Lecture 10 Flashcards
1
Q
Spleen
A
- Removal of spent RBCs
- Immune surveillance of the Blood
2
Q
Microanatomy of the Spleen
A
- Capsule: encases the spleen
- Trabeculae: sections and supports the spleen
- White Pulp PALS Marginal Zone: Immune System
- Red PULP Macrophage: Recycling ‘spent’ RBCs
3
Q
Capsule
A
Fibrous sheath that surrounds the spleen
4
Q
Trabeculae
A
- Fibrous projections that extend down from the capsule
- Provides structural support for the sinusoidal organ
- Blood vessels are embedded within hilar trabeculae
5
Q
White Pulp
A
Marginal Zone
1. Marginal Zone Sinuses
2. Peripheral White Pulp or Follicle
3. Germinal Centers
4. Periarteriole Lymphoid Sheath
6
Q
Red Pulp
A
- Vascular Sinusoid
- Splenic Cords (Cords of Billroth)
7
Q
Pathway of Antigens
A
- Course through Splenic and Central Arteries
- Portion of splenic blood flow runs through the white pulp
- Enter the Marginal Zone Sinuses
- Antigens
a. Screened by Marginal Zone B-Cells
b. Trapped and processed by Dendritic Cells
8
Q
Activated B-Cells
A
- Leave the Marginal Zone Sinus
- Trek to the Peripheral White Pulp
- Some develop Germinal Centers
9
Q
Activated (Mature) Dendritic Cells
A
- Leave the Marginal Zone
- Trek to the PALS
- Present Antigens to naïve T-Cells
10
Q
Stave Cells
A
- Lines the vascular walls
- Forms a longitudinal slotted filter
- Restricts the vascular recovery of ‘spent’ RBCs
a. increased diameter due to swelling
b. diminished flexibility
11
Q
Mucosa-Associated Lymphatic Tissues
A
- Tonsils: back of throat
- Adenoid: posterior nasal cavity
- Appendix: Ig intestine
- Peyer’s Patches: small intestine
- Lymphoid Follicles: where needed
12
Q
Mucosa
A
Tissues that line the endodermal surfaces of your body
1. Nasal cavity
2. Oral cavity
3. Pulmonary tract
4. Urinary-Genital tracts
5. Digestive tract
13
Q
MALTS
A
Present in the mucosal connective tissue
14
Q
MALTS (General Features)
A
- Mucosal surfaces are primary sites of pathogen entry
- MALTs are positioned within the connective tissue of musoca
- MALTs protect against exposure to external environments
- Organizational complexity varies form site to site
- Constitutive or induced
15
Q
Peyer’s Patches
A
- Located in the wall of the ileum of the small intestine
- Well-organized lymphoid follicles
Humans: clusters of 30-40 individual follicles