AP II Lab Exam 3

Question 1

Lymphatic System

Answer 1

Returns fluids leaked from blood vessels back to blood

Circulates ~ 3L interstitial fluid per day

Question 2

3 Parts of Lymphatic System

Answer 2

1. Lymph vessels (lymphatics - network of drainage vessels)
2. Lymph (interstitial fluid within lymph vessels)
3. Lymph nodes (cleanse lymph)

Question 3

Lymphoid Organs

Answer 3

Structural basis of immune system

Have well-defined anatomical sites and at least partial connective tissue capsules that separate the lymphatic tissue from neighboring tissues

House phagocytic cells & lymphocytes

Structures:
Spleen, thymus, tonsils, lymph nodes, red bone marrow

Question 4

Lymphatic capillaries

Answer 4

Blind-ended vessels (closed at 1 end) that weave between tissue cells and blood capillaries.

More permeable than blood capillaries.
Can take up larger molecules and particles (ex: proteins, cell debris, pathogens, cancer cells)

Absent from bones, teeth, and bone marrow.
Present in CNS but limited to locations in meninges (help drain interstitial fluid and CSF).

Can act as route for pathogens or cancer cells to travel throughout body

Question 5

Lymphoid Tissues

Answer 5

Aggregations of lymphocytes in the connective tissues of mucous membranes and various organs

Question 6

Diffuse Lymphoid Tissue

Answer 6

Lymphocytes are scattered

Prevalent in body passages that are open to the exterior — mucosa-associated lymphatic tissue (MALT)
Ex: respiratory, digestive, urinary, and reproductive tracts

Question 7

Lymphoid Nodules

Answer 7

Dense masses of lymphocytes and macrophages

Ex: lymph nodes, tonsils, appendix, Peyer patches (ileum)

Question 8

Peyer’s Patches

Answer 8

Clusters of lymphoid follicles in wall of distal portion of small intestine (aggregated lymphoid nodules)

Functions:
1. Destroy bacteria (preventing them from breaching intestinal wall)
2. Generate “memory” lymphocytes

Question 9

Red Bone Marrow

Answer 9

Primary lymphoid organ

Involved in hemopoiesis and immunity

Origination site of B & T cells (& blood cells)
Maturation site of B cells

Question 10

Thymus

Answer 10

Primary lymphoid organ
Bilobed; located between sternum & aortic arch in superior mediastinum

Member of endocrine, lymphatic,
and immune systems

Houses developing T lymphocytes
Secretes hormones (thymosin) that regulate their later activity

Each lobe has light central medulla & outer cortex populated by T lymphocytes

Degenerates (involutes) with age

Question 11

What 4 bones contain paranasal sinuses?

Answer 11

Maxillary, Sphenoid, Ethmoid, Frontal