Chapter 22 - Lymphatic System & Immunity

Question 1

Immunity/Resistance

Answer 1

ability to ward off damage or disease

Question 2

(2) types of immunity

Answer 2

**Innate - **non specific

1st/2nd line of defense

**Adaptive - **specific recognition of invaders

Question 3

Lymphatic system

Answer 3

lymph, lymphatic vessels, structures & organs containing lymphatic tissue & red bone marrow

Question 4

Functions of Lymphatic system

Answer 4

drain excess interstitial fluid

transport dietary lipids

carry out immune responses

Question 5

Lymphatic vessels begin as lymphatic ____

Answer 5

capillaries - closed at one end

Question 6

Lymphatic capillaries unite to form large lymphatic ____

Answer 6

vessels - resemble veins in structure but thinner walls & more valves

Question 7

Lymphatic: Capillaries → vessels → ???

Answer 7

passes through lymph nodes

Question 8

Lymph nodes

Answer 8

Encapsulated organs with masses and B and T cells

Question 9

Lymphatic capillaries

Answer 9

larger diameter than blood capillaries

unique one-way structure

permit intersitial fluid to flow in but not out

anchoring filaments pull opening wider when interstitial fluid accumulates

Question 10

Lacteals

Answer 10

specialized lymphatic capillaries in small intestine that carry dietary lipids into vessels & then blood

Question 11

Chyle

Answer 11

lymph with lipids

Question 12

Vessels exit lymph nodes to form lymph ___

Answer 12

trunks

Question 13

Principal lymph trunks are…? (5)

Answer 13

lumbar

intestinal

bronchomediastinal

subclavian

jugular

Question 14

Lymph passes from lymph trunks into (2) main channels before draining into…

Answer 14

thoracic & right lymphatic ducts

venous blood

Question 15

Most components of blood plasms filter freely though capillary walls to form interstitial fluid but more fluid filters out of blood capillaries than returns to them by …`

Answer 15

reabsorption

Question 16

excess filtered fluid drains into?

Answer 16

lymphatic vessels & becomes lymph

Question 17

lymph

Answer 17

interstitial fliud in lymphatic vessels

Question 18

Important function of lymphatic vessels

Answer 18

to return lost plasma proteins to blood stream

Question 19

(2) pumps aiding venous return also used maintain flow of lymph

Answer 19

1) skeletal muscle pump
2) respiratory

Question 20

Lymphatic tissue & organs

(2) groups based on function

Answer 20

1) primary lymphatic organs
2) secondary lymphatic organs

Question 21

primary lymphatic organs

Answer 21

sites where stem cells divide and become immunocompetent

- red bone marrow & thymus

Question 22

Secondary lymphatic organs

Answer 22

where most immune response occurs

lymph nodes, spleen, lymphatic nodules

Question 23

Thymus

Answer 23

in mediastinum between sternum & aorta

• 2 lobes seperated by capsule but held close by connective tissue

**trabeculae **(extensions of capsule) divide each lobe into lobules

• outer **cortex **& inner medulla

Question 24

Outer cortex of Thymus

Answer 24

composed of many **T cells **which came from red bone marrow

**Dendritic cells **derived from monocytes assist in T cell maturation

specialized **epithelial cells **assist in T cell maturation

• **macrophages **clear out dead cells

Question 25

Medulla

Answer 25

scattered, nore mature T cells epithelial, dendritic cells & macrophages

Question 26

Lymph nodes located?

Answer 26

~600 scattered throughout body located along lymphatic vessels **STROMA**: structural framework covered by **capsule **that has **trabeculae **which divides nodes into compartments **reticular fibers & fibroblasts** internal to capsule **PARENCHYMA: **functioning part divided into cortex (inner + outer) & medulla

Question 27

**Parenchyma **of Lymph Node

Answer 27

**Outer** **cortex** - aggregates of B cells (**lymphatic** **nodules/follicles)** – site of plasma cell and memory B cell formation **Inner cortex - **mainly T cells & dendritic cells **Medulla - **B cells, macrophages, antibody producing plasma cells from cortex

Question 28

**Flow of Lymph** - one direction

Answer 28

enters through **afferent lymphatic vessels → subscapular sinus → traneculae sinus → medullary sinus → efferent lymphatic vessels **

Question 29

Lymph nodes function as \_\_\_

Answer 29

filter foreign substances trapped by reticular fibers & destroyed by macrophages

Question 30

Spleen

Answer 30

largest single mass of lymphatic tissue in body

Question 31

Spleen consists of?

Answer 31

**Stroma ** **Parenchyma **

Question 32

**Parenchyma **of spleen consists of (2) different kinds of tissue

Answer 32

* *White pulp **- lymphatic tissue (lymphocytes and macrophages) arranged around central arteries (branches of **splenic** artery) - B & T cells carry out immune function **Red pulp **- blood-filled **venous sinuses **& **splenic cords ** (RBCs, macrophages, lymphocytes, plasma cells & granulocytes

Question 33

Within red pulp, spleen performs (3) functions

Answer 33

1) removal of ruptured RBCs by macrophages 2) storage of platelets 3) **hemopoiesis** - production of blood cells

Question 34

Lymphatic nodules

Answer 34

not surrounded by capsule Scattered throughout lamina propria of mucous membranes lining GI, urinary, reproductive tract (**Mucosa-associated Lymphatic tissue - MALT) ** small & solitary larger - **Tonsils, Peyers patches & appendix**

Question 35

Innate Immunity first line of defenses? provides...

Answer 35

: Skin and mucous membranes both physical & chemical barriers

Question 36

**Innate Immunity **- Physical barriers

Answer 36

epidermis mucous membranes nose hairs cilia of upper respiratory tract

Question 37

**Innate Immunity - **Fluids

Answer 37

Lacrimal apparatus of eye Saliva Urine Vaginal secretions, defecation & vomiting

Question 38

**Innate Immunity - **chemicals

Answer 38

sebaceous (oil) glands secrete sebum perspiration, gastric juice & vaginal secretions - (**all acidic)**

Question 39

Innate Immunity - 2nd line of defense?

Answer 39

Internal defenses

Question 40

**Innate Immunity - **Antimicrobial substances

Answer 40

**Interferons ** - produced by lymphocytes, macrophages & fibroblasts **complement system - **proteins in blood plasma & PMs enhance immune rxns **Iron-binding proteins -** inhibit bacteria growth by reducing available iron **Antimicrobial Proteins (AMPs) - **attract dendritic & mast cells that participate in immune responses

Question 41

Innate Immunity - Natural Killer (NK) cells

Answer 41

Lymphocyte but not a B or T cell - can kill variety of infected bodies & certain tumour cells - attack any cell displaying abnormal plasma membrane proteins release **perforin **or **granzymes **

Question 42

**Innate Immunity - **phagocytes

Answer 42

**Neutrophils & ****macrophages ** migrate to infected area (5) steps of phagocytosis - chemotaxis, adherence, ingestion, digestion, killing