebaceous glands
There are different structures that help in
insulating, also called as insulating
components and these are:
Hairs and adipose
tissues
▪ Found underneath the epidermis
▪ Consists of fibrous and fibroadipose tissue
▪ Supports the epidermis both physically and
metabolically
dermis
⟣ It is the germinal layer because it provides a
constant supply of new keratinocytes
⟣ Constant supply of new keratinocytes
⟣ Plenty of mitotic figures
stratum basale
The Stratum Basale cells are attached to
the basement membrane via
hemidesmosomes
⟣ Large, cuboidal to polygonal, some flattened cells
⟣ Numerous cytoplasmic prickles bound by
desmosomes to adjacent cells
⟣ Central nucleus
stratum spinosum
⟣ 2-3 rows of flattened cells
⟣ Nucleus: central
⟣ Cytoplasm filled with numerous “keratohyalin”,
coarse basophilic granules
stratum granulosum
⟣ Thin translucent layer of flattened eosinophilic
keratinocytes
- held by desmosomes
- no presence of organelles and nuclei
stratum lucidum
⟣ 15 to 20 layers of squamous keratinized cells
⟣ Birefringent filamentous keratins
⟣ End of keratinization, squames are fully
keratinized or cornified
⟣ Continuously shed at epidermal surface
stratum corneum
location of thick skin
palms and soles
melanocytes Contain _________ for melanin synthesis
tyrosinase
rod-like with regular cross-
striations, one end distends in a vesicle (tennis racket)
birbeck granules
2 zones of dermis
papillary and reticular
⟣ Coarse, irregular bundles of collagen
⟣ Fibroelastic
⟣ Blood vessels are larger and deeper
⟣ Cells are mainly fibroblasts and histiocytes
reticular dermis
Subcutaneous layer of loose connective tissue
beneath the dermis
hypodermis
⟣ Highly modified keratinized structures
⟣ Produced by hair follicles
hair
a terminal expansion of the follicle
where hair growth takes place
hair bulb
⟣ One or more associated with a hair follicle
⟣ Secrete an oily substance called sebum
⟣ Embedded in the dermis except in areas lacking
hairs
sebaceous glands
⟣ Also known as “Sudoriferous glands”
⟣ Morphologically, they are classified as simple,
coiled tubular glands
Sweat Glands
⟣ Important in thermoregulation
⟣ React by secreting in stressful situations
⟣ Act as an excretory organ by eliminating
metabolic waste products
⟣ Secrete watery fluid, ammonia, sodium, chloride,
urea, and uric acid by merocrine process
what gland is this
sweat glands
⟣ Found in the axillae, areola, inguinal, and genital
regions
⟣ Viscid, milky secretion which, when acted upon
by bacteria, produces an objectionable odor.
⟣ Discharge into hair follicles
apocrine sweat glands
white crescent shape at base of nail
lunula
underlying nail root; nail growth
occurs
nail matrix
: highly keratinized free edge
Eponychium
: skin beneath free end of nail
Hyponychium
⟣ Highly modified apocrine sweat glands
⟣ Located anterior to pectoral muscles
mammary glands
⟣ Compound tubulo-acinar gland
⟣ Embedded in a mass of adipose tissue
⟣ Subdivided by collagenous septa
mammary glands
single large duct draining each
lobe
lactiferous duct
skin surrounding the nipple, pigmented,
contains sebaceous glands not associated with
hair follicles
areola
▪ Process of blood cell formation
Hemopoiesis
▪ Appear in the primordium of the liver
▪ 6 weeks of gestation
hepatic phase
Blood vessels begin to penetrate cavities
created by degeneration of chondrocytes in
the cartilage models of bones during the 4th
month of gestation.
myeloid phase
the major blood-forming
organ until adult life
bone marrow
➢ Adult type
➢ Found in the medullary cavities of long bones
➢ Rich in adipose cells that do not produce blood cells
yellow bone marrow
Functions
▪ Storage organ, by virtue of its richness in fats
(bulalo)
▪ Reserve of hematopoietic tissue in pathologic
conditions
yellow bone marrow
what THEORY is this
▪ All formed elements of blood originate from a
single stem cell, the hemocytoblast
▪ Pluripotential stem cell
UNITARIAN OR MONOPHYLETIC
qhat THEORY?
▪ Blood cells arise from two stem cells
Myeloblasts
▪ Erythrocytes and granular leucocytes
Lymphoblasts
▪ Lymphocytes and monocytes
DUALISTIC OR DIPHYLETIC
_______ THEORY
▪ Existence of a primitive stem cell for each
type of blood cells.
POLYPHYLETIC
a primitive stem or parent cell in
myeloid and lymphatic tissues
hemocytoblast
➢ Formation of red blood cells
➢ Development of a mature erythrocyte takes about 3
days (lifespan of RBCs – 120 days)
ERYTHROPOIESIS
Major morphologic and histologic changes that
occur during the maturation
erythropoiesis
▪ Earliest stage that develops from the
pluripotentialstem cell or CFU
▪ Cell is large, rounded nucleus and uniformly
dispersed chromatin pattern.
▪ Present nucleoli; basophilic cytoplasm
Proerythroblast (Rubriblast)
▪ Smaller than the proerythroblast
▪ Nucleus contains coarse chromatin; absent
nucleoli
▪ Basophilic cytoplasm
Basophilic erythroblast (pre-rubricyte)
▪ Cells show mixed colors varying from
purplish blue to lilac to gray
▪ Nucleus has a denser chromatin network
▪ Coarser chromatin bodies that give a
checkerboard appearance
Polychromatophilic Erythroblast (Rubricyte)
▪ Hemoglobin is of sufficient quantity
(acidophilia)
▪ Decreased basophilia of cytoplasm
Polychromatophilic Erythroblast (Rubricyte)
▪ Same amount of hemoglobin as RBCs;
exhibits acidophilia
Normoblast (Acidophilic Erythroblast)
Small fragments of nucleus occasionally
remain and give rise to deeply staining bodies
called ?
Howell-Jolly bodies
▪ Youngest erythrocyte found in circulation.
▪ Normal value: less than 1%
▪ Supravital staining with cresyl blue
demonstrates a delicate reticulum of variable
appearance and size that stains dark blue in
the otherwise pink cytoplasm
reticulocytes
- dependable index of the rate
of formation of new red blood cells (take note
kasi eto raw fave question ni doc sa exam)
Reticulocytes
Reticulocytes will _______ in response to
blood loss
increase
▪ Biconcave disc
▪ Anucleated
▪ Large numbers in the bone marrow
parenchyma
▪ Released into the peripheral blood
erythrocyte
FORMATION OF GRANULES
granulopoiesis
▪ Round or oval nucleus; 2 or more nucleoli
▪ Sieve-like appearance of chromatin pattern
myeloblast
▪ From pluripotential stem cell
▪ Deeply staining basophilic cytoplasm, devoid
of granules
Myeloblast
▪ Larger
▪ Ovoid nucleus; indented prominent nucleoli
▪ Deeply staining basophilic cytoplasm
▪ Cytoplasm is more basophilic and contains
azurophilic granules
Promyelocyte
▪ Appearance of specific granules in the
developing myelocytes
▪ Neutrophilic, basophilic, and eosinophilic
▪ Reduction in size
Myelocyte
▪ Specific granules contain alkaline
phosphatase and phagocytin
Neutrophilic myelocyte
▪ Large and refractile and contain acid
hydrolytic and oxidase enzymes
Eosinophilic myelocyte
▪ Irregularly sized basophilic granules which
contain heparin, histamine, and serotonin
Basophilic myelocyte
▪ Nucleus with a deep indentation indicating
the beginning of lobe formation
▪ Cytoplasm is a deep pink color
Metamyelocyte
➢ Concerned with protection against blood loss by
promoting clotting at sites of tissue injury
➢ Platelets originate in the red bone marrow
➢ Fragmentation of the cytoplasm of huge
polymorphonuclear cells called megakaryocytes
thrombopoiesis
▪ Large cell with round or indented nucleus
▪ Loose chromatin pattern
▪ Inconspicuous nucleoli
Megakaryoblast
➢ Formation of monocytes
➢ Macrophage cell line shares with the granulocytes
and the common committed stem cell, the CFU-GM,
monoblast divides into a promonocyte.
➢ Half of the promonocytes rapidly proliferate to
generate monocytes
MONOPOIESIS
➢ Formation of lymphocytes
LYMPHOPOIESIS
➢ Formation of lymphocytes
LYMPHOPOIESIS
➢ Formation of lymphocytes
LYMPHOPOIESIS
▪ The cytoplasm increases its volume
▪ Basophilia diminishes
▪ Azurophilic granules become dispersed
Promegakaryocytes
▪ Very large and lobulated nucleus
▪ Azurophilic granules are widely scattered in
the central region of the cytoplasm but
generally absent from a narrow peripheral
zone of pale, blue ectoplasm
Megakaryocyte
__ liters of blood in a person weighing 150 pounds
5-6 L
plasma - __%, hematocrit- __%
55%, 45%
▪ Clear yellow fluid when blood clots
▪ Equivalent in composition to plasma
▪ Lacks fibrinogen and some other protein
factors
serum
8% of body weight
blood
the liquid that remains after the blood
has clotted.
serum
the liquid that remains when clotting is
prevented with the addition of an anticoagulant.
plasma
Major plasma protein found in the blood is
?
albumin
➢ Transports oxygen from the lungs to the tissues and
carbon dioxide from the tissues to the lungs
➢ Life span is 120 days
erythtrocytes
▪ Crenation (shrunken)
▪ Cockle-Burr appearance
hypertonic
▪ Swelling
▪ Hemolysis
hypotonic
➢ Spherical shaped cells, with nucleus and cytoplasm
➢ Normal Value: 5,000-10,000/mm3 of blood
leukocytes
▪ Increased leucocyte count
Leukocytosis
▪ A decrease leucocyte count
Leucopenia
➢ Most abundant
➢ Normal Value: 55 to 65%
➢ Normal life span is about 8 days
➢ Diameter is 10-12 um
neutrophils
➢ Specific granules lack lysosomal enzymes
➢ Contain alkaline phosphatase and phagocytins
➢ Significant antibacterial activity
neutrophils
➢ NV: 0.5-1.0%
➢ 10 um in diameter
➢ Nucleus is relatively large and irregularly
polymorphous
basophils
➢ Peroxidase positive and contain histamine
➢ Presence of specific receptors for IgE
basophils
➢ NV: 1-3%
➢ Life span is 8-12 days
➢ Average diameter of 10-12 um
➢ Bilobed nucleus
eosinophils
➢ Cytoplasm contains coarse acidophilic granules
➢ Contain lysosomal enzymes rich in peroxidase
➢ Increased in parasitic infestations, allergy
eosinophils
➢ Second most numerous of leucocytes in blood
➢ 25 to 35%
➢ 7-9 um in diameter
➢ No specific granules
lymphocytes
➢ Large spherical nucleus, which may be slightly
indented on one side, purplish blue color
➢ Cytoplasm is pale blue, has a thin rim
➢ Increased in chronic and viral infections
lymphocytes
➢ Largest of formed elements
➢ Average diameter: 14 to 16 um
➢ NV: 2-8%
➢ Cytoplasm is more abundant and has a grayish blue
tint
monocytes
➢ A colorless fluid
➢ Collected from tissues
➢ Returned to the blood stream
➢ Circulates in only one direction, towards the heart
lymph
➢ Biconcave discs
➢ 2 to 3 um in diameter
➢ Non-nucleated
➢ Forms in clusters or groups
➢ NV: 150,000 to 300,000/mm3
thrombocytes
2 main lymphatic trunks
▪ Thoracic duct
▪ Right lymphatic duct
➢ Polymorphonuclear WBC
➢ Most abundant
➢ Normal value: 55-65%
➢ Increased in bacterial infection
neutrophil
Unoxygenated blood from different organs
will come into the heart via WHAT ATRIUM
RIGHT ATRIUM
Blood coming from LA is _______________ blood
oxygenated
– pacemaker of the
heart
Sinoatrial Node (SA Node)
▪ Thin layer of loose connective tissue (LCT)
▪ Collagenous and elastic (C & E) fibers
▪ Blood vessels, nerves (N’s)
▪ Conducting portion
▪ Binds endocardium to myocardium
SUBENDOCARDIUM
▪ Found in subendocardium
▪ Part of the conductive system of the heart
Purkinje Fibers
Modified cardiac muscle cells located in the
AV bundle and its branches
purkinje fibers
➢ Main mass of the heart
➢ Cardiac muscles arranged in tracts or bundles
➢ Strands of connective tissues and vascular
network in between cells
➢ Thickest wall of the heart
MYOCARDIUM
_________ muscle cells
▪ Striated, involuntary, cylindrical with
branching, mononucleated or binucleated,
centrally located nucleus, intercalated discs
Cardiac
➢ Visceral layer of the pericardium
➢ Lined by a single layer of flat or cuboidal
mesothelial cells
EPICARDIUM
____________ cavity
▪ Space between epicardium and parietal
pericardium
▪ Serous fluid: secreted by mesothelial cells
▪ Layers glide freely
Pericardial
The central supporting structure of the heart, to
which most of the muscle fibers are attached and with
which the valves are connected is called the cardiac
skeleton. It consists of dense connective tissue.
cardiac skeleton
➢ Upper fibrous part of the interventricular
septum
➢ Attachment for free ends of fibers of cardiac
muscles
Septum Membranaceum (take note daw na upper fibrous part sha)
➢ Between arterial foramina & AV canals
➢ Provide support and maintain the integrity of
all four orifices
➢ Without these rings of support the orifices
would stretch and the valves would be unable
to function properly
Trigona Fibrosa
strongest valve
aorta
➢ Fibrous ring
➢ Principal attachment of muscular fibers of
atria, ventricles, and AV valves
➢ Main portion of the cardiac skeleton
➢ Dense connective tissue that surrounds the
openings of the four orifices
Annuli Fibrosi
➢ Trigonum fibrosum dextrum continuous with SM
Bundle of His
Tubular structures that convey blood away and
towards the heart
blood vessels
▪ Dark red colored
▪ Has the thickest arteries
tunica what
tunica media
Tunica ??
▪ Loose connective tissue (LCT)
▪ Collagenous, elastic fibers, Blood vessels, nerves
▪ Blue colored
▪ Has the thickest veins
Adventitia
➢ Blood supply of blood vessels
➢ Vessel within a vessel
vasa vasorum
➢ Nerve supply of blood vessels
➢ Walang lumen
nervi vasorum
➢ Also known as Conducting or Elastic arteries
LARGE ARTERIES
Also known as Muscular or Distributing Arteries
medium-sized arteries
➢ Similar to medium-sized arteries
➢ Average diameter: 300 um
SMALL ARTERIES
➢ Also known as “Metaarterioles”
➢ Diameter: 50 um
PRECAPILLARIES
➢ Thin-walled tubes which branch extensively
➢ Diameter: 5 to 10 um
➢ Length: not > 50 um
➢ Single layer of endothelial cells on a basement
membrane
capillaries
CAPILLARIES: _______________-
➢ Endothelium is uninterrupted
➢ Lack pores in the wall
➢ Found in muscles, nerves, connective tissues
➢ Skeletal muscle, gray matter of spinal cord (nerve)
CONTINUOUS
CAPILLARIES:
➢ Endothelium: lined of relatively large caliber and
irregular cross-sectional outline
➢ Tortuous path
➢ Greatly enlarged diameter
➢ Discontinuous lining in walls
➢ With phagocytic cells
➢ Discontinuous basal lamina
➢ Found in the liver, bone marrow, some endocrine
glands
SINUSOIDAL
capillaries:
▪ Endothelium: pores of 80-100 um closed by very
thin, porous diaphragm
▪ Pancreas, GIT, choroid plexus, ciliary body
fenestrated with diaphgram
▪ Pores are not closed
▪ Renal glomeruli (kidney)
_____________ capillary
fnestrated without diaphgram
Fenestrated ___________
▪ Wider lumen
▪ Larger fenestrae
▪ Lack diaphragm
▪ BM: not prominent
▪ Some endocrine glands, carotid, and aortic
bodies
sinusoidal
CAPILLARIES: _________–
➢ Endothelial cells: elongated along longitudinal
axis of vessels
➢ Surrounded by reticular fibers
➢ Specialized vessels of the spleen
➢ Splenic sinuses
SINUSES
➢ Larger caliber
➢ Thinner walls than arteries
VEINS
central vein of spinal cord is an example of
venule
____________Portion
* Warm, humidify, or clean the air
Conducting
_____________ Portion
* Exchange of gasses takes place
Respiratory
o Most abundant cell type; for ciliary
beating
o Each cell possesses about 300 cilia
on its apical surfaces
o Also contains mitochondria
Ciliated columnar cells
o Columnar cells with numerous
microvilli
o Immature cells
o Sensory/receptor cells
Brush cells
➢ LE: Stratified squamous non-cornified epithelium
➢ Lamina Propria: dense connective tissue
➢ Most dilated, anterior portion of the nose
vestibule
_____________REGION
➢ Pseudostratified columnar ciliated epithelium
with goblet cells
➢ Thick basement membrane
➢ LP: Mixed type of secretion, which are serous
and mucous,
RESPIRATORY
➢ Receptor organ for smell
➢ LE: PSCCE without GC (pseudostratified ciliated
columnar epithelium WITHOUT goblet cells)
➢ No distinct basal lamina
olfactory region
➢ Musculo-membranous tube
➢ Also known as the throat
PHARYNX
______pharynx
* Stratified squamous non-cornified epithelium
* Mucous glands
Laryngopharynx
➢ Also known as the voice box
➢ Continuation of laryngopharynx
LARYNX
o Upper part
o Respiratory epithelium (PSCCE)
o LP: loose connective tissue with
elastic fibers, lymphocytes, and
lymphatic nodules
o Laryngeal glands of mixed secretion
False Vocal Cords (Vestibular Folds)
o Lower part
o Stratified squamous non-cornified
epithelium
o LP: almost indistinct and contains a
vocal ligament (elastic)
True vocal cords (vocal folds)
➢ Also known as the windpipe
➢ Thin-walled tube
➢ Bifurcates into 2 primary bronchi
trachea
➢ Main bronchus
➢ Enters root of lungs with arteries, veins, lymphatic
vessels
bronchus
➢ 1mm or less in diameter
➢ No more cartilages
➢ No secreting glands and lymphatic nodules
BRONCHIOLES
➢ 0.5 mm or less in diameter
➢ LE: Simple cuboidal, ciliated cells, and club cells
➢ No cartilages and glands
➢ Has a smooth muscle layer continuous with less
mucosal folds
TERMINAL BRONCHIOLES
➢ LE: simple cuboidal, ciliated cells, and club cells
with scattered alveoli
RESPIRATORY BRONCHIOLES
➢ Fewer smooth muscle fibers with elastic connective
tissue
➢ Club cells or Exocrine bronchiolar cells
respiratory bronchioles
- Thin-walled tubes
- Discontinuous walls give off branches
- LE: simple squamous
Alveolar ducts
- Thin-walled outpocketings
- Clusters of two or more alveoli
- LE: simple squamous
Alveolar sacs
Type __ alveolar cells (Pneumocyte type I)
* Squamous or flattened cells
* Form the vast majority of the alveolar
surfaces (90-95% of alveoli are Type I cells)
* Have junctional attachments laterally with
each other or with type II alveolar cells
type I
Type __ alveolar cells (Pneumocyte type II)
* Cuboidal cells
* Secretes surfactant which lowers the
surface tension
* Cells contain secretory granules at its
supranuclear portion
* Thicker cells
TYPE II
➢ The alveolar septum where gases must pass in
exchange between the air and blood
➢ 3 layers:
* Alveolar epithelium
* Fused basement membranes
* Capillary endothelium
BLOOD-AIR BARRIER take note daw ung layers
➢ Free phagocytic cells
➢ Contain particles of dust called dust cells
➢ Dust cells
➢ In heart congestion, they become filled with
hemosiderin pigments
➢ Heart failure cells
alveolar macrophages
The inner layer is called the ___________
and covers the lungs, blood vessels, nerves, and
bronchi.
visceral pleura
____________ bronchiole – ends the conducting
portion of the respiratory system
Terminal
Provides defense or immunity against infectious
agents
immune systemz
_____________ TISSUE
➢ Aggregates of lymphocytes in different regions of the
body
➢ Parenchyma: Lymphocytes
➢ Stroma: Reticular tissue
LYMPHATIC
– produce and
maintain the trabeculae
Fibroblasts reticular cells
➢ 20 to 50% of WBC in circulation
➢ Round to ovoid nucleus
➢ Thin rim of bluish cytoplasm
lymphocytes
Both the T and B-lymphocytes are referred to as
?
memory cells
surface receptors of B CELLS
IMMUNOGLOBULINS
➢ Same size as an erythrocyte
➢ Dark nucleus
➢ Thin rim of surrounding cytoplasm
SMALL LYMPHOCYTE
_____ LYMPHOCYTE
➢ 10-15 μm
➢ More cytoplasm that is basophilic
➢ active B or T cells
LARGE LYMPHOCYTE
➢ Long-lived
➢ 75% of circulating lymphocytes
➢ T-cell receptors (TCRs)
T-LYMPHOCYTES
➢ B-cell receptors (BCRs) – immunoglobulins
➢ Monomers of IgM or IgD
➢ Most differentiate into plasma cells
➢ Provide humoral immunity
➢ Remain as long-lived memory B cells
B LYMPHOCYTES
______ LYMPHOID TISSUE
➢ Few lymphocytes
➢ Irregularly scattered in a loose manner
➢ Stroma: reticular cells and fibers
LOOSE
_____ LYMPHOID TISSUE
➢ Lymphocytes are abundant and closely packed
➢ Examples
* Ileum
* Colon
* Appendix
DENSE
________ LYMPHOID TISSUE
➢ Nodules or follicles
➢ Compact, circumscribed aggregates of B cells
NODULAR
_______________ LYMPHOID NODULE
* Aggregates of uniform cell density and
staining
PRIMARY
_____________ LYMPHOID NODULE
* Aggregates with larger, more euchromatic
cells centrally
* Lighter staining center
* Periphery that has darker staining cell
SECONDARY
the Secondary lymphoid nodule is composed of 2 parts:
GERMINAL CENTER AND MANTLE
➢ A central, pale staining portion of a secondary nodule
➢ This nodule becomes a secondary when there is
already an antigenic stimulation
➢ Large, activated B lymphoblasts (centroblasts)
* Immunoglobulin gene recombination
* Rapid proliferation
- Germinal Center
➢ Rapid proliferation of activated B lymphoblasts
➢ Smaller, naive lymphocytes pushed
➢ Crowded together peripherally
* Dark staining portion
* Small lymphocytes with dark staining nucleus
and closely packed cells
MANTLE
➢ Bilobed structure in mediastinum
➢ T cells are produced
* Site of T lymphocyte differentiation
* Selective removal of T cells reactive against
self-antigens
THYMUS
➢ Remains large & active in T cell production until
puberty
➢ Undergoes involution
* Filled with adipose tissue
* Decreasing lymphoid tissue mass and
cellularity
* Reduced T cell output
➢ Vascularized loose connective tissue capsule
THYMUS
THYMIC _______
➢ A peripheral zone of dense lymphatic tissue
consisting of T lymphocytes
➢ Do not form lymphatic nodules
➢ Blood supply: Capillaries
➢ Active site of lymphocyte production
CORTEX
THYMIC____________
➢ Few pale staining lymphocytes
➢ Reticular cells
* Extremely pleomorphic and have a
* More acidophilic cytoplasm
MEDULLA
- Large aggregates of epithelial cells arranged
concentrically - Secretes cytokines
Hassall corpuscles (landmark sha ng thymuz)
➢ Mucosa-associated lymphoid tissue
➢ Large and diffuse collections of:
* Lymphocytes
* IgA-secreting plasma cells
* Antigen presenting cells
* Lymphoid nodules
malt
➢ Contain 70% of all body’s immune cells
* Mostly B cells
* CD4 helper T cells
malt
➢ Large irregular masses of lymphoid tissue
➢ Mucosa of posterior oral cavity and nasopharynx
TONSILS
➢ Lining epithelium: Stratified squamous
non-keratinized epithelium
➢ Tonsillar crypts → 10 to 20 deep
invaginations
➢ Partial capsule of dense CT
Palatine
_____ tonsil
➢ SSE with crypts (Stratified squamous
non-keratinized epithelium)
➢ No distinct capsule
- Lingual
__________ tonsil
➢ PSCCE (Pseudostratified Columnar
Ciliated Epithelium with Goblet Cells)
➢ Thin capsule, shallow infoldings; no
crypts
Pharyngeal
➢ Nodular aggregates only used in the ileum
➢ Mucosa and submucosa
➢ No underlying CT capsules
PEYER PATCHES
➢ Short, small-diameter projection from the cecum
➢ Lamina propria and submucosa filled with
lymphocytes and lymphoid follicles
➢ Lumen may contain bacteria of large intestines
appendix
➢ 1.0 cm by 2.5 cm
➢ Along lymphatic vessels
➢ 400-450 nodes
➢ Axillae, groin, neck, thorax, abdomen, visceral
mesenteries
➢ Stroma: reticulin fibers and cells
➢ Bean-shaped encapsulated structures
LYMPH NODE
➢ Filters lymph
➢ Defend against the spread of microorganisms and
tumor cells
➢ Provide enclosed environments for:
* Antigen presentation
* Development of plasma cells secreting non-
IgA antibodies
lymph node
part of lymph node
* Concave depression
* Efferent lymphatic leaves
* A, V, N penetrate the organ
Hilum
part of lymph node
* Dense connective tissue
* Trabeculae extend internally through which
the blood vessels branch
Capsule
- Where most lymphocytes enter
- Lacks nodules
PARACORTEX
- Receiving lymph from the afferent lymphatics
CORTEX
➢ Upper part (yung may bilog, bukol)
➢ Lymphoid nodules
* Formed largely of developing B
lymphocytes
* Helper T lymphocytes
* Numerous macrophages
(1) CORTEX
➢ Middle part
➢ Lacks B cell lymphoid nodules
➢ Lymphoid tissue rich in T cells
(2) PARACORTEX
➢ Found in left upper quadrant of the abdomen
➢ 12 x 7 x 3 cm
➢ Made up of dense CT capsule/fibroelastic capsule
➢ Trabeculae
* Penetrate the parenchyma or splenic pulp
* Fibrous extensions into the organ
➢ No cortex and medulla
➢ Two regions: White pulp and red pulp
SPLEEN
➢ Defense against blood-borne antigens
➢ Main site of old erythrocyte destruction
➢ Production site of antibodies and activated
lymphocytes
spleen
➢ Only 20% of spleen
➢ Associated with a central arteriole
➢ Enclosed by Periarteriolar lymphoid sheath (PALS)
of T cells
whte pulp
➢ About 80%
➢ Filters blood
➢ Removes effete erythrocytes
➢ Recycles hemoglobin iron
red pulp
Splenic ________
* Blood filled
* Lined by unusual endothelial cells → Stave
cells
sinusoids
Presence of villi, fingerlike projections in the
mucosa
ileum
This segment of the large intestines or colon has
the most numerous aggregates of lymphatic
nodules
Mucosa
The spaces in tonsils are called ??
tonsillar crypts
Splenic cords/_________ cords – composed of
macrophages, and blood cells of all kinds
Billroth
