EXERCISE PHYSIOLOGY Flashcards
1
Q
Define homeostasis
A
The condition of equilibrium in the bodys internal environment
2
Q
What does AFFerent mean
A
AWay from control centre
3
Q
What does EFFerent mean
A
Towards control centre
4
Q
Describe the pathway of homeostasis
A
Regulated variable
Sensor
Control centre
Effector
5
Q
What happens to regulated variables when you get ill
A
They can get reset
eg temp gets reset and you get a fever
6
Q
What is negative feedback
A
Acts to reduce an effect
7
Q
Give an example of negative feedback when your cold
A
Feel cold
Shiver to trigger heat production
Return to normal level
8
Q
What is positive feedback
A
Acts to increase an effect
9
Q
Give an example of positive feedback in ovulation
A
Ovulation between days 12-14
Oestrogen provides positive feedback to the hypothalamus and pituitary gland
causing rise in oestrogen production in ovaries
Leads to ovulation
10
Q
What are feedforward loops
A
Are physiological responses in anticipation of a change in a variable
11
Q
Give an example of a feedforward loop
A
Heart rate increases prior to a running race
12
Q
What is a reflex
A
Requires knowledge from an integrating centre and a circuitry that connects the receptor and the effector
13
Q
What are local homeostatic controls
A
Are highly significant because they allow individual parts of the body to self regulate their responses
14
Q
How do cells communicate
A
Direct contact
Neighbouring cells through gap functions
Cell surface proteins trigger a response
Short distance release of chemicals (paracrine signalling)
Long distance release of chemicals (endocrine signalling)
15
Q
How much does the brain weigh
A
1.5kg
16
Q
What can primates do with neurones
A
Pack them
The neurones don’t increase in size when the brain does allowing you to pack neurones
17
Q
What happens to the brain as your body size increases
A
The brain also increases
18
Q
how many neurones in the brain
A
86 billion
19
Q
how much % of cardiac output is directed to the brain
A
15-20%
20
Q
How much of total energy does brain consume
A
20%
21
Q
What makes up the nervous system
A
Central nervous system (CNS)
Peripheral nervous system (PNS)
22
Q
What makes up the CNS
A
Brain
Spinal cord
23
Q
What makes up the PNS
A
Nerves
Ganglion
24
Q
What happens if you damage the CNS
A
It doesn’t regrow as encased in a bone structure
25
What happens if you damage the PNS
It can regrow as its plastic
26
What is somatic
CONTROLS VOLUNATRY MOVEMENT
Eg- Peripheral nerves exit spinal cord and contacts muscles
Stimulation of nerves cause contraction of muscle and moves body therefore voluntary
27
What is autonomic
CONTROLS INVOLUNTARY MOVEMENT
| Controls lungs, heart, smooth muscle, endocrine & exocrine glands
28
What are the 2 sections to the autonomic nervous system
Sympathetic
| Parasympathetic
29
What are 2 options in sympathetic
fight or flight
30
what are 2 options in parasympathetic
Rest and digest
31
What is the technical term for the forebrain
Prosencephalon
32
what is the technical term for the mid brain
Mesencephalon
33
what is the technical term for the hindbrain
Rhombencephalon
34
What are input senses
Visual
Auditory
Olfactory (smell)
Gustatory (taste)
Tactile (touch)
Vestibular (sense of head movement in space)
Proprioreceptive (sensations from muscles and joints of body)
35
What is vestibular sense
Sense of head movement in space
36
3 steps to making a decision
Sensory input
Integration
Motor output
37
What are the 2 major cell types in the brain
Neurones
| Glial cells
38
Describe neurones
Electrically exciteable
Communicate with other cells via synapses
Make up majority of nervous tissue
39
Describe glial cells
Non neuronal cells that maintain homeostasis
Form myelin
Provide support and protection for neurones
40
NEURONES
| how is info passed down a neurone?
Signal arrives at dendrite
Change electrical charge of cell up & down
If charge reaches threshold action potential occurs and travels down axon
When action potential reaches axon terminal it causes calcium to enter terminaL
Causes synaptic vesicles containing neurotransmitters to bind to the cell membrane and release contents into synaptic cleft
Neurotrasnmitter binds to specific receptors on dendrites of next neurone
41
NEURONES
| If neurotransmitteris inhibitory what happens
Lowers charge in receiving neurone
42
NEURONES
| If neurotransmitteris excitatory what happens
Increases charge in receiving neurone
43
NEURONES
| what does myelin do
Speed up transmission by up to 10x
44
What are the 5 types of glial cell found in the CNS
```
Astrocytes
Oligodendrocytes
Schwann cells
Microglia
Ependymal cells
```
45
GLIAL CELLS
| what are astrocytes
Regulate chemicals around neurones - glucose, iron
Regulate blood flow around brain (vasomodulation)
Nervous system repair (following injury to astrocytes)
46
GLIAL CELLS
| what are Oligiodendrocytes
Form myelin sheath on axons in CNS
| Each oligiodendrocyte can myelinate up to 50 axons
47
GLIAL CELLS
| what are Schwann cells
Form myelin in PNS, assist with regrowth of axons
48
GLIAL CELLS
| what are microglia
Creates brains immune system
| Hunt CNS for damaged cells/ infectious agents
49
GLIAL CELLS
| what are ependymal cells
Make up membrane called ependyma found in central canal of spinal cord
Producing cerebrospinal fluid
Build barriers between compartments
50
What are the 2 sections of the forebrain/ prosencephalon
Diencephalon
| Telencephalon
51
What makes up the telencephalon
Cerebrum
52
what makes up the diencephalon
Thalamus
Hypothalamus
Epithalamus
53
What 3 things make up the brainstem
Medulla
Pons
Cerebellum
54
Where is the medulla located
Lower half of brainstem,
| On top of spinal cord
55
What does the medulla control
Cardiac functions
Respiration
Reflexes
56
What is the function of the pons
Contains nuclei that relay signals from forebrain to cerebellum
Nuclei deal with sleep, respiration, swallowing, bladder control, hearing, taste, eye movement, facial expressions & posture
57
What is the functon of the cerebellum
Maintenance of balance and posture
Coordination of movement
Motor learning
58
What happens if the cerebellum is damaged
Movements still occur just less coordinated
59
What does the midbrain control
Tectum controls rapid orientation of head and neck
60
What does the diencephalon control
Thalamus acts as a switchboard
| Takes info from periphery and passes it to the cortex
61
What is the basal ganglia
Series of interconnected nuclei
| Needed for movement regulation, skill learning, addiction, selection of behaviours & movement
62
What are the 2 pathways through the basal ganglia
Direct
| Indirect
63
Where does the direct path through basal ganglia go
runs directly through basal ganglia, excitory effect on cortex, net effect is pro movement
64
Where does the indirect path through basal ganglia go
takes a longer loop through basal ganglia, has inhibitory effect on cortex, net effect is antimovement
65
What happens if basal ganglia is damaged
Body produces too much or too little movement
66
What is the function of the cerebral cortex
Plays key role in movement, attention, perception, memory, language, conciousness
67
What are the folds in the cerebral cortex called
Gyri
68
what are the grooves in the cerebral cortex called
Sulci
69
What is FMRI
Functional magnetic resonance imaging
Measures blood flow
Shows active areas of the brain that require glucose which is transported in the blood
Oxygenated & de-oxygenated blood have different levels of megneticity
70
What is DBS
Deep brain stimulation
Therapy that delivers high frequency electrical pulses directly deep onto the brain
For Parkinson's it targets nuclei in basal ganglia
71
What is the middle of the spinal cord made up of
Neurones
| & other cells (grey matter)
72
What is the outside of the spinal cord made up of
Fibres (White matter)
73
What are the 3 horns
Dorsal (back)
Ventral (front)
Lateral (side)
74
function of the dorsal horn
Contains sensory neruones
| Receive sensory info and send it to brain
75
Function of ventral horn
Contains neurones that send messages directly to muscles
76
Function of intermediate zone
Contain interneurons, these integrate info from sensory neurones and contact motor neurones (inhibition)
77
Which horn is sensory info collected in
Dorsal horn
78
Which horn are motor neurones located in
Ventral horn
79
What is spinal white matter
Fibre tracts that carry info to and from the brain
80
What do corticospinal fibres influence
The movement of every part of the body but ESPECIALLY individual finger use
81
What 2 tracts make up the lateral descending system
Corticospinal tract
| Rubrospinal tract
82
What 2 tracts make up the medial descending system
Vestibulospinal tract
| Retriculospinal tract
83
What is the medial descending system involved in the control of
Control of balance & posture
84
The medial lemniscus/ dorsal column pathway carries sensory info from joint to skin about what
Fine touch
Vibration
2 point discrimination
Proprioreception
85
What does the spinothalamic tract do
Conveys crude touch (sense of being touched but without knowledge of where)
Pain
Temperature
86
What does the vestibulospinal tract do
Sensory system that provides sense of balance and spatial orientation for purpose of coordinating movement with balance
Send most of output to spinal cord and muscles that move eyes
87
What does the reticulospinal tract do
Reticular formation is a set of interconnected nuclei located throughout brainstem
Maintain tone, balance & posture
88
What does the rubrospinal tract contain
Contains red nucleus'
89
What are dermatones
An area of skin supplied by nerves from a SINGLE spinal root
90
What does a single action potential cause
A single twitch
91
What do multiple action potentials in quick succession cause
Maximal contraction called tetanic
92
What is a tetanic contraction
maximal contraction
| Muscles cannot relax between action potentials
93
What is the primary motor cortex
The neurones have simple relationship to movement
Fire before movement onset
Code for basic parameters for movement, force, direction, extent, speed
94
What is the non primary motor cortex
Neurones in the non-primary motor cortex have a more complex relationship to movement
They code for more complex aspects of movement
95
What are the 2 cortexs found in the non primary motor cortex
Pre motor cortex
| Supplementary motor cortex
96
What does the pre motor cortex do
planning movement, spatial guidance, sensory guidance
97
What does the supplementary motor cortex do
connected to basal ganglia – coordinating temporal sequences of actions, bimanual coordination
98
What does the primary sensory cortex do
Code for touch, vibration, heat, pain, pressure, proprioreception
99
What is proprioreception split into
A. Joint position sense- ability to recognise joint position in space
B. Kinaesthesia – ability to appreciate and recognise joint movement or motion
C. Sensation of resistance – ability to appreciate and recognise force generated within a joint
100
What is the posterior parietal cortex for
Reaching movements
101
SLIDING FILAMENT MODEL
| What are binding sites
positions on actin filaments where myosin heads can attach
102
What are cross bridges
temporarily formed mechanical bridges between actin binding sites and myosin heads
103
SLIDING FILAMENT MODEL
| What is a power stroke
a ‘nod’ of the myosin head that applies force to the actin filament via the cross bridge, causes the slide
104
What are the 3 types of muscle
Skeletal
Cardiac
Smooth
105
Which muscle types are striated
Skeletal
| Cardiac
106
What is the cardiac muscle controlled by
sub-conscious autonomic nervous system
107
What is the smooth muscle controlled by
sub-conscious autonomic nervous system
108
Is skeletal muscle uni or multi nuclei
Multinuclei
109
What is a muscle surrounded by
fascia
110
Are A bands light or dark
DArk
111
Are I bands light or dark
LIght
112
Are A bands actin or myosin
Thick myosin filaments
113
Are I bands actin or myosin
Thin actin filaments
114
What are troponin and tropomyosin useful for
Important in regulation of muscle contraction
115
Define contraction
Activating of force generating sites within muscle fibres (cross bridges)
116
What is a motor unit
Group of muscle fibres that is innervated by a single motor neurone
117
Describe what happens to the action potential at a neuromuscular junction
Motor neurons action potential arrives at axon terminal
Depolarises plasma membrane
Ca2+ channels open
Ca2+ ions diffuse into axon terminal
Ca2+ binds to proteins
Synaptic vesicles release acetylcholine (Ach)
Ach diffuses from axon terminal to motor end plate, binding to nicotinic receptors
Binding of Ach opens ion channel
Na and K can pass through these channels (electrochemical gradient – Na moves in K moves out)
Local depolarisation of motor end plate
Muscle fibre action potential initiated
Propagation
118
What happens with cross bridges in a relaxed muscle
Low Ca2+
Cross bridge cannot bind with actin because tropomyosin is covering the binding site (troponin holds tropomyosin over binding site)
119
What happens with cross bridges in an active muscle
High Ca2+
Ca2+ binds to troponin
Tropomyosin moves away from cross-bridge binding site
Actin binds to cross bridge
120
What are the 2 proteins responsible for linking membrane action potential with calcium release in the cell
Dihydropyridine (DHP) receptor - found on membrane
| Ryanodine receptor - found in sarcoplasmic reticulum
121
When the muscle shortens what happens to actin
Actin slides over myosin
122
What are the 4 stages of a cross bridge cycle
1. Energised myosin cross bridges on thick filaments bind to actin
2. Cross bridge binding triggers release of ATP hydrolysis products from myosin, producing angular movement
3. ATP bound to myosin, breaking link between actin and myosin causing cross bridge to dissociate
4. ATP bound to myosin, is split energising myosin cross bridge
123
What are the 2 factors affecting muscle force
Tension
| Load
124
Define tension
The force that muscle exerts on object when it is contracting is called the tension of the muscle
125
Define load
The force that is exerted on a muscle by an object
126
In regards to tension and load what must happen for a muscle to shorten
Tension must EXCEED load
127
In regards to tension and load what must happen for a muscle to lengthen
Load must EXCEED tension
remember - Lengthen Load
128
Define summation
The increase of muscle tension from successive action potenials
129
Define tetanus
When successive stimulations result in a sustained contraction
130
What are the 2 types of tetanus
Fused
| Unfused
131
What is unfused tetanus
muscle fibre has time to PARTIALLY relax before next stimulation. The development of tension oscilliates
132
What is fused tetanus
muscle fibre has NO TIME to relax between stimulations
| The development of tension is continuous and smooth
133
What does CP stand for
Creatine phosphate
134
What does CP do
Provides energy very fast
Forms ATP from ADP
Only lasts 1-2s
135
Define glycolysis
Energy from glucose in absence of oxygen (anaerobic metabolism)
10 step process
136
Describe oxidative phosphorylation
Energy from glucose or fat in presence of oxygen (aerobic metabolism)
137
What is oxygen debt
To replenish glucose and creatine stores and remove lactic acid we require energy. To do this we use more oxygen to produce the energy needed after exercise has finished
138
What are the 5 mechanisms involved in muscle fatigue
```
Conduction failure
Lactic acid build up
Inhibition of cross bridge cycling
Fuel substrates
Central command fatigue
```
139
What is conduction failure
caused by potassium accumulation in the T tubules Fast recovery
140
What is lactic acid build up
acidic environment in muscle effects physiological functioning of proteins and the mechanisms involved in calcium release and re-uptake
141
What is inhibition of cross bridge cycling
accumulation of ADP and Pi in muscle fibres slows down in the cross-bridge cycling by preventing the release of cross bridges from actin molecules.
142
What are fuel substrates
muscle glycogen, blood glucose, dehydration
143
What is central command fatigue
failure to propagate signals from the brain to the motor neurons
144
what are the 3 types of muscle fibres
Type 1 slow oxidative
Type 2a fast oxidative
Type 2x fast glycolytic
145
Describe type 1 muscle fibres
```
SMALLEST
Slow contractile speed
High resistance to fatigue
Small diameter
low ATPase activity
Highly oxidative
Dark in colour due to lots of myoglobin & oxygen
```
146
Describe type 2a muscle fibres
```
small diameter
high ATPase activity
highly oxidative
moderately glycolic
white in colour
```
147
describe type 2x muscle fibres
```
BIGGEST
Fast contractile speed
Little resistance to fatigue
large diameter
high ATPase activity
Highly glycolic
White in colour
Most fibres in motor unit
```
148
define autocrine
can be signalled by the same cell
149
define paracrine
signalled by nearby cells
150
what does paracrine signalling use
cytokines
151
define endocrine
signal via distant multi cellular
152
what does endocrine signalling use
hormones
| secreted into blood from endocrine gland
153
What is the difference between endocrine and exocrine glands
EXOcrine secrete their products INTO DUCT
ENDOcrine are DUCTLESS and release HORMONES into blood
154
Define a hormone
chemical messengers carried by the blood to target cells
155
what are the 4 functions of hormones
```
1. help regulate...
metabolism
contraction of smooth & cardiac muscle
some immune system activities
glandular secretions
2. control growth and development
3. regulate operation of reproductive system
3. help establish circadian rhythm
```
156
how fast does the endocrine system work
relatively slowly but has long lasting effects
157
Give an example of some amines
thyroid hormones
dopamine
catecholamines
158
Give an example of peptides and proteins
insulin
| any hormone
159
Give an example of steroids
alderosterone
cortisol
androgens (testosterone)
160
Can steroids dissolve in plasma
often lipid based so can't dissolve
161
What does the responsiveness of a target cell to a hormone depend on...
1. the hormones conc in blood
2. abundance of target cells hormone receptor
3. influences exerted by other hormones
162
What are the 3 types of effects hormonal interactions can have
permissive
synergistic
antagonistic
163
Name some things the anterior pituitary gland secretes
```
Growth hormone (GH)
Thyroid stimulating hormone (TSH)
Adrenocorticotropic hormone (ACTH)
Prolactin
Follicle stimulating hormone (FSH)
Luteinizing hormone (LH)
```
164
What 2 hormones does the thyroid gland secrete
T3 (thyroxine)
| T4 (triiodothyronine)
165
what is T3 hormone required for
production of growth hormone from anterior pituitary gland
166
Physiological functions of cortisol during NON stressful situations
Affects responsiveness of smooth muscle cells to epinephrine & norepinephrine helping maintain normal blood pressure
required to maintain certain enzyme concs involved in metabolic homeostasis preventing blood glucose dropping too low
has anti-inflammatory and anti immune functions
167
Physiological functions of cortisol during STRESSFUL situations
Maintenance of plasma glucose conc
Enhanced vascular reactivity improving CV performance
Inhibition of inflammation and specific immune responses
Inhibition of nonessential functions - reproduction
168
What happens when the stress response is triggered
sympathetic nervous system is activated triggering release of epinephrine
At same time endocrine system releases cortisol from adrenal glands
169
What is growth hormone (GH) stimulated by
Growth hormone releasing hormone (GHRH)
170
What is growth hormone (GH) inhibited by
Somatostatin (SST)
171
What are the 3 sex hormones
Oestrogen
Progestogen
Testosterone
172
What is the function of the cardiovascular system
Transport oxygen, nutrients, metabolites to tissues
Removal of waste products
involved in body temp regulation
distribution and secretion of hormones
173
What is systemic circulation
Connected to heart in parallel
Choice of which part of body receives more or less of available blood
BOTTOM HALF OF DIAGRAM
174
What is pulmonary circulation
Connected to heart in series
Entire blood volume has to pass through it every time it circulates the body
TOP HALF OF DIAGRAM
175
What is the total blood volume roughly
approx 5 litres
176
What is driving pressure
Flow is created by the pressure difference between 2 points
| FLOW REQUIRES A PRESSURE DIFFERENCE
177
what is darcys law equation
flow = pressure difference / resistance
178
What is poiseuilles law and equation
determines resistance to flow
flow = pressure difference x r to power of 4
179
What happens to resistance to flow if you double vessel radius
Resistance reduces by a lot
180
What happens to resistance to flow if you halve vessel radius
Increases resistance by a lot
181
To get fastest flow do u want a wide vessel or a narrow vessel
narrower the vessel = faster the flow
182
what is the equation linking velocity, flow rate & cross sectional area
velocity = flow rate/ cross sectional area
183
What is the pericardium
protects the heart by providing lubrication during its constant movement
Also anchors heart against diaphragm & spine
184
Describe flow of blood
```
Arrives from superior & inferior vena cava
Right atrium
Tricuspid valve
Right ventricle
Pulmonary valve
Pulmonary arteries
To lungs to be oxygenated
Back through pulmonary veins
Left atrium
Mitral/ bicuspid valve
Left ventricle
Aortic valve
Aorta to body
```
185
What do pulmonary arteries do
take blood AWAY from heart to lungs to be oxygenated
186
What do pulmonary veins do
Bring oxygenated blood BACK TO heart
187
Can tetanic contractions occur in skeletal muscles
YES
188
Can tetanic contractions occur in cardiac muscles
NO
| If heart was always contracting there would be no relaxation period and the heart could not fill
189
Rate of firing in the SA node depends on...
Initial value of membrane potential
| The slope of the drift towards threshold
190
Explain cardiac conduction
SA node fires action potentials
Stimulus spreads through muscle fibres & stimulates both atria simultaneously
Stimulation in atria spreads from fibre to fibre through gap junctions
Reaches AV node, signal delayed to enable atria to empty before ventricular contraction begins
Bundle of HiS
Signal travels down the interventricular septum via 2 bundle branches
Ventricles begin to contract as stimulus spreads upwards depolarising muscle fibres via purkinje fibres
191
What does a P wave on an ECG represent
atrial contraction
192
What does a Q wave on an ECG represent
ventricular contraction
193
What does a R wave on an ECG represent
Ventricular contraction
194
What does a S wave on an ECG represent
Ventricular contraction
195
What does QRS on ECG form
QRS complex
| Ventricular contraction
196
What does a T wave on an ECG represent
relaxation of ventricles
197
When does the tricuspid valve open
when right atrial pressure BIGGER than right ventricle pressure
198
When does the tricuspid valve close
when right atrial pressure LOWER than right ventricular pressure
199
When does the bicuspid valve open
when left atrial pressure BIGGER than left ventricle pressure
200
when does the bicuspid valve close
when left atrial pressure LOWER than left ventricular pressure
201
When does the pulmonary valve open
when right ventricular pressure BIGGER than pulmonary artery pressure
202
When does the pulmonary valve close
when right ventricular pressure LOWER than pulmonary artery pressure
203
When does the aortic valve open
when left ventricular pressure BIGGER than aortic pressure
204
When does the aortic valve close
when left ventricular pressure LOWER than aortic pressure
205
what is systole
ventricular contraction
206
what is diastole
ventricular relaxation
207
Whta is cardiac output
Volume of blood pumped out by heart EVERY MIN
208
what are units for CO
ml per min
209
What is the equation for CO
CO = HR x SV
210
What symbol is CO sometimes given
Q
211
Describe parasympatehtic nerve activity
Takes place via vagus nerve
| Releases the neurotransmitter acetylcholine which slows HR
212
Describe sympathetic nerve activity
sympathetic fibres (cardiac nerves) increase HR by releasing norepinephrine
213
What is stroke volume regulated by
1. The force by which the muscle cells contract
| 2. The arterial pressure against which they have to eject the blood
214
define blood pressure
the driving force for flow in the cardiovascular system (pressure gradient between arteries and veins) and it must be maintained at all times
215
Where is blood pressure highest and lowest
Blood pressure highest close to heart and it declines as blood moves further away from it
216
What is mean arterial pressure (MAP)
is calculated from the values of systolic and diastolic blood pressure, NOT AN AVERAGE OF THE 2
217
What is the equation for MAP
diastolic + ((systolic - diastolic) / 3)
218
What is normal blood pressure
120/80
219
what factors effect blood pressure
Age - arteries become stiffer with age
Gender - women have lower blood pressure than men
Pressure higher in foot and lower in head due to hydrostatic pressure
220
What happens to BP in dynamic exercise (walking running etc)
remains relatively stable
221
What happens to BP in static exercise (lifting weights)
rises dramatically
222
What is the MAP blood pressure equation
MAP = CO x TPR (total peripheral resistance)
223
If TPR decreases what happens to MAP
Map decreases too
224
What is the sequence of events initating a muscle contraction
An action potential propagates along the length of the fibre depolarizing the t-tubule membrane, causing a release of calcium from the sarcoplasmic reticulum. This binds to troponin making the actin binding sites available for the attachment of an energised myosin head to form a cross bridge and subsequently generate tension in the muscle.
225
Damage to the basal ganglia can lead to what
unwanted spontaneous movements
226
All the motor neurones that innervate a single muscle are called a?
motor pool
227
A normal range for blood glucose concentration is?
70-110 mg/Dl
228
Motor neurones that control the lower limbs are found in which part of the spinal cord?
lumbar englargement
229
Length wise what is the difference between diastole and systole
diastole lasts twice as long as systole
230
In arteries what are adventitia
Provides structural strength and tethers the vessels in place
In large vessels the adventitia contains small blood vessels - the vasa vasorum (the vessels of the vessels)
231
In arteries what is elastin for
Gives vessels mechanical strength and their elastic properties (expend and recoil)
232
In arteries what does the endothelium do
filtering interface between blood and body
| Secretes various vasoactive products
233
In arteries what does smooth muscle do
supplies vessels with contractile power and regulates the diameter of the lumen
234
In arteries what are the pre capillary sphincters
controls blood flow to specific capillary beds selectively
235
What do arterioles do
responsible with altering levels of resistance to blood flow in order to distribute the valuable amount of blood to where it is needed without disturbing the control of mean arterial pressure
236
What is active hyperaemia
the increase in blood flow via local vessels dilating to increase blood flow to the tissue working hard according to the metabolic needs
237
What is flow autoregulation
concerned with the maintenance of blood flow rather than changing it. When the driving pressure drops the vessels dilate, and when it increases the vessels constrict
238
What does a tonic state mean when referring to muscles
partially contracted
239
what state is arterial smooth muscle constantly in
tonic state
240
what controls contraction of smooth muscles
autonomic nervous system
241
where is smooth muscle found
in organs
242
contraction time of smooth muscle
contract slowly but can sustain contractions for long periods of time without fatigue
243
do smooth muscles have striations
no
244
do smooth muscle have sarcomere
no
245
does smooth muscle have a neuromuscular junction
no
246
is there troponin in smooth muscle
no
| therefore actin binding sites always available
247
which filaments does calcium act on
| thick or thin
thick
248
What is moved in vesicle transport
larger molecules like proteins
249
what is moved in bulk flow
water and solutes
250
define filtration
fluid movement from the capillaries to the interstitial fluid
takes place when hydrostatic pressure exceeds colloid osmotic pressure
251
define absorption
fluid movement from the interstitial fluid to the capillaries
takes place when colloid osmotic pressure exceeds hydrostatic pressure
252
does hydrostatic pressure favour filtration or absorption
favours filtration
253
does osmotic pressure favour filtration or absorption
favours absorption
254
what happens when filtration exceeds absorption
the net accumulation of fluid in tissues is
| dealt with by the lymphatic system.
255
what are the 3 ways to change compliance of a vein
neural - Sympathetic stimulation releases norepinephrine to the smooth muscle of veins in the gastrointestinal (stomach & intestines), renal (kidneys), hepatic (liver), and cutaneous (skin) circulations causing vasoconstriction.
This reduces their capacitance and displaces blood towards the heart.
hormonal - The diameter of veins is affected by the presence of blood circulating epinephrine
endothelial - Paracrine vasoconstrictors and vasodilators (nitric oxide, endothelin -1) also operate in veins
256
during inspiration what happens to flow to the heart
flow to heart increases
257
during expiration what happens to flow to the heart
flow to heart impeded
258
what do lymph vessels do
collect filtered fluid from the interstitial space and return it to the circulating blood volume
259
what is ODEMA
Failure of lymphatic system leads to Oedema
Accumulation of excess fluid in the interstitial spaces (subcutaneous, abdomen, lungs)
Filtration exceeds lymphatic drainage
260
what is an endotherm
they generate their own internal body heat and do not rely on the energy of sunlight to warm the body
261
what is a homeotherm
Maintain their body temperature within very narrow limits despite wide fluctuations in ambient temperature
262
when is body temp highest
DAY OR NIGHT
during day
263
when is body temp lowest
DAY OR NIGHT
during night
264
what causes body temp to fluctuate
eating
exercise
circadian rhythm
265
give some examples of heat conservation/ production
Shivering thermogenesis
Voluntary muscular activity
Non shivering thermogenesis
266
Give some examples of heat loss
Sweating
| Blood reaching the skin
267
what is shivering thermogenesis
creating heat
268
what is non shivering thermogenesis
from tissue called brown adipose tissue
269
what is the therm-neutral zone
not having to activate heat loss NOR heat conservation/ production mechanisms
270
describe the physiological control of heat loss
1. Body temp increases
2. Thermosensors (in skin & brain and hypothalamus) detect change
3. Sends signal to brain then to hypothalamus
4. Send efferent signal to adrenal medulla which activates release of epinephrine/ adrenaline
5. Help blood vessels dilate
6. Sweat glands secrete fluid and heat is lost
271
why does vasodilation happen
Vasodilation happens due to a reduction of sympathetic stimulation
It also happens due to the release of acetylcholine from specialised sympathetic neurons
272
what are the 2 types of sweat gland
eccrine (all over body)
| Apocrine (head or hair)
273
why does vasoconstriction happen
happens as a result of norepinephrine acting on adrenergic receptors
274
how does shivering work/ what's so special
Shivering is a specialised form of muscular contraction in which muscles perform no external work and virtually all energy of contraction is converted into heat
Shivering is a result of stimulation by somatic motor neurons
275
what is cardiac arrhythmias
rhythm of heart becomes out of sync
276
define heatstroke
failure of thermoregulation with a body temp of >40.6
277
what are the signs of heatstroke
1. Dizziness
2. Disorientation
3. Dry skin
4. Increased HR
5. Collapsing
278
what is hyPOthermia
too cold
279
What is hyPERthermia
too hot
280
what happens to body temp at exercise
it is maintained but higher than at rest
281
what is acclimatisation
Acclimating to heat means that an individual can regulate body temperature more efficiently
Crucial for exercise in hot places
282
how does acclimatisation work
Involves the repeated exposure to heat either by habitation in a hot climate or use of environmental chambers
Acclimatisation begins after 5-10 days of prolonged exercise in heat, happens via adjustments in blood flow and sweating
283
what effects does an acclimatised individual have
```
Sweat more and sooner
Increased blood flow to skin
More dilute sweat
Increased blood volume and SV
Lower core body temp
Lower HR
Less fatigue
```
284
define basal metabolic rate
the amount of energy expended while at complete rest
285
what is the thermic effect of food
the energy required to digest and absorb food
286
define oxygen consumption/ VO2
the volume of oxygen used by your body to convert energy from the food into work
287
what is VO2 measured in
L/min
288
what is the most dense nutrient
fat
289
what is the least dense nutrient
carbs
290
what is the energy expenditure equation
energy expenditure = base metabolic rate (BMR) + physical activity level
291
define base metabolic rate (BMR)
rate at which person uses energy to maintain the basic functions at rest; breathing, keeping warm, keep heart beating
292
what are the factors that decrease metabolism
1. Sleep (decreased during sleep)
2. Age (decreased with increasing age)
3. Gender (women typically lower rate than men at any given size)
4. Fasting (BMR decreases, which conserves energy stores)
293
what are the factors that increase metabolism
1. Growth
2. Pregnancy
3. Infection
4. Body temp
5. Recent ingestion of food
6. Muscular activity
7. Emotional stress
8. Environmental temperature
294
how many kcal do men need to maintain weight
2500
295
how many kcal do women need to maintain weight
2000
296
what do baroreceptors detect
detect blood pressure
297
what happens to action potentials as MAP increases
firing rate of action potentials increase
298
what happens to action potentials as MAP decreases
firing rate of action potentials decrease
299
where is the medullary cardiovascular centre located
in the medulla oblongata
300
how does blood pressure increase through baroreceptors
A fall in BP causes carotid and aortic baroreceptors to detect a hypotensive stimulus
Leading to decreases in afferent baroreceptor nerve firing
This reduction in neural input to the brainstem causes a decrease in parasympathetic nerve activity to heart
Increases in sympathetic outflow to heart and vasculature
301
how quick are cardiovascular responses
within seconds
302
how quick are kidney responses
within hours
303
describe redistribution of CO during exercise
Blood flow decreases in kidneys, digestive tract & all other parts of body not directly involved in exercise
Blood flow through the brain remains fairly constant due to autoregulation
The fixed volume of the cranial cavity cannot accommodate large increases in blood flow
304
does vasoDILATION increase/ decrease peripheral resistance
Dilation Decrease peripheral resistance
305
does vasoCONSTRICTION increase/ decrease peripheral resistance
Constriction increases peripheral resistance
306
the net effect of vasoconstriction and vasodilation does what to peripheral resistance
reduction in TOTAL peripheral resistance
307
what happens to CO in trained/ untrained performers
CO is larger in trained performers
308
what happens to max HR in trained/ untrained performers
Max HR can not be increased by training therefore same
309
what happens to general HR in trained/ untrained performers
Trained have a lower HR for a given workload
310
what happens to SV in trained/ untrained performers
Higher in trained people
311
what does VO2 max test show
assessment of aerobic endurance or power
312
what do sub maximal exercise test show
used to asses physiological responses to a standardised workload
313
what is steady state exercise
the level of exercise at which the physiological responses remain relatively stable for an extended period of time
314
factors affecting steady state exercise
1. Delivery of adequate oxygen to exercising muscles
2. Ability of cells to utilise oxygen in the aerobic process of energy metabolism
3. The ability to eliminate heat
315
how long does it take to reach steady state exercise
3-5 mins
316
what are the 4 states to steady state exercise
1. Initial rapid rise occurs within 1st min
2. A more gradual rise occurs between 1-3mins
3. A plateau is reached between 3-5mins and maintained
4. Finally, extended exercise (1-4 hours) there may be a small continuous increase due to factors such as increase in core body temp
This is called drift
317
what are the mechanisms for the control of ventilation
1. The initial rapid rise in ventilation is explained by central command (that is, the motor cortex signals the respiratory control centre to increase ventilation). Mechanoreceptors in the muscles and limbs detect limb movement and physical deformation, and further supplement central command.
2. The subsequent gradual rise in ventilation may be explained by a fine-tuning of respiratory neurons in response to central command and feedback control from arterial chemoreceptors positioned in the carotid and aortic bodies.
318
mechanisms of control for CO
Initial rapid rise explained by central command & starlings law
Input from mechanoreceptors in muscles contribute to central command by feedback control
Chemoreceptors in muscle responsible for gradual rise to steady state exercise
319
what is the starling effect
when venous return of blood to heart increases, the my-filaments (actin & myosin) in cardiac muscle are stretched to a more optimal overlap
As a result the strength of contraction = greater & increased
320
what relationship do HR and vO2 have
a strong linear relationship
321
functions of respiratory system
1. Gas exchange between environment and blood
2. Control of acidity of body
3. Filtering of inhaled air
4. Vocalisation
322
how many lobes in right lung
3 lobes
323
how many lobes in left lung
2 lobes
324
what is the pleural sac
Double walled enclosure of lungs filled with pleural fluid
Reduces friction from movement on surface of lungs
Fixes lungs firmly on thoracic wall without any physical attachments
325
what is the function of rib cage and spine when talking about lungs
offer rigid protection to sensitive organs - heart and lungs
326
what are the functions of the airways
1. Warming up inspired air
2. Humidification of dry inspired air
3. Filtrated of inhaled foreign materials
327
what are the 2 types of airways
conducting zone
| exchange zone
328
what is the conducting zone in the airways
no gas exchange takes place
329
what is the exchange zone in the airways
where diffusion/ gas exchange takes place
330
what are the turbinates (conchae) in the nasal cavity
bony dividers that increase surface area of nasal cavity
331
what is airflow directly proportional to
Airflow is directly proportional to pressure difference between 2 points
332
what is airflow inversely proportional to
Airflow is inversely proportional to the resistance created by the airways
333
what is the main factor affecting resistance in the respiratory system
airway radius
334
what things affect viscosity
humidity
| concentration of air (high altitude)
335
What is boils law
P1 x V1 = P2 x V2
P is presure
V is volume
336
what type of process is normal expiration
passive process
| no muscle contaction required
337
how could you describe intrapleural pressure
negative and subatmospheric
338
what type of process is forced expiration/ heavy breathing
active
| requires contraction of muscles
339
what does surfactant do
Surfactant; promotes diffusion, increase lung compliance & prevents the collapse of smaller alveoli.
340
what does reduced surface tension of lungs mean
Alveolar spaces are less prone to collapsing
| The lung is more compliant and is inflated easier
341
can residual volume be measured with a spirometer trace?
no
342
can functional residual capacity be measured with a spirometer trace?
no
343
define tidal volume
The amount of air that is moved in and out of the lungs with EVERY BREATH during normal breathing
344
define reserve volume
The amount of ADDITIONAL air that can be moved in and out of the lungs during heavier breathing
345
define vital capacity
The TOTAL amount of air that can be moved in and out of the lungs during MAXIMAL respiratory effort
346
define functional residual capacity
The amount of air that is LEFT in the LUNGS at the END of a normal EXPIRATION
347
define residual volume
The amount of air that is LEFT in the LUNGS at the end of MAXIMAL EXPIRATION
348
what is anatomical dead space
refers to the part of the airways where gas exchange does not take place and is a fixed volume
349
what is alveolar dead space
refers to areas of lungs where gas exchange can take place but that are not properly perfused with blood
350
define minute ventilation
is the amount of air that is moved by the lungs in ONE MINUTE
351
What is the minute ventilation equation
minute ventilation = tidal volume x breathing frequency
352
what does hyperpnoea do to minute ventilation
minute ventilation increases in proportion to metabolic rate
353
what does hyperventilation do to minute ventilation
minute ventilation increases more than metabolic rate does
354
what is daltons law
= the pressure of a gas mixture is equal to the sum of the pressures of the individual gases
355
how much % of nitrogen is in the air
78.1%
356
how much % of oxygen is in the air
20.9%
357
how much % of carbon dioxide is in the air
0.033%
358
how to find the partial pressure of a gas
times the air% of the gas (eg 20.9% for oxygen) by atmospheric pressure (760mmHg)
760mmHg x 20.9% = 159 mmHg
359
what is atmospheric pressure
760 mmHg
360
what does ficks law mean
From Ficks law it is obvious that greater solubility for a particular gas means a greater rate of diffusion for that gas.
(CO2 is a lot more soluble than O2, and it diffuses across the membrane easier)
361
What is more soluble CO2 or O2
CO2 is more soluble than O2
362
what does movement if molecules depend on
temperature
pressure difference
solubility
363
what is how many polypeptide chains in Hb
4 polypeptide chains
364
how many haem groups in Hb
4 haem groups
365
what is in the middle of each haem group
an Iron molecule that binds to oxygen
366
does oxygen that is bound to Hb contribute to partial pressure
no does not contribute
367
What is the shape of the dissociation curve
sigmoidal shape
368
what does a shift to the left mean for the oxygen dissociation curve
increased affinity for oxygen
369
what does a shift to the right mean for the oxygen dissociation curve
decreased affinity for oxygen (BOHR SHIFT)
370
what affects oxygens binding to haemoglobin
acidity
DPG concentration
CO2
Temperature
371
how much co2 is carried as bicarbonate ions (HCO3-)
70%
372
what is it called when carbon dioxide is bound to haemoglobin
carbaminohaemoglobin
373
how much of co2 is carried bound to haemoglobin
23%
374
when does haemoglobin carry co2
when the binding sites aren't occupied with oxygen they occupy them with co2
375
what is the role of H+ ions in the blood
act as a buffer by binding to empty binding sites
376
can ventilation be voluntary
yes
377
how can ventilation be made voluntary
hyperventilation
holding your breath
speaking
swallowing
378
what does the Hiring-Breuer reflex do
protects the lungs by initiating a signal that inhibits inspiration (the switch-off point).
379
describe slowly adapting pulmonary stretch receptors
These receptors are located within airway smooth muscle
and they are active only when tidal volume approaches
the physical limitations of the lung tissue for expansion.
380
describe rapidly adapting pulmonary stretch receptors
These receptors are dense in the trachea and large airways.
They respond to stimuli such as cigarette smoke, inhaled
particles and cold air, by initiating reflexes such as coughing and sneezing and by causing bronchoconstriction.
381
what creates the ventilatory drive
```
carotid chemoreceptors (carotid bodies)
aortic chemoreceptors (aortic arch)
```
382
control of ventilation in steady state exercise
| phase 1
Ventilation increases abruptly and as early as in the first breath after exercise has commenced. It is thought to be controlled by neural mechanisms.
383
control of ventilation in steady state exercise
| phase 2&3
Ventilation increases gradually until steady state exercise is achieved. Chemical stimuli are more likely to contribute to this part of the response
384
what drives phase 1 of control of ventilation
neural mechanisms
Muscle afferents
Central command
Learnt response
385
what drives phase 2 of control of ventilation
chemical mechanisms
Temperature
PCO2 and pH oscillations
Plamsa K+, catecholamines
Hypoglycaemia, metabolic rate
386
what is the Haldane transformation correction factor
1.5
387
how to calculate volume of inspired oxygen
volume of inspired air x percentage of inspired O2
388
how to calculate volume of expired oxygen
volume of expired air x percentage of expired O2
389
how to calculate oxygen consumption
volume of inspired oxygen - volume of expired oxygen
390
what does RQ stand for
respiratory quotient
391
define RQ
The ratio between the rate by which O2 is consumed and CO2 is produced depends on the fuel that is used to provide the energy needed for metabolic functions
392
with RQ when does the rate of CO2 production vary
it is different when carbs, fats & proteins are used as fuels
393
what is the RQ equation
CO2 production/ O2 consumption
394
what are the functions of the renal system
1. Regulation of water, ions balance
2. Removal of metabolic waste products from blood and excretion
3. Removal of foreign chemicals from blood
4. Gluconeogenesis
5. Production of hormones/ enzymes (EPO, Renin)
395
what generates the high pressure in the glomerulus
afferent and efferent arterial blood flow causes high pressure
396
what's the benefit of glomerulus having lots of pores
lots of pores so you can squeeze fluid & other small molecules out of blood
397
what cells allow filtration
podocytes
| which are found on capillary wall
398
where is the bowmans space
between glomerulus and bowmans capsules
399
what stays in glomerulus and what gets filtered
Amino acids, RBC and large proteins stay as they're too large
Na+ & glucose get filtered
400
describe the route through kidneys
```
glomerulus
bowmans capsule
PCT (proximal convoluted tubule)
Loop of henle
DCT (distal convoluted tubule)
Collecting duct
```
401
what happens in PCT
selective reabsorption
402
Is selective reabsorption active or passive
active process (uses ATP)
403
what happens during selective reabsorption
Na+, glucose & H2O being reabsorbed back into body
404
what are the 2 sides in the loop of henle
descending
| ascending
405
what happens in the descending loop of henle
water moves out nephron back into body
406
what happens in the ascending loop of henle
Na+ & Cl- pumped out
407
what happens to nephron in loop of henle
crosses from cortex to medulla
408
is medulla hyPERtonic or hyPOtonic
hyPERtonic
409
what happens in DCT
more reabsorption
410
what hormone acts in collecting duct
ADH
411
what does each nephron consist of
renal corpuscle which contains the glomerulus (tuft of capillaries) and a renal tubule (bowmans capsule)
412
in the kidney what are juxtaglomerular cells
Mechanoreceptors
| They sense blood pressure in the afferent arteriole
413
in the kidney what are macula dense cells
chemoreceptors that respond to the changes in the NaCl (salt) content of the fitrate
414
what makes up the juxtaglomerular apparatus
juxtaglomerular cells
| macula dense cells
415
define GFR
GFR is the amount of blood filtered by the glomeruli EACH MINUTE
416
What affects GFR
Capillary permeability
Surface area of capillary bed
Hydrostatic pressure that drives fluid out of capillaries
Osmotic forces within capillaries which oppose the exit of fluid
417
what happens if there are proteins in urine and what is it called
Proteinuria
| indicates a problem with filtration membrane
418
what are tubular secretion mechanisms important for
1. Disposing of drugs and drug metabolites
2. Eliminating undesired substances or end products that have reabsorbed by passive processes (urea & uric acid)
3. Removing excess K+
4. Controlling blood pH
419
in the kidneys what is RC
Renal clearance
420
Define renal clearance (RC)
the amount of a substance filtered per minute, divided by its plasma concentration
measured in mL/min
421
what is inulin
Neither reabsorbed nor secreted, not harmful to body, small enough to get filtered out by glomerulus
422
what is a healthy GFR
approx 120ml/min
423
Define the filtration fraction
the proportion of plasma that enters the kidneys that is subsequently filtered at the glomerulus and passes into the renal tubules
424
what is the typical filtration fraction?/ % of blood filtered
filtration fraction 0.16-0.20
| therefore 20% of blood entering kidney is filtered
425
how much of our lean body weight is water in %
60%
426
how many thirds of our total body water is located within cells (intracellular fluid)
2/3
427
how many thirds of our total body water is located outside cells (extracellular fluid)
1/3
428
KIDNEYS
| where does sodium reabsorption happen
all tubular segments except descending limb of loop of henle & medullary collecting duct
429
KIDNEYS
| is sodium reabsorption an active or passive process
active process
430
KIDNEYS
| where are majority of aquaporins clustered
proximal nephron
431
kidneys
| What is water reabsorption dependant on
sodium reabsorption
432
KIDNEY
| active sodium reabsorption key points
-Active transport out of cells into interstitial fluid
-Transport achieved by Na+/K+/ ATPase pump
Keeps intracellular conc of Na + low to allow movement of Na+ from lumen
-PCT has co transport/ counter transport of organic molecules (glucose & amino acids)
-Cortical collecting ducts via Na+ channels
433
what is the function of aquaporins
Function of aquaporins in medullary collecting duct cells is to increase water reabsorption
434
what is ADH also known as
vasopressin
435
factors determining rate of tubular Na+ reabsorption
1. Aldosterone (Most major)
2. Atrial natriuretic peptide (ANP)
3. Local effect of blood pressure on tubules
436
what inhibits Na+ reabsorption
High pressure also inhibits Na+ reabsorption (as well as reducing renin release)
437
How does renin increase Na+ reabsorption
- Release of Renin converts the peptide angiotensinogen to angiotensin 1
- Angiotensin 1 then converted to angiotensin 2 by ACE enzyme
- Angiotension 2 acts on angiotensin receptors located around body
- Activation of these receptors in adrenal gland stimulates aldosterone release, increasing Na+ reabsorption
438
How does ANP increase Na+ reabsorption
- ANP is synthesised and sorted in atrial myocytes
- ANP is released in response to stretching of the atria
- This occurs when circulating blood volume increases
- An increase in circulating levels of ANP causes an increase of Na+ excretion
439
what do diuretics do
promote the loss of Na+ and H2O
440
How does alcohol act as a diuretic
inhibits the release of vasopressin/ adrenaline from pituitary gland
441
What is the function of the glomerulus/ bowmans capsule
forms ultra filtrate of plasma
442
what is function of PCT
bulk reabsorption of solutes and water
secretion of solutes and organic acids and bases (except K+)
443
what is the overall function of loop of henle
establishes medullary osmotic gradient
| secretion of urea
444
what is the overall function of descending limb
bulk reabsorption of water
445
what is the overall function of ascending limb
reabsorption of NaCl
446
what is the function of DCT
Fine tuning of reabosprtion/ secretion of small quantity of solute remaining
447
what is the function of cortical and medullary and collecting ducts
fine tuning of water reabsorption
| Reabsorption of urea
448
what is normal blood pH specifically
ranges from 7.35-7.45
449
What range of pH is acidosis
7-7.35
450
What range of pH is alkalosis
7.45-7.8
451
What does excretion of HCO3- do to H+ ions
increases plasma H+ ion
452
What does addition of HCO3- do to H+ ions
decreases plasma H+ ion
453
describe metabolic acidosis
Rate and depth of breathing are elevated
As CO2 is eliminated by respiratory system, PCO2 falls below normal
Kidneys secrete H+ and retain/ generate bicarbonate to offset the acidosis
454
describe metabolic alkalosis
Pulmonary ventilation is slow and shallow allowing carbon dioxide to accumulate in blood
Kidneys generate H+ and eliminate bicarbonate from the body by secretion
455
what do the kidneys do during exercise
1.Conserve body water
Excrete metabolites such as
1. H+
2. Creatine (excess created from muscle breakdown)
3. Other proteins
456
what is rhabdomyolis
condition where skeletal muscle cell damage can cause acute renal failure & sometimes death
457
what sport is linked with rhabdomyolis
cross fit in unfit athletes
458
what is autocrine signalling
signalled by the same cell
459
what is paracrine signalling and what does it use
signalled by a nearby cell
| Using cytokines
460
what is endocrine signalling and what does it use
signalled by distant multicellular organisms
| Uses hormones
461
what does the parasympathetic nervous system release to slow HR
Acetlycholine
462
what does the sympathetic nervous system release to increase HR
norepinephrine
463
what is starlings law/ frank starling mechanisms
as SV increases so does venous return
464
talk about the ability to sustain a contraction for smooth muscle, skeletal muscle & cardiac muscle
```
skeletal = shortest duration
cardiac = middle duration
smooth = longest, can sustain contraction for long periods of time without fatigue
```
465
does smooth muscle have troponin
no therefore actin binding sites always available
