Immune System - Lymphatic system and the immune system

Question 1

Immunity

Answer 1

Ability to resist damage from pathogens, toxins and internal threats

Question 2

Immune System

Answer 2

Lymphoid tissues / Lymphatic System
Immune cells
Chemicals that coordinate and carry out immune functions
“self ” from “non-self” - a targeted response

Question 3

Immune system Functions:

Answer 3

Recognize and remove abnormal “self ” cells

Removes dead or damaged cells

Protects the body from disease-causing invaders
Bacteria, viruses, fungi, protozoans (one cell), parasites
Pollens, chemicals, and foreign bodies
Immunogens: trigger the body’s immune response

Question 4

Response

Answer 4

Nonspecific Innate Immunity and Specific Acquired Immunity

Question 5

Lymphatic System

Answer 5

System of vessels / cells / organs that carries excess fluids to the bloodstream and filters pathogens from the blood
drain body fluids and return them to the bloodstream
Lymph: interstitial fluid (fluid that fills spaces between cells) once it has entered the lymphatic system

Question 6

Function of lymphatic system;

Answer 6

Fluid Balance
Lipid Absorption
Defence against pathogens
Pathogen
Substance or microorganism that causes disease or damage to the tissues of the body
use humans as a source of nutrients and as an environment to survive in

Question 7

Lymphatic System and Drainage

Answer 7

Tonsils, the lymph nodes, the spleen, the thymus
Lymph nodes -located along lymphatic vessels
Groups in the cervical (neck), axillary (armpit), and inguinal (groin) areas

Question 8

Lymph: Carries fluid from tissues to circulatory system

Answer 8

Vessels begin as CLOSED-ended capillaries,

Feed into larger lymphatic vessels

Empty into the bloodstream by ducts. –

Lymph travels through the lymph nodes

Doesn’t circulate ie not pumped by heart

Forced through the vessels by contraction of skeletal muscles -
Valves, (one way semi lunar valves)
one-way flow of lymph

Question 9

Lymphatic System - Capillaries

Answer 9

Where fluid enters the lymphatic system

In virtually all tissues
between arterioles and venules

Thinner walls than veins

Overlapping epithelial ‘flaps’
fluid moves into capillaries only

Question 10

Lymphatic System: small intestine

Answer 10

Lymphatic capillaries called lacteals

Lipids and some lipid soluble proteins and vitamins form milky fluid = chyle

Enter lacteals

Enter blood stream

Question 11

Lymphatics Circulation;

Answer 11

Lymphatic capillaries > Vessels > Trunks > 2 ducts
Drainage
Right: Right lymphatic duct drains into right subclavian vein
right sides of the head, thorax, and right arm
Left: Thoracic duct drains into the left subclavian vein
remaining portions of the body

Question 12

Lymphatic Organs

Answer 12

Tissue: Many lymphocytes / defence cells
Lymphocytes: Red bone marrow

Question 13

Tonsils

Answer 13

Palatine tonsils
Pharyngeal tonsils (adenoids when enlarged)
Lingual tonsil

Protective ring of lymphatic tissue around the nasal and oral cavities and the pharynx
Pathogens

Question 14

Lymph nodes

Answer 14

Distributed along the lymphatic vessels

Lymph passes through before entering blood

Superficial or deep

Superficial aggregations
(1) inguinal nodes in the groin, (2) the axillary nodes in the axilla (armpit), and (3) the cervical nodes in the neck.

Dense capsule with extensions: trabeculae
lymphatic tissue: Lymphocytes and lymphatic nodules
lymphatic sinuses: macrophages

Question 15

Lymph flows through nodes
and activates&raquo_space;>

Answer 15

Activates – stimulating lymphocytes to divide
Nodules: germinal centres
Remove pathogens: macrophages

Question 16

Lymph flows through nodes
and activates&raquo_space;>

Answer 16

Activates – stimulating lymphocytes to divide
Nodules: germinal centres
Remove pathogens: macrophages

Question 17

What is the spleen and its role?

Answer 17

Filters blood
Respond to foreign substances, destroy old RBC

White pulp
Lymphatic tissue surrounding arteries
Lymphocytes can be stimulated to divide

Red pulp
Surrounding veins
Macrophages and red blood cells
Macrophages remove foreign substances and worn-out red blood cells through phagocytosis

Also functions as a blood reservoir

Question 18

Thymus

Answer 18

2 lobed gland

Divided into lobules

Cortex (dark)
Many lymphocytes

Medulla (light)
Fewer lymphocytes

Maturing T-cells
Mature T-cells migrate to medulla, enter blood and travel to other lymphatic tissue

Question 19

Cells of the Immune System (6 in total)

Answer 19

Circulate in the blood but leave and function extra vascular

(1) eosinophils
(2) Basophils (blood); related mast cells (tissues)
(3) neutrophils
(4) monocytes and macrophages
(5) lymphocytes and plasma cells
(6) dendritic cells

formed in the bone marrow and released into the circulation

Classified: morphologically and functionally
Phagocytes
Cytotoxic cells
APCs

display fragments of foreign proteins on their cell surface

Question 20

What are Leukocytes?

Answer 20

white blood cells (WBCs): Key cells for immune response

Question 21

Basophils and Mast cells

Answer 21

Release mediators that contribute to inflammation

Histamine, heparin (anticoag) and other cytokines
Allergic and immune responce

Basophils (circulation)

Mast cells (tissue):
lungs
GI tract
skin

Question 22

Eosinophils

Answer 22

Allergic reactions and parasitic diseases

Digestive tract, lungs, urinary and genital epithelia, and connective tissue of the skin

Cytotoxic: release substances from their granules that directly damage or kill the parasites

Question 23

Neutrophils

Answer 23

Phagocytic cells

most abundant WBC

segmented nucleus

Most remain in the blood but can leave if attracted to an extravascular site of damage or infection

Kill / ingest bacteria
release a variety of cytokines
including fever-causing pyrogens

Question 24

Monocytes and Macrophages

Answer 24

Monocytes precursors of tissue macrophages

Once in the tissues, monocytes enlarge and differentiate into phagocytic macrophages

Key scavengers within tissues
Antigen Presenting Cell (APC)
Antigens: Immunogens that react with B and T lymphocytes

APCs can insert fragments of processed antigen into its membrane - becomes part of surface protein complexes

they can bind to and activate other types of immune cells.

Question 25

Lymphocytes

Answer 25

Key cells that mediate the acquired immune response of the body

Most in lymphoid tissue

3 subtypes
B Lymphocytes (APCs)
T lymphocytes
Natural Killer cells

Question 26

Dendritic cells

Answer 26

Long processes

Antigen-presenting cells

Found in skin (Langerhans cells)

Other organs

Once capture antigens migrate to lymph nodes
Present antigens to lymphocytes which activates lymphocytes

Question 27

Phagocytosis and antigen presentation

Answer 27

> Macrophages and Neutrophils key cells that phagocytose
- Some B lymphocytes and dendritic cells also present antigen

> Some pathogens bind directly to phagocyte receptors / others precoated by antibodies;
- Stimulates internalisation
- Digests pathogen
- Part of it (antigen) presented on surface

Question 28

What do lymphatic capillaries do?

Answer 28

remove fluid from tissues and absorb lipids from small intensine

Question 29

Lymph nodes filter _____

Answer 29

lymph

Question 30

Name lymphocytes;

Answer 30

B cells originate and mature in red bone marrow
T-cells:
Pre-T cells are produced in red bone marrow a
migrate to the thymus and mature to become T cells.

^^ Both circulate to other lymphatic tissues.
B cells and T cells are responsible for much of immunity.
Increase in number and circulate to lymphatic and other tissues

Question 31

Leukocytes;

Answer 31

Other leukocytes function as phagocytes, granulocytes, cytotoxic cells