Lymphoid & Integumentary System Flashcards
•Lymphatic +vascular system = hemilymphatic sys which a 2’dry defense
•Produces defensive cells like T lymphocytes, plasma cells, macrophages, etc
•Filters and transport lymph and blood
•Produce IG’s
•Phagocytize foreign bodies
LYMPHATIC SYSTEM
Cells located in the l. propria of digestive, respiratory and urogenitals
Diffuse and unencapsulated lymphatic tissue
Lymphocytic pop’ns
forming nodules-small, spheroidal or ovoid
aggregates
Dense unencapsulated lymphatic tissue
Composed of lymphocytes and
macrophages
Primary nodule/follicle
Collections of lympha. tissue in the small intestine
Peyer’s patch
Has pale germinal center surrounded by dark staining corona or cortex or
mantle zone of small lymphocytes=
active nodule
Secondary nodule
Aggregated lymph nodules in the pharyngeal
mucosa
Tonsils
Formed by by a single layer of
lymphatic tisue 2’drly protruding into the lumen
Palatine & Lingual tonsils in M,H,R,S
Tonsil with crypt
A group of tonsillar follicles
Tonsil without crypt
A blind sometimes branched invagination of the
surface epithelium
Crypt
A bean shaped which vary in size fr a mm to sev’rl cm
Lymph gland
Form the fine stromal elements
Reticular fibers
Divided into outer cortex and inner
medulla
Parenchyma
Divided into nodular, internodular and deep zones
Occupied by the nodular follicles=primary & secondary
Concentrate on the 1’ry nodules and germinal
centers
B cells
Occupy the paracortical zones
T cells
Result from the differentiation of B cells in the germinal centers that move into the periphery of
the nodules
Plasma cells
Cortical nodular fusion is
common in this animal
Horse
Nodules
have large germinal centers in this animal
Oxen
Consist of branching reticular fibers and cells surrounded by medullary sinuses and lymph
capillaries=medullary cords
Medulla
Stellate cells with fine network of interlacing processes that traps antigen for presentation
Dendritic cell
Specifically called interdigitating cell (IDC) and follicular dendritic cell respectively
T and B cells
• sinuses are filled with blood not
lymph
• Capsules and trabeculae contain
smooth muscle fibers
• Described as miniature of spleen but look like lymph node
• Occur in ruminants along the vertebral columns and jugular furrow
Hemal nodes
•Blood and lymph intermixes in the
sinuses thus called hemorrhagic
lymph node
•Occur in the perirenal (sheep &
goat) and lumbar regions (ox)
Hemolymph node
• largest mass of lymphatic tissue
• capsule is dense collagenous that
extends into the parenchyma
dividing it into small compartments
• Smooth muscles and elastic fibers
are present in the capsule and
trabeculae
Spleen
Distinct cortex and medulla is absent instead, scattered in the parenchyma – white and red pulp
• Contains splenic phagocytic sinuses and cords
• Regions between splenic corpuscles and
trabeculae, called so for its
vascularity
Red pulp
Few trabeculae and muscle fibers but
abundant lymphatic tissue ex. Human and marsupials
Defensive spleen
Many trabeculae & smooth muscle and less lymphatic tissue-ex.horse, dog & cat
Storage spleen
Occur in ruminants and swine
Intermediate spleen
•Derived from the 3rd & 4th paryngeal
pouches
•Parenchyma is divided into outer
cortex and deep medulla
•Parenchymal cells are chiefly of the T cells or thymocytes
•Capsule enclosing the organ is
composed of dense collagenous fibers that penetrate the parenchyma , dividing the organ into lobes
Thymus
Densely populated of the thymocytes
than the medulla obliterating the cytoreticulum
formed by the epithelio-reticular cells
Cortex
Organ is distinguished by the Hassal or Thymic corpuscle of various sizes.
Medulla
Contribute to the blood-thymus barrier
Epithelial-reticular cells
Movement of thymocytes through
post capillary venules to secondary lymphatic organs
- significant aspect of cell-mediated immunity
Peripherlization
Hormones of
thymus
- influence the development of progenitor cells into
T-cells
Thymosin and thymopoietin I&II
•Is a blind sac opening into the dorsal
proctodeal wall of the cloaca
•Parenchymal cells are chiefly of the B
cells
•Dense collagenous capsule penetrate
deeply as septa and dividing the organ into
lobes
•Wall of the organ is columnar or
pseudostratified
Bursa of Fabricius
Characterized by moderate concentration of scattered lymphocytes.
Diffuse unencapsulated lymphatic tissue
Round, oval, or irregularly circumscribed aggregation of mostly
small, densely packed lymphocytes
Lymphatic nodule
Central pale area (with large lymphocytes)
Germinal center
(Marginal or peripheral zone) – dense of small lymphocytes
Corona
Collection of lymphatic nodules and diffuse lymphatic tissue.
Present at the connective tissue in a specific region
TONSILS
Characterized by deep invaginations of the surface epithelium called crypts
Tonsil with crypt
Smooth, somewhat folded, or bulging surface, but lack deep invaginations of the epithelium.
Tonsil without crypt
Lymphatic nodules surrounded by
diffuse lymphatic tissue
Cortex
Connective tissue, with some
smooth muscle and elastic fibers, covers the lymph node
Capsule
Part of capsule that moves inward
Trabeculae
Blood-filled sinuses between cellular cords
occur along blood vessels of
ruminants
lack lymphatic vessels
Hemal nodes
• Has capsule rich in smooth muscle and elastic fiber
• Parenhcyma is divided into red
and white pulp
• White pulp – PALS, lymphatic
nodules
• Red pulp - RBC
Spleen
Red pulp contains venous sinuses (wide channels lined by elongated,
longitudinally oriented endothelial cells)
Sinusal spleen
Poorly develop or no sinus
Non-sinusal spleen
Covered by a thin capsule of connective tissue that
projects inward as septa, partially dividing the organ into lobules
Thymus
Occur in the medulla of each lobule; concentric whorls of acidophilic and flattened reticular cells
Hassal’s corpuscle
•Effective barrier between the internal and external environment.
•Temperature regulation
•Secretory function
•Assists in Ca homeostasis thru UV light conversion of 7
dehydrocholecalciferol into cholecalciferol in the sebaceous glands
•Skin pigments protection against UV radiation
•Provides general behavioral pattern, sexual behavioral displays and
mechanical protection
•Skin is an extensive sensory organ
Integumentary system
Stratified squamous epithelium keratinized
Epidermis
Single layer of pyramidal,
cuboidal or columnar cells
Stratum basale
Light staining cells flattened
toward the surface, cells have many cellular
processes presenting spinous appearance
Stratum spinosum
Spindle-shaped cells
contain keratohyalin granules (thick or absent)
Stratum granulosum
Layer of pale acidophilic cells of
dead or dying with indistinct nuclei; not a distinct
feature of the epidermis of domestic
animals(when present-digital pad, teat,nose &
periopole)
Stratum lucidum
Layer of closely packed cells, thickness depends on the location in the body
Stratum corneum
Follow the contour of
the stratum basale
Papillary (superficial)
Dense collagenous tissue
Reticular (deep)
Finger-like projections
extending into the epidermis from the dermis
Dermal papillae
Complimentary projections
of the epidermis into the dermis
Epidermal peg
Confluent
epidermal peg
Epidermal ridge
Layer of loose collagenous tissue
Subcutaneus
Thick infiltration of adipose tissue (digital pad, equine digital cushion)
Panniculus adiposus
• Highly cornified, thickened, pigmented and
hairless region
•Thickest epidermis of the carnivores
•Digital cushion /panniculus adiposus
•Merocrine glands occur in the dermis and epidermis
Digital pad
Thinnest epidermis
•Stratum corneum is not well developed
•Dermis is not extensive
Scrotum
•Planum nasale (carnivores)- thick & highly cornified devoid of
sebaceous gland
•Planum nasolabiale (ox),planum nasale (small ruminants), planum
rostrale (swine)-contain merocrine glands
Nose
In growth of the presumptive epidermis and basement membrane into the underlying dermis
Hair follicles
Formed by the invagination of the epidermis (s. basale & s.spinosum)
External root sheath
Formed by several layers of flattened cells with or without
trichohyalin granules
Internal root sheath
Follicles terminate in a hollow, cone-
shaped epidermal peg
Hair bulb
A smooth muscle, contraction of which erects the hair and helps to express the contents of the sebaceous glands
Arrector pili
Secrete sebum composed of f.a., choloesterol,and
vitamin D
Sebaceous gland
Primary gland in humans
Merocrine
Predominant in domestic animals
Apocrine
