ch 20 pq

What structure does lymph pass through on its way back to the circulatory system?
A) Alveoli
B) Capillaries
C) Lymph nodes
D) Nephrons

C) Lymph nodes

What makes lymphatic capillaries more permeable than blood capillaries?
A) Tight junctions
B) Endothelial cells with one-way minivalves
C) Smooth muscle lining
D) Negative pressure system

B) Endothelial cells with one-way minivalves

What opens the minivalves in lymphatic capillaries?
A) High blood pressure
B) High oxygen levels
C) Increased extracellular fluid (ECF) volume
D) Low temperature

C) Increased extracellular fluid (ECF) volume

What propels lymph through the lymphatic vessels? (Select all that apply)
A) Skeletal muscle contraction
B) One-way valves
C) Cardiac muscle contractions
D) Breathing (thoracic pressure changes)
E) Pulsations of nearby arteries
F) Contractions of smooth muscle in vessel walls

Answer: A, B, D, E, F

Which cells help activate T cells and phagocytize foreign substances?
A) B lymphocytes
B) Dendritic cells
C) Macrophages
D) Mast cells

C) Macrophages

Why is lymph flow slow through lymph nodes?
A) They have no valves
B) High resistance inside the node
C) More afferent than efferent vessels
D) Nodes collapse during infection

C) More afferent than efferent vessels

What is true about the thymus?
A) Fights infections directly
B) Produces red blood cells
C) Filters lymph
D) Does not directly fight antigens

D) Does not directly fight antigens

Which of these is NOT part of MALT?
A) Peyer’s patches
B) Appendix
C) Tonsils
D) Thymus

D) Thymus

How are lymphatic capillaries different from blood capillaries?

A) They are very permeable and take up proteins, cell debris, pathogens, and cancer cells.

B) They have a continuous basement membrane and tightly joined endothelial cells.

C) They primarily transport oxygen and nutrients to tissues.

D) They are typically found in the central nervous system and bone marrow.

A) They are very permeable and take up proteins, cell debris, pathogens, and cancer cells.

What forms the one-way minivalves in lymphatic capillaries?

A) Overlapping endothelial cells.

B) Tight junctions between endothelial cells.

C) Smooth muscle sphincters.

D) Specialized collagen fibers.

A) Overlapping endothelial cells.

What causes the minivalves in lymphatic capillaries to open?

A) Active transport of fluid into the lymphatic capillaries.

B) A decrease in intralymphatic pressure.

C) Contraction of smooth muscle cells surrounding the capillaries.

D) An increase in extracellular fluid (ECF) volume.

D) An increase in extracellular fluid (ECF) volume.

What happens to pathogens that enter the lymphatic capillaries?

A) They are immediately destroyed by enzymes within the lymphatic fluid.

B) They are directly transported to the bloodstream for systemic circulation.

C) They travel through the lymphatic system and encounter immune system cells.

D) They are filtered out and expelled from the body at the site of entry

C) They travel through the lymphatic system and encounter immune system cells.

What do lymphatic vessels do with excess fluid from tissues?
A) Store it in the spleen
B) Excrete it from the body
C) Return it to the bloodstream
D) Use it to create hormones

C) Return it to the bloodstream

Select the correct statement about lymph transport

A)Lymph transport is faster than that occurring in veins.

B)Under normal conditions, lymph vessels are very high-pressure conduits.

C)Lymph transport is only necessary when illness causes tissue swelling.

D)Lymph transport depends on the movement of adjacent tissues, such as skeletal muscles.

D) Lymph transport depends on the movement of adjacent tissues, such as skeletal muscles

About 3 liters of fluid are lost to the tissue spaces every 24 hours and are returned to the bloodstream as lymph.

True or False?

TRUE

Like blood, lymph flows both to and from the heart. T OR F?

FALSE

Peyer's patches are mucosa-associated lymph tissue located in the __________.

A) wall of colon

B) liver

C) spleen

D) wall of small intestine

D) wall of small intestine

Which lymphoid organ(s) serve(s) in immune surveillance and blood cell recycling?

a) thymus

b) tonsils

c) lymph nodes

d) spleen

d) spleen

There are more efferent lymphatic vessels leaving a lymph node than there are afferent vessels entering a lymph node. T OR F?

false