Histology Midterm Quiz 2 Content

Front 1

Endocardium consists of what 3 layers?

Back 1

1. Endothelium - lined by simple squamous epithelium
2. Inner sub-endothelial layer - dense irregular CT w/ collagen and elastic fibres and occasional SMC
3. Outer sub-endothelial layer - loosely arrounged collagen and elastic fibres (and some purkinje fibres).

Front 2

Heart wall is composed of what 3 layers?

Back 2

1. Endocardium
2. Myocardium
3. Epicardium

Front 3

Which layer of the heart wall is the thickest?

Back 3

Myocardium

Front 4

Myocardium consists of (4 things)?

Back 4

1. Cardiac muscle cells
2. SA and AV nodes
3. Purkinje fibres
4. Cardiac skeleton

Front 5

Cardiac skeleton is comprised of what 3 parts?

Back 5

1. Fibrous rings
2. Fibrous triangle
3. Fibrous part of the interventricular septum

Front 6

What lines external to the epicardium?

Back 6

Visceral pericardium

Front 7

What is in the pericardial cavity?

Back 7

Serous fluid, which lubricates the surfaces for frictionless cardiac movement

Front 8

Which layer of the blood vessels contains vasa vasorum and/or nervi vasorum?

Back 8

Tunica externa/adventitia

Front 9

Which layer is the thickest in elastic arteries?

Back 9

Tunica media

Front 10

Internal elastic membrane is indistinct in elastic arteries. T or F?

Back 10

True

Front 11

The external elastic membrane of muscular arteries is distinct. T or F?

Back 11

It is not always clearly defined.

Front 12

External elastic membrane of arterioles is absent. T or F?

Back 12

True

Front 13

Tunica media of arterioles are super thick. T or F?

Back 13

False. Tunica media has 1 to 3 layers of smooth muscles (thin).

Front 14

Capillaries are composed of (4 things)?

Back 14

1. Endothelial cells
2. Associated basal lamina
3. Pericytes
4. Thin adventitial CT layer

Front 15

Endothelial cells in continuous capillaries are held together by?

Back 15

Tight Junctions

Front 16

Where can you find fenestrated capillaries?

Back 16

In GI Tract

Front 17

Where are porous capillaries found?

Back 17

Kidney glomerulus

Front 18

Which layer is thinner in veins? Tunica media or Tunica externa?

Back 18

Tunica media (whereas tunica media is the thickest in arteries)

Front 19

Are lymph capillaries larger or smaller than blood capillaries?

Back 19

LARGER!

Front 20

What layer is absent in LARGE lymph vessels?

Back 20

Internal elastic membrane is usually absent

Front 21

What are arteriovenous anastomoses?

Back 21

Direct connections b/w arterioles and venules without an intervening capillary bed

Front 22

What is the function of arteriovenous anastomoses?

Back 22

- Regulation of blood pressure (faster and direct regulation)
- Thermoregulation (keeps body warm)
- Erection

Front 23

Blood can be specially stained by?

Back 23

Wright's stain

Front 24

Composition of settled or centrifuged blood?

Back 24

- 45% packed cell volume or hemocrit (erythrocytes) in lowest layer
- 1% buffy coat in middle layer (thrombocytes and leukocytes)
- Plasma in uppermost layer

Front 25

A mature erythrocyte has how many nucleus?

Back 25

NON-nucleated in most domestic animals.

Front 26

What is anisocytosis?

Back 26

Variation in SIZE of the erythrocytes.

Front 27

What is poikilocytosis?

Back 27

Variation in the SHAPE of the erythrocytes.

Front 28

What is anemia?

Back 28

Decreased # of erythrocytes in blood.

Front 29

Rouleaux formation is prominent in which animals?

Back 29

Prominent in horses and cats, intermediate in dogs and pigs.

Front 30

What are Heinz Bodies? Are they pathological?

Back 30

Heinz Bodies are inclusions within RBC's composed of denatured hemoglobin, and they are pathological.

Front 31

Life span of RBC in dogs, cats, cow, pigs, and horse/sheep?

Back 31

Cow: 160 days
Horse/sheep: 150 days
Dogs: 120
Pigs: 85 days
Cats: 75 days

Front 32

What are the 3 polymorphonuclear granulocytes (leucocytes)?

Back 32

Neutrophil, eosinophil, basophil

Front 33

What are the 2 mononuclear agranulocytes (leucocytes)?

Back 33

Lymphocytes and monocytes

Front 34

Which species have more lymphocytes than neutrophil?

Back 34

Food animals! Pig, cow, sheep, goat, and chicken

Front 35

Which species have more neutrophil than lymphocytes?

Back 35

(non-food animals) Horse, dog, cat - NEUTRAL animals...

Front 36

Which polymorphonuclear granulocyte has a multi-lobulated nucleus? Bi-lobulated nucleus?

Back 36

Neutrophil has a multi-lobulated nucleus, and eosinophil has a bi-lobulated nucleus.

Front 37

In which species shows a mulberry-like appearance from extremely large and tightly packed granules in eosinophils?

Back 37

Horses

Front 38

Basophils are similar to what kind of cells, in that they both release histamine and heparin (mediate inflammatory reactions)?

Back 38

Mast cells

Front 39

What is the most prominent circulating lymphocyte?

Back 39

T-Lymphocyte

Front 40

Where is B-lymphocyte derived from in birds?

Back 40

Cloacal bursa

Front 41

3 types of lymphocytes are?

Back 41

B-lymphocyte
T-lymphocyte
NK cell

Front 42

Which leucocyte (WBC) is the biggest?

Back 42

Monocyte

Front 43

All phagocytic cells (i.e. macrophages) are derived from?

Back 43

Monocyte

Front 44

What is the primary site of hematopoisis (blood cell formation) in adult animals?

Back 44

Bone marrow

Front 45

Fate of blood cells from embryo:

Back 45

-Early embryo: hematopoisis in wall of yolk sac
-Later in embryo: hematopoitic cells migrate to fetal liver
-Subsequently cells from liver migrate to bone marrow, spleen, lymph nodes, and thymus of embryo

Front 46

Which part of the bone marrow is actively involved in hematopoisis?

Back 46

Red marrow is actively involved, whereas yellow marrow is inactive and contains FAT.

Front 47

Lymphocytes are derived from which stem cell?

Back 47

Lymphoid stem cells (NOT myeloid stem cells)

Front 48

Myeloid stem cells form all other blood cells, except for which cells?

Back 48

Lymphocytes!

Front 49

What are the 2 main classifications of leucocytes?

Back 49

Polymorphonuclear granulocyte and mononuclear agranulocyte

Front 50

What are the 3 stromal cells of the immune system?

Back 50

1. Reticular cells
2. Epithelial reticular cells
3. Dendritic cells

Front 51

From the 3 stromal cells of the immune system, which cell forms reticular fibres?

Back 51

Reticular cells (NOT epithelial reticular cells)

Front 52

Major function of dendritic cells in the immune system?

Back 52

Capture and present antigens to lymphocytes and form stroma of lymphatic tissue

Front 53

4 types of dendritic cells in the immune system?

Back 53

1. Follicular dendritic cells
2. Interdigitating dendritic cells
3. Intra-epidermal macrophage (Langerhan's cell)
4. Veiled cells

Front 54

What is the function of primary lymphoid organs?

Back 54

Produce lymphocyte PRECURSORS

Front 55

What are the 5 primary lymphoid organs?

Back 55

1. Embryonic yolk sac
2. Thymus
3. Gut-Associated Lymphoid Tissue (GALT) - Payer's patches
4. Cloacal Bursa in birds
5. Bone marrow

Front 56

What is the function of secondary or peripheral lymphoid organs?

Back 56

House mature immunocytes, and it is the site of immune responsiveness

Front 57

What are the 3 secondary lymphoid organs?

Back 57

1. Lymph nodes
2. Spleen
3. Mucosa-Associated Lymphoid Tissue (MALT) - in GI tract, thyroid, breast, lung, eye, skin, etc.

Front 58

Lymph nodes contain afferent or efferent vessels?

Back 58

BOTH afferent and efferent vessels

Front 59

The capsule surrounding the lymph nodes is composed of?

Back 59

Dense irregular CT and a few elastic fibres

Front 60

Trabeculae of lymph nodes extend from what to what?

Back 60

Trabeculae extend from the CAPSULE into the PARENCHYMA

Front 61

Sinuses of lymph nodes in the order of how lymph drains:

Back 61

1. Subcapsular sinus
2. Trabecular sinus
3. Medullary sinus

Front 62

Which cells lie free within the stromal mesh in the sinus lumen of lymph nodes?

Back 62

Lymphocytes and macrophages

Front 63

Where are primary and secondary lymphatic nodules located in the lymph nodes?

Back 63

Outer cortex

Front 64

Which lymphatic nodule of the outer cortex contains germinal centres, which have a dark zone (large lymphocytes w/ intense mitotic activity) and a light zone (sm. lymphocytes w/ few mitotic activity)?

Back 64

Secondary lymphatic nodules

Front 65

The medullary cords in the medulla of lymph nodes are composed of what 3 cells?

Back 65

1. Lymphocytes
2. Plasma cells
3. Macrophages

Front 66

In which species is the cortical and medullary tissues reversed?

Back 66

PIGS

Front 67

What is different about the thymus from other lymphoid organs?

Back 67

Thymus is divided into LOBULES; each lobule has a peripheral dark zone (cortex) and a central light zone (medulla)

Front 68

The cortex of thymus contains what 2 things?

Back 68

1. Epithelial reticular cells
2. Lymphocytes

Front 69

Where are Hassal's/thymic corpuscles located?

Back 69

Medulla of thymus

Front 70

The blood-thymic barrier is formed by what 3 things?

Back 70

1. Capillary endothelium
2. Perivascular space
3. Sheath of epithelial cell process

Front 71

Thymus has both afferent and efferent lymphatic vessels. T or F?

Back 71

FALSE. Thymas has NO afferent lymphatic vessels.

Front 72

4 functions of spleen:

Back 72

1. Serves as filter for blood by removing abnormal or worn out RBC's
2. To store RBC and platelets, as well as Fe for Hb synthesis
3. Erythropoiesis in fetus
4. It is a lymphatic tissue involved in immune responses against blood-bourne antigens

Front 73

The splenic parenchyma is composed of 2 things:

Back 73

RED AND WHITE PULP

Front 74

Reticular cells are of mesenchymal origin and form a reticulum in lymphatic organs EXCEPT FOR??

Back 74

Thymus and cloacal bursa (they have epithelial reticular cells, which are stellate shaped)

Front 75

Why is the red pulp of the spleen RED?

Back 75

Splenic cords in the red pulp are enmeshed with RBC's (as well as macrophages, lymphocytes, plama cells and other WBC's).

Front 76

White pulp consists of?

Back 76

1. Lymphatic nodules
2. Periarterial lymphatic sheaths (PALS)

Front 77

Reticular cells or epithelial reticular cells in the spleen?

Back 77

Reticular cells

Front 78

What is in the periarterial lymphatic sheats (PALS) in the white pulp of the spleen?

Back 78

T-cells; and in the periphery of the sheaths: mixture of T-cells, B-cells, and macrophage

Front 79

Where is the marginal zone of spleen?

Back 79

Between white and red pulp; forms the periphery of the white pulp, bounded by circumferential reticular network w/ B-cell and macrophages

Front 80

Where does the splenic artery end up?

Back 80

SPLENIC ARTERY --> TRABECULAR ARTERY --> ARTERY OF THE WHITE PULP --> PULP ARTERIOLES (in red pulp now) --> SHEATHED CAPILLARIES / ELLIPSOIDS

Front 81

3 theories regarding the junction of the terminal capillaries of spleen:

Back 81

1. Closed Theory
2. Open Theory
3. Mix of both

Front 82

What is the closed theory of the terminal capillaries of spleen?

Back 82

The terminal capillaries open DIRECTLY into the splenic sinuses/venules

Front 83

What is the open theory (spleen)?

Back 83

The terminal capillaries OPEN into the spaces b/w the reticular cells of red pulp, then enter the venous sinuses thru slits in their walls of the sinus.

Front 84

Regarding the mixed theory of spleen's terminal capillaries, when does the open form predominate?

Back 84

Open form predominates when spleen is distended/swollen; closed form when spleen is contracted.

Front 85

Spleen does no have which lymph vessel?

Back 85

NO afferent vessel (like thymus)

Front 86

Whre do efferent capsular and trabecular lymph vessels originate from? And where do they drain into?

Back 86

Originate in the white pulp and drain into splenic lymph nodes

Front 87

Which species have poorly developed sinuses in the spleen (non-sinusual spleen)?

Back 87

Cat
Horse
Pig
Ruminants
(SINUSES ABUNDANT ONLY IN DOGS)

Front 88

Where are ileal peyer's patches present in young ruminants, pigs, and carnivores?

Back 88

Distal jejunum and ileum

Front 89

Which lymphatic structure lies beneath or in contact with the epithelium?

Back 89

Tonsils

Front 90

Tonsils with a smooth surface are called what and in which species?

Back 90

Palatine tonsil of DOG AND CATS

Front 91

Tonsils with deep invaginations are called what, found where, and in what species?

Back 91

Referred to as tonsillar fossulae; lingual tonsil in horse, palatine tonsil in horses and ruminents

Front 92

Lymphatic nodules, located beneath the epithelium (tonsils) frequently possess what?

Back 92

Germinal centre

Front 93

In what species are hemal nodes found in?

Back 93

ONLY IN RUMINANTS!

Front 94

Tell me about the hemal node...

Back 94

- Cortex and medulla are NOT distinct
- NO lymph vessels
- Receive all their antigens from... BLOOD only!

Front 95

What is the most important function of the respiratory system?

Back 95

Gas exchange

Front 96

What are the 3 regions of the nasal cavity?

Back 96

1. Cutaneous
2. Respiratory
3. Olfactory

Front 97

How does the epithelium change in the cutaneous region of nasal cavity?

Back 97

- Rostrally: nasal vestibue is lined by stratified squamous keratinized epith.
- At mid-vestibule: thinner and NON-keratinized
- Caudally, the transitional zone is lined by stratified cuboidal or non-ciliated pseudostr. epith.

Front 98

In horses, this structure in the cutaneous region of nasal cavity contains hairs, sebaceous and sweat glands.

Back 98

Nasal diverticulum aka fake nostrils

Front 99

The caudal 2/3 of the nasal cavity is what?

Back 99

Respiratory region

Front 100

Respiratory region is lined by which epithelium?

Back 100

Ciliated pseudostratified columnar epithelium

Front 101

What are the 4 types of cells found in the respiratory region of the nasal cavity?

Back 101

1. Ciliated cells
2. Secretory cells
3. Brush cells
4. Basal cells

Front 102

How is cilia different from microvilli?

Back 102

Microvilli: cytoplasmic infolding
Cilia: microtubule

Front 103

What lines the olfactory region (dorsocaudal) of nasal cavity?

Back 103

Ciliated pseudostr. columnar epith.

Front 104

What 3 cells are found in the olfactory region?

Back 104

1. Neurosensory olfactory cells (bipolar)
2. Sustentacular cells
3. Basal cells

Front 105

What is the function of vomeronasal organ?

Back 105

Sexual behaviour by detection of odor of opposite sex

Front 106

What side of the vomeronasal organ has neurosensory, sustentaculr and basal cells?

Back 106

Medial

Front 107

Pharyngeal tonsil is found in?

Back 107

Dorsal portion of the nasopharynx

Front 108

The typical respiratory epithelium?

Back 108

Ciliated pseudostr. columnar

Front 109

Elastic cartilage is found in what parts of the larynx?

Back 109

Epiglottis and cuneiform process of the arytenoid cartilage

Front 110

Trachea is lined by what epithelium?

Back 110

Pseudostr. ciliated columnar epithelium w/ goblet cells

Front 111

Pyramidal-shaped cells abundant in young animals found in the trachea are?

Back 111

Neuroendocrine cells

Front 112

What is often observed in the epithelium of the trachea?

Back 112

A variety of migratory cells (lymphocytes, globular leucocytes, and mast cells)

Front 113

The dorsal free ends of the U-shaped hyaline cartilage in the trachea are bridged by what?

Back 113

Smooth muscle

Front 114

Lungs are covered by what pleura?

Back 114

Visceral or pulmonary pleura

Front 115

The visceral pleura of the lungs are lined by:

Back 115

Simple squamous epithelium AND a layer of CT which is continuous with interalveolar septa.......

Front 116

The visceral pleura of the lungs is the thickest in what species? and thinnest?

Back 116

Thickest in ruminants; thinnest in the dog and cat.

Front 117

The lung is divided into 2 sections:

Back 117

1. Intrapulmonary conducting airways
2. Gas exchange area

Front 118

Gas exchange occurs in the intrapulmonary conducting pathways (i.e. bronchi and bronchioles). T or F?

Back 118

FALSE. Only in the gas exchange area (alveoli)

Front 119

What happens to the # of clara cells as you go proximodistally in the bronchi?

Back 119

Epithelial height and # of goblet cells decrease while clara cells increase in #.

Front 120

What happens to the cartilages and smooth muscles in the bronchi as you go proximodistally?

Back 120

Cartilages decrease, whereas smooth muscles increase.

Front 121

What structure marks the END of the conducting division of air flow?

Back 121

Terminal bronchioles

Front 122

Which epithelium lines the bronchioles?

Back 122

Simple columnar or cuboidal epithelium with CILIATED and CLARA cells

Front 123

Cartilage and glands are absent in the propria-submucosa of what structure in the respiratory system?

Back 123

Bronchioles

Front 124

Parenchyma of the lungs are?

Back 124

Gas exchange area: respiratory bronchioles, alveolar duct & sac, and alveoli

Front 125

Where is the focus of MOST lung disorders?

Back 125

Respiratory bronchioles (aka transition zone)

Front 126

How are respiratory bronchioles different from terminal bronchioles?

Back 126

They are similar except, epithelium of respiratory bronchioles is interrupted by ALVEOLI

Front 127

In what species are respiratory bronchioles extensive?

Back 127

Carnivores

Front 128

In what species are respiratory bronchioles short or absent?

Back 128

Horse, cow, and pig

Front 129

The alveolar duct arises from what and terminates as what?

Back 129

Arises from respiratory bronchiole and terminates in clusters of alveoli called alveolar sac

Front 130

What are the 3 cell types in the alveoli?

Back 130

1. Pneumocyte Type I
2. Pneumocyte Type II
3. Pulmonary macrophages (in lumen)

Front 131

Which pneumocyte is prominent?

Back 131

Type I (95%)

Front 132

Which pneumocyte is a squamous epithelial cell with central nucleus?

Back 132

Type I

Front 133

Which pneumocyte produces pulmonary surfactant?

Back 133

Type II (granular alveolar cell)

Front 134

Air-blood barrier is composed of:

Back 134

1. Pneumocyte I cell
2. Basal lamina of pneumocyte I and basal lamina of capillary endothelial cells
3. The capillary endothelial cell
4. Plamalemma of RBC