Test 2 Flashcards
1
Q
Components of blood
A
Plasma-55%
Cells-45% (White blood cells-
2
Q
Components of plasma
A
Water (90%) Ions Proteins Gases Nutrients Wastes Hormones
3
Q
Components of cells
A
Red blood cells
White blood cells
Platelets
4
Q
Where do blood cells develop
A
Stem cells in bone marrow
5
Q
Hematopoiesis
A
Blood cell formation
6
Q
Where does hematophiesis occur?
A
Red bone marrow (skull, pelvis, ribs, sternum, humerus, femur)
7
Q
Describe erythrocytes
A
Red blood cells Transport O2 in blood Bioconcave discs Anucleate Hemoglobin Life span of 100-120 days
8
Q
Iron-containing protein, bonds to O2
A
Hemoglobin
9
Q
Decrease in oxygen-carrying ability of blood
Low red blood count or deficient hemoglobin content
A
Anemia
10
Q
Abnormal hemoglobin
Genetic disorder
Carriers of 1 allele are resistant to malaria in Africa
A
Sickle-cell disease
11
Q
Explain leukocytes
A
White blood cells
Defend body against infection and tumors
Locate areas of tissue damage by responding to chemicals
12
Q
What are the types of white blood cells
A
Neutrophils Eosinophil Basophils Lymphocytes Monocytes
13
Q
Granulocytes
A
Neutrophils
Eosinophils
Basophils
14
Q
Agranulocytes
A
Lymphocytes
Monocytes
15
Q
Small cytoplasmic granules stain light purple and give the cytoplasm a coarse appearance
Polymorphonuclear
Highly mobile and phagocytic
Migrate out of blood vessels
A
Neutrophils
16
Q
Large, numerous cytoplasmic granules that stain orange
Nuclei have two lobes
Involved in allergic reactions
Weak phagocytes
A
Eosinophils
17
Q
Nuclei have multiple lobes
A
Polymorphonuclear
18
Q
Large but sparse cytoplasmic granules
Least numerous of white blood cells
Motile
Contain histamine and heparin
A
Basophils
19
Q
Smallest WBCs
Largest spherical nuclei
A
Lymphocytes
20
Q
8 functions of blood
A
- deliver O2 and nutrients to all body cells
- transport waste products from cells for elimination
- transport hormones
- maintain body temp
- maintain pH
- maintain fluid volume
- prevent blood loss
- prevent infection
21
Q
Lymphocytes that directly attack infected or cancerous cells
A
T lymphocytes
22
Q
Lymphocytes which produce antibodies
A
B lymphocytes
23
Q
Largest white blood cells
Dark, kidney bean shaped nuclei
Motile and highly phagocytic (Emily bacteria and viral infected cells)
A
Monocytes
24
Q
Bone marrow become cancerous leading to huge numbers of white blood cells and is treated with chemotherapy, radiation, stem cell transplants
A
Leukemia
25
Cell fragments which are needed for clotting blood
Platelets
26
Stoppage of bleeding
Hemostasis
27
Steps of Hemostasis
Vascular spasm
Platelet plug forms
Coagulation
28
Step of Hemostasis when the damaged blood vessel constricts
Vascular spasm
29
The step of Hemostasis when platelets stick and bind to damaged site and release chemicals to attract more platelets
Platelet plug forms
30
Step of hemostasis when the blood clotting and the fibrin threads forms mesh that traps red blood cells
Coagulation
31
How long does it take for Hemostasis to occur
Blood clot forms in 3-6 minutes
32
Clot in unbroken blood vessel
Thrombus
33
Coronary thrombosis =
Heart attack
34
Thrombus breaks away from vessel wall and floats freely
Embolus
35
Cerebral embolus =
Stroke
36
Hereditary bleeding disorder, lack clotting factors
Hemophilia
37
Foreign substance that immune system recognizes
Antigen
38
y-shaped proteins secreted by white blood cells that attach to antigens
Antibodies
39
Clumping caused by antibodies bonding to antigens on red blood cells
Agglutination
40
What are the red blood cell surface proteins
A antigen
B antigen
Rh antigen
41
What antigens does blood type A have on the surface of its red blood cells
A
42
What antigens does blood type b have on the surface of its red blood cells
B
43
What antigens does blood type AB have on the surface of its red blood cells
A and B
44
What antigen does blood type O have on the surface of its red blood cells?
None
45
In blood typing, clumps mean
An antigen is present
46
What are the two circuits which the heart pumps blood to?
Pulmonary and systemic
47
Where does the heart pump blood to in the pulmonary circuit?
To and from the lungs
48
Where does the heart pump blood to in the systemic circuit
To and from everywhere but the lungs
49
What are the three kinds of blood vessels
Arteries
Capillaries
Veins
50
Carry blood away from the heart and carry to the capillaries
Arteries
51
Microscopic vessels where exchange between cells and blood takes place
Capillaries
52
Received blood from capillaries and carry it back to the heart
Veins
53
Two sets of pumping gamblers in the heart
Left and right atrium
| Left and right ventricle
54
Receives systemic blood
Right atrium
55
Pumps blood to the lungs (pulmonary)
Right ventricle
56
Receives blood from the lungs
Left atrium
57
Pumps blood to organ systems (systemic)
Left ventricle
58
Pericardial sac
Surrounds the heart
59
Parts of the heart wall
Myocardium
| Endocardium
60
Middle layer of the heart wall
Thickest part
Thick muscle layer
Myocardium
61
Inner lining of the pumping chambers of the heat
Continuous with endothelium (inner layer of blood vessel)
Simple squamous epithelium
Endocardium
62
Describe cardiac muscle cells
```
Shorter than skeletal muscle fibers
Have single nucleus
Have striations
Depend of aerobic metabolism
Connected by intercalated discs
```
63
Blood flow of the heart
Superior/inferior venae cavae➡️right atrium➡️right ventricle➡️pulmonary semilunar valve➡️pulmonary veins➡️left atrium➡️left ventricle➡️aorta
64
Which ventricles myocardium is thicker?
Left
65
Why does the left ventricle have thicket myocardium?
Because it has a harder job--sending blood to the entire body
66
What to heart valves insure?
One way blood flow
67
Regurgitation
Backward blood flow
68
Key note on the anatomy of the heart
The heart has 4 chambers, the right atrium and ventricle with the pulmonary circuit and the left atrium and ventricle with the systemic circuit. The left ventricles greater workload makes it more massive than the right, but the two pump equal amounts of blood. AV valves prevent backflow from the ventricles into the atria, and semilunar valves prevent backflow from the outflow vessels into the ventricles
69
Coronary circulation meets the heavy demands of ___ for ____
Myocardium
Oxygen
Nutrients
70
Coronary arteries
Involved in blood supply to the heart
| Left and right arteries-both branch from aorta base
71
Drainage of the heart is to
The right atrium
72
How do the capillaries drain?
Great and middle cardiac veins
73
Where does the drainage of the heart empty to?
Coronary sinus
74
A blood clot in an artery
Embolism
75
What causes a heart attack?
Buildup of plaque in the walls of an artery. This can lead to restriction or cessation (stopping) of blood flow in the artery. A portion of the myocardium may die
76
Myocardial infarction
Heart attack
77
Types of blood vessels
Artery
Vein
Capillaries
78
Blood vessel which carries blood away from the heart
Artery
79
A blood vessel that carries blood towards the heart
Vein
80
Microscopic blood vessels that carry blood from small arteries to small veins
Capillaries
81
Pathway of blood
Artery➡️arteriole➡️capillary➡️venuole➡️vein
82
Blood vessel structure starting with inner to outer
Tunica intima
Tunica media
Tunica adventitia
83
The endothelium of the blood vessel
Tunica intima
84
Smooth muscle and elastic connective tissue of the blood vessel
Tunica media
85
Fibrous type of vessel connective tissue
Tunica adventitia
86
Describe the three layers of arteries and their function
Intima-smooth lining
Media-allows constriction and dilation of vessels; thicker than in veins; muscle innervated by autonomic fibers
Adventitia-provides flexible support that resists collapse or injury;thicker than veins; thinner than media
87
Describe the three layers of veins and their functions
Intima-smooth lining w semi-lunar valves to ensure one way blood flow
Media-allows constriction and dilation of vessels; thinner than in arteries; muscle innervated by autonomic fibers
Adventitia- provides flexible support that resists collapse or injury; thinner than in arteries; thicker than media
88
Describe the three layers in capillaries and their function
Intima-makes up the entire wall of the capillary; thinness permits transport across vessel wall
Media-absent
Adventitia-absent
89
What are the functions of capillaries?
- Most import vessels functionally
- tiny
- 100,000 / 1 cubic cm of muscle tissue
- primary exchange vessels
- the small size and large number ensures slow blood flow
90
Describe the function of arteries
- distributors; carry blood vessels to the arterioles which then takes to capillaries
- arterioles are important in maintaining normal blood pressure and circulation
91
Resistance vessels
Arterioles
92
Valves which regulate blood flow into the capillaries
Precapillary sphincters
93
Describe the function of veins
Collectors and reservoir vessels (able to hold blood)
94
The great ability to stretch, meaning something can hold large amounts of blood with almost no change in blood pressure
Capacitance
95
Which structure has capacitance
Veins
96
Maintain one way blood flow in veins
Valves
97
Describe the reservoir function of veins
Pooled blood is moved toward the heart as valves are forced open by pressure from volume of blood from below
98
Two circulatory routes
Systemic
| Pulmonary
99
Blood is pumped from the left side of the heart
Systemic circulation
100
Blood is pumped to all tissues of the body
Systemic
101
Blood is pumped from the right side of the heart
Pulmonary
102
Blood is pumped to the gas exchange tissues of the lungs
Pulmonary
103
Branch into vessels of increasing size
Veins
104
Vessels can vary
In size and location from person to person
105
Deep veins
Veins found deep in the body
106
Superficial veins
Veins found near the surface
107
Modified cardiac muscle that specializes in contraction
Conduction system of the heart
108
Four main structures that compose the conduction system of the heart
Sinoatrial (SA) node
Atrioventricular (AV) node
AV bundle
Purkinje system
109
Describe the SA node
- Initiates the mechanical contraction of the heart
- located in the right atrium just below the junction of the superior vena cava
- possesses an intrinsic rhythm
110
Pacemaker of the heart
SA node
111
Intrinsic rhythm
Impulses are initiated at regular impulses without any stimulation by nerve impulses from the brain and cord
112
Describe the AV node
- impulses travel here from SA node
- contract
- action potential enters through three internodal bundles of conducting fibers
113
What happens as an impulse passes through the AV Node?
The impulse slowly passes through the AV node then speeds up as the impulse is relayed through the AV bundle (bundle of His) into the ventricles
114
What conducts impulses through the ventricles?
the right and left AV bundle branches and the Purkinje fibers. This causes them to contract simultaneously
115
Describe an artificial Pacemaker?
- Devices that electrically stimulate the heart
- Electrodes sewn directly into the epicardium or directly inserted into the heart chamber
- Inferior to the heart’s natural pacemaker
116
Impulse conduction generates
tiny electrical currents in the heart that spread through surrounding tissues to the surface of the body
117
What is a ECG/EKG?
An electrocardiogram
| graphic record of the hearts electrical activity—the impules that preced the actual contraction
118
Where are electrodes attached for an ECG/EKG
to a voltmeter and to the limbs and chest of the subject
119
Letter A of a EKG
```
At rest (baseline)
Heart wall is completely relaxed—no change in electrical activity
```
120
Letter B of an EKG
Action potential reaches the first electrode (relatively negative)
P wave represents the depolarization of the atria
121
Letter C of an EKG
Action potential reaches the second electrode (pen returns to baseline)
Atrial walls are completely depolarized—no change recorded
122
Letter D of an EKG
End of action potential passes the first electrode (relatively positive)
QRS Complex occurs as atrial walls repolarize and ventricular walls depolarize (massive depolarization of ventricles overshadows atrial repolarization)
123
Letter E of an EKG
Action potential passes second electrode (returns to baseline)
Atrial walls are completely repolarized and ventricular walls are completely depolarized
124
Describe EKG waves
- Represent the dynamic events that happen during the contraction of the heart
- Letters are arbitrary and do not stand for any words
125
Describe F Wave of EKG
T wave appears as the ventricular walls replarize
126
Describe G Wave of EKG
Once the ventricles are completely repolarized it is back to the baseline ECG
127
Describe a Transesophageal Echocardiogram
Allows for visuals of heart from behind the heart (video)
| Device is inserted into the esophagus
128
Describe Bradycardia
- Slow heart rhythm—below 60 beats per minute
- Slight bradycardia is normal during sleep and in conditioned athletes when awake
- Can be caused by damage to the SA node
129
Describe Tachycardia
- Very rapid heart rhythm—more than 100 beats per minute
- Normal during and after exercise and during the stress response
- Can result from improper autonomic control of the heart, blood loss, shock and a host of other factors
130
Describe Ventricular Fibrillation
- Complete disruption of the normal heart rhythm
| - Death may occur within minutes if the heart beat is not corrected by defibrillation or other means
131
First sound heard when listening to heartbeat
- "Lub"
| - occurs when atrioventricular valves close
132
Second sound heard when listening to heartbeat
- "dup"
| - occurs when semilunar valves close
133
What are the two parts of the two parts which the lymphatic system consists of?
- Lymphatic vessels
| - Lymphoid tissues and organs
134
What are the lymphatic system functions?
- Transport fluids back to the blood
| - Play essential roles in body defense and resistance to disease
135
excess tissue fluid carried by lymphatic vessels
lymph
136
Properties of lymphatic vessels
- One way system toward the heart
- No pump
- Lymph moves toward the heart
137
What happens as lymph moves towards the heart?
- Milking action of skeletal muscle
| - Rhythmic contraction of smooth muscle in vessel walls
138
Describe Lymph campillaries
- Walls overlap to form flap-like minivalves
- Fluid leaks into lymph capillaries
- Capillaries are anchored to connective tissue by filaments
- Higher pressure on the inside closes minivalves
139
How do lymphatic collecting vessels work?
- Collects lymph from lymph capillaries
- Carries lymph to and away from lymph nodes
- Returns fluid to circulatory veins near the heart
140
What ducts is lymph returned to?
Right lymphatic duct
| Thoracic duct
141
What materials does lymph return to blood?
water
blood cells
proteins
142
What harmful materials enter lymph vessels?
Bacteria
Viruses
Cancer cells
Cell debris
143
What are the function of lymph nodes?
- Filter lymph before it is returned to the blood
| - Defense cells within lymph nodes
144
What are lymph nodes two lines of defense?
macrophages
| lymphocytes
145
engulf and destroy foreign substances
macrophages
146
provide immune response to antigens
lymphocytes
147
Describe the structure of lymph nodes
Most of kidney-shaped, less than 1 inch long
cortex
medulla
148
outer part of a lymph node that contains follicles
cortex
149
collections of lymphocytes
follicles
150
inner part of a lymph node which contains phagocytic macrophages
medulla
151
What is the flow of lymph through nodes?
- Lymph enters the convex side through afferent lymphatic vessels
- Lymph flows through a number of sinuses inside the node
- Lymph exits through efferent lymphatic vessels
- Fewer efferent than afferent vessels causes flow to be slowed
152
what organs contribute to lymphatic function
spleen
thymus
tonsils
peyer's patches
153
Describe the spleen
- Located on the left side of the abdomen
- Filters blood
- Destroys worn out blood cells
- Forms blood cells in the fetus
- Acts as a blood reservoir
154
Describe the thymus
- Located low in the throat, overlying the heart
- Functions at peak levels only during childhood
- Produces hormones (like thymosin) to program lymphocytes
155
Describe tonsils
- Small masses of lymphoid tissue around the pharynx
- Trap and remove bacteria and other foreign materials
- Tonsillitis is caused by congestion with bacteria
156
Describe Peyer's Patches
- Found in the wall of the small intestine
- Resemble tonsils in structure
- Capture and destroy bacteria in the intestine
157
What is a MALT
Mucosa-Associated Lymphatic Tissue
| Acts as a sentinal to protect respiratory and digestive tracts
158
What are MALT organs
- Peyer’s patches
- Tonsils
- Other small accumulations of lymphoid tissue
159
The body is constantly in contact with
bacteria, fungi, and viruses
160
What are the bodies 2 defense systems for foreign materials
nonspecific defense system
| specific defense system
161
Nonspecific Defense System
- Mechanisms protect against a variety of invaders
| - Responds immediately to protect body from foreign materials
162
Specific Defense System
- Specific defense is required for each type of invader
| - Also known as the immune system
163
Lines of Defense of the nonspecific defense mechanism
first and second
164
lines of defense of the specific defense mechanism
third line of defense
165
First line of defense
- skin
- mucous membranes
- secretions of skin and mucous membranes
166
second line of defense
- phagocytic cells
- antimicrobial proteins
- the inflammatory response
167
third line of defense
- lymphocytes
- antibodies
- macrophages
168
Body surface coverings, specialized human cells, and chemicals produces by the body
nonspecific body defenses
169
Examples of nonspecific mechanisms
intact skin and mucous membranes
170
Describe the skin as a first line of defense
physical barrier to foreign materials
-the pH of skin is acidic to inhibit bacterial growth
EX)) sebum is toxic to bacteria and vaginal secretions are very acidic
171
Describe the stomach as a first line of defense
Secretes hydrochloric acid
| Has protein-digesting enzymes
172
Saliva and lacrimal fluid contain ____ as a line of defense
lysozyme
173
Mucus traps
microorganisms in digestive and respiratory pathways
174
Describe Phagocytes
- Engulfs foreign material into a vacuole
| - Enzymes from lysosomes digest the material
175
Describe a natural Killer cell
- Can lyse and kill cancer cells
| - Can destroy virus- infected cells
176
Describe the inflammatory response as a second line of defense
- Triggered when body tissues are injured
- Produces four cardinal signs
- Results in a chain of events leading to protection and healing
177
What are the four cardinal signs of inflammation
- Redness
- Heat
- Swelling
- Pain
178
What are the functions of the inflammatory response
- Prevents spread of damaging agents
- Disposes of cell debris and pathogens
- Sets the stage for repair
179
Describe complement
- A group of at least 20 plasma proteins
- Activated when they encounter and attach to cells (complement fixation)
- Damage foreign cell surfaces
- Has vasodilators, chemotaxis, and opsonization
180
What are the antimicrobial chemicals
complement
| interferon
181
Describe interferon
- Secreted proteins of virus-infected cells
| - Bind to healthy cell surfaces to inhibit viruses binding
182
Describe a fever
- Abnormally high body temperature
- Hypothalmus heat regulation can be reset by pyrogens (secreted by white blood cells)
- High temperatures inhibit the release of iron and zinc from liver and spleen needed by bacteria
- Fever also increases the speed of tissue repair
183
Describe specific defense as a third line of defense
- antigen specific
- systemic
- has memory
184
if something is antigen specific it
recognizes and acts against particular foreign substances
185
if a specific defense is systemic it
is not restricted to the initial infection site
186
specific defenses have memory, meaning
it recognizes and mounts a stronger attack on previously encountered pathogens
187
types of immunity
humoral
| cellular
188
humoral immunity
- Antibody-mediated immunity
| - Cells produce chemicals for defense
189
cellular immunity
- Cell-mediated immunity
| - Cells target virus infected cells
190
an antigen is
Any substance capable of exciting the immune system and provoking an immune response
191
6 examples of common antigens
- Foreign proteins
- Nucleic acids
- Large carbohydrates
- Some lipids
- Pollen grains
- Microorganisms
192
Describe the concept of self-antigens
We have many surface proteins but our immune cells do not attack them because we recognize them as our own proteins. If our cells end up in another person's body or vice versa then there is a immune response because they are foreign. This restricts donors for transplants
193
Describe allergies
- Many small molecules (called haptens or incomplete antigens) are not antigenic, but link up with our own proteins
- The immune system may recognize and respond to a protein-hapten combination
- The immune response is harmful rather than protective because it attacks our own cells
194
What are the cells of the immune system
lymphocytes
| macrophages
195
Describe lymphocytes
- Originate from hemocytoblasts in the red bone marrow
- B lymphocytes become immunocompetent in the bone marrow
- T lymphocytes become immunocompetent in the thymus
196
Describe macrophages
- Arise from monocytes
| - Become widely distributed in lymphoid organs
197
Explain a humoral immune response
- B lymphocytes with specific receptors bind to a specific antigen
- The binding event activates the lymphocyte to undergo clonal selection
- A large number of clones are produced (primary humoral response)
- Most B cells become plasma cells
- -Produce antibodies to destroy antigens
- -Activity lasts for four or five days
- Some B cells become long-lived memory cells (secondary humoral response)
198
Describe a secondary response
- Memory cells are long-lived
- A second exposure causes a rapid response
- The secondary response is stronger and longer lasting
- Memory cells are long-lived
- A second exposure causes a rapid response
- The secondary response is stronger and longer lasting
199
Describe Active Immunity
- Your B cells encounter antigens and produce antibodies
| - Active immunity can be naturally or artificially acquired
200
Describe passive immunity
- Antibodies are obtained from someone else
- Immunological memory does not occur
- Protection provided by “borrowed antibodies”
201
What ways can antibodies be obtained from someone else
- Conferred naturally from a mother to her fetus
| - Conferred artificially from immune serum or gamma globulin
202
Describe monoclonal antibodies
- Antibodies prepared for clinical testing or diagnostic services
- Produced from descendents of a single cell line
203
Examples of uses for monoclonal antibodies
- Diagnosis of pregnancy
| - Treatment after exposure to hepatitis and rabies
204
Describe antibodies
- Soluble proteins secreted by B cells (plasma cells)
- Carried in blood plasma
- Capable of binding specifically to an antigen
205
Describe antibody structures
- Four amino acid chains linked by disulfide bonds
- Two identical amino acid chains are linked to form a heavy chain
- The other two identical chains are light chains
- Specific antigen-binding sites are present
206
Antibody classes
```
lgM
lgA
lgD
lgG
lgE
```
207
can fix complement
lgM
208
found mainly in mucos
lgA
209
important in activation of B cell
lgD
210
can cross the placental barrier
lgG
211
involved in allergies
lgE
212
How do antibodies inactivate antigens?
- Complement fixation
- Neutralization
- Agglutination
- Precipitation
213
Describe cellular immune response
- Antigens must be presented by macrophages to an immunocompetent T cell (antigen presentation)
- T cells must recognize nonself and self (double recognition)
- After antigen binding, clones form as with B cells, but different classes of cells are produced
214
What are the types of T cell clones
cytotoxic T cells
helper T cells
Suppressor T cells
215
Cytotoxic T cells
- Specialize in killing infected cells
| - Insert a toxic chemical (perforin)
216
Helper T cells
- Recruit other cells to fight the invaders
| - Interact directly with B cells
217
Suppressor T cells
- Release chemicals to suppress the activity of T and B cells
- Stop the immune response to prevent uncontrolled activity
218
A few members of each T cell clone are
memory cells
219
tissue transplanted from one site to another on the same person
autografts
220
tissue grafts from and identical person (twin)
isografts
221
tissue taken from an unrelated person
allografts
222
tissue taken from a different animal species
xenografts
223
which graft is ideal for donation
autografts and isografts
224
how often are xenografts successful
never
225
what increases the success of an allograft
closer tissue match
226
Describe allergy hypersensitivity
Abnormal, vigorous immune responses
227
What are the different types of allergies
- immediate hypersensitivity
| - Delayed hypersensitivity
228
Describe immediate hypersensitivity
- Triggered by release of histamine from IgE binding to mast cells
- Reactions begin within seconds of contact with allergen
- Anaphylactic shock
229
Dangerous systemic response of immediate allergies
anaphylactic shock
230
Describe delayed hypersensitivity
- Triggered by the release of lymphokines from activated helper T cells
- Symptoms usually appear 1–3 days after contact with antigen
231
Describe immunodeficiencies
-Production or function of immune cells or complement is abnormal
-May be congenital or acquired
Includes AIDS – Acquired -Immune Deficiency Syndrome
232
Describe autoimmune diseases
- The immune system does not distinguish between self and nonself
- The body produces antibodies and sensitized T lymphocytes that attack its own tissues
233
What are examples of autoimmune diseases
```
MS
Myasthenia gravis
Juvenile diabetes
Rheumatoid arthritis
Systemic lupus erythematosus
glomerulonephritis
```
234
white matter of brain and spinal cord are destroyed
MS
235
impairs communication between nerves and skeletal muscles
myasthenia gravis
236
destroys pancreatic beta cells that produce insulin
juvenile diabetes
237
destroys joints
rheumatoid arthritis
238
affects kidney, hear, lung and skin
SLE
239
impairment of renal function
glomerulonephritis
240
Describe self tolerance breakdown
- Inefficient lymphocyte programming
- Appearance of self-proteins in the circulation that have not been exposed to the immune system
- -Eggs
- -Sperm
- -Eye lens
- Cross-reaction of antibodies produced against foreign antigens with self-antigens
- -Rheumatic fever
241
Describe the lymphatic system and body defenses from a developmental standpoint
- Except for thymus and spleen, the lymphoid organs are poorly developed before birth
- A newborn has no functioning lymphocytes at birth; only passive immunity from the mother
- If lymphatics are removed or lost, severe edema results, but vessels grow back in time
