Exam II: 4A Edema and Microcirulation

Question 0

Explain the capillary network.

Answer 0

• Blood is supplied to each capillary network by arterioles

- Blood leaves the capillary network by draining into Venules

Question 1

What is the major function of the capillary network?

Answer 1

Nutrient and waster exchange w/ tissues

Question 2

Where is lymph drained?

Answer 2

Away form the tissues by the lymphatic\\ network

Question 3

What is lymph?

Answer 3

A fluid that:

1) is created in the Interstitial spaces of tissues
2) Put back into the cirulation

Question 4

How do we normally exchange things between the vasculature and interstitium?

Answer 4

1) Diffusion across endothelial cell membranes
2) Movement thru fenestrations
3) Transport via small vesicles (pinocytosis)

Question 5

What is the Starling forces (pressures) ?

Answer 5

Fluid movement across clefts and fenestations

Question 6

What is Pc, P i, Pi c, Pi i?

Answer 6

Pc= Capillary hydrostatic pressure
Pi= Interstitial hydrostatic pressure
Pi c= capillary oncotic(proteins) pressure
Pi i= intersitial oncotic(proteins) pressure

Question 7

What do capillaries consist of?

Answer 7

Simple squamous epithelial cells

Question 8

Where does Pc = capillary hydrostatic pressure (BP), moves things?

Answer 8

• It moves things OUT to the fenestrations (especially things that do not have a concentration gradient).
• They have to fit!

Question 9

What are 4 things that can’t fit thru the fenestrations???

Answer 9

1. RBC
2. WBC
3. platelets
4. Big chunk proteins

Question 10

What is the second force Pi c do? (capillary oncotic pressure)

Answer 10

Osmotic force created by proteins to force material IN.

Question 11

On the arterial end which force (Pc or Pi c) is greater?

Answer 11

Pc is ! This is called FILTRATION!

-You will loose fluid in this capillary. (cell will have access to it)

Question 12

What is the pathway for lymphatic vessels?

Answer 12

Lymphatic capillaries–>Lymphatic Venules & Veins–>Lymphatic Ducts(Right Lymphatic Duct & Thoracic Duct)

Question 13

What does the thoracic ducts collect? And where is it located?

Answer 13

• Collects lymph from MOST of the body regions.
• It ascends into the root of the neck on the left side & opens into the Left subclavian vein near the junction of the left internal jugular vein.

Question 14

Where does the right lymphatic duct receive lymph from ? And where does it empty?

Answer 14

• The right side of the head, neck, and trunk and from the right upper extremity.
• Empties into the right Subclavian vein.

Question 15

What are lymph nodes?

Answer 15

• “beads” or “swellings” along certain lymphatic vessels.

- FILTERS

Question 16

Where are lymph nodes most extensively found?

Answer 16

In the axillary, breast, neck, abdomen, thorax, pelvis, and groin.

Question 17

What is EDEMA?

Answer 17

• Palpable swelling due to expansion of extracellular fluid
• 2 types: 1) pitting 2) non-pitting
• This can be seen when you press your finder into the skin, it is temporary depressed.

Question 18

What happens to the excess fluid with Edema?

Answer 18

It becomes infiltrated with protein or other material so that it cannot move freely within the tissue spaces.

Question 19

When does Edema occur?

Answer 19

When the volume of interstitial fluid exceeds the capacity of the lymphatics to return it to the circulation.

Question 20

What is Edema caused by?

Answer 20

1. Excess filtration (typically reflected by increase of Pc)
2. Decreased absorption (typically reflected by decrease of Pi c)
3. increased capillary permeability
4. blocked lymphatics

Question 21

On the venous side which force (Pc and Pi c) will be more dominate?

Answer 21

Pi c does! this is called ABSORPTION

Note:
Why? Pc goes down, why did the BP fall?
1) further away from the heart
2) LOSS of FLUID!!!

Why does “Pi c “ go up?
Concentration of protein (protein is too big!) is greater on the venous side

Question 22

Why does Edema not happen?

Answer 22

B/c we take excess fluid, soak it up but they in lymph nodes and back into blood.

Question 23

In regards to (Pi c), why would protein [ ] be low?

Answer 23

Protein [ ] low:

• Excreting it in the urine
• You are not enough protein
• No protein in the blood = Edema
• The liver processes the plasma protein

Question 24

What causes Edema ?

Answer 24

• Elevation in Pc
• Drop in Pi c
• Increase permeability of capillaries
• lymphatic system backed up, because of infection? metastasis?