323 Midterm Flashcards
1
Q
Homeostasis
A
Condition of equilibrium or balance in the body’s internal environment
2
Q
Intrinsic Controls
A
Local control inherent to the organ.
3
Q
Extrinsic Control
A
initiated outside an organ
accomplished by the nervous and/or endocrine systems.
4
Q
Feedback Loop
A
- A response of a system made after a change; can be negative or positive.
- Primary type of homeostatic control.
5
Q
Feedforward Loop
A
Anticipate change
6
Q
A negative feedback loop opposes…
A
Initial change.
7
Q
Control centre
A
Compares sensor input with a set point.
8
Q
Effector
A
Makes a response to produce a desired effect.
9
Q
Main Goal of a Negative Feedback Loop
A
To keep an internal environment stable
10
Q
Negative Feedback Loop is Activated When…
A
When the controlled variable reaches the extremes of the set range.
11
Q
A positive feedback loop…
A
Amplifies initial change (reinforces stimulus); does not contribute to homeostasis.
12
Q
Does a negative or a positive feedback loop occur more often? And why?
A
Negative feedback loop because It is used to counteract systems positive only occurs when we need more of something
13
Q
Negative feedback loop example
A
Blood pressure control.
14
Q
Positive feedback loop example
A
Contractions during childbirth, blood clotting.
15
Q
Effect of Ageing on Homeostasis
A
Slows down with age
16
Q
Does feedback or feedforward occur more
A
Feedback
17
Q
Frequency of Homeostasis Mechanisms
A
Feedback more so than feedforward.
18
Q
Feedforward mechanism example
A
Saliva production in response to smelling food
18
Q
Feedforward regulation occurs through..
A
The Central Command.
18
Q
Central Command
A
prime the body for changes that are about to take place during exertion; originates in the CNS.
19
Q
Central Command Example
A
Increased oxygen demand leads to increased cardiac output.
20
Q
What systems does blood pressure depend on (4)
A
- Circulatory
- Urinary
- Nervous
- Endocrine
21
Q
What are macromolecules?
A
large molecules built from smaller organic molecules
22
Q
4 main macromolecules
A
- Carbohydrates
- Lipids
- Proteins
- Nucleic acids
23
What breaks down macromolecules? And which of the 4 does this exclude
Hydrolysis
| excludes: Lipids
24
How is are lipids broken down?
Lipolysis
25
What is the simplest macromolecule
carbohydrates (saccharides)
26
Hydrogen oxygen ratio
2:1
27
What is the simplest sugar?
monosaccharides
28
3 main types of carbohydrates
1. Monosaccharides
2. Disaccharides
3. Polysaccharides
29
Glucose is important for
production of adenosine triphosphate (ATP)
30
Fructose
aid in glycolysis and replenish liver glycogen stores
31
ribose and deoxyribose
pentose sugars found in nucleic acids. deoxyribose is found in DNA, ribose in RNA
32
How are disaccharides formed?
when two monosaccharides are joined in a dehydration synthesis (one of the monosaccharides is always glucose)
33
Three main disaccharides
1. Sucrose
2. Lactose
3. Maltose
33
Sucrose
- most common dietary dissachride
- occurs naturally
- Glucose-fructose
34
Maltose
- found in beer, cereal, and germinating seeds
- contributes to a small amount of the dietary carbohydrate consumption
- glucose-glucose
35
Lactose
- only natural source is from milk and milk sugar products
- least sweet
- galactose-glucose
36
What are Polysacchrides?
long chain of monosaccharides
37
4 main types of polysaccharides
1. Starch
2. Glycogen
3. Cellulose
4. Chitin
38
Starch
A storage carbohydrate in plants
39
Two main forms of starch
amylose and amylopectin
40
amylose vs amylopectin
Amylose: long straight chains twisted to form helix (breaks down slow)
Amylopectin: highly branched chain (breaks down fast b/c increase in SA)
41
Glycogen
Animal storage of carbohydrates. Found in liver and muscles. Highly branched, fast to break down.
42
Glycogen is converted into glucose via
Glycogenolysis
43
most abundant organic polysaccharide
Cellulose
44
Chitin
A structural supporting polysaccharide, found in exoskeletons of all arthropods.
45
Function of Proteins
perform essential functions
46
Proteins are made up of
polymers of specific amino acids (20)
47
Protein function is determined by..
structure and shape
48
Primary vs Secondary vs Tertiary protein structure
Primary: sequence of amino acids
Secondary: alpha helices or beta
sheets
Tertiary: 3D folding pattern
49
Enzymes
Catalyst in reactions
50
What would happen without enzymes
life could not exist
51
Energy Input
Energy in ingested food.
52
External Work
Energy expended when skeletal muscles are used to move external objects.
53
Thermal Energy
Energy from nutrients not used to perform work. About 75% of all energy input.
54
Internal Work
All forms of biological energy expenditure that do not accomplish mechanical work outside the body.
55
Neutral Energy Balance
Energy input = Output. Body weight remains constant.
56
Positive Energy Balance
Intput is greater than output. Body weight increases.
57
Negative Energy Balance
Energy input is less than output. Body weight decreases.
58
Metabolic Rate
Total amount of energy we need to expend in order to perform a given task.
59
Basal Metabolic Rate (BMR)
Minimal internal energy expenditure needed to maintain in order to meet basic body functions.
60
In order for BMR to be measured, a person should be...
At physical and mental rest, in a comfortable temperature, and having comsumed no food within 12 hours.
61
Influence of Exercise on Metabolic Rate
During exercise, metabolic rate increases due to extra energy requirements. Following exercise, metabolic rate is increased due to higher muscle mass.
62
Metabolism
Process which breaks down food to release and store chemical energy which can then be used for body processes.
63
Anabolic vs Catabolic
Anabolic: make Bigger
Catabolic: make simpler
64
Exothermic vs Endothermic Reaction
Exo: release energy
Endo: require energy
65
Callular Metabolism
Makes use of all chemical reactions occurring within cells.
66
Activation Energy
Energy needed to get a reaction started.
67
How do Enzymes affect Activation Energy
Enzymes lower the activation energy, but don't change the reaction itself.
68
Enzyme Pathways
Enzymes control only a single type of chemical reactions. If one enzyme is not present, the entire process stops.
69
Metabolic Regulation
Cell uses specific molecules to regulate enzymes in order to promote or inhibit certain chemical reactions.
70
Competitive Inhibition
Substance that resembles the normal substrate competes with the substrate for the active site found on an enzyme.
71
Non-Competitive Inhibition
Inhibitor binds to an allosteric site on the enzyme, Can block the the enzymes and change shape of the enzyme or the binding site.
72
Allosteric Site
A specific receptor site on some part of an enzyme molecule remote from the active site.
73
Allosteric Activatiors
increase reaction rates
74
Cofactors and Coenzymes
Non-protein helper molecules that cause enzymes to work properly
75
Most common coenzymes are...
Dietary vitamins.
76
Feedback Inhibition
When a reaction product is used to regulate its own further production.
77
Feedback Inhibition
When a reaction product is used to regulate its own further production.
78
Metabolic Reactions are controlled by...
Cellular demands
79
ATP is used...
Any time something is built up or broken down in the body.
80
ATP Makeup
Nucleotide derivative (base, sugar, three phosphates). Base is adenine, sugar is ribose. Third bond is unstable.
81
Most common energy source in the Body
Carbohydrates.
82
Sugar Catabolism
Breaks down polysaccharides into individual monosaccharides.
83
Glucose and ATP
Glucose is the most common fuel for ATP used in cellular respiration.
84
Triglyceride Breakdown
Tryglicerides can be used for energy via beta-oxidation.
85
Amino Acid use
Either for the buildup of new proteins or the breakdown in ATP production.
86
Amino acids are used in ATP production during...
Chronic starvation.
87
Preferred fuels for ATP production
Glucose, triglycerides, amino acids, in that order from most to least preferred.
88
ATP-ADP Cycle acts as a...
Energy shuttle.
89
Exergonic Reaction
A chemical reaction that releases energy.
90
Endergonic Reaction
Reaction that absorbs free energy from its surroundings.
91
Oxidation-Reduction Reactions for ATP
Used for ATP production when energy is released during oxidation reactions and captured when ATP is formed.
92
Anabolic Reactions in ATP
ATP to complex molecules.
93
Catabolic Reactions in ATP
complex molecules to ATP.
94
Exception to Saccharide H:C:O Ratio
Deoxyribose. Should be 2:1:1
95
Three Phases to Cellular Respiration
Glycolysis, Kreb's Cycle, Electron Transport Chain
96
Glycolysis
The breakdown of glucose into pyruvate.
96
Glycogenolysis
Breakdown of glycogen into glucose.
97
Glycolysis occurs in...
Cytosol
98
Glycolysis Reactants and Products
Two ATP, one glucose, one NAD+; two pyruvate, 4 ATP, and 2 NADH.
99
Most important step in glycolysis
Step III, catalysed by phosphofructokinase (PFK). First commited step of glycolysis.
100
Up-Regulation of Glycolysis
When a cell is very low on ATP, the concentration of AMP will increase. High concentrations of AMP triggers glycolysis.
101
Down-Regulation of Glycolysis
High levels of ATP and citrate (first product of the CAC) trigger a decrease in glycolysis.
102
Anaerobic Respiration
convert energy in ht presence of oxygen
103
The Kreb's Cycle (Citric Acid Cycle)
Second stage of cellular respiration, start of aerobic respiration. Will only continue if oxygen is available.
104
Kreb's Cycle Takes place in...
The Matrix of the mitochondria.
105
Total Products at the end of the Citric Acid Cycle
Four ATP, ten NADH, and two FADH2.
106
Electron Transport Chain
Last step of cellular respiration. Generates most of the ATP created in cellular respiration.
107
ETC Creates ATP through...
Four redox reactions leading to moving hydrogen ions across a gradient.
108
Chemiosmosis
Pumping protons through specific channels in mitochondrial membranes from inner to outer.
109
ATP Synthase
The enzyme that make ATP from ADP and inorganic phosphate.
110
Total Cellular Respiration Products
38 ATP per glucose molecule in ideal circumstances.
111
Real-life Number of Expected ATP Production during Cellular Respiration
30-32 ATP per glucose molecule.
112
Fermentation
metabolism without oxygen
113
Fermentation used in humans
Lactic Acid Fermentation
114
Fermentation is common in...
RBC and skeletal muscle without sufficient oxygen.
115
Lactate Accumulation leads to...
Soreness and muscle fatigue.
116
Late Fermentation
Lactic acid is metabolised by the liver and NAD+ is recycled to enable glycolysis again
117
Other Body Fuel Sources
Fat and amino acids.
118
Protein as a Fuel Source
Only used during starvation.
119
Regulation of Body Systems if done by...
Nervous and endocrine systems working together.
120
Primary aim of the endocrine system
Maintain homeostasis
121
Endocrine vs. Nervous Pathways
Nervous uses the nerves and neurotrasmitters, very fast responses. Endocrine uses the blood and hormones, responses not as quick but longer lasting.
122
Exocrine Glands
Glands which secrete products into ducts, which lead to outside the body.
123
Method of Nervous and Endocrine System
Need to have signals bind to receptors on target in order to get cells to initiate a response.
124
Nervous System Signals
Neurotransmitters.
125
Endocrine System Signals
Hormones
126
Hormone Targets
Hormones travel to a specific organ by using the blood and bind to a specific protein receptor cell.
127
Three Main Hormone Pathways
Endocrine, paracrine, autocrine.
128
Endocrine Pathway
Hormones travel through the blood stream and are picked up elsewhere.
129
Paracrine Pathway
Hormones affect nearby cells to the one they were produced in.
130
Autocrine Pathway
Hormones affect the same cell that produced them
131
Hormones are either...
Lipid soluble or water soluble
132
Hormone Regulation
Can be controlled through alterations to hormone receptors, either up-regulated or down-regulated
133
Up-Regulated vs Down-regulated hormones
Up: more sensitive
Down: less sensitive
134
Down-Regulated Hormone Receptors
Receptors become less sensitive.
135
Hormone Synergistic vs Antagonistic Effect
Synergistic: work together
Antagonistic: oppose
136
Hormones are typically released in...
Short Bursts.
137
Hormone Secretion is Regulated by...
- Chemical changes in blood
- nervous system signals
- other hormones
138
Most endocrine glands are under...
Negative feedback control in order to maintain homeostasis.
139
Hypothalamus
The main link between the endocrine and nervous systems. Releases 7 hormones which drive the endocrine system
140
Hypothalamus Hormones: How many releasing How many inhibiting
5 releasing hormones
| 2 inhibiting hormones
141
Pituitary Gland and Hypothalamus Connected via...
infundibulum (stalk) and the hypophyseal portal system (for blood and hormones)
142
Ademohypophysis
- anterior lobe
| - makes up 75% of the weight of the pituitary
143
Anterior Pituitary Gland Cell Types
Somatotrophs, lactrotrophs, thyrotrophs, gonadotrophs, and corticotrophs.
144
Human Growth Hormone (hGH)
Most plentiful anterior pituitary hormone, aids in muscle and bone growth.
145
Thyroid Stimulating Hormone (TSH)
Stimulates the production of thyroid hormones from the thyroid glands
146
Prolactin (PRL)
Together with other hormones, intiates and maintains milk secretion by the mammary glands
147
Follicle-Stimulating Hormone (FSH)
- In females, intiates follicle development and secretion of estrogen
- In males, stimulates sperm production in the testes
148
Adrenocroticotropic Hormone (ACTH)
Controls the production and secretion of adrenal cortex hormones (glucocorticoids)
149
Neurohypophysis
- Posterior lobe of pituitary
- Made of neural tissue.
- stores but does not release hormones
150
Anti-Diuretic Hormone (ADH)
Decreases urine output as part of a negative feedback loop where osmoreceptors in hytpothalamus monitor blood osmotic pressure
151
Thyroid Gland shape and composed of
- butterfly shape
| - Composed of follicular cells and parafollicular cells
152
Follicular Cells
Stimulated by TSH to produce thyroid hormones (T3 and T4).
153
Thyroid Hormones function
- increase ATP production
| - accelerate body growth with hGH and insulin
154
Parafollicular Cells produce
calcitonin
155
Calcitonin
Regulates calcium homeostasis by lowering calcium blood levels
156
Parathyroid Glands
Two glands, inferior and superior, located on the posterior thyroid
157
Parathyroid Hormone
works with calcitonin and calcitriol to regulate calcium homeostasis
158
Adrenal Glands
Located on top of each kidney, consists of an outer cortex and inner medulla
159
Three main types of Adrenal Cortex Hormones
- Mineralocorticoids
- glucocorticoids
- weak androgens
160
Mineralocorticoids.
Regulate mineral homeostasis
161
Glucocorticoids
Affect glucose homeostasis
162
Weak Androgens
Hormones with masculinizing effects
163
Aldosterone
Major mineralocorticoid secrete, regulates sodium and potassium homeostasis
164
Aldosterone is controlled via...
The renin-angiotension-aldosterone (RAA) pathway
165
Adrenal Cortex Androgen Examples
Dehydroepiandrosterone (DHEA)
165
DHEA
In females, promotes libido and is converted to estrogens.
| In males- no effect
166
Adrenal Medulla
Stimulated by the sympathetic nervous system to secrete catecholamines
167
Catecholamines
Dopamine, norepinephrine, epinephrine
168
Pancreas Exocrine Functions
Production and secretion of digestive enzymes
169
Pancreas Endocrine Functions
Through the pancreatic islets (Islets of Langerhans), insulin and glucagon are released
170
Alpha Cells vs Beta Cells
Alpha: Secrete glucagon
Beta: secrete insulin
171
Pineal Gland
Attached to the third ventricle, secretes melatonin
172
Thymus promotes
maturation of the immune system's T cells.
173
Hormonal Regulation of Metabolism
Mainly caused by insulin and glucagon
174
Fed State
High blood glucose levels. Release of insulin increases glucose uptake,
175
Fasting State
Blood glucose levels are low. Release of glucagon increases break down of glycogen, formation of glucose, and glucose release from the liver
176
Without insulin...
Glucose cannot enter muscle or fat
177
ATPase
Enzyme which splits terminal phosphate from compound.
178
Oxidative Respiration
Breaks down fuel with oxygen in the mitochondria.
179
EEG
Non-invasive recording of brain electrical activity
180
EEG Waveforms
Beta, Alpha, Theta, Delta
181
Beta Waves
High frequency, low amplitude waves observed in awakened states. Conscious and logical thought, tend to have stimulating effects
181
Alpha Waves
Frequency between beta and theta. Associated with deep relaxation
182
Theta Waves
Associated with daydreaming and sleep.
183
Delta Waves
Slowest recorded brain waves, often found in infants and young children. Associated with the deepest level of sleep
184
EEG and Sleep
Sleep stages are often categorized based on prominent EEG waveform
185
Non-REM Sleep Stages
Stage I-IV.
186
Non-REM Stage I-IV
1: More theta and loss of alpha activity
2: Theta and Delta waves increase.
3: Higher voltage delta
4: More than 50% slow delta
187
Formed Elements of Blood
- Red blood cell
- white blood cells
- Platlets
188
Function of Blood
- transport oxygen and nutrients
- defense
- homeostasis maintenance
189
Blood Transportation Pathway
- GI tract (pickup nutrients)
- liver (detoxify)
- Through heart into the lungs (pick up oxygen)
- Body
190
Blood Protection
Prevents blood loss through platelets and infection through white blood cells.
191
Blood Colour
The more oxygenated, the more bright red. The less oxygenated, the more dull red.
192
Blood Viscosity
The thickness of the blood indicates how easily it flows (resistance)
193
Blood Temperature
Should be slightly higher than normal body temperature at 38 degrees C.
194
Normal range of human Blood pH
7.35-7.45
195
Weight of Blood in males and females
4-5 L in women, 5-6 in men.
196
3 major groups of Plasma Proteins
1. Albumin
2. globulin
3. fibrinogen
197
Blood Serum
Blood plasma without the clotting factors.
198
Albumin
- Created in the liver,
- most abundant
- Binding protein for lipid transportation
199
Globulins are made of and produce?
- made of alpha, beta, and gamma types
| - produced by plasma cells
199
Fibrinogen
- Least abundant plasma protein
| Essential component in - blood clotting.
200
RBC Life Span
About 120 days.
201
Hemopoiesis
Red blood cell production / formation.
202
Hemopoiesis before vs after Birth
Before: occurs in a number of tissues
After: red bone marrow
202
Erythropoietin (EPO)
- Hormone secreted by the live & kidney in response to low oxygen
- stimulate the production of red blood cells by bone marrow.
203
Erythrocyte
Red blood cells
204
EPO Control
Reduced O2 carrying capacity is detected by the kidneys and they release EPO.
205
Erythrocyte Function
Primary function is to transport oxygen and carbon dioxide by using haemoglobin.
206
Haemoglobin increases
oxygen carrying capacity
207
Sex-Dependent Haemoglobin Differences
Men: more cause of more testosterone which increases EPO production
208
Haemoglobin and Blood Pressure
release nitric oxide to regulate blood pressure and blood flow.
209
Erythrocyte End of Life
When they reach 120 days, erythrocytes are eaten by macrophages found in the bone marrow, liver, and spleen.
210
Leukocytes
White blood cells.
211
Granular vs Agranualr Leukocytes
Granular Neutrophils, eosinophils, basophils.
| Agranular: leukocytes, lymphocytes and monocytes
212
Neutrophils
Rapid responders to sites of infection.
| majority of leukocytes
213
Eosinophils
contain antihistamine molecules and can also phagocytose for parasitic infections.
214
Basophils
Intensify inflammatory response.
215
Lymphocytes
Made up of Natural Killer Cells, B cells, and T cells.
216
B Cells
Produce antibodies which bind to specific foreign components.
216
T Cells
Provide cellular-level immunity by physically attacking foreign cells.
217
Memory Cells
Form after exposure to a pathogen. Used for future rapid responses.
218
Monocytes
Form macrophages when they leave the bloodstream
219
White Blood Cell Elevation
Usually indicates an infection.
220
Platelets
Cellular fragments used for blood clotting
220
Megakaryocyte
Large platelet precursor cell found in the bone marrow. Breaks up to form platelets.
221
Hemostasis
Stoppage of bleeding.
222
Platelet Life Span
10 Days once activated.
223
Three Steps of Hemostasis
1. Vascular spasm
2. formation of platelet plug
3. coagulation.
224
Vascular Spasm
When damaged, smooth muscle of a blood vessel will contract dramatically in order to slow blood flow.
225
Platelet Plug
Platelets encountering area of vessel rupture clump together
226
Extrinsic vs Intrinsic Coagulation Pathway
Extrinsic is shorter, faster, and uses less fibrin than intrinsic
227
Lymphatic System
Composed of a network of vessels, ducts, nodes, and organs. Provides defense against infection as well as carrying fluids around the body.
228
Main Functions of the Lymphatic System
1. Drain Interstitial fluid
2. immune response
3. transport dietary fat
229
Interstitial Fluid Drainage
Hydrostatic pressure causes leakage of fluid from capillaries, the lymphatic system drains it back into the blood.
230
Dietary Fat Absorption
Lacteals can transport dietary lipids instead of blood vessels.
230
Lymphatic Capillaries
terminal lymphatics, vessels where interstitial fluid enters the lymphatic system
231
Chyle
Milky fluid found in the lymphatic system made up of proteins and dietary lipids
232
Movement of Lymph
- passively pumped.
| - One-way semi-lunar valves prevent back flow
233
Lymphatic Trunks
Larger lymphatic vessels draining into the lymphatic ducts
234
Right Lymphatic duct
Receives lymph from the right upper part of the body
235
Lymphatic Ducts
The largest lymphatic vessels, receiving lymph from all over the body and dumping it into the junction of the jugular and subclavian veins.
236
Primary Lymphoid Organs
Red bone marrow and the thymus gland
237
Red Bone Marrow
where B cells mature
238
Thymus
Where T cells mature.
239
Major Histocompatibility Complex (MHC)
Mechanisms which prevent T and B cells from attacking self-antigens and healthy body tissue.
239
Secondary Lymphoid Organs (3)
1. Lymph nodes
2. spleen
3. lymphatic nodules.
240
Naive Lympocytes
Fully functional but not yet activated by antigen
241
Afferent vs Efferent Lymphatic Vessels
Afferent: Vessels which bring lymph into a lymph node.
Efferent: vessels leaving lymph nodes
242
Spleen
Largest singly mass of lymphatic tissue in the body.
243
Two main components of the spleen
Red and white pulp
244
Red Pulp
filters blood and stores platelets.
245
White Pulp
mounts adaptive B and T cell responses in the body.
246
Lymphoid Nodules
Dense cluster of lymphocytes without surrounding fibrous capsules
247
Locations of Lymphoid Nodules
Respiratory and Digestive Tracts
248
Immune Function Type
Innate and adaptive immune responses.
249
Innate vs Adaptive Immune Response
Innate: Non-specific & fast
Adaptive: specific & slow
250
2 Types of Innate Immune Responses
1. Barrier defence
| 2. Internal defence
251
Barrier Defence
prevents pathogens from entering the body
252
Internal Innate Mechanisms
Destroys pathogens after they enter
253
Antimicrobial Substances
Discourage microbial growth
254
Interferons
attack virus infected cells by releasing antiviral proteins
255
Iron-binding Proteins
Reduce available iron
256
Complement Proteins
Augment immune responses.
257
Granzymes
Enzymes that attack proteins of target cells following perforin activity.
258
Phagocytosis
Cell eating.
259
Inflammation Response
Brings in phagocytic cells to the damaged area to clear debris.
260
Vasodilation
Increases blood flow to area which leads to redness and heat.
261
Cytokines
Chemicals released by the immune system communicate with the brain.
262
Helper T Cells
Activate cytotoxic T cells and B cells immune responses.
263
Antigens of the Pathogen
Trigger for adaptive immune responses.
264
Cytotoxic T-Cell
A type of lymphocyte that, when activated, kills infected cells. Stimulated by the active T-Cell.
265
Memory Cells
responsible for immunological memory and protective immunity.
266
Acquiring Immunity
naturally or artificially.
267
Active Process
All cells working together to mount a response and generating memory cells.
268
Passive Response
acquiring high levels of antibodies without the body producing them.
269
Naturally Acquired Active Immunity
Someone gets sick and recovers from infection and has long-lasting B and T memory cells.
270
Naturally Acquired Passive Immunity
Antibodies are passed from mother to fetus via the placenta and breast milk.
271
Artificially Acquired Active Immunity
Antibodies are made due to exposure to a vaccine.
272
Artificially Acquired Passive Immunity
A person getting a direct injection of antibodies which provides a quick and short-lived level of protection. i.e., anti-venom.
273
Artery vs Vein
Artery: takes blood away from the heart.
Vein: brings blood tot he heart
274
Arterioles
Small vessels that receive blood from the arteries.
275
Capillaries
Microscopic vessel through which exchanges take place between the blood and cells of the body.
275
Venules
Small vessels that gather blood from the capillaries into the veins.
276
Artery Properties
Thicker walls, smaller lumen, have to take greater pressures.
277
Vein Properties
Thinner walls, reduced pressure, larger lumen.
278
Blood Vessel Layers
Tunica interna (intima), tunica media, tunica externa.
279
Tunica Intima
The innermost layer of a blood vessel
280
Tunica Media
The middle and thickest layer of tissue of a blood vessel wall, composed of elastic tissue and smooth muscle cells
281
Tunica Externa
Outer layer of a blood vessel which connects it to surrounding tissues, holding it in position.
282
Elastic Arteries
Closer to the heart; allow stretch as blood is pumped into them and recoil when ventricles relax.
283
There is no pressure gradient during...
The resting state.
284
The Great Veins
Superior and inferior vena cava
285
Great Arteries
Pulmonary trunk and aorta.
286
Two Distinct CV Circuits
Pulmonary and Systemic.
287
Pulmonary Circuit
Carries blood to the lungs for gas exchange and returns it to the heart.
288
Systemic Circuit
carries oxygenated blood to the tissues and deoxygenated blood back to the heart.
289
Autorhythmicity
The ability of cardiac muscle to initiate its own electrical potential at a fixed rate.
290
Myocardial Contractile Cells
Cells which conduct impulses and are responsible for contraction of the heart muscle.
291
Myocardial Conducting Cells
initiate and propagate autorhythmic impulses which travel through the heart.
292
Sinoatrial (SA) Node
initiates the electrical impulses that determine the heart rate; often termed the pacemaker for the heart.
293
Atrioventricular (AV) node
creates a critical pause in the electrical impulse pathway.
294
AV Node Delay
Forces the impulse to slow down by about 100ms as it passes through the AV node, allowing the atria to complete contraction and fill the ventricles with 20% more blood.
295
Purkinje Fibres
Muscle fibres that conduct impulses in the walls of the ventricles from the AV bundle branches.
296
Stimulation Frequency (fast to slowest)
```
SA node
AV node
AV bundle
AV bundle branches
Purkinje
```
297
Cardiac Refractory Period
Allows time for ventricular filling and adequate force production
298
Absolute Refractory Period
The minimum length of time after an action potential during which another action potential cannot begin. About 200ms.
299
Relative Refractory Period
period after firing when a neuron is returning to its normal polarized state and will fire again only if the incoming message is much stronger than usual. About 50-250 ms.
300
Systole
Contraction
301
Diastole
Relaxation
302
EKG Waveforms
P wave, QRS complex, T wave.
303
P Wave
atrial depolarization.
304
QRS Complex
ventricular depolarisation.
305
T Wave
ventricular repolarization.
306
Cardiac Cycle- Mechanical events
1. Late diastole
2. Atrial systole
3. Isovolumetric ventricular contractions
4. Ventricular depolarization
5. Isovolumetric relaxation
307
Isovolumetric Contraction
ventricles contract while not ejecting any blood, meaning the blood volume stays constant.
308
Ventricular Ejection Phase
Pressures are greater than arterial pressure. Left ventricle creates more pressure.
309
End Diastolic Volume (EDV)
Volume of blood in each ventricle at end of ventricular diastole
310
End Systolic Volume (ESV)
Volume of blood remaining in each ventricle after systole
311
Stroke Volume
The amount of blood ejected from the heart in one contraction
312
Heart Sounds
Lub-Dub.
313
Lub
closing of the AV valves during early systole.
314
Dub
closing of the semilunar valves during early diastole.
315
Dicrotic Notch
The interruption of smooth flow due to the brief backflow of blood Leads to a spike in BP.
316
Blood Pressure
The force exerted by the blood upon the walls of the blood vessels or the chambers of the heart.
317
Pulse Pressure
The difference between systolic and diastolic BP
318
Mean Arterial Pressure
"Average" blood pressure in the arteries.
319
Normal BP
120/80.
320
Blood Flow and Blood Pressure Variables
- Cardiac Output
- Compliance
- Blood Volume
- Blood Viscosity
- Vessel length and diameter.
321
Compliance
Ability of a vessel to expand to accommodate increased content
322
Compliance and BP
Decreased compliance (hypertension) increases resistance and BP.
323
Vessel Diameter and Blood Pressure
Increased diameter leads to decreased blood pressure
324
Respiratory Pump Inhalation vs Exhalation
Inhilation: volume of thorax increases, intrathoracic pressure decreases, increases BP
325
Blood Flow Redirection
In order to maintain homeostasis, different parts of the body have higher or lower blood needs, meaning blood moves to where there is a higher demand.
326
Decreased BP and Baroreceptors
- decrease firing rate
- sympathetic reflexes
- accelerating HR
327
Increased BP and Baroreceptors
- increase firing rate
- parasympathetic reflexes
- decelerating HR
328
Chemoreceptors and Blood Pressure
Chemoreceptors sense O2, CO2, and H+ concentrations in the blood.
329
Chemoreceptors and the Cardiac Cycle
Chemoreceptors sends messages to the CV and respiratory centres in the medulla oblongata.
330
Neurological Control of BP
- Can decrease cardiac function
- augment cardiac function
- control contractions of smooth muscle in tunica media.
331
Endocrine Control of BP
Mostly done through catecholamines and blood volume-regulating hormones.
332
Catecholamines
"Fight-or-flight" epinephrine and norepinephrine
333
ANH and BP
Atrial natriuretic hormone is antagonistic to ADH and angiotension II. Promotes water loss and vasodilation (through inhibition of angiotensin II). Suppresses renin, aldosterone, and ADH.
334
Autoregulation mechanism
self regulatory mechanism
335
Bayliss Effect
Intrinsic property of smooth muscle that allows them to respond to changes in mechanical load.
336
Short Term BP Control
- Baroreceptors
| - Cardiovascular system
337
Long term BP Control
Renal/Blood volumes
338
Very Short Term BP Control
Autoregulation mechanisms
339
The Valasalva Maneuver
Forced expiration against a closed glottis increases intrathoracic pressure
340
Valsalva Phase I
increase BP & HR decreases.
341
Valsalva Phase II
BP recovery & HR increases.
342
Valsalva Phase III
BP decreased & HR Increased
343
Valsalva Phase IV
BP overshoots & HR decreases.
344
Tachycardia vs Bradycardia
Tachy: Rapid HR, over 100 bpm.
Brady: Slow HR, under 60
345
Respiration
Exchange of gases between the atmosphere, blood, and cells
346
3 Respiration Processes
1. Ventilation (breathing)
2. External (pulmonary)
3. internal (tissue)
347
Conducting Zone
organs and structures not directly involved in gas exchange.
348
Respiratory Zone
Location of gas exchange
349
Conducting Zone Functions
- Provide a route for moving air
- remove debris and pathogens
- warm and humidify the air.
350
Trachea
Provides structural support.
351
Bronchi
traps debris and pathogens.
352
Respiratory Zone Portions
- respiratory bronchiole - which leads to the alveolar duct
| - alveolar sac
353
Bronchoconstriction
Parasympathetic: constriction of the bronchioles.
354
Bronchodilation
Sympathetic: dilation of the bronchioles
355
Alveolus
increase surface area for gas exchange.
356
Type I Alveolar Cells
- Highly permeable to gases
| - Where gas exchange occurs.
357
Type II Alveolar Cells
- Secrete pulmonary surfactant
| - reduces surface tension.
358
Simple Squamous Epithelium
gas to exchange via simple diffusion.
359
Pulmonary Arteries
Arising from the pulmonary trunk, carry deoxygenated blood to the alveoli
360
Pulmonary Capillary Network
Pulmonary arteries become this as they reach the alveoli
361
Respiratory Membrane
Capillary wall meets the alveolar wall, allowing gas exchange to occur.
362
Boyle's Law
P1V1 = P2V2 If volume increases, pressure decreases.
363
Intra-Alveolar Pressure
Pressure of the air within the alveoli, changes with phases of breathing.
364
Intrapleural Pressure
Pressure of the air within the pleural cavity, Changes with phases of breathing.
365
Competing Forces in the Thorax
- Elasticity
| - Alveolar fluid surface tension
366
Pleural Cavity Surface Tension
Force pulling the lungs outwards
367
Expiration Types (4)
- Quiet
- diaphragmatic
- costal
- forced
368
Quiet Breathing
occurs at rest and it automatic
369
Diaphragmatic Breathing
Deep breathing
370
Costal Breathing
Shallow breathing
371
Forced Breathing
Vigorous breathing
372
Tidal Volume
Amount of air that moves in and out of the lungs during quiet breathing. About 500ml.
373
Inspiratory Reserve Volume (IRV)
extra volume that can be brought into the lungs
374
Expiratory Reserve Volume (ERV)
Amount of air that can be forcefully exhaled after a normal tidal volume exhalation.
375
Functional Reserve Capacity (FRC)
The amount of air that remains in the lungs after a normal tidal expiration
376
Anatomical Dead Space
air that is present in the airway that never reaches the alveoli to participate in gas exchange
377
Alveolar (Physiological) Dead Space
Air found in alveoli that cannot function. Those affected by disease or abnormal blood flow.
378
Respiratory Rate Control
changes in blood CO2, O2, and pH levels
379
Dorsal Respiratory Group (DRG)
stimulating the diaphragm and interconstal muscles, causing inspiration.
380
Ventral Respiratory Group (VRG)
stimulates the accessory muscles of the thorax and abdomen, leading to both forced inspiration and expiration.
381
Dalton's Law
Total pressure is sum of all partial pressures
382
Henry's Law
Behaviour of gases in contact with a liquid.
383
Atmospheric and Alveolar Air
Differ in absolute concentration. Alveolar air has more CO2, less O2 and more H2O.
384
Other Gas Exchange Factors
- Diffusion distance
| - available surface area.
385
Perfusion
Flow of blood into the pulmonary capillaries.
386
Sites of Gas Exchange
- Lungs (external respiration)
| - tissues (internal respiration)
