A & P Flashcards
1
Q
How much of an adult’s body weight is blood?
A
- 4 to 6 litres
- 8%
2
Q
What is blood?
A
- liquid connective tissue
- pick up and delivery system
- heat regulation
3
Q
2 Basic Components of Blood
A
1) plasma- liquid
2) formed elements (cells)-suspended in plasma
4
Q
What % of our blood volume is plasma?
A
55%
5
Q
Blood Plasma
A
- blood minus it’s formed elements
- non living
6
Q
Composition of Blood Plasma
A
- water
- dissolving substances (ex. nutrients, oxygen, salts, hormones, waste)
7
Q
What are the most abundant solutes?
A
-plasma proteins
8
Q
4 Plasma Proteins
A
1) albumins
2) globulins
3) fibrinogen
4) prothrombin
9
Q
Albumins
A
-thicken and maintain blood volume
10
Q
Globins
A
-antibodies that protect against infections
11
Q
Fibrinogen
A
-blood clotting
12
Q
Prothrombin
A
-blood clotting
13
Q
Blood Serum
A
- blood plasma
- minus clotting factors
- contains antibodies
14
Q
Does amount of blood vary with gender and size?
A
Yes.
15
Q
What is normal pH?
A
7.35 to 7.45
16
Q
3 Main Types of Formed Elements
A
1) RBC’s/Erythrocytes
2) WBC’s/Leukocytes
3) Platelets/Thrombocytes
17
Q
RBC’s/Erythrocytes
A
-approx. 4.5 to 5.5 million per mm cubed of blood
18
Q
WBC’s/Leukocytes
A
-5000 to 10000 per mm cubed of blood
19
Q
Platelets/Thrombocytes
A
300000 per mm cubed of blood
20
Q
How much is 1 drop of blood?
A
1 mm cubed
21
Q
RBC Structure
A
- most numerous of formed elements
- tiny biconcave disks
- shape increases surface area to maximize function
22
Q
What is the primary component of RBC’s?
A
-protein hemoglobin
23
Q
Do RBC’s have a nucleus or organelles?
A
No.
24
Q
What is the life span of a RBC?
A
-4 months
25
What is the exchange or oxygen and carbon dioxide between blood and cells dependant on?
-hemaglobin
26
Hemoglobin
- transports oxygen as oxyhemoglobin
| - transports carbon dioxide as carbaminohemoglobin
27
How many hemoglobin molecules are in each RBC?
- 200 to 300 million
| - greater in males
28
How many globulin chains are in hemoglobin?
-4
29
What are globulin chains attached to?
-a heme group
30
Anemia
- blood disorder
| - blood cannot carry adequate oxygen to body cells
31
When can anemia occur?
- deficiency of RBC
| - deficiency of hemoglobin
32
Types of Anemia
Related to # of RBC's:
- aplastic
- pernicious
- folate deficiency
- blood loss/hemorrhagic
Related to Hemoglobin:
- iron deficiency
- sickle cell
33
Aplastic Anemia
- decreased # of RBC's (and WBC and platelets)
- following destruction of hemopoietic elements in bone marrow (toxins, drugs, chemotherapy, etc.)
- treat via bone marrow transplant
34
Pernicious Anemia
- decreased # of RBC's
| - dietary deficiency of B12
35
Folate Deficiency Anemia
- similar to pernicious anemia (decrease in RBC's)
- due to folate (folic acid) deficiency, which is common in alcoholics and malnourished
- treated with vitamins
36
Blood Loss/Hemorrhagic Anemia
- decrease RBC's
| - caused by hemorrhage
37
Iron Deficiency Anemia
- lack of hemoglobin
- tired
- treated with supplementation
38
Sickle Cell Anemia
- severe/fatal
- genetic
- caused by abnormal hemoglobin that forms solid crystals when blood oxygen Is low
- causes RBC shape to become distorted (can't function properly)
39
Polycythemia
- bone marrow produces too many RBC's
- blood is too thick (cannot flow properly)
- results in stroke or heart attack
40
Erythropoeisis (formation of RBC's)
- begins in red bone marrow
- hemocytoblast to RBC in 4 days
- RBC's are continually destroyed/replaced (200 billion a day)
41
What is the average life span of a circulating RBC?
-105 to 120 days
42
Destruction of RBC's
- eaten by macrophages in liver and spleen
- recycle as much of RBC as they can
- hemoglobin is broken down
- amino acids, iron and bulirubin are released
43
2 Main Systems of Blood Classification
1) ABO
| 2) Rh
44
ABO
- identified by 'self antigens' in plasma membrane of RBC's
| - we are born with the antigens
45
Antigen
-activates responses from immune system (production of antibodies)
46
Antibody
- substance made by the body in response to stimulation by an antigen
- destroys or neutralizes the antigen
47
Non Self Antigen
-foreign proteins that stimulate an immune system response
48
Agglutination
-an antibody reacting with an antigen to make them clump/stick together
49
4 Blood Types
- A
- B
- AB
- O
-the letter stands for the type of 'self antigen' in the plasma membrane of the individuals RBC's
50
What prevents agglutination?
- there are no antibodies in the blood that are the same as the self antigen on the RBC
- matching appropriate blood types
51
Rh Positive
-Rh antigen is present in plasma membrane of RBC
52
RH Negative
-Rh antigen is NOT present in plasma membrane of RBC
53
Rh System
- follows same principle as ABO (avoids antibody/antigen reactions)
- important to consider in blood transfusions
54
What % of the US population is Rh+?
82%
55
O-
-universal donor
56
AB+
-universal recipient
57
When does Erythroblastosis Fetalis occur?
- the mother is Rh-
- the father is Rh+
- baby inherits father's Rh=
- the mother carries a second Rh+ fetus
58
Does plasma naturally contain anti Rh bodies?
No, but if Rh+ is introduced into an Rh- person's body, then anti Rh antibodies will appear in blood plasma.
59
WBC's
- aka leukocytes
| - defense/immunity
60
What are WBC's categorized as?
1) granulocytes
| 2) agranulocytes
61
Granular Leukocytes
-granules in cytoplasm
- neutrophils
- eosinophils
- basophils
62
Non Granular/Agranular Leukocytes
-NO granules in cytoplasm
- lymphocytes
- monocytes
63
Neutrophils
-granulocytes
- most numerous type of WBC (65%)
- phagocytes
- attracted to damaged cells at infection site by chemotaxis
64
Eosinophils
-granulocytes
- weak phagocytes (abundant in mucous membranes
- protection against parasites)
65
Basophils
-granulocytes
- secrete heparin (anticoagulant)
- secrete histamine (during inflammatory reactions)
66
Lymphocytes
-agranulocytes
- smallest WBC's
- 2nd most numerous (25%)
- different from phagocytes
- B lymphocytes produce antibodies
- T lymphocytes directly attack foreign cells
67
Differential WBC Count Test
-gives proportions of each type of WBC as a % of total WBC count
68
Do disorders affect all types of WBC the same way?
No.
69
How many leukocytes does 1 drop of blood contain?
- 5000 to 9000
| - different % of each type
70
What are some WBC disorder's that can be detected?
- leukopenia
- leukocytosis
- leukemia
71
leuko
-white
72
Leukopenia
-low WBC count (less than 5000/mm cubed)
73
Leukocytosis
- high WBC count ( greater than 10000/mm cubed)
- more common than leukopenia
- due to bacterial infections
74
Leukemia
- blood cancers
- WBC's don't function properly
- WBC count (greater than 100000/mm cubed)
75
Monocytes
-agranulocytes
- largest WBC
- mobile
- highly phagocytic
- aggressive phagocytes (due to size, can engulf larger pathogens and cancer cells)
76
Macrophages
- large eaters
| - specialized monocytes that grow to several times their original size after they migrate out of the blood
77
What 2 types of tissue are RBC's and WBC's produced in?
1) myeloid (red bone marrow)
| 2) lymphatic
78
What are the precursors of RBCs, WBCs and platelets?
-hematopoietic stem cells
79
Myeloid (red bone marrow) Tissue
- in adult sternum, ribs and hip bones
| - forms al types of blood cells (most lymphocytes and monocytes develop in lymphatic tissue)
80
Lymphatic Tissue
- in lymph nodes, thymus and spleen
| - forms lymphocytes and monocytes
81
Platelets
- thrombocytes
| - small disks
82
3 Important Properties of Platelets
1) agglutination
2) adhesiveness
3) aggregration
83
How many platelets does the average adult have?
250000/mm cubed (no difference in gender)
84
What is vitamin k?
-coagulation (koagulation)
85
What does vitamin k do?
- stimulates liver cells to increase synthesis of prothrombin
- faster production of thrombin
- faster clot
86
Thrombus
- stationary blood clot
| - stays where it formed
87
Thrombosis
-condition of having a thrombus
88
Embolus
-part of the thrombus that dislodges and circulates through the bloodstream (may block a vessel)
89
Embolism
-condition of having an embolus
90
Hemophilia
- inability to form blood clots
- x linked inherited disorder (x recessive)
- cannot produce plasma proteins involved in blood clotting
- life threatening (must be treated)
91
Where is the heart located?
- 2/3 Lt of midline
- 1/3 Rt of midline
- apex lies on diaphragm
- base (upper portion) lies below 2nd rib
- between body of sternum and thoracic vertebrae
- positioning makes CPR possible
92
Shape of Heart
-triangle
93
Size of Heart
-fist sized
94
What cover the heart?
-pericardium (loose fitting sac)
95
2 Parts of the Pericardium
1) fibrous portion
| 2) serous portion
96
Fibrous Portion of the Pericardium
- tough
- loose fitting
- inextensible
- attaches to the lg blood vessels that leave the top of the heart
97
Serous Portion of the Pericardium
Parietal Layer
-lies inside the fibrous pericardium
Visceral Layer
- aka epicardium
- outside of the heart
98
What is between the 2 serous layers of the pericardium?
- pericardial space
- filled with pericardial fluid
- lubricates (decreases friction)
99
Epicardium
-visceral layer of the serous portion of the pericardium
100
Myocardium
- cardiac muscle tissue that makes up the bulk of the heart wall/wall of each heart chamber
- synctium (joined cells)
101
Endocardium
- thin layer of smooth tissue (endothelial tissue)
| - lines the inside of each heart chamber and blood vessels
102
What is the interior of the heart divided into?
- 4 chambers
- 2 atria
- 2 ventricle
103
Atrium/Atria
- 2 upper chambers
- receiving chambers
- blood from body returns to atrium via veins
104
What divides the Lt and Rt atrium's?
-interatrial septum
105
What is different about the walls of atrium's and ventricle's?
-atrium's walls are smaller and thinner
106
Ventricles
- 2 lower chambers
- discharging/pumping chambers
- blood leaves ventricles via arteries
107
What divides the 2 ventricles?
-interventricular septum
108
Which ventricle has a thicker myocardium?
-left
109
The heart is a...
-pump
110
Systole
-contraction of the heart
111
Diastole
-relaxation of the heart
112
What controls the direction of blood flow?
-valves
113
What do valves do?
-prevent the back flow of blood
114
4 Valves of the Heart
- 2 atrioventricular valves (AV valves)
| - 2 semilunar valves (SL valves)
115
Atrioventricular (AV) Valves
- separate atria from ventricles
| - prevent blood from sowing back into the atria from ventricles when they contract
116
Tricuspid Valve
- Rt side
| - 3 flaps
117
Bicuspid/Mitral Valve
- Lt side
| - 2 flaps
118
Chordae Tendinae
-attach AV valves to wall of heart
119
Semiunar (SL) Valves
Pulmonary SL Valve
- at entrance of pulmonary artery
- between Rt ventricle and pulmonary artery
Aortic SL Valve
- at entrance of aorta
- between Lt ventricle and aorta
120
Atrial Systole
-with each heart beat, the LA and RA contract simultaneously to fill the LV and RV with blood
121
Ventricular Systole
-the LV and RV contract simultaneously
122
2 Pumps of the Heart
-RA and RV perform different functions to the LA and LV
123
Coronary Circulation
-blood supply to the heart muscle
124
Why does the myocardium need a constant blood supply?
-it is constantly working
125
Where does the blood that supplies oxygen and nutrients to the myocardium flow through?
-Rt and Lt coronary arteries (1st branches of aorta)
126
Where does most of the blood supply of the heart go to?
-myocardium of the Lt ventricle
127
Where do coronary veins return blood to?
-Rt atrium
128
Myocardial Infarct (MI)
- aka heart attack
| - blockage of blood flow through the coronary arteries
129
Angia Pectoris
-chest pain cause by inadequate oxygen to the heart
130
Coronary Bypass Surgery
-veins from other parts of the body are used to bypass blockages in coronary arteries
131
Conduction System of the Heart
-coordinated via a specialized network of fibres that can rapidly conduct impulses
132
The myocardium is autorythmic, meaning it can...
-produce it's own action potentials
133
How are changes in rhythm of myocardial contraction controlled?
-motor neuron pathways of both efferent divisions of the autonomic NS
134
4 Specialized Structures Embedded in the Heart Wall
1) sinoatrial node (SA node)
2) atrioventricular node (AV node)
3) AV bundle (bundle of his)
4) subendocaridal branches (purkinje fibres)
135
Sinoatrial (SA) Node
- pacemaker
- initiates impulse/heartbeat and sets it's pace
- in wall of the RA (near opening to SVC)
136
Atrioventricular (AV) Node
-in the RA, along lower part of the intertribal septum
137
AV Bundle (bundle of his)
-in the septum of the ventricle
138
Subendocardial Branches (purkinje fibres)
-in the walls of ventricles
139
Electrocardiogram (EEG)
-recording of the electrical impulses of the heart
140
How many waves/deflections does a normal EEG have?
3
141
3 Waves/Deflections of an EEG
- P Wave
- QRS Complex
- T Wave
142
P Wave
-represents depolarization (triggers contraction) of the atria
143
QRS Complex
-represents depolarization of the ventricles
144
T Wave
-represents depolarization of the ventricles (just before relaxation phase)
145
Cardiac Cycle
-complete heartbeat
146
Heartbeat is _____ and _____.
- regular
| - rhythmic
147
How long is each heartbeat/cycle?
0.8 sec long
148
What is the average beats/min?
72
149
What is each cycle/heartbeat subdivided into?
- systole (contraction phase)
| - diastole (relaxation phase)
150
Stroke Volume
-amount of blood that one ventricle ejects with each beat
151
Cardiac Output
-volume of blood that flows out of a ventricle per unit of time (ex. ml/min)
152
What does blood volume depend on?
- stroke volume
| - cardiac output
153
Phases of the Cardiac Cycle
1) atrial systole
2) isovolumetric vernacular contraction
3) ejection
4) isovolumetric ventricular relaxation
5) passive ventricular filling
154
Atrial Systole
atria contract---pressure gradient---blood flows into relaxed ventricles
155
Isovolumetric Ventricular Contraction
intraventricular pressure begins to increase---AV valves close---first heart sound
156
Ejection
SL valves open---blood leaves heart
157
Isovolumetric Ventricular Relaxation
ventricles relax---SL valves close, AV valves open---second heart sound
158
Passive Ventricular Filling
intraventricular pressure drops, intraatrial pressure rises---AV valves open---blood enters ventricles
159
Systolic
- first heart sound
- 'lub'
- longer sound
- caused by contraction of ventricles and vibrations of closing valves
160
Diastolic
- second heart sound
- 'dub'
- shorter sound
- caused by vibrations of the closing semilunar valves during relaxation of the ventricles
161
What does injury to a blood vessel cause?
-rough lining
162
What do clotting factors at an injury site produce?
-prothromblin activator
163
What is a 'platelet plug'?
-platelets temporarily accumulate at injury site
164
What converts prothrombin into thrombin?
-prothrombin activator and calcium
165
Prothrombin
-blood protein
166
Thrombin
-protein for blood clotting
167
What produced fibrin?
-thrombin reacts with fibrinogen
168
Fibrin
- traps RBC's to form clot
| - looks like a tangle of threads
169
How many km of blood vessels are in the body?
100 000 km
170
Angiogenesis
-formation of blood vessels in embryonic development and continuing throughout life
171
Blood Vessels
- arteries
- veins
- capillaries
172
Arteries
- carry blood away from heart
| - elastic and muscular
173
Where do arteries carry blood from?
-away from the heart ventricles
174
What is the only artery that isn't oxygenated?
-the pulmonary artery
175
What is the largest artery?
-aorta
176
Where does blood flow through to get from heart to body?
aorta---arteries---arterioles---metarterioles
177
Metarterioles
- control blood flow to capillary bed
| - end at the precapillary sphincters (wrap around entrance to capillaries)
178
Capillaries
-connect arteries and veins via arterioles and venues
179
Microcirculation
-microscopic blood vessels
180
Capillary Beds/Networks
-site of gas and nutrient exchange between blood and tissue fluid around cells
181
How many capillary beds are there?
| Where is the highest concentration?
- over 1 billion
| - highest concentration in tissues with high metabolic rate
182
Veins
-carry blood to the heart atria
183
Largest Veins
-IVC and SVC
184
Where does the blood flow of veins travel?
capillary beds/networks---venules---veins---vena cava
185
4 Materials in the Wall of Blood Vessels
1) endothelial tissue/endothelium (lining)
2) collagen fibres
3) elastic fibres
4) smooth muscle tissue
186
Endothelial Tissue/Endothelium (vessel wall)
- smooth surface of lumen
- influences blood flood and clotting
- simple squamous epithelium
- allows for exchange of gases, nutrients, etc.
- intercelluar clefts between the cells and 'fenestrations' dictate movement of substances in and out
187
Collagen Fibres (vessel wall)
- strength and flexibility (less than elastic fibres)
- keeps open
- strengthens walls
188
Elastic Fibres (vessel wall)
- made of elastin (protein polymer) which can stretch more than 100% when at work in the body
- arranged concentrically in lg elastic arteries (allowing for distention and recoiling)
- passive tension for normal BP
189
Smooth Muscle Tissue (vessel wall)
- NOT in capillaries
| - highest contraction is in elastic and muscular arteries---contraction---active tension
190
3 Layers of Veins and Arteries
1) tunica intima (inner)
2) tunica media (middle)
3) tunica adventitia/externa (outer)
191
Tunica Intima in Arteries
- inner
| - single layer of squamous epithelial cells
192
Endothelium
-lines entire surface of circulatory system
193
Tunica Media of Arteries
- mid layer
- smooth muscle with thin layer of elastic tissue
- important in BP regulation (smooth muscle--ANS)
194
Is the tunica media thicker in veins or arteries, and why?
- thicker in arteries
| - to withstand systole
195
Tunica Adventitia/Externa in Arteries
- outer layer/collagen fibres
| - reinforces wall to withstand pressure
196
Is the Tunica Adventitia/Externa thicker in arteries or veins?
-thicker in arteries
197
Tunica Intima in Veins
- inner layer/endothelium
| - one way valves to prevent back flow of blood (not found in arteries)
198
Tunica Media of Veins
-middle layer
-smooth muscle with thin layer of elastic tissue
-
199
Why is the tunica media thinner in veins than arteries?
-lower BP in veins
200
Tunica Adventitia/Externa in Veins
- outer layer
| - thinner than in arteries
201
What is the only layer than capillaries have?
Tunica Intima
- very thin
- flat epithelial cells
- allows substances to quickly pass through wall
202
Arteries/Arterioles (function)
- move blood from heart to capillaries
- distribution of gases, nutrients, etc. with movement of blood under high pressure
- maintain arterial blood supply by constriction/dilation
203
Veins/Venules (function)
- collect blood from capillaries for return to the heart
- low pressure vessels (act as reservoirs)
- can expand to hold more blood
204
Capillaries (function)
-exchange vessels for nutrients, wastes and fluids
205
Types of Circulation
1) systemic
2) pulmonary
3) hepatic portal
4) fetal
206
Systemic Circulation
-carries blood throughout the body
207
Pulmonary Circulation
- carries blood to/from lungs
| - arteries deliver deoxygenated blood to lungs for gas exchange
208
Does blood from veins from spleen, stomach, pancreas, GB and intestines go right into the IVC?
- no
- sent to the liver via hepatic PV
- blood passes through liver before re entering regular venous return to the heart via HV's that drain into IVC
209
Where does hepatic circulation run?
-sent through second capillary bed in the liver returning to normal pathway pf blood returning to heart
210
Where do hepatic PV's exist?
Between 2 Capillary Beds:
- 1 in the digestive organ
- 1 in the liver
211
What does hepatic circulation assist with?
- homeostasis of blood glucose levels (liver cells store excess glucose as glycogen)
- detoxification
212
Fetal Circulation
- circulation before birth
- modifications required for fetus to efficiently secure oxygen and nutrients from maternal blood instead of it's own lungs and organs which aren't fully developed or functional
213
Unique Structures of Fetal Circulation
- umbilical arteries (umbilical cord)
- placenta
- umbilical vein (umbilical cord)
- ductus venosus
- forame ovale
- ductus arteriosus
214
Umbilical Arteries
-2 small umbilical arteries that carry oxygen poor blood from the developing fetus to the placenta
215
Placenta
- attached to uterine wall
| - site of exchange of oxygen, nutrients, waste, toxins, and waste products between maternal and fetal blood
216
Fetal Circulation
- 1 umbilical vein carries oxygen rich blood from the placenta to the fetus
- gives 2 or 3 branches at the fetal liver, then continues as the ductus venosus
217
Ductus Venosus
- continuation of the umbilical vein along the undersurface of the fetal liver
- moves most of the blood returning from the placenta to the fetus past the fetus' immature liver into the IVC
218
Foramen Ovale
- opening in the intertribal septum
- moves blood from the RA into the LA
- allows most of the blood to bypass the fetus' underdeveloped lungs
219
Ductus Arteriosus
- connects pulmonary artery/trunk with the aortic arch
| - allows another portion of the blood to bypass the fetus' underdeveloped lungs and enter systemic circulation
220
What happens when the umbilical cord is cut?
- vessel in umbilical cord no longer function
| - umbilical vein becomes round ligament of liver
221
When is the placenta expelled?
-after the baby is born
222
What does the ductus venosus become?
-ligamentum venous of liver
223
What does the foramen oval do when the baby breathes?
- closes
| - establishes pulmonary circulation
224
How long does structural closure of the foramen ovale take?
-up to 9 months
225
Where are fossa ovalis found?
-in the wall of the Rt atrial septum
226
What contracts as soon as breathing starts?
-ductus arteriosus
227
What does the ductus arteriosus become?
-ligamentum arteriosum
228
Hemodynamics
- numerous mechanisms that influence the dynamics of the circulation of blood
- essentail for health and survival
229
Circulation control mechanisms must...
- maintain circulation
| - vary the volume and distribution of blood circulated
230
Primary Principle of Circulation
-blood moves due to pressure gradient along it's pathway according to 2 principles
231
2 Principles of Circulation
1) fluid doesn't flow when the pressure is the same throughout the system
2) fluid flows only when it's pressure is higher in one area than in another and it flows from it's higher pressure area to it's lower pressure area
232
How is blood flow between 2 points predicted?
-pressure gradient
233
Arterial BP
- BP is the push/force of blood in blood vessels
| - highest in arteries, lowest in vein (allows for proper circulation of blood)
234
What is arterial BP directly proportional to?
-arterial blood volume
235
2 main Factors in Determining Arterial BP
1) cardiac output
2) peripheral resistance
*both are proportional to blood volume
236
Cardiac Output
-amount of blood that flows out of a ventricle of the heart per unit of time
237
What is the resting CO from Lt ventricle?
5000ml/min
238
What does CO influence?
-flow rate to various organs of the body
239
What is cardiac volume determined by?
-volume of blood pumped out of the ventricle by each beat (SV and HR)
240
SV
-stroke volume
241
HR
-heart rate
242
Factors that Affect SV (stroke volume)
- strength of myocardial contractions
- length
- neurotransmitters
- hormones
243
Starling's Law of the Heart
-the more stretched out heart muscle fibres are, the stronger the contraction will be (as long as it is not hyperextended)
244
Factors that Affect HR (heart rate)
- autonomic NS
- sympathetic (cardiac/NE)
- parasympathetic (vagus nerve/Ach)
- cardiac pressoreflexes
245
Cardiac Pressoreflexes
- control centres that receive info. from stretch receptors in the AO and carotid sinuses
- if high BP is detected, a motor message will be sent to the SA node to decrease HR
246
Reflexes That Influence HR
- emotions (ex. anxiety, fear, anger, relief, etc.)
- exercise
- hormones
- blood temp. (increased blood temp = increased HR)
- pain (can result in fainting)
- stress response (sympathetic NS)
247
Peripheral Resistance
-force that acts against the flow of blood
248
Blood Viscosity
-comes from proportion of RBC's and partly from blood protein concentration (ex. polycythemia, anemia, hemmorage)
249
Where is the vasomotor centre located?
-in the medulla
250
What does the vasomotor centre stimulate?
-constriction of blood vessels
251
Vasomotor Pressorelexes
- stretch receptors in the AO and carotid sinuses response to increased BP
- messages are sent to inhibit the vasomotor centre
252
Vasomotor Chemoreflexes
- same location as stretch receptors
| - sensitive to excess carbon dioxide, low oxygen and decreased arterial pH in the blood (vasoconstriction)
253
Avg. BP
120/80
254
What can affect BP?
- exercise/fitness level
- stress
- age, gender, race, weight
- stress, emotions
- hormones
- disease
- tobacco, alcohol, caffeine, and other drugs
255
How is BP brought back to normal?
-feedback loops
256
Hypertension
- high BP
| - if too high, can rupture blood vessels
257
Hypotension
- low BP
| - if too low, blood may stop flowing
258
Why is hypertension a 'silent killer'?
-no symptoms
259
Sphygmomanometer
-used to measure BP
260
Central Venous Pressure
- venous blood pressure within the Rt atrium
| - close to zero
261
What does central venous pressure influence?
-the pressure that exists in the lg peripheral veins
262
Strong Heart Beat
- blood is entering and exiting the heart effectively
| - low central venous pressure
263
Weak Heart Beat
- flow of blood into the Rt atrium will be slowed
| - high central venous pressure
264
What keeps venous blood moving through the circulatory system to RA?
- continued heart beat
- adequate BP
- semilunar valves in veins that ensure blood flow in one direction (towards heart)
- contraction of skeletal muscles (pumping action which squeezes veins)
- changing pressures in the chest cavity during breathing (pumping action in the veins in the thorax)
265
Pulse
-alternate expansion and recoiling of an arterial vessel wall
266
How is a pulse possible?
-pressure changes within arteries and the elasticity of arterial walls
267
What does a pulse provide info. about?
-cardiovascular system, blood vessels and circulation (ex. rate, strength, rhythm and heart beat)
268
How many major pulse points are there?
9
269
Functions of Lymphatic System
- maintain fluid balance
- immunity
- fat absorption and transport
270
Structure of Lymphatic System
- lymph
- lymphatic vessles
- lymph nodes
- thymus
- tonsils
- spleen
271
Interstitual Fluid (IF)
-blood plasma filters out of capillaries into tiny spaces between cells of tissues
272
Lymph
-excess IF that isn't absorbed by tissue cells or reabsorbed by the blood before it flows out of the tissue and drains into lymphatic capillaries
273
Where is lymph drained to?
-venous blood...heart
274
What does lymph include?
-proteins, fats, etc.
275
Lymphatic Vessels
- permit one way movement (lymph to heart)
| - collects excess IF (as lymph) and returns it to the blood stream via veins
276
2 Types of Lymphatic Vessels
1) lymphatic capillaries
| 2) lymphatic ducts
277
Lymphatic Capillaries
- microscopic
| - open at one end (blind ended)
278
Where are lymphatic capillaries found?
-tissue spaces wherever blood capillaries are (except bone, teeth, bone marrow and CNS)
279
What are the walls of lymphatic capillaries made of?
- simple squamous epithelium
| - very porous due to structure
280
What are lymphatic capillaries in the intestinal wall (digestive system) called?
-lacteals
281
What are the differences between lymphatic capillaries and lymphatic veins?
- capillaries have thinner walls
- capillaries have more valves
- capillaries contain lymph nodes
282
What determines if fluid will move in or out of lymphatic capillaries?
-fluid pressure
283
What happens when fluid pressure is greater in interstitial spaces than in lymphatic capillaries?
-'doors' are pushed open and fluid moves in
284
What happens when fluid pressure is greater inside lymphatic capillary than in interstitial spaces?
-'doors' are pushed shut (preventing lymph from leaking backwards)
285
Rt Lympahtic Duct
- drains lymph from Rt upper extremity, Rt side of head, neck and upper torso
- via the Rt subclavian vein
286
Thoracic Duct
- largest lymphatic vessel
| - drains lymph fro the rest of body (via Lt subclavian vein)
287
Cisterna Chyli
- structure found along thoracic duct
| - storage for lymph moving towards the venous system
288
Function of Lymphatic Vessels
- remove high molecular weight substances and even particulate matter from interstitial spaces
- lacteals absorb fats/nutrients from sm intestine
289
Shunts
-mixture of blood
290
Circulation of Lymph
- no pump!
| - relies on breathing and skeletal muscle contractions
291
What do lymph nodes do?
- filter lymph
- defense
- wbc formation
292
Where are lymph nodes located?
-in clusters along the pathway of lymphatic vessels where they converge to form larger trunks
293
Structure of Lymph Nodes
- oval shaped
- fibrous capsule
- biological filters
294
Flow of Lymph
- in to node via afferent lymph vessels
| - drained away from node by efferent lymph vessels
295
2 Functions of Lymph Nodes
1) defense functions
| 2) hematopoiesis
296
Defense Functions of Lymph Nodes
- mechanical filtration (trapping particles)
| - biological filtration (cells destroy and remove particles)
297
Hematopoeisis Function of Lymph Nodes
-maturation of lymphocytes and monocytes
298
What do wbc's do?
- eliminate antigens and pathogens
| - phagocytosis
299
What causes lymph nodes to swell?
-increased numbers of immune system cells fighting infection in the gland
300
Clinical Importance of Lymphatic Drainage of the Breast
-cancer cell infections can spread along lymphatic pathways t o lymph nodes and other organs
301
Hemodynamics
-movement of blood
302
What 2 sets of vessels is the lymphatic drain the breast?
- drains skin over the breast (minus skin , areola and nipple)
- drains underlying substances of breast, plus the skin of areola and nipple
303
Where is more than 85% of lymph from breasts, and where is the remainder?
- axillary region
| - the rest enters nodes almond lateral edges of sternum
304
What are the 3 masses of lymphoid tissue around the openings of the mouth and throat?
1) palatine tonsils (tonsils) are the largest and most often
2) pharyngeal tonsils (adenoids)
3) lingual tonsils
305
What is the primary organ of the lymphatic system?
-thymus
306
What is the vital role of the thymus?
- immunity
| - thymosin enables lymphocytes to T cells
307
Where is lymphoid tissue located?
-in mediastinum
308
Involution
-lymphoid tissue is largely replaced by fat and CT
309
When does the thymus do most of it's work?
-in childhood
310
Largest Lymphoid Organ
-spleen
311
What shape is the spleen?
-ovoid
312
How is the spleen often injured?
-trauma to abdomen
313
Splenectomy
-surgical removal of spleen
314
Functions of Spleen
1) defense- filtration and phagocytosis of bacteria/pathogens
2) tissue repair- reservoir of monocytes that migrate to sites of injury to promote healing and repair
3) hematopoiesis- monocytes and lymphocytes complete their development in the spleen
4) destroys and recycles- destroys old RBC's and platelets, stores breakdown products of RBC's (ex. iron and hemoglobin) which can be reused
5) blood reservoir
