Histology-Exam 2 Flashcards
(146 cards)
1
Q
Mesenchymal Cells
A
Spindle to stellate cells
Scant Cytoplasm
Surrounded by amorphous (no shape) ground substance.
Rich in Hyaluronic acid/ thin reticular/ collagen fibers.
Stem cells for other connective tissue types and smooth muscle.
2
Q
Adipocytes
A
Fat cells, Specialize in storing fat
Do not make ECM
Originate from Mesenchymal cell
Surrounded and supported by reticular collagen and fibroblasts.
Will typically be removed by prestaining for H&E
- Brown adipocytes: Prenatal and juvenille, heat producing (multiple small droplets)
White Adipocytes: Peripheral nucleus ( looks like ring)
3
Q
Fibroblasts
A
most common in connective tissue proper.
Fusiform- elongated nucleus
Fibroblast Replicating (active) ( more abundant)
Fibrocyte: just sitting (smaller then fibroblast)
Difference is maturity
Produce extracellular matrix
4
Q
ECM: Amorphous (Functions)
A
Lubrication
Diffusion
Blockage (barrier)
Adhesion
5
Q
ECM: Amorphous (Components)
A
GAGs (Hyaluronic acid (eases migration (mesenchyme), molecular diffusion and lubrication).
GAGs and Proteoglycans (Dermatan [ Chondroitin, Keratan, heparan ] sulfate (lubricants, space filling)
Glycoproteins ( Laminin (adhesion of epithelial cells) (found in: Basal lamina, endomysium, sub-endothelium)
6
Q
ECM: Fibrous
A
Produced by fibroblasts mainly but not only. Strong resistant flexible.
Protein fibers: Collagen, reticular fibers, elastin
7
Q
Collagen Type 1
A
Fibrillar and most abundant/ strongest
Found in: Bone, ligament, tendon, skin
8
Q
Collagen Type 2
A
Fibrillar
Found in: Cartilage
9
Q
Collagen Type 3
A
Fibrillar
Found in: Viscera retinaculum ( Lymph nodes, kidney, liver, ect)
Very delicate, Argyrophillic and sometimes PAS + because of high sugar content. Silver stain works well
Produced by fibroblasts
10
Q
Collagen Type 4
A
Network (Sheet)
Found in Basement Membrane
11
Q
Collagen Type 5
A
Linking (anchoring)
Found in basement membrane
12
Q
Elastic fiber
A
Fibrillin and Elastin
Interspersed with collagen bundles, provide stretching ( arteries/ lungs)
Produced by fibroblasts and smooth muscle cells (in blood vessels)
13
Q
Embryonic connective tissue
A
Mesenchymal ( loose matrix, hyaluronic acid, stellate cells (lattice)
Mucous/ Mucinous ( Fibroblasts and collagen, Mucinous matrix)
14
Q
Where can you find Mucinous in adult chickens?
A
Combs and waddles
15
Q
Dermal Mucinousis
A
In adult sharpei’s, excess mucin under skin, keeps producing and increases size of folds.
16
Q
Connective Tissue Proper
A
Loose, Dense, Reticular, Elastic, and Adipose tissue
17
Q
Loose connective tissue
A
Various cell types Thin fibers (collagen, reticulin, elastin) Soft, Spacious
18
Q
Dense Connective Tissue
A
Thick Collagen ( more collagen= dense/ fibrous tissue)
Few cells (fibroblasts)
Regular or irregular
Trichrome stain is good
19
Q
Reticular connective tissue
A
Reticulin Fibers
Few Cells
Visceral Stroma ( lymph node, spleen, liver)
Gomori/ GMS is a good stain, Silver stains
20
Q
Elastic connective tissue
A
Elastin fibers
Moderate number of cells (fibroblasts)
Sometimes combined with smooth muscle
21
Q
Adipose Tissue
A
Adipocytes
Supported by fine collagenous tissue
Empty cells: fat is lost in processing
Sudan stain is good for fat staining.
22
Q
What is the germ layer Connective tissue arrises from?
A
Mesoderm
23
Q
Connective tissue Function
A
Produce intercellular substance (binding)
Join tissue elements and fill gaps
Provide support (scaffolding or mortaring)
Defend organism by giving rise to blood cells, immune cells.
Healing (scarring) very regenerative when needed.
24
Q
Extracellular matrix
A
most abundant component and basis for its classification.
25
Epidermis is from which germ layer
ectoderm
26
Epidermis
```
Stratified Squamous epithelium
Keratinocytes present (undergo terminal differentiation (keratinization)
```
27
Strata of Epidermis ( Top to bottom
```
Stratum Corneum
Stratum Granulosum
*Humans: Stratum Lucidum
Stratum Spinosum
Stratum Basale (basal layer)
```
28
Stratum Basale
Single layer (cuboidal ish or columnar ish cells)
anchored to basement membrane (hemidesmosomes)
Attached to other cells: Desmosomes
Actively reproductive via mitosis.
29
Stratum Spinosum
Multilayered (polygonal cells)
Attached to other cells: Desmosomes prominent due to tissue sharing
Some reproductive activity
30
Stratum Granulosum
Single to few layers (plump squamous)
Attached to other cells: Desmosomes (less visible)
Cytoplasm filled with keratohyaline granules
May be invisible in thin skin
31
Stratum Corneum
Few to many layers (squamous cells)
Attached to other cells (desmosomes rarely visible)
Terminally differentiated cells - SQUAMES
May be preceded by stratum lucidum (thick skin)
These cells are dead, no reproduction.
32
Other Cells in Epidermis
Melanocytes: Usually in basal layer.
Synthesizes melanin pigment in melanosomes. Melanosomes then interact with Keratinocytes and MQ.
Langerhans cells: Dendritic cells
Antigen presenting cells.
33
What layer will you find hair and hair follicles
Dermis
34
Parts of Hair Cell
Bulb (base with germinal cell matrix)
Medulla (central cuboidal/columnar cells, absent in wool)
Cortex (Flat cells, longitudinal to axis)
Outer cuticle (Scaly (squamous) cells) (Pointing upwards)
35
Parts of Hair Follicle
Dermal Papilla (vascular) goes into hair bulb
Hair Follicle:
Inner root sheath: From germinal cell matrix.(Cuticle, pointing downwards)
Outer Root sheath: Scaly Squamous cells
Connective tissue sheath: Abuts follicular basement membrane
36
Single (simple) Hair Follicles
Ruminants and horses, vertical in sheep.
37
How many hair follicles are grouped together in the pig?
3
38
What kind of hair follicles do carnivores have?
Compound ( single primary, multiple secondary, union at sebaceous gland opening)
39
Tactile hairs are
Specialized hair follicles. Blood filled sinuses in connective tissue sheath.
40
Differences in Avian skin
- Epidermis is thinner than mammals
Stratum germinativum (layers usually not obvious) (basal layer, intermediate layers, vacuolated layer)
Stratum Corneum
- No glands ( except uropygial gland ( except in emus and ostriches)
- No papillae
41
Types of Feathers
Contour (wing and Tail)
- Central shaft with quill or calamus ( hollow, Rachis ( upper part of shaft which contains barbs and barbules with hooks)
Down: Hook less barbules
Filoplumes: Hair like, no barbules
42
What muscle gives feathers movement?
Arrector Plimae smooth muscle (Pillorector muscle) (absent in filoplumes)
43
Feather Follicle layers
Stratum Corneum
Stratum germinativum
connective tissue layer
44
What stain is ideal for mucinous connective tissue?
Alcian blue
45
What are Beaks?
Specialized structure with thick keratinized outer layer called ramphotheca (all dead tissue)
- Usually include herbst corpuscles
46
What is a Hoof
Keratinized epidermis covering distal end of digit.
47
Laminitis is also known as...
Founders disease
48
What causes laminitis?
- Sepsis
| - Diet change ( specifically high grain to low grain quickly)
49
What mammals have scales?
Pangolins
50
What are epidermal scales ?
modified epidermis: Modified and thickened stratum corneum ( keratin) Can be shed ( corneal layer only)
Found in snakes, chicken leg, beak, ect
51
What are dermal scales?
Fish primarily, some reptiles, turtle shell, and toads.
| Derived from mesenchyme ( mesodermal) Remnants of dermal skin, bony base, cannot be shed
52
Dermis
```
Connective tissue ( collagenous (loose irregular most superficial (papillary), and dense irregular deeper (reticular)
Contains vascular (blood and lymphatic), nerves (receptors), and glands
```
53
Sebaceous Glands
```
Stratified epithelium
Holocrine Secretion: destroying cell
Produces Sebum (lipid product).
Opens into lumen of hair follicle.
Meibomian Gland ( sebaceous gland of eyelid)
```
54
What is Meibomian Gland adenoma?
Benign common tumor of eyelid in older dogs (looks like roxies barnacle)
55
Sweat (sudoriferous) Glands
Simple Cuboidal Epithelium
Apocrine (membrane bound blebs of cytoplasm) or Merocrine ( exocytosis, cytoplasm intact) secretion.
Secretes: GAGs and proteoglycans.
Opens into Epidermal surface or lumen of hair follicle
Surrounded by: Myoepithelium
56
Mammary Glands
Tubuloacinar glands
Apocrine Secretion: membrane bound blebs of cytoplasm)
Secretion product: Milk (lipids protein sugars)
Open into: interlobular ducts (cuboidal/ columnar epithelium)
Surrounded by myoepithelium
57
Uropygial glands
In birds
Holocrine secretion of oily sebum for preening.
Radiating simple tubules or branched alveoli (acini)
Opens to: Primary duct through papilla on epidermal surface.
58
What kind of muscle is the arrector pili muscle and where is its origin and insertion?
Smooth muscle
Origin: Superficial Dermis
InsertionL Connective tissue sheath of hair follicle
59
What do Pacinians Corpuscles look like and where are they found?
Look like onions.
| Found in : dermis and visceral organs (hard to find on histology)
60
Where are Herbst Corpuscles found?
Found in Dermis of Beaks, lower legs, scattered throughout
61
What parts are there to Herbst Corpuscle?
Central Nerve, Fluid Filled Lamellae and the outer capsule. Also hard to find on histology
62
Subcutis is made of
adipose tissue
| Big cells with nuclei in periphery
63
Why is adipose tissue important
vital for energy storage and thermoregulation.
64
Types of tumors found involving adipose tissue.
Lipomas: Benign tumor
Liposarcoma: Neoplasia
65
What are the two parts of the CNS?
Brain and Spinal Cord (include meninges, CSF, Cerebrum, Cerebellum, brain stem, spinal cord)
66
How does the PNS break down?
Autonomic Nervous system (Sympathetic and parasympathetic) and somatic nervous system (includes nerves (cranial and spinal) ganglia, plexuses of ANS)
67
What is the Job and structure of neurons?
Job: Function and metabolism
Structure: Dendrites, Soma, axon, telodendron.
Two main properties: irritability and conductivity.
Ectoderm Origin
68
What cells are names of glial cells?
Astrocytes
Oligodendrocytes
Microglial cells
Ependymal Cells
69
What germ layer is nervous tissue from?
Ectoderm
70
What are the names of the covers of spinal cord ( from furthest out to inner surface)?
Pachymenix ( thick) - Dura Matter
Leptomeninx ( thin, fine) Arachnoid and Pia matter
( Dura mater, arachnoid membrane attaches to dura mater, subarachnoid space(contains CSF) and then Pia Mater (Highly Vascular, adherent to brain and spinal cord))
71
What are the divisions of the brain?
Forebrain (prosencephalon (cerebrum and diencephalon.)
Midbrain (mesencephalon)
Hindbrain ( mesencephalon and medulla oblongata)
*Midbrain and hindbrain are part of brain stem.
72
Grey Matter Vs. White Matter
Grey: contains neurons, glial cells, axons and blood vessels. Grey matter is peripheral in brain and central in spinal cord.
White: contains myelinated axons and glial cells, blood vessels. White matter is peripheral in spinal cord and central in the brain.
73
Oligodendrocytes
Functions: Provide support and myelin sheath to axons within the CNS. Will work on several axons at once.
Can be destroyed by virus/ toxins resulting in primary demyelination.
Small dark nuclei ( between myelin sheaths or around neurons)
Ectoderm Origin
74
Microglia
Functions: Immune surveillance, Immunoregulation, Reparative ( phagocytic)
Glitter cells are globular / swollen after having phagocytized debris from injured cells. Derived from monocyte ( macrophage of CNS)
Mesoderm Origin
75
Astrocytes
Functions: Transport of Nutrients, Part of BBB, Antigen presentation
CNS fibroblast
Two Types: Protoplasmic (grey matter), and Fibrillar (white matter)
Can be seen with GFAP staining
Ectoderm origin
76
Components of CNS origins
```
Ectoderm ( sensitive to hypoxia)
- Neurons
- Astrocytes
- Oligodendrocytes
Mesoderm (not as sensitive to hypoxia)
- Microglia
- Vascular epithelium
```
77
What is lipofuscin?
Can occur in cells with age. Yellow cells.
78
Stimulatory Synapse Vs Inhibitory Synapse
Stimulatory Synapse: Synaptic vesicles contain acetylcholine
| Inhibitory Synapse: Synaptic vesicles contain GABA
79
Where can you find Ependymal Cells
- Choroid plexuses and produce CSF
| - Central Canal of spinal cord (cilia present to help circulate CSF)
80
What is CSF?
Transudate formed by capillaries and ependymal cells, the choroid plexuses of the lateral, 3rd and 4th ventricles of brain.
Functions: Nourishes CNS tissue/ acts as a cushion
Produced and must be drained away at constant rate. Total volume renewed 3x a day.
81
Cerebellum (Grey Matter) layers
Molecular Layer ( contains basket cells)
Ganglionic Layer ( purkinje cells)
Granular cell layer: Granule cells in stratum granulosum
White matter is the core- Myelinated nerve fibers.
82
What is the difference between a fetal cerebellum/ newborn cerebellum and an adult?
Fetal/ Newborn cerebellum have an exterior cortical lamina ( another granule cell later ahead of the molecular cell layer)
83
What are the connective tissues called around a nerve?
Endoneurium : Around the individual nerve cells.
Perineurium: Around the individual nerve fiber
Epineurium: Around a bundle of fibers.
84
What is the origin of cardiac tissue?
Mesoderm
85
What is Hardware disease? And who is affected?
Disease in cows. Infection of pericardial sac due to hardware/ items puncturing retinaculum next to heart and causing infection of pericardial sac
86
What is the purpose of the cardiovascular system?
Deliver O2 and nutrients to living tissue. Remove CO2 and waste products to be metabolized/ excreted.
87
Parts of Cardiovascular System
Heart- Blood pumps via system of "pipes"
Arteries- Efferent vessels (from heart) Transporting blood w/ nutrients and O2 to tissues.
Veins- Afferent vessels (into heart) Transports blood and waste/CO2 to lungs
Capillaries - thin connections between arteries and veins.
All components lined by endothelial cells
88
What kind of epithelial tissue lines the cardiovascular organs?
Simple squamous epithelium
89
Capillaries
Composed of endothelium, basement membrane w/o smooth muscle.
Intercellular junctions can be: Zona occludens ( tight junctions) or Zona adhaerens ( terminal bar)
Function: Serves as site of gas exchange, nutrient exchange, immune cell exit into interstitium
90
What are the three types of capillaries?
Continuous: Lacks pores/ openings (sites of minimal to no substance exchange) (Found in Nervous system, BBB, Blood Testis Barrier)
Fenestrated: Pores/ Fenestrations in wall of endothelial cells, closed by diaphragm (sites of high exchange) (Found in: Choroid plexuses, eye, intestines, endocrine glands, kidneys)
Sinusoidal: discontinuous, large gaps/ pores. Discontinuous basement membrane (sites of high particle and even cell exchange) (Found in Liver, none marrow, spleen)
91
Which two capillaries need Electron microscopy to tell apart?
Continuous and Fenestrated
92
What are pericytes?
Origin: Mesenchymatous (mesoderm)
- Rouget Cells: elongated nucleus with cytoplasmic projections/ own basal lamina.
- Partially encircle endothelial cells in capillaries/ venules.
- Capable of Contractility ( actin, myosin, tropomyosin)
- Paracrine communication with endothelium.
Think of pericytes- parisite.
93
What is angiogenesis?
Formation of new blood vessels.
94
Capillary Beds are ....
abundant in organs w/ high metabolic rate. (Kidney, liver, cardiac, skeletal muscle)
- Metarterioles are narrowest branches of arterioles surrounded by smooth muscles and branch into capillaries.
95
What happens with capillaries when you blush?
Contracted pre-capillary sphincters are present when you are not blushing, when they relax the capillaries fill with blood and you blush.
96
What is the structure of blood vessels?
Layers:
- Lumen: Site of Blood cell movement
- Intima/ inner (endothelium (simple squamous) Sub-endothelium (fibroblasts/ minimal ECM) Internal elastic membrane ( elastic fibers)
- Media ( smooth muscle) Connective tissue( Fibroblasts + Fibers (collagenous and elastic)
- Adventitia (connective tissue) Fibroblasts and fibers (collagenous and elastic) Vasa Vasorum ( blood vessels supplying blood to media/ adventitial layers)
97
What is the vasa vasorum?
small blood vessels on surface to supply blood to media/ adventitial layers
98
Arterioles Structure
- Intimal layer ( no sub endothelial membrane), very thin/ absent, elastic membrane
- Median (4-5 smooth muscle layers) No outer elastic membrane
- Adventitial Layer ( thin)
99
Small caliber arteries
aka muscular arteries (majority)
Follow general. structure except median layer
Median layer: up to 40 smooth muscle layers, elastic layer present, and thickness depends on caliber.
100
Large Caliber arteries
aka elastic arteries
aorta/ branches best example
Follow general vessel structure except outer elastic layer is indistinguishable.
highest amount of elastic fibers, has yellow walls.
101
Venules
Function: participate in metabolite exchange (thinnest/ smallest)
Intima layer: just endothelium layer (no sub endothelium/ no elastic layer.), some pericytes.
Median muscular layer: few layers of smooth muscle
Adventitial layer : Thin collagenous connective tissue ( not well defined)
102
Veins- Small to medium caliber
- Majority of veins
Intima layer +/- subendo layer
Median- Few layers of smooth muscle/ collagenous fibers
Adventitial layer: prominent collagenous connective tissue
Valves are present as extensions of intima ( mostly elastic fibers covered by endothelium)
103
Veins Large Caliber
Intima layer +/- subendo layer
Median- Few layers of smooth muscle/ collagenous fibers
Adventitial layer: prominent collagenous connective tissue + smooth muscle fibers ( vasa vasorum)
Valves present
104
Lymphatics
Similar to veins/ venules but w.o blood cells. Filled with protein rich lymph.
105
Lymphatic Capillaries
* dead end start, not coming from anywhere*
- lined by epithelial cells (larger than in capillaries)
- openings between cells, overlapping edges prevent back-flow.
106
Lymphatic vessels
Endothelium
- valves present, minimum smooth muscle or connective tissue
Lymph is high in protein so it will be pink, will usually be lost in processing.
107
What are the embryonic origins of cardiovascular structures?
All come from mesoderm except cardiac septa and valves which come from ectoderm.
108
What are the stages of vessel development?
Vasculogenesis: Purpose and end: endothelial cell differentiation
Angiogenesis: Formation of vessels
109
Congenital Defects of the heart
- PDA: Persistent ductus arteriosus ( ductus arteriosus remains patent/ open) Results in non oxygenated blood in aorta
- Persistent right aortic Arch ( Normally left aortic arch, food intake issues occur due to constriction of esophagus)
- Valvular Pulmonary Stenosis : Narrow Valve opening.
- Arterial Pulmonary Stenosis: Narrowing of walls of arteries
- Aortic stenosis: Narrowing of opening of aorta
- Intra Atrial septal defect: Septum didn't close
- Patent Foramen ovale: Can happen but not the most problematic.
- Inter-ventricular Septal defect: Not livable must be surgically corrected.
- Tetralogy of Fallot: 4 defects in 1
- Dilation/ hypertrophy of right ventricle
- Inter ventricular septal defect
- Pulmonary Stenosis
- Enlarged Aorta
110
What part of the atrium usually closed after birth?
Foramen ovale
111
Why have a foramen ovale?
So most of O2 rich blood by passes the lungs in fetus ( O2 rich blood coming from placenta and does not need/ cant breath while in utero)
112
What is the function of blood?
- distribution system of the body.
- involved in CO2/O2 exchange, enzyme/vitamin/ and hormone delivery to tissues
- Removes tissue wastes
- regulates body temperature
- maintains osmotic balance
- regulates cellular and fluid pH
- defends against micro-organisms.
113
What are the cellular and fluid components of blood?
- Connective tissue made of formed elements in a fluid matrix.
Formed elements - RBC (erythrocytes), White blood cells ( leukocytes), and platelets ( called thrombocytes in some species)
Fluid portion can be plasma or serum. Will be plasma if blood has been introduced to an anticoagulant.
Serum does not contain clotting factors, plasma contains clotting factors.
114
Function of Erythrocytes?
- transport CO2/O2 to and from tissues. O2 is carried via hemoglobin ( making up 33% of cytoplasmic protein content. (it also imparts flexibility/ deformity of RBC.)
115
What is the membrane composition of RBC
◦ RBC Membrane composition:
50% proteins ( glycoproteins are used to determine blood type ),
40% Lipid,
10% Carbohydrate.
116
What is the Blood types of dogs and cats
Blood Types
- Feline: A, B, AB,
- Canine: Dog Erythrocyte Antigen (DEA system with 8 subtypes)
117
How is the morphology of RBC determined?
◦ Morphology: Variation in size and shape ( species dependent)
Size variation = anisocytosis,
Variation in shape: poikilocytosis.
118
What is the morpholgy of RBC of each species?
‣ Canine RBC: largest RBC ( in mammals (7um in diameter (is biconcave disk shape with central parllor.
‣ Feline RBC: slightly smaller than canine RBC, with little central parlor +/- spikes along cell membrane (crenation)
‣ Equine RBC: Stack on top of each other ( called Rouleaux formation)
‣ Bovine RBC: Slight size variation in RBC ( anisocytosis)
‣ Caprine RBC: Variation in shapes of RBC (poikilocytosis), smallest RBC (4.1 UM)
‣ Camelids RBC: Elliptical shaped without nuclei.
‣ Avian, Fish, Reptiles, Amphibians RBC: Elliptical shaped with nuclei
119
What are Granulocytes?
have specific cytoplasmic granules, neutrophils, eosinophils, and basophils. Also called PNM ( polymorphonuclear leukocytes due to nuclear shape (segmented)
120
Which are bigger RBC or Leukocytes?
Leukocytes are larger in size and less numerous than erythrocytes. They also have primary ( azurophilic granules), typically not seen under microscope.
121
What are Agranulocytes?
lack specific cytoplasmic granules, include lymphocytes/ monocytes, also called mononuclear leukocytes due to lower amount of nuclear segmentation.
122
What is the Morphology of a neutrophil?
Specific granules stain "neutrally" with routine hematological stains and are typically not visible under the microscope. Cytoplasm appears pale pink in color while nucleus is dark purple and looks pinched/ segmented.
123
What is the function of a neutrophil?
Bacterial defense
- Phagocytosis of bacterial organisms (NADPH oxidase enzyme and free radicals such as superoxide, hydroxyl radical and H2O2 aid in killing bacteria. Primary granules contain myeloperoxidase which enhances bactericidal potency of H2O2.
- Secondary granules contain lysozyme and lactoferrin. Lysozyme breaks down peptidoglycan of bacterial cell wall.
- Heterophils found in avian, reptiles and some mammals (rabbits) Functionally equivalent to neutrophils, granules are rod shaped and orange red in color.
124
What is the morphology of an Eosinophil?
Specific cytoplasmic granules stain orange red with acidic dyes. Can differentiate between species based on appearance of eosinophilic granules. Nucleus similar to that of a neutrophil, may be less dense/ lighter in color with fewer segmented areas.
125
What is the function of an eosinophil?
- Less phagocytic abilities than neutrophils. - Poor bacterial/ viral defense.
- Allergic disease ( type 1 hypersensitivity allergic reactions ( releases histamninase, removes antigen antibody complexes).
- Also Kills helminths. It binds to opsonized parasites via surface receptors to IgG and complement, Releases NADPH oxidase which generates extracellar oxidants. Exocytose granules in the area of the invading parasite.
- Granule contents that aid in defense. Peroxidase, major basic protein, eosinophilic cationic protein
126
What is the Morphology of a basophil?
- Specific cytoplasmic granules stain light lavender to grey in cat; dark purple in other species ( should match color of nuclear chromatin)
- Nucleus slightly lighter then neutrophil ( can be more ribbon shaped/ tortuous especially in dog.
127
What is the function of a basophil?
- Allergic and inflammatory disease
- Release of histamine and serotonin (serotonin mediates vasodilation in allergic rxn)
- Have receptors for IgE and IgG (IgE immediate degranulation anaphylactic reaction)
- Helminth defense
128
What is the morphology of a lymphocyte?
Most numerous leukocyte in ruminants and pigs. Size us variable (small to large 6-15 um) small lymphocytes are about the same size as a RBC. Tend to be larger in ruminants. High nuclear to cytoplasmic ratio ( thin rim of light blue cytoplasm, and round dark purple nucleus that takes up most of the cell.
129
What is the functions of a lymphocyte?
T Lymphocytes:
- Cellular immunity
- CD4 develop into subsets of helper T cells, recruitment and activation of other immune cells, defense against helminths.
- CD8: Destroy virus infected and neoplastic cells.
- T lymphocytes also control hematopoiesis. B lymphocytes:
- function in humoral immunity with the production of immunoglobulin (antibodies)
130
What is the morphology of a monocyte?
- Largest leukocyte (can be 2x size neutrophil (15- 20 um in diameter.
- Cytoplasm: grey to light blue often containing round clear vacuoles.
- Rarely you can see fine dusting of pink-
purple azurophillic granules.
- Nucleus: chromatin is lighter than other leukocytes, appears lacy or patchy.
- Shape is variable: Oval to kidney bean shape, butterfly or horseshoe shaped.
131
What is the function of a monocyte?
- include phagocytosis
- antigen presentation to T lymphocytes
- release of cytokines involved in regulation of inflammation and hematopoiesis. - Circulation in blood as precursors of the mononuclear phagocyte system.
- Become Macrophages in tissues (Histiocytes in skin, Kupffer cells in liver, pulmonary alveolar macrophages in lungs.
132
What is the morphology of platelets?
Not truly cells, membrane bound fragments of cytoplasm, no nucleus, and appears light blue and small with reddish purple small granules.
133
What is the function of platelets?
- Called thrombocytes in avians, fish, amphibians, and reptiles.
- Usually 200,000- 400,000/ uL of blood (varies via species).
- Plays important role in hemostasis.
- Forms plug to stop bleeding.
134
Where can you find simple squamous epithelium?
Lining of vessels, Serous lining of cavities (pleura, pericardium, peritoneum, mesothelium)
135
Where can you find simple Cuboidal epithelium?
Covering ovary/ thyroid.
136
Where can you find simple columnar epithelium?
Lining of intestines ( w/ brush border), gallbladder.
137
Where can you find stratified squamous (non keratanized)?
Mouth esophagus, larynx, vagina, anal canal
138
Where can you stratified squamous (keratinized)?
Epidermis
139
Where can you find stratified cuboidal?
Sweat glands/ developing ovarian follicles
140
Where can you find stratified columnar?
Conjunctiva
141
Where can you find transitional epithelium?
Bladder, ureter, renal calyces.
142
Where can you find pseudostratified epithelium?
Lining of trachea, bronchi, nasal cavity
143
What is merocrine secretion?
secretion of products via exocytosis
| example some sweat glands
144
What is apocrine secretion?
secretion of pinched off portion of cytoplasm.
| example some sweat glands and mammary glands
145
What is holocrine secretion?
secretion of disintegrated cells.
Example: sebaceous glands.
Once all particles are gone they die.
146
Endocrine glands vs. Exocrine glands
Endocrine: lacks ducts, secreted substances are hormones and are carried through body by interstitial fluid, that has specificity to a target cell. Endocrine system, thyroid gland hormone.
Exocrine: have ducts, secretions are carried to specific sites. Simple glands are unbranched, compound glands are branched.
