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Histology > Exam #3 > Flashcards

Exam #3 Flashcards

1
Q

__________ on leukocytes allow the recognition and binding of surface components of such invaders.

A

Toll-like receptors (TLRs)

p.262 Junq

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2
Q

___________ destroy various unhealthy host cells, including those infected with virus or bacteria, as well as certain potentially tumorigenic cells.

A 
Natural killer (NK) cells
p.262 Junq
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3
Q

Decscribe (i.e. where, why, how) – Hydrochloric acid (HCl) and organic acids

A

Organic acids in specific regions lower the pH locally to either kill entering microorganisms directly or inhibit their growth.
p.264 Junq

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4
Q

Decscribe (i.e. where, why, how): Defensins

A

Short cationic polypeptides produced by neutrophils and various epithelial cells that kill bacteria by disrupting the cell walls.
p.264 Junq

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5
Q

Decscribe (i.e. where, why, how): Lysozyme

A

An enzyme made by neutrophils and cells of epithelial barriers, which hydrolyzes bacterial cell wall components, killing those cells.
p.264 Junq

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6
Q

Decscribe (i.e. where, why, how): Complement

A

A system of proteins in blood plasma, mucus, and macrophages that react with bacterial surface components to aid removal of bacteria.
p.264 Junq

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7
Q

Decscribe (i.e. where, why, how): Interferons

A

Paracrine factors from leukocytes and virus-infected cells that signal NK cells to kill such cells and adjacent cells to resist viral infection.
p.264 Junq

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8
Q

Define the role of Helper T cells – Cluster of differentiation?

  • Where do they mature?

- What class of molecules do they bind?

A 
(CD4+) Release cytokines  that promote differentiation of B cells into plasma cells, and generally enhance immune response. 
○ Mature in the medulla of the thymus. 
○ Binds MHC class II molecules.
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9
Q

Define the role of Cytotoxic T cells – Cluster of differentiation?

A 
Cytotoxic T cells (CD 8+): Bind specific antigens on foreign cells or virus-infected cells displayed by MHC class I molecules.
		○ i.e. contact and kill intruding cells.
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10
Q

Features common to all APCs (2)

A
  1. ) An active endocytotic system
  2. ) Expression of MHC class II molecules for presenting peptides of exogenous antigens.
    p. 268 Junq
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11
Q
  1. ) Stem cells for ALL LYMPHOCYTES originate in _________.

2. ) Where do a.) B cells, and b.) T cells mature?

A
  1. ) red bone marrow
  2. ) a.) B cells mature in the bone marrow.
    b. ) T cells migrate to, and mature in the thymus.
    p. 268 Junq
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12
Q

Receptors of B cells are ________ that bind ________ directly; those on T cells react only with _____ on _______ molecules and this requires the additional cell surface proteins ______ or ______.

A
  • immunoglobulins that bind antigens directly
  • antigen on MHC molecules and this requires the additional cell surface proteins CD4 or CD8.
    p. 268 Junq
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13
Q

Will T LCs induce a strong immune reaction or no reaction if they encounter an MHC that they encountered during development?

A

If the MHCs on cells of a tissue graft are not similar to those that T lymphocytes encountered during their development, the grafted cells will induce a strong immune reaction by T cells of the recipient.
p.266 Junq

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14
Q

List four secondary lymph structures

A

1.) Tonsils
2.) Lymph nodes (e.g. axillary, cervical)
3.) Spleen
4.) MALT in small intestine
#16

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15
Q

List two primary lymphatic structures

A

1.) Thymus
2.) Red bone marrow
#16

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16
Q

What is the purpose of central tolerance?
In which organ is it regulated?
What regulates peripheral tolerance?

A
  • Central tolerance prevents autoimmunity –A main function of the thymus.
  • Regulatory T cells regulate peripheral tolerance.
    p. 272 Junq
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17
Q

What is the difference in staining between the cortex and medulla of the thymus? What accounts for this difference?

A

Dark staining of the cortex due to greater density of T lymphoblasts (thymocytes) and small lymphocytes and their intensely-staining nuclei in the cortex than in the medulla.
p.272 Junq, p.467 Ross

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18
Q

List the three types of thymic cortical TECs and their main function(s)

  1. ) –3 things
  2. ) – 2 things
  3. ) –3 things
A

1.) Squamous TECs: Line the CT of the capsule and septa around the microvasculature.
○ They also help regulate the BLOOD-THYMUS BARRIER, which prevents unregulated exposure of thymocytes to antigens.
○ Must antigenically isolate the cortex from the blood in order for the maturation of T-cells to occur normally.

2.) Squamous Cortical TECs: Express MHC class II molecules and form a sheetlike corticomedullary barrier between the two regions of each lobule.

3.) Stellate TECs: Have processes containing keratin tonofilaments joined by desmosomes –Form a *cytoreticulum* to which macrophages and developing lymphocytes attach instead of to reticulin fibers. 
○ These cells are APCs, expressing MHC class II and class I molecules. 
○ Also secrete numerous cytokines for T cell development, justifying this organs inclusion among endocrine glands.

p.273 Junq

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19
Q

Unlike lymph nodes, the thymus does not possess _______ lymphatic vessels. However, ______ channels are present.

A

afferent lymphatic vessels. However, efferent channels are present.

p.329 Wilson

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20
Q

The thymus does not contain __________.

A

lymphoid nodules

p.329 Wilson

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21
Q

Large aggregates of B cells called ________ or _______ transiently characterize all secondary lymphoid organs.

A

lymphoid nodules or follicles

p.272 Junq

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22
Q

Which MHC classes are important for the development of CD8+ and CD4+ T cells (one for each)?

A 
CD8+ = MHC class I
CD4+ = MHC class II
p.275 Junq
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23
Q

T lymphocytes are said to be _____ restricted, why?

A

MHC restricted, because TCRs only recognize antigenic peptides when presented as part of MHC molecules (interacting with both the MHC and the peptide it presents).
p.270 Junq

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24
Q

What is the function of dendritic cells in immunity?

What is their origin?

A

Attach to and activate B cells in 2˚ lymphoid nodules, which then aggregate as a small 1˚ lymph nodule.
○ Mesenchymal in origin.
p.271 Junq

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25
Q

What is characteristic of 2˚ lymphoid nodules? What is happening there?

A

Secondary nodules are characterized by a lightly stained GERMINAL CENTER filled with large lymphoblasts (or centroblasts) undergoing immunoglobulin gene recombination, rapid proliferation, and quality control.
p.272 Junq

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26
Q

The thymus is the site of _______ differentiation and the selective removal of _______________, a key part of inducing central self-tolerance.

A

T-lymphocyte differentiation and the selective removal of T cells reactive against self-antigens, a key part of inducing central self-tolerance.

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27
Q

In the thymic medulla, the lymphocytes are ______ numerous than in the cortex.

A

less numerous

p.331 Wilson

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28
Q
  1. ) What structures are the key histologic features for identification of the thymus?
  2. ) What are they?
  3. ) Where are they?
A
  1. ) Hassall’s corpuscles. – No other organ has these bodies
  2. ) These structures are concentric layers of degenerating medullary epithelial cells.
  3. ) Hassall’s corpuscles are located ONLY in the thymic MEDULLA.
    p. 331 Wilson
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29
Q

In specimens stained w ith hematoxylin and eosin, Hassall’s corpuscles are _____-ophilic structures.

A

eosinophilic structures

p.332 Wilson

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30
Q

Epithelial reticular cells are in close proximity to _______ and, as such, are part of the ________ that prevents the migration of blood-borne antigens into the thymic cortex.

A
  • are in close proximity to blood vessels.
  • part of the blood-thymus barrier.
    p. 333 Wilson
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31
Q

The _______ are enclosed by epithelial reticular cells as part of the blood-thymus barrier, which assures the development of ______________________.

A

-The thymic lymphocytes are enclosed by epithelial reticular cells.

  • immunocompetence of the lymphocytes in the absence of blood-borne antigens.
    p. 334 Wilson
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32
Q

Before merging with the bloodstream, all lymph is ______ and has _______ added by at least one lymph node.

A

all lymph is filtered and has antibodies added by at least one lymph node.
p.277 Junq

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33
Q
  1. ) The most abundant cells of lymph nodes are… (5 general types).
  2. ) _____ are present within lymphoid nodules.
A
  1. ) lymphocytes of all types, plasma cells, dendritic cells, macrophages, and other APCs.
  2. ) FDCs –i.e. Follicular dendritic cells (p.271 Junq)
    p. 277 Junq
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34
Q
  1. ) Where in the lymph nodes are lymph nodules located?

2. ) What are largely formed by?

A
  1. ) Fill most cortical areas.
  2. ) Formed largely by helper T LCs and proliferating B lymphoblasts.
    p. 279 Junq
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35
Q

Each lymphoid nodule is organized around the long, interdigitating processes of _________, but these are not readily seen by routine light microscopy.

A

follicular dendritic cells (FDCs)

p.279 Junq

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36
Q

How can you histologically distinguish the paracortex from the outer cortex in a lymph node?
What is the paracortex rich in?

A

The paracortex does not have precise boundaries, but it can be distinguished from the outer cortex by its lack of B-cell lymphoid nodules

Paracortex rich in T-lymphocytes –only seen w/ immunohistochemistry.
p.279 Junq

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37
Q

What is the important entry point for ≈ 90% of lymphocytes into lymph nodes? Where are they located?

A

High endothelial venules (HEVs) –Postcapillary venules in the paracortex.
p.279 Junq

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38
Q

What is unusual about HEVs?

A

Unusual endothelial lining of CUBOIDAL CELLS, with apical glycoproteins and integrins that facilitate rapid diapedesis of LCs from the blood to the paracortex.
p.279 Junq

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39
Q

If draining from an infected or inflamed region, lymph arriving at a lymph node may contain _______ and _______.

A

microorganisms and cytokines.

p.280 Junq

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40
Q

Antigens arriving at lymph nodes that have not yet been phagocytosed will be internalized by ______ in the lymph nodes and presented on _______ molecules.

A
  • APCs
  • MHC class II molecules.
    p. 280 Junq
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41
Q

If activated by antigens in the lymph node, _____ will proliferate rapidly in ________ of follicles with the help of ______ cells, often enlarging the entire lymph node.

A
  • B cells will proliferate rapidly in germinal centers of follicles
  • Th cells
    p. 280 Junq
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42
Q

Activated cytotoxic T cells in the ______ proliferate to a much lesser extent than B cells, and without forming _______.

A
  • in the paracortex
  • without forming follicles.
    p. 280 Junq
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43
Q

What happens to newly made B cells that have been activated against a specific antigen in the lymph node? (2)

A
  1. ) differentiate as plasma cells and move to the medulla or 2.) Move to downstream sites beyond the lymph node where they produce antibodies.
    p. 280 Junq
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44
Q

The _____ contains lymph nodules, some of which have _________.

A
  • cortex contains lymph nodules
  • germinal centers
    p. 307 Wilson
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45
Q

The medulla of the lymph node has cords of _________ and _______ that will lead to the _________ emerging at the hilus.

A
  • cords of lymphoid tissue and sinuses
  • efferent lymphatic vessels
    p. 307 Wilson
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46
Q

The stroma of lymph nodes, spleen, and tonsils consists of _________ tissue (i.e. type _____ collagen). What stain best visualizes this?

A

reticular connective tissue (i.e. type III collagen) –SILVER STAIN
p.308 Wilson

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47
Q
  1. ) On either side of the lymph node trabeculae are _______ that are continuations of the ________.
  2. ) What are these structures are what do they do?
A
  1. ) Sinuses that are continuations of the subcapsular sinus.
  2. ) Trabecular Sinuses –Convey lymph deep into the organ and lead to the medullary sinus.
    p. 307 Wilson
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48
Q

_______ in the capsule and _______ of lymph nodes produce the reticular fibers and collagen fibrils that are found there.

A

Fibroblasts in the capsule and trabeculae

p.308 Wilson

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49
Q

FDCs are present in which portion of the lymph node?

A

FDCs are present within lymphoid nodules.

p.308 Wilson

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50
Q
  1. ) Lymph is transported to the lymph nodes via _______ vessels, which enter at the ________.
  2. ) _______ cells line this channel, and they are drained by the ________.
A
  1. ) via Afferent lymph vessels, which enter at the CT capsule.
  2. ) Flattened endothelial cells –drained by the subcapsular sinus.
    p. 309 Wilson
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51
Q

The afferent lymph vessel is lined with __________ epithelium that rests on a ________.

A
  • simple squamous epithelium
  • thin basal lamina
    p. 309 Wilson
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52
Q

The subcapsular sinus distributes the lymph to the _______ in the cortex.

A

trabecular sinuses

p.310 Wilson

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53
Q

The proximity of the ________ with the subcapsular and trabecular sinuses allows the cells of the immune system to respond to antigens present in the lymph fluid.

A

cortical nodules

p.310 Wilson

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54
Q

Lymph is drained from the lymph node via the __________ and the _______ vessels.

A

medullary sinuses and the efferent lymph vessels.

p.310 Wilson

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55
Q

________ are the only organs of the body with both afferent and efferent lymphatic channels. The other organs possess only _______ lymphatic vessels.

A
  • Lymph nodes
  • efferent lymphatic vessels
    p. 310 Wilson
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56
Q

In lymph nodes, dendritic cells are located in both the ________ and ________ sinuses and function as _______ cells and ________ cells.

A
  • subcapsular and trabecular sinuses
  • phagocytic cells and antigen-presenting cells.
    p. 311 Wilson
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57
Q

Often, _______ are found in the nodules as evidence of their response to antigens.

A

germinal centers

p.312 Wilson

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58
Q

Secondary nodules are characterized by a _______________ filled with large ____________. What processes are they undergoing? (3)

A
  • lightly stained germinal center
  • lymphoblasts (or centroblasts)
  • immunoglobulin gene recombination, rapid proliferation, and quality control.
    p. 272 Junq
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59
Q

What are medullary cords of lymph nodes? What do they contain? Do they stain lighter of darker than medullary sinuses?

A

Medullary Cords are masses of lymphoid tissue extending from the paracortex.
○ Contain T and B lymphocytes, as well as macrophages and many plasma cells.
○ DARKER STAINING
p.313 Wilson

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60
Q

The ________ and ______ converge to form the efferent lymphatic channels, which leave the lymph node at the ______.

A
  • medullary and cortical sinuses
  • hilus
    p. 313 Wilson
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61
Q
  1. ) The medullary sinuses are _____ spaces lined by a_________ that separate the ________. What do they do?
  2. ) What do their lumens contain/do, and what do the sinuses contain?
A

1.) The medullary sinuses are dilated, thin-walled spaces lined by discontinuous epithelium that separate the medullary cords. They allow the passage of lymph fluid (and LCs and plasma cells) out of the lymph nodes.

2.) The lumens include a meshwork of reticular cell processes (which act as a final lymph filter).
Contain macrophages and sometimes neutrophils.
p.279 Junq, p.316 Wilson

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62
Q

Lymph nodules occupy the ________, but do not extend into the ________.

A

occupy the cortex but do not extend into the medulla

p.314 Wilson

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63
Q

The majority of lymphocytes enter the node via the __________ in the ______ and _______.

A

postcapillary venules in the medulla and paracortex.

p.314 Wilson

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64
Q

In lymph nodes, B lymphocytes differentiate into _______, which accumulate in _________.

A 
differentiate into plasma cells, which accumulate in medullary cords.  
#36
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65
Q

Which part(s) of the body drain into the right lymphatic duct? Where does it drain?

A

-Right upper body –superior to the umbilicus, and from the midline laterally to the right.
-Drains into the right internal jugular/subclavian veins.
#42

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66
Q

Which part(s) of the body drain into the thoracic duct? Where does it drain?

A

-Everything that’s not in the right upper body.
-Drains into the LEFT SUBCLAVIAN VEIN.
#42

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67
Q

As is true of other ____________ organs, the spleen is a production site of _______ and _______, which here are delivered directly into the ______.

A
  • secondary lymphoid organs
  • antibodies and activated lymphocytes
  • directly into the blood
    p. 281 Junq
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68
Q

The spleen’s volume varies with its content of _______.

A

content of blood

p.281 Junq

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69
Q

In the spleen large trabeculae originate at the _____, on the ______ surface of the spleen, and carry branches of what four things into the splenic pulp?

A
  • hilum, on the medial surface of the spleen
  • the splenic artery, vein, lymphatics, and nerves.
    p. 281 Junq
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70
Q

PALS, located in ______ pulp, consist primarily of _______ with some macrophages, DCs, and plasma cells. They surround __________.

A
  • located in white pulp, consist primarily of T cells
  • They surround central arterioles.
    p. 282 Junq
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71
Q

The presence of _____________________ distinguishes PALS from the splenic nodule.

A

a central artery/arteriole in the PALS –In the nodules, the artery is displaced to the periphery as the germinal center becomes filled with immunoblasts and other immune cells.
p.323 Wilson

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72
Q

In PALS, the central area around the blood vessel contains primarily _______, whereas the peripheral area or marginal zone has mostly __________.

A

B-lymphocytes
T-lymphocytes
p.323 Wilson

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73
Q

The lymphocytes, either in _______ or in the _____________, constitute the white pulp.

A
  • nodules or in the periarterial sheath around the central artery
    p. 324 Wilson
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74
Q

In the red pulp, the various types of blood cells are monitored by ___________, and _______ are removed from circulation by the _________.

A
  • monitored by the macrophages
  • effete or damaged cells are removed from circulation by the phagocytes.
    p. 324 Wilson
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75
Q

After surgical removal of the spleen (splenectomy), the number of _________ in the circulation increases, although most such cells are then removed by macrophages in sinusoids of the bone marrow and liver.

A

abnormal erythrocytes

p.285 Junq

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76
Q

The spleen has no _______ lymphatics, why?

A

NO AFFERENT LYMPHATICS – because it filters blood, NOT LYMPH.
p.281 Junq

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77
Q

What re the four components to MALT?

A

lymphocytes, IgA-secreting plasma cells, APCs, and lymphoid nodules.
p.276 Junq

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78
Q

In what tissues is MALT found?

A

mucosa or inner lining of the digestive, respiratory, and genitourinary tracts.
p.276 Junq

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79
Q
  1. ) Give three examples of structures formed by large aggregates of MALT lymphocytes?
  2. ) How are MALT LCs typically distributed?
A
  1. ) Tonsils, Peyer patches (ileum), and the appendix.
  2. ) Dispersed diffusely in the CT.
    p. 276 Junq
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80
Q

Most of the lymphocytes in MALT are _______; among T cells, _________ predominate.

A
  • B cells
  • Among T cells, CD4+ helper T cells predominate.
    p. 276 Junq
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81
Q

Describe palatine tonsils (i.e. location, epithelium, lymphoid tissue location, and capsule).

A
  • Posteriorly on soft palate
  • stratified squamous
  • Has crypts, under and around which is the LCs an 2˚ nodules.
  • Dense CT capsule under crypts.
    p. 276 Junq, p.327 Wilson
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82
Q

Describe Lingual tonsils (i.e. location, epithelium, lymphoid tissue location, and capsule).

A
  • Situated at base of tongue
  • Stratified squamous
  • Has crypts
  • NO CAPSULE
    p. 276 Junq
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83
Q

Describe pharyngeal tonsils/adenoids (i.e. location, epithelium, lymphoid tissue location, and capsule).

A
  • (SINGLE MEDIAL MASS) Posterior wall/roof of nasopharynx in soft palate
  • Pseudostratified ciliated columnar
  • Thin capsule
  • NO CRYPTS
    p. 276 Junq
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84
Q

Where are Peyer patches found?

A

Located in the mucosa and submucosa of the ileum.

p.276 Junq

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85
Q

What is the main cellular component of the epidermis?

A

Mainly stratified squamous keratinizing epithelium composed of cells called keratinocytes.
p.365 Junq

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86
Q

What is the most important cytoskeletal element in keratinocytes of the stratum basale? Explain their maturation.

A

Cytoskeletal KERATINS –During differentiation, the cells move upward and the amount and types of keratin filaments increase until they represent half the total protein in the superficial keratinocytes.
p.366 Junq

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87
Q

What two types of junctions are present in the stratum basale, what do they joint, and what is their function?

A

• Hemidesmosomes in the basal cell membranes join them to basal lamina.
• Desmosomes bind the cells of this layer together in their lateral and upper surfaces.
p.366 Junq

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88
Q

Describe the morphology and location of cells in the stratum basale.

A

Single layer of basophilic cuboidal or columnar cells on the basement membrane at the dermal-epidermal junction.

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89
Q

All the layers are found in thin skin except the _________, and the ________ is thinner in thin skin.

A
  • except the stratum lucidum
  • outer cornified layer
    p. 341 Wilson
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90
Q

What gives the cells of the stratum spinosum their spiny appearance?

A

Tonofibrils: Bundles of keratin filaments that converge and terminate on the numerous desmosomes holding the cell layers together.
○ The cells extend slightly around the tonofibrils on both sides of each desmosome = SPINY APPEARANCE.
p.366 Junq

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91
Q

Explain how the skin acquires its barrier against water loss

A

One of the last activities of keratinocytes –Lamellar granules undergo exocytosis, producing a lipid-rich impermeable layer around cells = SKINS BARRIER AGAINST WATER LOSS.
p.367 Junq

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92
Q

In which epidermal layer do cells begin the terminal differentiation process? What is the process called?

A

Keratinization –Stratum Granulosum.

p.367 Junq

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93
Q

Describe the cell morphology and staining of the stratum lucidum, and well as their cytoplasmic contents.

A

Thin, translucent layer of flattened eosinophilic keratonicytes held together by desmosomes.
• No nuclei or organelles.
Cytoplasm almost exclusively packed keratin filaments.
p.367 Junq

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94
Q

The Color of Skin is Dependent Upon upon what three things?

A

• Content of MELANIN
• Content of CAROTENE
• Number of blood vessels in dermis
p.368 Junq

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95
Q
  1. ) Where are melanocytes found?

2. ) What two pigments do they produce and what color?

A

1.) Found in the stratum basale of the epidermis and in hair follicles.
2.) Eumelanins – Brown or black
Pheomelanins –Red hair
p.368 Junq

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96
Q

The _______ is the ______-stained, most superficial layer.

A

stratum corneum is the lightly stained, most superficial layer.
p.342 Wilson

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97
Q

Melanocytes have _____-staining, _____ cell bodies attached by ________ to the basal lamina, but ________ attachments to the neighboring keratinocytes.

A

pale-staining, rounded cell bodies attached by hemidesmosomes to the basal lamina, but lacking attachments to the neighboring keratinocytes.
p.382 Junq

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98
Q

Ultrastructurally a melanocyte has numerous small _______, short cisternae of ______, and a well-developed _________.

A

numerous small mitochondria, short cisternae of RER, and a well-developed Golgi apparatus
p.382 Junq

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99
Q

Which cells contain the most melanin?

A

Keratinocytes.
“Although melanocytes produce melanosomes, the kera- tinocytes are the melanin depot and contain more of this pigment than the cells that make it.”
pp.368-369 Junq

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100
Q

One melanocyte plus the keratinocytes into which it transfers melanosomes make up an ________ unit.

A

epidermal-melanin unit.

p.369 Junq

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101
Q

People with fair skin have have _______ UV penetration and ______ vitamin D3 synthesis.

A

increased UV penetration and increased vitamin D3 synthesis.

p.369 Junq

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102
Q
  1. ) What type of cell are Langerhans and where are they seen most clearly?
  2. ) What is their function and what crucial function do they take part in?
A
  1. ) Dendritic epidermal APCs most clearly seen in the stratum spinosum.
  2. ) They present antigens to T LCs and guard the epidermis as a major component of the skin’s ADAPTIVE IMMUNITY.
    p. 370 Junq
103
Q

What are Merkel cells and where are they found (within the skin and body area in general ?

A
  • Tactile mechanoreceptors for light touch.
  • Joined by desmosomes to keratinocytes of the basal epidermal layer in sensitive areas, e.g. fingertips, lips, nips…and at the BASES OF SOME HAIR FOLLICLES.

p.370 Junq

104
Q

Merkel cells originate from the same stem cells as _______ and are characterized by small, ______-derived dense-core ______ granules containing ________.

A
  • keratinocytes
  • Golgi-derived dense-core neurosecretory granules containing peptides.
    p. 371 Junq
105
Q

The basolateral surfaces of the Merkel cells contact __________ of ________ fibers penetrating the basal lamina.

A

expanded terminal discs of unmyelinated sensory fibers penetrating the basal lamina.
p.371 Junq

106
Q

Nutrients for keratinocytes diffuse into the avascular epidermis from the dermal vasculature through the _________. This structure always occurs between which two layers?

A

Basmement lamina –Always occurs between the stratum basale and the dermis.
p.372 Junq

107
Q

What types of collagen are present in the papillary dermis?

A
  • Collagen types I and III in the CT
  • Type VII collagen in the basal lamina, anchoring the dermis to the epidermis.
    p. 372 Junq
108
Q
  1. ) Which dermal layer is primarily responsible for the skins elasticity?
  2. ) What two types of fibers predominate in its CT?
  3. ) What is found between these two types of fibers?
A
  1. ) Reticular dermis
  2. ) Type I collagen and elastic fibers.
  3. ) Abundant PROTEOGLYCANS rich in DERMATAN SULFATE.
    p. 372 Junq
109
Q

What is the glassy membrane with regards to hair?

A

An acellular hyaline layer separating the follicle from the dermis.
p.375 Junq

110
Q

The nail plate is bound to a bed of epidermis, the _______, which contains only the _______ and ________ epidermal layers.

A
  • the nail bed
  • basal and spinous epidermal layers.
    p. 377 Junq
111
Q

What is the name for the epidermal skin fold that covers the nail root? What layer is it from?

A

Cuticle/Eponychium –Epidermal stratum corneum.

p.377 Junq

112
Q

Nails undergo a process of keratinization similar to hair formation, but without __________.

A

but without keratohyaline granules

p.378 Junq

113
Q

The nail root matures and hardens as the _______.

A

nail plate

p.378 Junq

114
Q

The distal end of the plate becomes free of the nail bed at the epidermal fold called the ________.

A

hyponychium

p.378 Junq

115
Q

The nearly transparent nail plate and the thin epithelium of the nail bed provide a useful window on the amount of ________ in the blood by showing ______________.

A
  • oxygen in the blood
  • the color of blood in the dermal vessels.
    p. 378 Junq
116
Q

Describe sebaceous glands in general terms (composition, secretions, location, etc.)

A

Branched acinar glands with several acini converging at a short duct that usually empties into the upper portion of a hair follicle.

  • Secretes sebum with antimicrobial properties.
  • Embedded in the mitotic layer of the dermis near the base in all skin except for the palms and soles.
    p. 378 Junq
117
Q

Describe the acinar cells of sebaceous glands

A

Prominent nucleolus, clear euchromatic nucleus, clear cytoplasm filled with sebum.
p.378 Junq

118
Q

A hair follicle and its associated sebaceous glands make up a __________.

A

pilosebaceous unit

p.378 Junq

119
Q

The acini of sebaceous glands are the classic example of ________ secretion.

A

holocrine secretion

p.380 Junq

120
Q

What are the terminally differentiated acini cells of sebaceous glands called?

A

Sebocytes – release cebum.

121
Q

Secretion from sebaceous glands increases greatly at ________, stimulated primarily by _______ in men and by ______ and _______ _______ in women.

A
  • increases greatly at puberty
  • testosterone in men and by ovarian and adrenal androgens in women.
    p. 380 Junq
122
Q

Sebum helps maintain the _______ skin layer, as well as the _______, and exerts weak _______ and _______ properties.

A
  • stratum corneum layer and hair shafts
  • weak antibacterial and anti-fungal properties.
    p. 380 Junq
123
Q

Sebaceous glands in the dermis are always found near __________.

A

hair follicles

p.362 Wilson

124
Q

The _______ part of eccrine glands is generally more pale-staining than the _______ and has _______ epithelium with three cell types. What are they (describe them) and what do they do?

A
  • The secretory part of eccrine glands are generally more pale-staining than the ducts
  • stratified cuboidal epithelium
    1. ) Clear cells: Produce sweat (abundant mitochondria and microvilli).
    2. ) Dark Cells: Filled with strongly EOSINOPHILIC GRANULES, line most of the lumen and do not contact the basal lamina. Granules undergo merocrine secretion.
    3. ) Myoepithelial cells: On basal lamina –contract to move watery secretion into the duct.
    p. 380 Junq
125
Q

What is the main location of apocrine sweat glands and when do they appear?

A

Axillary and perineal skin –appear mainly after puberty.

p.380 Junq

126
Q

The secretory components of apocrine glands have _______ lumens than those of the eccrine glands and consist of _______, _______ cells with numerous secretory granules that also undergo _______.

A
  • much larger lumens
  • simple cuboidal, eosinophilic cells
  • undergo exocytosis
    p. 380 Junq
127
Q

What type of secretion do apocrine sweat glands undergo?

A
  • MEROCRINE* –The glands are misnamed.

p. 380 Junq

128
Q

The ducts of apocrine glands are similar to those of the eccrine glands, but they usually open into _______________ and may contain a __________ product.

A
  • hair follicles at the epidermis
  • may contain a PROTEIN-RICH PRODUCT.
    p. 380 Junq
129
Q

Apocrine sweat glands are innervated by _______ nerve endings, whereas eccrine sweat glands receive ________ fibers.

A

Apocrine = adrenergic nerve endings.
Eccrine = cholinergic fibers.
p.380 Junq

130
Q

The _______ of the papillary layer results in its _______ staining properties.

A
  • cellularity of the papillary layer
  • darker staining properties
    p. 349 Wilson
131
Q

The serosa of the GI tract is the _______ layer (regarding depth; innermost or outermost?).

  1. ) What type of epithelium?
  2. ) Covers _______ organs and is continuous with _______ and _______.
A

Outermost.

  1. ) Mesothelial (simple squamous) covering.
  2. ) Covers peritoneal organs and is continuous with mesentery and omentum.
132
Q

Mesenteries are continuous with the _______, a ________ membrane that lines the cavity.

A

Peritoneum, serous membrane

p.290 Junq

133
Q

In places where the digestive tract is not suspended in a cavity but bound directly to adjacent structures, such as in the _______, the serosa is replaced by a ________, a connective tissue layer that merges with the surrounding tissues and lacks _________.

A
  • such as in the esophagus
  • thick adventitia
  • lacks mesothelium
    p. 290 Junq
134
Q

Located just below the epithelium, the ________ is rich with macrophages and lymphocytes, many for production of _______ antibodies.

A
  • lamina propria
  • IgA antibodies
    p. 291 Junq
135
Q

What are the two plexuses that comprise the enteric nervous system and which layers are they in.

A
  1. ) Submucosal (Meissner’s) nerve plexus –Submucosa
  2. ) Myenteric (Auerbach’s) plexus –Muscularis Externa (ME)
    p. 289 Junq
136
Q

The vermillion zone of the lips has __________ epithelium. It marks the transitional zone between the ________ and _______. It lacks ______ or ______ glands, but has rich _________.

A
  • Thin keratinized stratified squamous epithelium.
  • oral mucosa and skin.
  • lacks salivary or sweat glands, but has rich SENSORY INNERVATION.
    p. 292 Junq
137
Q

What give the vermillion zone its red/pink color?

A

Capillary loops near surface impart pink/red color.

138
Q
  1. ) What are the non-keratinized portions of the oral cavity (5)?
  2. ) What are the keratinized portions of the oral cavity (2)?
A
  1. ) Soft palate, lips, cheeks, mouth floor and pharynx.

2. ) Gums and hard palate.

139
Q

The hard palate has underlying ______ (i.e. _______ in direct contact with ________).

A
  • underlying bone

- i.e. periosteum in direct contact with lamina propria

140
Q
  1. ) The papillary and tonsillar areas of the lingual surface are separated by a ______-shaped groove called the ___________.
  2. ) The papillae occupy which area of the tongue?
A
  1. ) V-shaped groove called the sulcus terminalis.
  2. ) Anterior two-thirds
    p. 292 Junq
141
Q

The lingual papillae are elevations of the __________.

A

mucous membrane

p.293 Junq

142
Q
  1. ) Describe the size of vallate papillae.
  2. ) Location?
  3. ) Special glands and their purpose?
A
  1. ) LARGEST papillae.
  2. ) 8-12 are normally aligned in front of the terminal sulcus.
  3. ) Salivary (von Ebner) glands: Ducts of these small, serous glands empty into the groove surrounding each vallate papillae, washing away food so taste buds can receive and process new stimuli.
    p. 294 Junq
143
Q

Describe the shape, relative amount, keratin and taste bud content of filiform papillae.

A
  • MOST NUMEROUS
  • Elongated conical shape.
  • HEAVILY KERATINIZED.
  • DOES NOT CONTAIN TASTE BUDS.
    p. 293 Junq
144
Q

The tongue is derived from the ________ arches and ________ myotomes.

A

BRANCHIAL arches and OCCIPITAL myotome.

145
Q
  1. ) Describe the relative amount of fungiform papillae and among which other papillae they are dispersed among.
  2. ) Keratinization?
  3. ) Shape and characteristics of their core.
A
  1. ) Much less numerous, interspersed among the filiform papillae.
  2. ) Lightly keratinized.
  3. ) Mushroom-shaped, with well-vascularized and innervated cores of lamina propria.
    p. 293 Junq
146
Q
  1. ) Which three tongue papillae contain taste buds/cells and on what surface? Which has the most?
  2. ) Why does the fourth not contain taste buds?
A
  1. ) Circumvallate (lateral), Foliate (lateral), and Fungiform (dorsal) all contain taste buds.
    - Circumvallate has the most.
  2. ) Filiform does not contain taste buds due to its heavy keratinization.
    p. 294 Junq, p.400 Wilson
147
Q

The esophageal mucosa has __________ epithelium.

A

non-keratinized stratified squamous epithelium.

p.299 Junq

148
Q

Describe the distribution of muscle in the muscularis externa throughout the length of the esophagus

A

○ Skeletal muscle (upper 1/3)
○ Smooth + Skeletal muscle (≈ middle 1/3)
○ Smooth muscle (last 1/3)

149
Q

Explain how the process of swallowing begins and ends

A

Begins with voluntary (skeletal) muscle action, but finishes with involuntary (smooth muscle) peristalsis.
p.301 Junq

150
Q

Describe the three components of the esophageal mucosa

A

1.) Non-keratinized stratified squamous epithelium.
2.) Lamina propria.
3.) Muscularis mucosae (single layer of longitudinally oriented smooth muscle).
#60

151
Q

Describe the outer-most covering of the esophagus throughout its length.

A 
Outer layer is ADVENTITIA until it pierces the diaphragm, after which it is covered by SEROSA (distal 1-2cm).
#60, p.301 Junq
152
Q

Which two organs in the alimentary canal have submucosal glands?

A

Esophagus and duodenum

p.429 Wilson

153
Q

Gastric pits are shallow in the ______ and _____, and much deeper in the ________.

A
  • Shallow in the fundus and body
  • much deeper in the pylorus.
    p. 435 Wilson
154
Q

The neck/isthmus mucous cells have a dual function, what are the functions?

A

Mucous secretion and they also may be STEM CELLS for the surface mucous cells.
p.436 Wilson

155
Q

In the alimentary canal, goblet cells are located in the ________ and the _______, but not the ________.

A

mucosa of the small and large intestine and the appendix…
BUT NOT THE STOMACH!
p.436 Wilson

156
Q

The gastric pits of the stomach are lined by _________ epithelial cells (_________) that secrete ________.

A
  • simple columnar epithelial cells
  • surface mucous cells –that secrete a protective mucus.
    p. 438 Wilson
157
Q

Compare the mucosa, pits and glands of the fundus to those of the cardia.

A

Fundus: Elongated mucosa compared to cardia.
Shallow pits and deep glands.
p.435 Wilson

158
Q

Compare the length of the pits to the length of the glands in the cardiac stomach.

A

In the cardiac stomach, the length of the pits is approximately equal to the length of the glands.
p.434 Wilson

159
Q

Where is gastrin secreted (and by what cell) and what does it do?

A 
Pylorus –from the parietal cells. Stimulates contraction and secretion. 
#73
160
Q

What are G cells, what do they secrete, and where are they found?

A

-Entero-endocrine cells found in the pylorus
-Produce GASTRIN which increases gastric motility and secretions.
#80

161
Q

What is pernicious anemia?

A 
Lack of INTRINSIC FACTOR secreted by PARIETAL CELLS causes VITAMIN B12 deficiency. 
#85
162
Q

At the pylorus, the middle layer is greatly thickened to form the _______.

A

Pyloric sphincter.

p.309 Junq

163
Q

Describe the gastric pits and glands of the pylorus

A 
Deep pits, shallow branched glands
#74
164
Q

As you progress down the stomach, the _______ get deeper and the ________ get shallower, but more _______.

A 
the PITS get deeper and the GLANDS get shallower, but more BRANCHED. 
#74
165
Q

What do the cardiac and pyloric glands have in common?

A

They lack both parietal and chief cells, primarily secreting abundant mucous.
p.307 Junq

166
Q

What are the three layers of the cardia muscularis mucosa?

A

1.) Outer longitudinal layer
2.) Middle circular layer
3.) Inner oblique layer
#74

167
Q

Gastric glands constitute the greatest part of the mucosa in the ______ and ______.

A

fundus and body.

168
Q

_____ and _____ cells, characteristic of the ______ and _______, are absent from the pyloric region.

A
  • Parietal and chief cells
  • fundus and main body
    p. 444 Wilson
169
Q
  1. ) What are Plicae circulares?
  2. ) Where are they most developed?
  3. ) What is their purpose?
A
  1. ) Permanent circular folds in the small intestine consisting of mucosa and submucosa.
  2. ) most developed in jejunum
  3. ) Increase SA for absorption
    p. 309 Junq, #11
170
Q

The submucosal (Meissner’s) and muscularis mucosa (Auerbach’s) plexuses are both independent of the ______.

A 
CNS
#8
171
Q

What are the distinguishing features of each segment of the small intestine and of the large intestine.

A

Duodenum: Submucosal (Brunner’s) glands
Jejunum: Plicae circularis (best developed here)
Ileum: Peyer’s patches (in lamina propria)

Large intestine: Lacks villi, but retains Crypts of Lieberkuhn.
#9
172
Q

What three types of modifications increase the luminal SA of the small intestine?

A

1.) Plicae circularis
2.) Villi
3.) Microvilli
#10

173
Q

Describe the villi and associated cells (2) of the small intestine mucosa.

A
  • Villi are mucosal outgrowths projecting into the lumen.
  • Enterocytes: Absorptive simple columnar epithelium covering the villi.
  • Goblet cells: Protective mucous (high MW glycoproteins = mucins) secreting cells interspersed between the enterocytes.
    p. 309 Junq
174
Q

What is a lacteal?

A

Lacteal: Central lymphatic canal at the center of each villus.
-Absorb fats (major place for fat absorption) and IF.

175
Q

What are the role of Paneth cells and where are they found?

A

Produce lysoszyme IN THE BASE OF THE CRYPT to regulate bacterial flora in the gut lumen – prevents bacteria from blocking the lumen of the Crypt.

p.452 Wilson, #13

176
Q
  1. ) How does the frequency of small intestinal villi vary from the duodenum to the ileum?
  2. ) How does the frequency of small intestinal Goblet cells vary from the duodenum to the ileum?
A
  1. ) duodenum > jejunum > ileum

2. ) Duodenum

177
Q
  1. ) Describe the enteroendocrine cells of the small intestine, i.e. they are _____-type cells.
  2. ) Give two examples of their secretions.
A

1.) Many of these cells are of the “open” type, in which the constricted apical end of the cell contacts the intestinal lumen and has chemoreceptors similar to those of taste buds, sampling levels of certain nutrients such as sugars to regulate hormone release BASALLY.
2.) Cholecystokinin: regulates pancreatic bicarb and bile release.
Secretin: Causes bicarb buffer production by pancreas. (#20)
p.312 Junq

178
Q

What is an exclusive feature of the duodenal submucosa that is useful for identification? What do they do?

A

Brunner’s glands in submucosa.
-Produce alkaline mucous to neutralize stomach acid in chyme.
#20

179
Q

What are two submucosal features useful in identifying the jejunum? One mucosal feature as well.

A

Mucosal: Increasing goblet cells.
Submucosal: No submucosal glands, many prominent PLICAE CIRULARES.
#22

180
Q
  1. ) What are M cells, where are they located,
  2. ) what characterizes them?
  3. ) what do they do?
A
  1. ) Specialized epithelial cells in mucosa of ileum. Overlying the lymphoid follicles of Peyer’s Patches.
  2. ) these cells are characterized by the presence of basal membrane invaginations or pockets containing many intraepithelial lymphocytes and antigen-presenting cells
  3. ) M cells selectively endocytose antigens and transport them to the underlying lymphocytes and dendritic cells, which then migrate to lymph nodes for an appropriate immune response. THEY ARE NOT ABSORPTIVE CELLS.
    p. 314 Junq
181
Q

Where does bile acid resorption take place and what two cofactors are needed for this?

A 
Mucosa of the ileum –Need intrinsic factor and vitamin B12 for absorption. 
#25
182
Q

Where are Brunner glands located, what type of glands are they, and what do they do?

A
  • Proximal part of the duodenum in the submucosa and mucosa.
  • They are large clusters of branched tubular mucous glands with small excretory ducts opening among the INTESTINAL CRYPTS.
  • They secrete ALKALINE MUCOUS to neutralize chyme.
    pp. 315-316 Junq
183
Q

What are Peyer’s patches and where are they located?

A
  • Well-developed MALT consisting of large lymphoid aggregates.
  • Present in lamina propria and submucosa of the ILEUM.
    p. 316 Junq
184
Q

What is characteristic about the muscularis of the colon?

A

Has longitudinal and circular layers, but fibers of the outer band gathered into three separate longitudinal bands called TENIAE COLI.
p.316 Junq

185
Q

What is the longest segment of the small intestine?

A

Jejunum

186
Q

An absence of what two structures distinguish the jejunum from the duodenum and the ileum?

A

Peyer’s patches (ileum) and submucosal/Brunner’s glands (duodenum).
p.460 & 466 Wilson

187
Q

Concerning the muscularis externa, when the inner layer of muscle contracts, the _______ is constricted. When the cells of the outer layer contract, the __________ compressed.

A
  • lumen is constricted
  • the length of the tube is compressed.
    p. 461 Wilson
188
Q

Which parts of the small intestine are suspended by mesentery?

A

Jejunum and ileum

p.466 Wilson

189
Q

The colonic epithelium lacks a ______ _______.

A

Brush border

p.471 Wilson

190
Q

The surface of the colonic mucosa is relatively even as a result of _________.

A

the absence of villi

p.472 Wison

191
Q

The wall of the colon is puckered into a series of large sacs called _________.

A

haustra

p.316 Junq

192
Q

The large intestine/colon/bowel contains abundant _______ in the lamina propria.

A 
MALT
#30
193
Q

The appendix is suspended by ________ and is covered by the _________ epithelium of the ________.

A
  • suspended by the mesentery
  • simple squamous epithelium of the serosa.
    p. 475 Wilson
194
Q

The distal end of the GI tract is the ________.

A

Anal canal

p.317 Junq

195
Q

At the rectoanal junction, the _________ lining of the rectum is replaced by _________ epithelium.

A
  • simple columnar mucosal lining of the rectum
  • stratified squamous epithelium
    p. 317 Junq
196
Q

Many more goblet cells are found in the ______ than in any other part of the alimentary canal.

A

Rectum –lots of mucous.

p.478 Wilson

197
Q

What are the two transitional zones in the rectum/anus called, and what do they transition from/to?

A

1.) Pectinate line: Simple columnar (rectum) to Stratified squamous non-keratinized (anal canal).
2.) Hilton’s line (white line): Stratified squamous non-keratinized (anal canal) to Stratified squamous KERATINIZED (skin of anus)
#38 –IMAGE of #2?????

198
Q

Explain the innervation of the rectum/anus

A 
Dual innervation of both somatic and autonomic
#37
199
Q

The submandibular and sublingual glands produce a _________ secretion, while that of the minor glands is mostly _______.

A
  • seromucous secretion
  • mostly mucous
    p. 323 Junq
200
Q

Saliva is modified by the ___________ draining the secretory units, with much _______ reabsorbed while certain growth factors and digestive enzymes are added.

A
  • cells of the duct system
  • Na+ and Cl−
    p. 323 Junq
201
Q

The short intercalated ducts are lined with ______ epithelium.

A

cuboidal epithelium

p.324 Junq

202
Q

The striated ducts are composed of _______ cells with characteristics of ________ cells: i.e. _________________________.

A
  • columnar cells
  • ion-transporting cells
  • basal membrane invaginations with mitochondrial accumulations.
    p. 324 Junq
203
Q
  1. ) What is the function of a striated duct?
  2. ) What is the characteristic feature?
  3. ) What type of epithelium?
A

1.) Astriated ductis a glandductwhich connects an intercalatedductto an interlobularduct.
2.) It is characterized by the basal infoldings of its plasma membrane, characteristic of ion-pumping activity by the numerous mitochondria.
3.) Simple columnar cells
(Wiki)

204
Q
  1. ) What are intercalated ducts?

2. ) What type of epithelium do they have?

A
  1. ) The portion of anexocrine glandleading directly from theacinusto a striated duct.
  2. ) Simple cuboidal
    p. 325 Junq
205
Q

What are the purpose of the basal infoldings on striated ducts?

A

Striated ducts reabsorb Na+ ions from the initial secretion and their folded cell membranes present a large surface area with ion transporters, facilitating rapid ion transcytosis and making the secretion slightly hypotonic
p.325 Junq

206
Q
  1. ) Give four histologic characteristics of serous cells

2. ) Which portions are eosinophilic and which are basophilic?

A

1.) Pyramidal in shape, round nuclei, well-stained RER, apical secretory granules.
2.) Basal = basophilic, Apical = eosinophilic
#8

207
Q

What type of epithelium do main excretory ducts have near their openings?

A 
Nonkeratinized stratified squamous epithelium near its opening. 
#12
208
Q

Plasma cells in the connective tissue surrounding the small intralobular ducts release ______. Why?

A

IgA –Protect against specific pathogens in the oral cavity.
p.325 Junq

209
Q

Give the predominating secretions for the three types of salivary glands.

A

Parotid Gland: Branched acinar glands with exclusively serous acini.

Submandibular Gland: Mixed serous and mucous.

Sublingual Gland: Mixed, but predominantly mucous. 
#14
210
Q

What are serous demilunes and where are they found?

A 
Mucous acini capped with serous cells –Mostly seen in sublingual, but also seen in submandibular glands. 
#19
211
Q

What do the acini secrete in a.) Parotid glands, and b.) Submandibular glands?

A

a.) Amylase
b.) Lysozyme
#20

212
Q

What are the ion transport/secretion functions of a.) intercalated ducts, and b.) Striated ducts

A

a.) Intercalated: Absorb Cl- and secrete HCO3-
b.) Striated: ACTIVELY resorbs Na+ and secretes K+ and HCO3- = HYPOTONIC SALIVA
#20

213
Q
  1. ) What are the secretory components of the IgA complex?

2. ) How do they stain?

A
  1. ) Serous demilunes

2. ) PAS positive (glycoprotein content).

214
Q
  1. ) While the pancreas and parotids gland look similar, what two things does the pancreas lack that the parotid gland has?
  2. ) What does the pancreas have that parotid glands don’t?
A
  1. ) STRIATED DUCTS and MYOEPITHELIAL CELLS.
  2. ) Centroacinar cells
    p. 327 Junq, #30
215
Q
  1. ) What kind of INTRAlobular duct predominates in the pancreas?
  2. ) What do they secrete and what stimulates this secretion?
A

1.) Intercalated ducts (NO STRIATED DUCTS)
2.) HCO3- rich fluid (to protect against acidic chyme) stimulated by SECRETIN and PARASYMPATHETIC AUTONOMIC STIMULATION.
#29, p.329 Junq

216
Q

What type of epithelium do the INTERlobular ducts of the pancreas possess?

A 
Columnar epithelium
#29
217
Q

What enzymes do the pancreatic acini secrete (3) and what are they activated by and what stimulates their release?

A

1-2.) Trypsinogen and Chymotrypsinogen – Zymogens activated by ENTEROPEPTIDASE in the duodenum.
3.) Trypsin inhibitor (protective)

-Release stimulated by Cholecytsokinin (CCK).
#31
218
Q

What are two things that protect the pancreas form autodigestion?

A

1.) Trypsin inhibitor: Restricts protease activation to the duodenum.
2.) Alkaline secretion (HCO3-) by duct cells neutralizes acidic pH.
#32

219
Q

About 75% of the blood entering the liver is _______-rich (but ______-poor) blood from the _______ arising from the stomach, intestines, and spleen; the other 25% comes from the _______ and supplies the organ’s _______.

A
  • nutrient-rich (but O2-poor)
  • portal vein
  • hepatic artery and supplies the organ’s O2.
    p. 331 Junq
220
Q

What are the functions of the RER and SER of the liver hepatocytes?

A

• RER –plasma protein synthesis
• SER –Detox, biotransformation (i.e. bile acid synthesis, conjugation of bilirubin).
#48

221
Q

What are Kupffer cells and where are they found?

A 
Liver macrophages (APCs) that remove effete RBCs, bacteria, and debris –Located within the sinusoid lining.
#51, p.332 Junq
222
Q

What is the role of liver Stellate cells/Ito cells (3) and where are they located?

A
  1. ) Storage of Vitamin A and other fat-soluble vitamins in lipid droplets.
  2. ) Store fat.
  3. ) Secrete ECM following tissue injury.
  • Located in the perisinusoidal Space of Disse
    p. 332 & 333 Junq, #50
223
Q

Hepatocyte plates are supported by _______.

A

Reticular fibers

p.333 Junq

224
Q

What three structures make up the portal triad and what do they do?

A

■ A venule branch of the portal vein, with blood rich in nutrients but low in O2,
■ An arteriole branch of the hepatic artery that supplies O2,
■ One or two small bile ductules of cuboidal epithelium, branches of the bile conducting system.
p.333 Junq

225
Q

Between all of the anastomosing plates of hepatocytes of a hepatic lobule are important _______ that emerge from the peripheral branches of the ________ and _______ and converge on the lobule’s _______

A
  • vascular sinusoids
  • portal vein and hepatic artery
  • converge on the lobule’s central vein
    p. 333 Junq
226
Q

The ______ and ________ mixes in the hepatic sinusoids.

A

Venous and arterial blood mixes

p.333 Junq

227
Q

What type of epithelium does the bile ductule have?

A

Cuboidal epithelium

228
Q

What facilitates most key hepatocyte functions that involve uptake and release of nutrients.

A

Hepatocyte/plasma contact in the perisinusoidal Space of Disse.
p.333 Junq

229
Q

Where do hepatic sinusoids originate and converge?

A

Emerge from the peripheral branches of the portal vein and hepatic artery and converge on the lobule’s central vein.
p.333 Junq

230
Q

What type of cells are hepatic stellate (Ito) cells?

A

Mesenchymal cells

p.334 Junq

231
Q

Central venules from each lobule converge into larger veins, which eventually form two or more ____________ that empty into the ________.

A
  • large hepatic veins
  • inferior vena cava
    p. 334 Junq
232
Q
  1. ) Blood always flows from the ______ to the ______ of each hepatic lobule.
  2. ) What does this mean for the peripheral lobule cells?
  3. ) Which way does bile flow?
A
  1. ) periphery to the center
  2. ) Consequently, oxygen and metabolites, as well as all other toxic or nontoxic substances absorbed in the intestines, reach the lobule’s peripheral cells first and then the more central cells
  3. ) Opposite of blood – From the center to the periphery, ending near the portal tracts (p.336 Junq).
    p. 335 Junq
233
Q

Hepatocytes near the _______ can rely on aerobic metabolism and are often more active in ________, while the more ________ are exposed to lower concentrations of nutrients and oxygen and are more involved with _________ and _________.

A
  • near the portal areas, more active in protein synthesis.
  • the more central cells, detoxification and glycogen metabolism.
    pp. 335-336 Junq
234
Q

What are the three enterocyte surfaces?

A

○ Sinusoidal (basal/basolateral)
○ Intercellular
○ Canalicular (apical)

235
Q
  1. ) Which hepatocyte surface processes nutrients and other blood components?
  2. ) Which hepatocyte surface are involved in exocrine secretion of bile? What structure does this surface form?
A
  1. ) Basolateral (sinusoidal)
  2. ) Apical (smaller) –Bile canaliculi
    p. 336 Junq
236
Q

What are cholangiocytes and where are they found?

A

Cuboidal epithelial cells lining the bile ductules

p.336 Junq

237
Q

Some bile components are synthesized in ________, but most are taken up from __________; all are quickly secreted into _________.

A
  • hepatocyte SER
  • the perisinusoidal space
  • the bile canaliculi
    p. 336 Junq
238
Q

The fibrosis characteristic of cirrhosis produces connective tissue that can fill the ________ and interfere with ______________________.

A
  • perisinusoidal space
  • metabolic exchange between the hepatocytes and the sinusoids.
    p. 337 Junq
239
Q

Which enterocyte organelle is ultimately responsible for bile production and how?

A

SER –detoxification and biotransformation ends in bile excretion.
p.337 Junq

240
Q

What is hemosiderin, what does it do, and where is it found?

A

Small, electron-dense ferritin complexes (primarily in Kupffer cells) that mediates temporary storage of glucose, TGs, and iron.
p.338 Junq

241
Q

What is the space of mall, where is it, and what does it fill with?

A

A small space between the stroma of the portal canal and the outermost hepatocytes.
• Receives plasma that drains from the perisinusoidal space to the periportal connective tissue.
p.638 Ross

242
Q

Explain what concepts are being emphasized in each of the three structure-function liver diagrams.

A
  1. ) Classic Hepatic Lobule: Emphasizes ENDOCRINE function of hepatocytes as blood flows past them toward the central vein, i.e. Blood from portal areas to central/hepatic venule.
  2. ) Portal Lobule: Based on bile secretion, i.e. emphasizes hepatocyte EXOCRINE function – Bile flowing from THREE classical lobules to portal triad (bile ductule) in center.
  3. ) Hepatic Acinus: Based on metabolic and blood supply; BVs run in this segement –Emphasizes the different oxygen and nutrient contents of blood at different distances along the sinusoids, with blood from each portal area supplying cells in two or more classic lobules.
    p. 339 Junq
243
Q

Liver Zone One (_______ Zone): Most affected in _______ —> Two other characteristics of zone 1.

A

Zone One (Periportal Zone): Most affected in viral hepatitis.

  1. ) This zone first receives oxygen, hormones, and nutrients from the bloodstream.
  2. ) Most glycogen and plasma protein synthesis by hepatocytes occurs here.
244
Q

Liver Zone Three (_______ Zone): Nearest to _______.

Three other characteristics.

A

Zone Three (Centrilobular Zone): Nearest to central vein.

  1. ) Poorly oxygenated
  2. ) Is the first to show ischemic necrosis and fat accumulation if metabolism is altered.
  3. ) Is the site of most drug, alcohol, and ammonia detoxification.
245
Q

________ nuclei and _______ are characteristic features of hepatocytes.

A
  • Large euchromatic nuclei
  • prominent nucleoli
    p. 489 Wilson
246
Q

What are the functions of the liver (7)

A

1.) Bile formation.
2.) Storage of glycogen, buffer for blood glucose.
3.) Synthesis of urea.
4.) Metabolism of cholesterol and fat.
5.) Endocrine secretion –plasma proteins, IGF.
6.) Detoxification
7.) Processing of several steroid hormones and Vitamin D.
#60

247
Q

The hepatic, cystic, and common bile ducts are lined with a ________ having a ________ epithelium of _________.

A
  • mucous membrane
  • simple columnar epithelium
  • cholangiocytes
    p. 339 Junq
248
Q

The mucosa of the gall bladder is lined by _________ epithelial cells that possess numerous _______ on their apical surface.

A
  • simple columnar epithelial cells
  • microvilli on their apical surface
    p. 507 Wilson
249
Q

Describe the tissue layers of the gall bladder

A

Highly folded mucosa (NOT VILLI) –No muscularis mucosa, no submucosa, JUST LAMINA PROPRIA then muscular layer and adventitia/serosa.
p.339 Junq

250
Q

The lining epithelial cells of the gallbladder have prominent ________, ________, and large intercellular spaces, all indicative of cells actively ________, in this case for ___________.

A
  • prominent mitochondria, microvilli
  • transporting water, in this case for concentrating bile
    p. 339 Junq
251
Q

To move _______ into the _______, contraction of the gallbladder muscularis is induced by ________. Release of this inducer is stimulated by what?

A
  • stored bile into the duodenum
  • cholecystokinin (CCK) form the EE cells of the duodenum.
  • Release of CCK is, in turn, stimulated by the presence of ingested fats in the small intestine.
    p. 340 Junq
252
Q

What is the function of the gall bladder?

A

Stores and concentrates bile.

253
Q

The parotid gland has significant amounts of _______, which the other salivary glands do not have.

A 
Adipose tissue
#75

Histology (9 decks)

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