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KNES 323 > Final (after midterm) > Flashcards

Final (after midterm) Flashcards

1
Q

How are the majority of oxygen molecules transported in the body?

A

by hemoglobin of the erythrocytes

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2
Q

How is the rest of oxygen transported

A

Dissolved in blood and transported directly in bloodstream

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3
Q

Describe the structure of hemoglobin

A
  • 4 subunits
  • Forms quaternary protein structure
  • Each subunit is arranged in a ring like shape with iron atoms bound to the heme in the centre of the subunit
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4
Q

what is oxyhemoglobin

A

When oxygen binds to hemoglobin

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5
Q

Why can oxygen be more quickly picked up and dropped off once O2 molecules bind to the hemoglobin

A

conformational change

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6
Q

What is conformational change

A

Change in shape of macromolecule often induced by environmental factors

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7
Q

what is Heme

A

Portion of hemoglobin that contains iron and binds O2

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8
Q

What happens after the first O2 molecule is dropped off

A

the next O2 molecule dissociates more readily helping facilitate internal respiration

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9
Q

What happens when all 4 heme sites are occupied

A

hemoglobin is saturated 100%

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10
Q

What happens when 1-3 heme sites are occupied

A

the hemoglobin is partially saturated

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11
Q

Hemoglobin saturation level

A

refers to the percent of the available heme units bound to O2 at any given time

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12
Q

Oxygen hemoglobin dissociation curve

A

graph describing the relationship of partial pressure to the binding of O2 to heme and its subsequent dissociation from heme

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13
Q

Key points of O2-Hb Dissociation Curve

A
  • gases diffuse from higher to lower partial pressures

- affinity of an O2 molecule for heme increases as more O2 molecules are bound

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14
Q

What happens as the O2 increases in O2-Hb Dissociation curve

A

there is a greater number of O2 bound to heme

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15
Q

Partial pressure of O2 inside arteries vs inside veins

A

Arteries: 100 mmHg
Veins: 40 mmHg

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16
Q

Highly active tissues vs Less active tissues

A

High: lower partial pressure
Less: higher partial pressure

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17
Q

what causes hemoglobin and O2 to dissociate faster?

A

Higher temperature

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18
Q

Low temperature inhibits

A

Dissociation

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19
Q

Highly active tissues release..

A

A large amount of heat

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20
Q

Highly active tissues increase

A

the ability for O2 to dissociates from hemoglobin which helps provide active tissues with more O2

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21
Q

What hormones affect the O2-Hb curve

A

Androgens
Epinephrine
Thyroid
Growth hormone

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22
Q

How do hormones affect the O2-Hb curve

A

stimulates the production of 2,3- diphosphoglycerate (DPG) by erythrocytes

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23
Q

What is a byproduct of glycolysis

A

Diphosphoglycerate (DPG)

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24
Q

Elevated DPG promotes

A

dissociation of O2 from hemoglobin

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25
Q

What factors influence the O2-Hb curve

A

Partial pressure
Temperature
Hormones
Blood pH

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26
Q

what is the Bohr effect?

A

phenomenon that arises from the relationship between pH and O2’s affinity from hemoglobin

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27
Q

How does acidic blood affect the O2-Hb curve

A

promotes O2 dissociation from hemoglobin

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28
Q

How does high pH affect the O2-Hb curve

A

inhibits O2 dissociation from hemoglobin

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29
Q

Left shift of O2-Hb curve

A

increased affinity for O2

decrease everything else

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30
Q

Right shift for O2-Hb curve

A

Decreased affinity for O2

increase everything else except pH decreases

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31
Q

3 ways Co2 is transported

A
  1. in form of bicarbonate
  2. blood plasma as some Co2 molecules dissolved in the blood
  3. bound to hemoglobin on erythrocytes
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32
Q

Majority of the CO2 molecules are transported in the form of

A

Bicarbonate

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33
Q

Where is bicarbonate produced

A

Erythrocytes after CO2 diffuses into the capillaries

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34
Q

Carbonic anhydrase causes

A

CO2 and H2O to form carbonic acid

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35
Q

Carbonic acid dissociates into what?

A

Bicarbonate and Hydrogen

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36
Q

H3O builds up in

A

the erythrocytes

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37
Q

Chloride shift phenomenon

A

HCO3 leaves erythrocytes and moves down its concentration gradient into the plasma to exchange for Cl ions

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38
Q

How does chloride shift occur

A

Exchanging one negative ion for another negative ion

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39
Q

What occurs at the pulmonary capillaries?

A

the chemical reaction that produced HCO3 is reversed and CO2 and H2O are products

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40
Q

What forms Carbonic acid

A

H and HCO3

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41
Q

Dissolved CO2 route

A

travels from the tissues to the bloodstream to the pulmonary capillaries and is diffused across the respiratory membrane into the alveoli and is exhaled through pulmonary ventilation

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42
Q

Urinary systems vital roles in maintaining homeostasis

A
  • cleansing the blood
  • regulation of pH
  • regulation of bp
  • regulating the concentration of solutes in the blood
  • determined the concentration of RBC
  • Concerts calcidiol to calcitriol (last step in vitamin D activation
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43
Q

Final synthesis step in vitamin D activation

A

Concert calcidiol to calcitriol

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44
Q

What symptoms might someone experience if the kidneys fail?

A 
weakness
lethargy
shortness of breath
anemia
widespread edema
Metabolic acidosis 
rising potassium levels 
heart arrhythmias
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45
Q

Incontinence

A

failure of nervous control or the anatomical structures leading to a loss of control of urination

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46
Q

4 types of Incontinence

A
  1. Stress
  2. Urge
  3. Overflow
  4. Neurogenic
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47
Q

Kidney is a regulator of

A

Plasma

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48
Q

Kidneys receive how much of resting cardiac output?

A

20-25%

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49
Q

Adrenal gland is located where

A

superior aspect of kidney

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50
Q

What is the responsibility of the adrenal cortex

A

influence renal function through the production of the hormone aldosterone

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51
Q

What is the role of Aldosterone?

A

stimulate sodium reabsorption

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52
Q

what does the adrenal medulla release?

A

catecholamines (epinephrine and norepinephrine)

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53
Q

Renal colums are

A

Connective tissue extensions that radiate downward from the cortex through the medulla to separate the renal pyramids

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54
Q

Renal pyramids are

A

bundles of collecting ducts that transport urine from the nephrons to the calyces of the kidney for excretion

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55
Q

What structure divides the kidney into 6-8 lobes?

A

Renal columns

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56
Q

Renal pyramids and columns together constitute…

A

Kidney lobes

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57
Q

Renal hilum

A

entry site for structures servicing the kidneys

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58
Q

what emerges from the hilum?

A

renal pelvis

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59
Q

What 2 structures form the renal pyramid

A

Major and minor calyxes

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60
Q

renal arteries vs renal veins

A

arteries: from descending aorta
Veins: return cleansed blood to the inferior vena cava

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61
Q

Nephrons

A

Functional units of the kidney responsible for cleansing the blood and balancing the contents of the circulatory system

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62
Q

Afferent arterioles supply blood through

A

high pressure glomerulus capsule

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63
Q

Bowman’s capsule

A

continuous sophisticated tubule whose proximal end surrounds the glomerulus and receives the filtrate

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64
Q

What two structures form the renal corpuscle?

A

Glomerulus and Bowman’s capsule

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65
Q

Blood flow through kidneys

A 
Renal artery 
segmental arteries
interlobular arteries
Arcuate arteries
Interlobular arteries
Afferent arterioles
Glomerulus 
Efferent arterioles
Peritubular capillaries 
Interlobular veins
Arcuate veins
interlobar vein
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66
Q

What is found in the renal corpuscles

A

proximal convoluted tubules and distal convoluted tubules

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67
Q

Cortical nephrons

A

short loop of Henle that barely dips beyond the cortex

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68
Q

Juxtamedullary nephrons

A

long loops of henle extending deep into the medulla

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69
Q

Principal task of the nephron

A

balance the plasma to hemostatic set points and excrete potential toxins in the urine

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70
Q

3 principle functions of nephron

A
  1. Filtration
  2. Reabsorption
  3. Secretion
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71
Q

Tubules

A

Get rid of toxins

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72
Q

Control of nephron in 3 areas

A
  1. maintain bp
  2. aid in RBC production
  3. Assist in calcium absorption
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73
Q

What is the projection in Bowman’s capsule

A

Filtration slits

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74
Q

Filtration slits

A

small gaps between the digits basically forming a strainer for the blood

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75
Q

fenestrations permit and prevent

A

Permit very rapid movement of filtrate from the capillary to the Bowman’s capsule
Prevent filtration of blood cells or large proteins

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76
Q

Substances pass freely at what size

A

4-8nm

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77
Q

Factors that affect the ability of substance to cross the barrier

A
  1. Size

2. Electric charge

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78
Q

Filtrate does not contain ____ or ________ and has a slight predominance of ____ charged substances

A

RBC’s or large proteins

Positively

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79
Q

Proximal convoluted tubule is formed by

A

simple cuboidal cells with prominent microvilli on luminal surface

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80
Q

What is the most essentially function of the proximal convoluted tubule?

A

microvilli create a large surface area to maximize the reabsorption and secretion of solutes

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81
Q

Descending vs ascending loop of henle

A

Descending: initial short thick portion and long thin portion
Ascending: initial short thin portion and long thick portion

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82
Q

Thick portion of loop consist of

A

simple cubiodal epithelium

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83
Q

Thin portion of loop consist of

A

simple squamous eppithelium

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84
Q

Distal convoluted tubule is formed by

A

simple cuboidal epithelium

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85
Q

differences in distal and proximal convoluted tubule

A

distal is shorter and less active in absorption/secretion fewer microvilli and no brush border

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86
Q

Juxtaglomerular apparatus

A

juncture just outside Bowman’s capsule

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87
Q

What happens at the Juxtaglomerular apparatus

A

afferent and efferent arterioles enter and leave Bowman’s capsule

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88
Q

Macula densa and juxtaglomerular cells together

A

monitor the composition and rate of fluid flowing through the distal convoluted tubule

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89
Q

Mascula densa releases

A

Paracrine signlas

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90
Q

Juxtaglomerular cell

A

a modified smooth muscle cell lining the afferent arteriole that can contract or relax in response to ATP or adenosine

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91
Q

Paracrine signals consist of

A

ATP and adenosine

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92
Q

What happens if the osmolarity of the filtrate is too high

A

filtration and urine formation decrease and water is retained

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93
Q

What happens if the osmolarity of filtrate is too low

A

filtration and urine formation increase and water is lost by way of the urine

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94
Q

Active renin

A

Protein which cleaves several amino acids from angiotensinogen to produce angiotensin I

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95
Q

Angiotensin II

A

Systemic vasoconstrictor in turn increases blood pressure and stimulates the release of aldosterone from adrenal cortex

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96
Q

What does aldosterone stimulate?

A

Na reabsorption by the kidney which also results in water retention and increased blood pressure

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97
Q

Natriuretic hormones

A

Peptides that stimulate kidney to excrete Na

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98
Q

What do Natriuretic hormones inhibit

A

aldosterone release
Na recovery
ADH release

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99
Q

Collecting ducts are lined with

A

simple squamous epithelium with receptors for ADH

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100
Q

Aquaporin channel proteins

A

allow water to readily pass from the duct lumen through the cells and into the interstitial spaces to be recovered by the vasa recta

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101
Q

Absence of ADH

A

water is excreted in the form of dilute urine

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102
Q

Glomerular filtration rate

A

Volume of filtrate formed by both kidneys per minute

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103
Q

At rest the heart pumps

A

~5 litres of blood/minute

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104
Q

How much blood enters the kidneys to be filtered

A

1 litre (20%)

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105
Q

Filtrate volume in men and women

A

Men: ~180 litres/day
Women: ~150litres/day

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106
Q

What percent of filtrate is returned to circulation by reabsorption. How much urine will be produced/day

A

95% of filtrate

~1-2 Litres of urine

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107
Q

Glomerular filtration rate is influenced by the

A

Hydrostatic pressure and colloid osmotic pressure

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108
Q

Particle movement in filtration is constrained by

A

Particle size

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109
Q

Hydrostatic pressure

A

pressure produced by fluid against a surface

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110
Q

What occurs if you have fluid on both sides of a barrier

A

both fluids exert a pressure in opposing directions

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111
Q

Net fluid movement is in what direction

A

Direction of the lower pressure

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112
Q

Osmosis

A

movement of solvent across a membrane that is impermeable to solute

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113
Q

Osmotic pressure exists until

A

the solute concentration s the same on both sides of a semipermeable membrane

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114
Q

water will be pulled

A

to the higher solute concentration

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115
Q

Glomerular filtration occurs when

A

glomerular hydrostatic pressure exceeds the pressure of Bowman’s capsule

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116
Q

Blood colloid osmotic pressure is higher

A

in the glomerular capillary

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117
Q

osmotic pressure is higher

A

in the glomerular capillary (30 mmHg) rather than the bowman’s capsule

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118
Q

Absence of proteins in the lumen result in

A

osmotic pressure in the capsule to be near zero

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119
Q

what is the only pressure moving fluid across the capillary wall into the lumen of Bowman’s space

A

hydrostatic pressure

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120
Q

What works agaisnt the hydrostatic pressure

A

capsular pressure and osmotic

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121
Q

Net filtration pressure

A

~10 mmHg

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122
Q

To cope with narrow range of filtration pressures the kidney employs

A

auto-regulatory processes

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123
Q

A blood pressure goes up smooth muscle afferent arterioles ____ while efferent arterioles slightly ____

A

contracts, dilate

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124
Q

net result of the autoregulatory system

A

relatively steady flow of blood into the glomerulus and a relatively steady filtration rate over a wide range of alterations to systemic blood pressure

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125
Q

When blood pressure falls below 60 mmHg

A

renal function is impaired and can cause systemic disorders that are severe enough to threaten survival

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126
Q

Reduction of stimulation results in

A

vasodilation and increased blood flow through the kidneys during resting conditions

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127
Q

Sympathetic stimulation increases

A

vasoconstriction resulting in diminished glomerular flow which produces less filtrate

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128
Q

Renin is released when

A

blood pressure falls too much

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129
Q

Angiotensin II stimulates

A

aldosterone production to augment blood volume through retention of more Na and water

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130
Q

4 main structures responsible for recovery

A
  1. Proximal convoluted tubule
  2. Loop of Henle
  3. Distal convoluted tubule
  4. Collecting ducts
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131
Q

Reabsorption/ Secretion steps

A
  1. Plasma volume entering afferent arteriole = 100%
  2. 20% of volume filters
  3. > 19% of fluid is reabsorbed
  4. > 99% of plasma entering the kidney returns to systemic circulation
  5. <1% of volume is excreted to external environment
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132
Q

Glomerular corpuscle main function

A

filters blood to create a filtrate mainly void of cells and large proteins

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133
Q

When the filtrate enters the PCT

A

it undergoes modification through secretion and reabsorption before true urine is produced

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134
Q

Where is majority of the water in filtrate recovered

A

PCT
Loop of Henle
DCT

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135
Q

How much of filtrate reaches the collecting ducts

A

~10%

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136
Q

Proximal convoluted tubule recovers

A

majority of Na, K, glucose, amino acids and other organic substances

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137
Q

The amount of water absorbed or lost is directly regulated by _______ _______ and indirectly by ______

A

Directly: anti-diuretic hormone (water) and aldosterone (sodium)
Indirectly: renin

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138
Q

Collecting ducts are heavily influenced by

A

ADH and regulate column of water reabsorbed

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139
Q

If plasma osmolarity rises

A

more water is recovered and urine volume decreases (dehydrated)

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140
Q

If plasma osmolarity decreases

A

Less water is recovered and ruin volume increases (well-hydrated)

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141
Q

Aldosterone is secreted by ____ in response to

A

adrenal cortex

angiotensin II stimualtion

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142
Q

Aldosterone stimulates

A

principal cells to manufacture luminal Na and K channels

ATPase pumps on the basal membrane of the cells

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143
Q

Antagonist for Aldosterone

A

Atrionatriuretic peptide (ANP)

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144
Q

ANP promotes

A

excretion of salt and water from the body

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145
Q

ANP is released

A

if atrial pressures are high

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146
Q

Obligatory water reabsorption

A

Water flows passively to maintain an isotonic fluid environment inside the capillary

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147
Q

Facultative wate reabsorption occurs in

A

the collecting ducts through the activation (and inactivation) of aquaporins

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148
Q

Apical surface

A

one facing the lumen or open space of a cavity or tube

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149
Q

Basal surface

A

faces the connective tissue base to which the cell attaches if the cell membrane closer to the basement membrane if there is a stratified layer of cells

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150
Q

Symport vs Antiport mechanism

A

Symport: two ions are transported in the same direction across the membrane
Antiport: two ions are transported in opposite directions across the membrane

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151
Q

Recovery of bicarbonate

A

In the lumen of the PCT combines with H+ to form carbonic acid
Enzymatically catalyzed into Co2 and water which then diffuses across the apical membrane into the cell

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152
Q

2 sections of the Loop of Henle

A

Thick and thin descending section

Thin and thick ascending section

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153
Q

Cortical vs Juxtamedullary nephrons

A

Cortical: do not extend far into the medulla
Juxta: loops that extend variable distances some very deep into the medulla

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154
Q

As the filtrate moves through the loop the osmolarity changes from ___ in the cortical to ______ at the bottom of the loop

A

isosmotic with blood

Very hypertonic solution

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155
Q

Ascending loop made of

A

cuboidal epithelium and is impermeable to water

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156
Q

Hypotonic filtrate

A

removing Na from the filtrate and retaining water

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157
Q

additional Na in the interstitial space contributes to

A

Hyperosmotic medulla

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158
Q

Counter current

A

Descending and ascending loops are next to each other and fluid flows in opposite direction

159
Q

Blood flows slowly in the vasa recta particularly for 3 reasons

A
  1. Maintenance of the countercurrent multiplier system
  2. Allows blood cells to lose and regain water without crenating or bursting
  3. A rapid flow would remove too much Na and urea in turn destroying osmolar gradient
160
Q

How does urine pass through the ureter?

A

propelled by waves of peristalsis to drain into the bladder

161
Q

Physiological sphincter

A

One way valve that allows urine to enter the bladder and prevent reflux of the urine from the bladder back into the ureter

162
Q

Urinary bladder

A

collects urine from both ureters

made up of detrusor muscle

163
Q

Detrusor muscle

A

irregular cross crossing bands of smooth muscle

164
Q

Interior surface of Urinairy bladder is made of

A

Transitional epithelium structurally suited for the large volume fluctuations of the bladder

165
Q

Micturation

A

voluntary control of urination that relies on consciously preventing relaxation of the external urethral sphincter to maintain urinary continence

166
Q

Normal micturition

A

result of stretch receptors in the bladder wall that transmit nerve impulses to the sacral region of the spinal cord to generate spinal reflex

167
Q

Parasympathetic neural outflow

A

causes contraction of the detrusors muscle and relaxation of the involuntary internal urethral sphincter

168
Q

Voiding

A

regulated voluntary skeletal muscle of the external urinary sphincter

169
Q

Why do women have a higher instances of UTIs?

A

They have much shorter urethra which is less of a barrier to fecal bacteria than males who possess a much longer urethra

170
Q

What is the minimum amount of urine that they kidneys must produce per day to rid the bod of wastes?

A

500mL/day

171
Q

Virtual absence of urine production

A

Anuria

172
Q

Excessive urine production

A

Polyuria

173
Q

Oligouria

A

Output below minimum urine production caused by severe dehydration or renal disease

174
Q

Ph of urine is often between values of

A

low of 4.5 to a high 8

175
Q

Specific gravity

A

measure of urine weight vs pure water weight

used as an indication of osmolarity

176
Q

UTI

A

presence of leukocytes in the urine

177
Q

Protein found in the urine indicates

A

damage to the glomerulus allowing protein to “leak” into filtrate

178
Q

what are Ketones and if in the urine what does this indicate

A

Byproduct of fat metabolism
Indicate that the body is using fat as an energy source as compared to glucose
Deficiency of carbs or proteins or Diabetes

179
Q

Where in the body does ammonia come from and how is it excreted

A

When proteins are broken down their nitrogen groups are removed
Rapidly converted to urea in the liver and transported to kidneys for excretion

180
Q

How are calcium and vitamin D related in the body?

A

When vitamin D is absorbed it must be activated, causing OH group to be added to calcidiol to form calitrol which increases absorption of Ca2+ in the digestive tract

181
Q

Not enough Ca2+ leads to

A 
Osteoporosis
Rickets
Problems with cell proliferation 
Neuromuscular function 
Blood clotting 
Inflammatory respinse
182
Q

What organs produce EPO

A

Kidney - 85%

Liver

183
Q

Consequence of kidney failure related to RBC could be

A

Anemia due to loss of EPO production

184
Q

Consequences of kidney failure related to vascular volume

A

High or low blood pressure
Stroke
Heart attack
Aneurysm

185
Q

Loss of glucose control could cause ___ in the kidneys

A

Osmotic dieresis

186
Q

Water makes up how much of the body mass

A

infants: 75%
Adult women: 55%
Adult men: 60%
Older adults: 45-50%

187
Q

What is intracellular fluid composed of?

A

all fluids enclosed in cells by their plasma membranes

188
Q

Extracellular fluid is composed of

A

Fluid that surrounds all cells in the body and consists of interstitial fluid and blood plasma

189
Q

Majority of extracellular fluid is

A

Interstitial fluid

190
Q

Blood plasma and extracellular fluid contains high concentrations of

A

Na and Cl

191
Q

Intracellular fluid contains high concentrations of

A

K+ and HPO4(2-)

192
Q

How much water is generated metabolically?

A

300mL

193
Q

How much water do we typically ingest and lose in a day?

A

2.5L

194
Q

What organ provides the greatest regulation to homeostatic fluid levels

A

Kidneys

195
Q

Plasma osmolarity

A

Sensory receptors in the thirst centre of the hypothalamus that monitor concentration of solutes of the blood

196
Q

Kidneys ____ water but cannot ___

A

Conserve

Replace

197
Q

What happens when there is a decreased blood pressure due to lowered blood volume?

A

Baroreceptors in aorta and carotid arteries detect decreases in BP that results from lowered BV
Heart is signals to increase rate and strength of contractions to compensate
Blood vessels constrict

198
Q

Second step when there is decreased blood pressure due to lowered blood volume

A

Kidneys activate renin-angiotensin hormonal system
Angiotensin II stimulates thirst and the release of aldosterone from adrenal glands
Aldosterone increase Na+ absorption in distal tubules

199
Q

Role of ADH in fluid balance

A

increases aquaporin numbers in collecting ducts to allow more water to be absorbed

200
Q

7 most important electrolytes in terms of body functioning

A
  1. Sodium
  2. Potassium
  3. Chloride
  4. Calcium
  5. Phosphate
  6. Magnesium
  7. Bicarbonate
201
Q

Highest levels of sodium are found where

A

in the extracellular fluid

202
Q

what happens if there is an increase in salt intake but not fluid

A

Thirst response stimulated by the body to increase water

Vasopressin is secreted to increase renal absorption

203
Q

Highest levels of potassium are found in

A

Intracellular fluid

204
Q

Highest levels of potassium are found in

A

Intracellular fluid

205
Q

Major extracellular anion

A

Chloride

206
Q

Role of chloride in electrolyte balance

A

Major contributor to osmotic pressure gradient between ICF and ECF
Maintain electrical neutrality of ECF

207
Q

_____ & ______ are reabsorbed from the renal filtrate.

______ is excreted into the renal filtrate

A

Sodium and chloride

Potassium

208
Q

Signal transmission at a chemical synapse

A
  1. Action potential travels to synaptic end of presynaptic neuron
  2. Triggers calcium channels to open
  3. Calcium influx causes synaptic vesicles to release their neurotransmitter into synaptic cleft through exocytosis
  4. Neurotransmitters travel across cleft abd bind to receptors on postsynaptic neuron
  5. Ligand gated channels open, causing either inhibition or excitation
209
Q

Calcium role in intracellular fluids

A

Weak base to buffer

210
Q

Where is magnesium found?

A

Bone matrix

211
Q

Role of Magnesium in the body

A

activates several enzyme systems needed for metabolism of carbs and proteins

212
Q

Buffer

A

substance that minimizes changes in pH by dampening hydrogen ion concentrations

213
Q

3 buffer systems

A
  1. Phosphate
  2. Proteins
  3. Bicarbonate-carbonic acid buffers
214
Q

Phosphate buffer system is used in.

A

intracellular fluid and urine from kidneys

215
Q

What occurs in the phosphate buffer system

A

Monohydrogen phosphate ions act as a weak base and dihydrogen phosphate ions act as a weak acid

216
Q

Protein buffer system

A

Protein molecules act as both a weak acid and base

Working across the whole body

217
Q

What is the most important protein buffer?

A

Hemoglobin

218
Q

How does hemoglobin works to regulate pH

A

Co2 diffuses into RBC and combines with water to form carbonic acid which dissociates into bicarbonate and hydrogen ions
Bicarbonate diffuses into the blood and is replaced with Cl ions in RBC
Hydrogen ions are buffered by Hb molecules

219
Q

More bicarbonate or carbonic acid in the blood? Why?

A

Bicarbonate because many of our metabolic wastes are acids so we need the weak base to offset this

220
Q

How does breathing regulate pH

A

When holding our breath our Co2 levels rise
Co2 combined with water to form carbonic acid lowers pH
When we hyperventilate or normally breath excess Co2 becomes expired increasing pH

221
Q

Increased breathing at rest leads to

A

decrease in Co2, and increase in blood pH

222
Q

Decreased breathing at rest leads to an

A

increase in CO2 and decrease in blood pH

223
Q

Major side effect of acidosis

A

Depression of the central nervous system

224
Q

Major effect of alkalosis

A

Over-excitability of the central and peripheral nervous system

225
Q

Respiratory acidosis, respiratory alkalosis, metabolic acidosis and metabolic alkalosis

A

Resp. aci: increased PaCO2
Resp. alka: decreased PaCO2
Met. acido: decrease HCO3
Met. alka: increased HCO3

226
Q

ROME

A

Respiratory
Opposite
Metabolic Equal

227
Q

Functions of muscular tissue?

A 
producing body movements
stabilizing body positions
Storing and mobilizing substances within the body
Generating heat 
Supporting soft tissue
Guarding entrances and exits
228
Q

Properties of muscular tissue

A

electrical excitability
Contractility
Extensibility
Elasticity

229
Q

Contractility of the muscle

A

stimulated muscles cells shorten or contract through sliding filament theory

230
Q

Extensibility of muscle

A

Capacity to stretch to the normal resting length after contracting

231
Q

Spasticity

A

Lack of extensibility

232
Q

elasticity of the muscle

A

ability to recoil or bounce back to the muscles original length after being stretched

233
Q

3 types of muscular tissues

A
  1. cardiac
  2. smooth
  3. skeletal
234
Q

Characteristics of cardiac muscle

A

short branching cells with single nucleus and light striations
Joined via intercalated discs
have gap junctions to allow communication
involuntary control

235
Q

Characteristics of smooth muscle

A 
Long cells containing a single nucleus 
Cylindrical shape with tapered end 
No striations
Involuntary control
takes the longest to contract
236
Q

Characteristics of skeletal muscle

A

Long and multi nucleated
Cylindrical shape and heavily striated
Voluntary control
Arranged in bundle of contractile filaments

237
Q

Characteristics of oxidative muscle fibres

A

appear dark red
generate ATP through aerobic respiration
High concentrations of mitochondria and capillaries
Slow velocity of twitch contractions
very fatigue resistant

238
Q

Characteristics of glycolytic muscle fibres

A

Appear lighter
mainly generate ATP through glycolysis
Low concentrations of mitochondria and capillaries
faster twitch contraction velocities
Fatigue rapidly but are good for short duration explosive movements

239
Q

Characteristics of Oxidative-glycolytic fibres

A

appear red-pink in colour
Generate ATP through both aerobic and anaerobic glycolysis
High concentrations of mitochondria and capillaries
Moderate velocity and power twitch contractions
fairly fatigue resistant and are good for sustained speed events

240
Q

The force developed by the whole muscle is dependent on

A

the recruitment pattern and proportion of fibre types present in the muscle

241
Q

Sarcolemma

A

The cell membrane of the muscle fibres which is covered with transverse tubules

242
Q

Transverse Tubules

A

Contain interstitial fluid and facilities rapid conduction of action potentials

243
Q

Sarcoplasm

A

Cytoplasm within the muscle cells which contains large quantities of glycogen and myoglobin

244
Q

Mitochondria

A

The powerhouse of the cell where ATP is created

245
Q

Sarcoplasmic Reticulum

A

Contains the calcium required for trigger a muscular contraction

246
Q

Myofibril

A

The contractile organelles of the muscle cell

247
Q

Thin vs Thick filaments

A

Thin: 8nm diameter and 1-2 um in length
Thick: 16nm diameter and 1-2um in length

248
Q

Anatomy of a sarcomere

A

Z disc: separates one sarcomere from another
A band: dark middle part of the sarcomere where the actin and myosin overlap
I band: Lighter band which only consists of the thin Actin filaments
H zone:Narrow region in the centre of each A band which only consists of the thick Myosin filaments
M line: Region in the centre of the H zone containing proteins to hold the myosin filaments together at the centre f the sarcomere

249
Q

Myofibrils built from three main types of proteins

A
  1. Contractile proteins: generate force during contraction
  2. Regulatory Proteins: switch contractions on/off
  3. Structural proteins: maintain alignment of thick and thin filaments, give myofibrils their elasticity and link myofibrils to sarcolemma and extra cellular matrix
250
Q

What are the two contractile proteins in skeletal myofibrils

A

Actina and myosin

251
Q

Actin vs Myosin

A

Actin: main protein for thin filament
Myosin: main protein for thick filament

252
Q

Myosin heads are responsible for

A

grabbing and pulling the actin filament past itself during cross bridging

253
Q

What are the two binding sites of myosin heads

A

ATP and Actin

254
Q

What proteins control access to myosin binding sites

A

Tropomyosin and troponin

255
Q

Tropomyosin

A

When muscles are relaxed the myosin binding sites on actin are covered by the tropomyosin filament

256
Q

Troponin

A

Is the gatekeeper that controls when tropomyosin will open the myosin binding sites

257
Q

Tintin

A

Forms elastic filaments around myosin linking them to the M line and Z discs
Elasticity and extensibility

258
Q

Nebulin

A

Wraps around the actin filament and helps anchor them to the Z discs
Regulates length of actin filaments during development

259
Q

Alpha Actinin

A

Structure component of Z discs and enables actin and titin to bind

260
Q

Myomesin

A

Structural component which forms the M line of the sarcomere
Binds to titin and enables adjacent myosin filaments to bind

261
Q

Dystrophin

A

Binds the thin filaments to the integral membrane proteins in the sarcolemma
Reinforces the sarcolemma and aids in force transmission to the tendons

262
Q

Somatic motor neuron

A

Neuron transmitting the efferent signal from the brain to the muscle fibre

263
Q

Synapse between the motor neuron and sarcolemma occurs at ________ and inititates ______

A

motor end plate

Propagation of a muscle action potential

264
Q

Muscle action potential at the NMJ steps

A
  1. voltage gated calcium channels open causing an influx of calcium
  2. Acetylcholine binds to ligand-gated Na channels on the motor endplate causing an influx of Na into the muscle
  3. Depolarizes the muscle and results in Ca release from the sarcoplasmic reticulum
  4. Acetylcholine is rapidly broken down by acetylcholinesterase of Ca from the sarcoplasmic reticulum
265
Q

Sliding filament theory

A
  1. Myosin cross bridges pull on actin filaments
  2. Actin filaments slide inwards toward the H zone
  3. X discs come toward each other and the sarcomere shortens
  4. Causes the shortening of the whole muscle fibre and ultimately the entire muscle
266
Q

Contraction cycle

A
  1. Myosin head hydrolyzes previously bound ATP and is orientated to the Actin filament
  2. Myosin head binds to actin to form cross bridge
  3. Myosin head pivots pulling the actin filament towards the centre of the sarcomere (power stroke)
  4. ATP binds to the myosin head detaching from the actin cross bridge
267
Q

What happens with calcium ions when action potential isn’t present

A

Calcium ions concentrations are maintained in the sarcoplasmic reticulum

268
Q

What happens to tropinin and tropomyosin without calcium ions

A

tropinin stays inactive and tropomyosin doesn’t move to open the myosin binding sites on the actin filament

269
Q

What happens with calcium when action potential is present

A

calcium ions are rapidly released from the sarcoplasmic reticulum

270
Q

Isotonic vs Isometric

A

Isotonic: tension is constant while muscle length changes
Isometric: muscle contracts but does not change length

271
Q

Concentric vs Eccentric

A

Concentric: angle of the joint decreases
Eccentric: angle of the joint increases

272
Q

Schematic of the series elastic elements

A
  1. Muscle at rest
  2. Isometric contraction
  3. Isotonic contraction
273
Q

Isotonic shortening phase

A

Cross bridges are visible in skeletal muscle length

Tension is constant

274
Q

Tone

A

established by the alternating involuntary activation of small groups of motor units in a muscle
Keeps the muscle firm even when relaxed
Only maintain form and do not produce movement

275
Q

The strength of the muscle contraction depends on

A

How many motor units are activated

276
Q

Motor unit recruitment

A

increasing the number of active motor units

Weakest first

277
Q

Fewer muscle fibres per motor unit prodcues what kind of movements

A

Precise and delicate

278
Q

Larger number of muscle fibers per motor unit produce what kind of movements?

A

Powerful and coarsely controlled

279
Q

Latent period

A

delay between the arrival of AP and the initiation of contraction

280
Q

Contraction period

A

Ca2+ binds to troponin and the actin-myosin cross bridges are formed

281
Q

Relaxation period

A

Ca2+ is actively pumped back into the SR and myosin heads detach from actin and muscle tension decreases

282
Q

Refractory period

A

Muscle tissue is unable to response to a subsequent AP

283
Q

Wave summation

A

occurs when a second action potential triggers muscle contraction before the first contraction has finished resulting in a stronger contraction because the muscle hasn’t reset

284
Q

Unfused (incomplete) vs Fused (complete) tetanus

A

Unfused: produced partial summation of individual twitches
Fused: produces full summation of individual twitches

285
Q

Passive length tension relationship

A

as the muscle is stretched beyond resting length it produces a force (non-contracting) due to the elastic components of the muscle and fascia

286
Q

Active length tension relationship

A

Force produced by contractile mechanism

287
Q

Optimum length; Length-tension relationship

A

maximum active force

288
Q

Active force of a muscle contraction depends on

A

the length of the sarcomeres in the muscle before contraction

289
Q

When is the number of active cross bridges the greatest in a muscle? If it was stretched beyond this what happens?

A

When it is at the optimum length

Number of active cross bridges decrease because the overlap between actin and myosin decrease

290
Q

What happens when the velocity of a concentric muscle action is increased?

A

less force is capable of being generated during that concentration

291
Q

What happens when the velocity of an eccentric muscle action is increased?

A

more force is capable of being generated during that contraction

292
Q

Force-velocity relationship and equation

A

Force production decreases as the velocity of the contraction increases
Power = Force x velocity

293
Q

How are improvements of maximal power output of a muscle achieved?

A

by increasing the maximal force we can move and/or increasing movement velocity

294
Q

The lighter the load the _____ we can move

A

faster

295
Q

Which muscle fibers are most likely going to be used for high force-velocity activities?

A

Tye 2a and 2b

296
Q

Pennation angle and force production relationship

A

As pennation angle increases, the max force generation increases at cost of velocity.
As pennation angle approaches 0, muscle fibers can produce less force but can do it more quickly

297
Q

Heavy strength training _______ pennation angle. Sprint training __________pennation angle

A

Increases

Decreases

298
Q

The electrical potential difference within muscles measured by EMG amplitude is a function of both:

A

muscle fiber recruitment and motor unit firing rates

299
Q

An increase in EMG activity during a prolonged contraction could be a result of additional recruitment. However, it could also be a result of:

A

Changes in peripheral factors, including an increase in intracellular action potentials as a result of altered calcium ion availability

300
Q

Two kinds of muscle fatigue

A

Peripheral and central

301
Q

What are some mechanisms of central fatigue?

A
  • psychological factors

- protective reflexes

302
Q

What are three areas in which peripheral fatigue might occur?

A
  • neuromuscular junction
  • excitation contraction coupling
  • Ca2+ signal
303
Q

What are some mechanisms for peripheral fatigue at the neuromuscular junction?

A
  • decreased neurotransmitter release

- lowered receptor activation

304
Q

What are some mechanisms for peripheral fatigue during excitation contraction coupling?

A

change in muscle membrane potential meaning that action potential can’t propagate as easily

305
Q

What are some mechanisms for peripheral fatigue during Ca2+ signalling?

A
  • sarcoplasmic reticulum has a calcium leak
  • lowered calcium release
  • lower calcium troponin interaction
306
Q

How do muscles produce ATP to power their contraction cycle?

A
  • creatine phosphate
  • fermentation
  • cellular respiration
307
Q

How does creatine phosphate work?

A

Catalyzes transfer of a phosphate group from creatine phosphate to ADP and rapidly yield ATP

308
Q

What are the characteristics of PCr?

A
  • does not require oxygen to be present

- provides peak power output for 10-15 seconds

309
Q

What is anaerobic glycolysis?

A

Reaction that converts blood glucose into pyruvic acid to generate ATP

310
Q

What are the characteristics of anaerobic glycolysis?

A
  • does not require oxygen to be present

- provides peak power output for 30-40 seconds and can be sustained at high levels for up to 2 minutes

311
Q

What is cellular respiration?

A

Pyruvic acid can enter mitochondria and undergo a series of oxygen requiring reactions to generate large amounts of ATP

312
Q

What are the characteristics of cellular respiration?

A
  • requires oxygen
  • requires more processing time
  • can be used for long haul activities
313
Q

Lactate

A

metabolic fuel source within the brain

314
Q

is a metabolic fuel source within the

A
  • elevated body temp
  • heart and lungs working harder
  • muscles used undergo tissue repair process
315
Q

What is the effect of endurance based activities on muscle fibers?

A
  • can induce changes in type 2x to become more like 2a
  • promotes increase capillary and mitochondrial density
  • improves neuromuscular connections, metabolism, and efficiency of respiratory muscles
316
Q

What is the effect of strength based activities on the muscle fibers?

A
  • induce changes in type 2x fibers and transition them more towards 2b
  • promotes increased capillary and mitochondrial density
  • improves bone density, metabolism, helps offset age related declines across the body
317
Q

Muscle spasm

A

sudden involuntary contraction of single muscle within a large group of muscles

318
Q

Muscle cramp

A

Involuntary and often painful muscle contractions. Caused by inadequate blood flow to muscles, overuse and injury, and abnormal blood electrolyte levels

319
Q

What type of muscle fibers cannot undergo mitosis

A

Mature skeletal

320
Q

How does muscle tissue grow?

A

Through hypertrophy or enlargement of already existing muscle cells

321
Q

Hyperplasia

A

increase number of muscle fibers

322
Q

What happens to our muscle tissue as we age?

A

It declines. Muscle strength and flexibility decreases, reflexes slow, and slow oxidative fiber numbers increase

323
Q

What are the main three forms of stretching?

A
  • static stretching
  • dynamic stretching
  • proprioceptive neuromuscular facilitation
324
Q

Static stretching _____ athletic performance?

A

decreases

325
Q

Dynamic stretching ______ performance

A

increases and decreases

326
Q

Proprioceptive neuromuscular facilitation _____ performance

A

decreases

327
Q

What happens to ROM when stretching is performed?

A

It improves across all styles of stretching

328
Q

Reductions in performance following stretching are though to be due to:

A
  • changes in tendon stiffness and the force-length relationship
  • contractile ‘fatigue’ or damage
  • diminished electromechanical coupling
  • reduced central drive
329
Q

The shape of cardiac cells enables:

A

greater sarcomere lengthening and shortening across cardiac cycle

330
Q

What is the role of intercalated discs in cardiac muscle?

A

Enable cardiac cells to have a strong attachment to one another and prevent separation during heart beats with desmosomes

331
Q

What is the role of gap junctions in cardiac muscle?

A

Allow muscle action potentials to spread from one muscle fiber to another

332
Q

What is different about cardiac muscle action potentials? Why?

A

Action potentials are slower. Helps to:

  • prevent tetanus
  • reduce fatigue
  • enable adequate filling time for the heart chambers
333
Q

______________ muscle cells have more mitochondria than skeletal muscle

A

cardiac muscle cells

334
Q

What law dictates that as you dive deeper and hydrostatic pressure increases, the volume of your lungs shrink?

A

Boyle’s law

335
Q

What are the three possible outcomes of excessive pressure on the lung and chest during apnea?

A
  1. Alveolar collapse
  2. Infiltration of liquid
  3. Disruption of the alveolar-capillary
336
Q

What is Henry’s Law?

A

At constant temperature, the amount of gas absorbed is proportional to the solubility coefficient of the particular gas and their partial pressure

337
Q

What might expanding air in the lung cause?

A
  • expanding air may cause pneumothorax
  • arterial gas embolisms occur when nitrogen bubbles are forced into bloodstream through alveoli, resulting in blockages of smaller vessels
  • cerebral arterial gas embolisms can also result
338
Q

What is decompression sickness?

A

Caused by nitrogen dissolved in tissues due to rapid decrease in pressure

339
Q

How can we decrease risk of arterial gas embolism?

A
  • avoidance of breath holding
  • avoidance of rapid ascent
  • not diving with pulmonary infections or disease
340
Q

Adding a snorkel increases what space in the lungs?

A

Dead space

341
Q

Instead of increasing snorkel length or volume, it would be more beneficial to increase:

A

tidal volume

342
Q

The deeper we go with a snorkel, the more challenging it is to breathe in. Why?

A

Because the pressure on the chest wall is increased, so it pushes against the lungs trying to expand.

343
Q

The mammalian diving response consists of what four behaviours?

A
  • apnea
  • bradycardia
  • peripheral vasoconstriction
  • splenic contraction
  • can also have blood pressure fluxes
344
Q

Mammalian diving response is triggered by what nerve?

A

trigeminal

345
Q

Apnea time during diving depends on:

A
  1. physiological response to hypercapnia and hypoxia
  2. intensity of metabolism
  3. capacities for O2 and CO2
  4. psychological tolerability to hypercapnia and hypoxia
346
Q

Describe the changes in cardiac rhythm during the mammalian diving response

A
  • There is an initial anticipatory tachycardia
  • When face is submerged, trigeminal nerve is triggered and there is increased parasympathetic input to SA node
  • arrhythmias can arise
347
Q

Describe the changes in artery constriction during the mammalian diving response

A
  • increase in sympathetic outflow to periphery, reducing blood flow to peripheral tissues and skin
  • anaerobic metabolism on periphery (lactate increases)
  • blood is centralized to brain and heart
  • 100% increase of cerebral flow through middle cerebral artery
348
Q

Describe the changes that take place in arterial pressure during the mammalian diving response

A
  • peripheral vasoconstriction increases total peripheral resistance and increases BP
  • involuntary breathing can also cause swings in BP
349
Q

Describe changes in cardiac output during mammalian diving response

A
  • haemodynamics at the onset of maximal breath hold after full inspiration can be compared to second phase of Valsalva
  • high lung volumes reduce ventricular filling and therefore cardiac output
350
Q

Describe the contraction of the spleen during mammalian diving response

A
  • spleen is significant reservoir of blood
  • contraction occurs during diving and exercise
  • increased adrenergic activity
351
Q

What is considered high altitude?

A

high altitude: 1500-3000m

  • very high altitude 3000-5000m
  • extreme altitude: above 5000m
  • ‘death zone’: above 8000m
352
Q

People exposed to high altitudes who are not adapted to them are at increased risk for:

A
  • acute mountain sickness
  • HAPE
  • HACE
  • chronic mountain sickness
353
Q

Normobaric hypoxia occurs when:

A
  • atmospheric pressure remains the same

- the fraction of inspired oxygen content has been reduced to levels below 17%

354
Q

Hypobaric hypoxia occurs when:

A
  • the fraction of inspired oxygen content has been unaltered (stays at 21%)
  • atmospheric pressure has been reduced
355
Q

What is barometric pressure?

A

measure of the pressure exerted by the weight of air above us

356
Q

As we ascent, barometric pressure

A

falls

357
Q

What is our first cardiovascular response to being at high altitude

A

Resting cardiac output increases via a rapid increase in heart rate

358
Q

When gaining altitude, the increase in cardiac output matches the decrease in ______________________

A

arterial oxygen content

359
Q

After a few days, how do cardiovascular responses change when we are at high altitude?

A

cardiac output returns to normal or slightly below. HR remains elevated by SV is decreased to compensate

360
Q

What mechanisms have been proposed for the drop is stroke volume and cardiac output at high altitude?

A
  • response to correct for respiratory alkalosis that arises from hypoxic ventilatory response
  • related to an activation of the sympathetic nervous system (increases in plasma catecholamines and muscle sympathetic nerve activity)
  • could improve coupling of the right ventricle to pulmonary circulation
  • an adaptive decrease in the oscillatory component of pulmonary arterial load
361
Q

Describe the changes in blood viscosity at altitude

A
  • increased blood viscosity
  • initially from dehydration due to water loss from increased ventilation and urine output
  • with a few weeks partial acclimatization, RBC production is increased via erythropoiesis
362
Q

What are some mechanisms to reduce plasma volume when we ascent to high altitude?

A
  • increased respiration rates
  • increased perspiration rates
  • increased urine output
  • decreased water intake
363
Q

Why would there be increases to pulmonary vascular resistance at high altititudes?

A
  • hypoxemia induces pulmonary vasoconstriction

- results in mild pulmonary hypertension

364
Q

Pulmonary vascular resistance increases the risk of what happening?

A

mild interstitial edema and incidence of HAPE

365
Q

What is the first respiratory response to occur when we are at high altitude?

A
  • hypoxemia induces increased ventilation (hyperventilation)
366
Q

Why do we see reduced A-a gradients at high altitude?

A
  • diffusion limitations
  • ventilation/perfusion mismatching
  • opening of shunts
367
Q

What are the diffusion limitations at high altitude?

A
  • there is lower driving pressure for oxygen to move from air to blood (steeper on the curve)
  • reduced oxygen saturation levels move arterial blood on steeper part of O2-Hb curve
  • this means it is harder to pick up oxygen, and harder to drop it off at the tissues as well
368
Q

What are the ventilation/perfusion mismatching issues at high altitude?

A
  • increased pulmonary artery vasoconstriction causes there to be increase in interstitial edema to develop
  • this decreases ability for oxygen to diffuse into pulmonary capillaries (has to diffuse across fluid)
369
Q

How does the opening of shunts contribute to the decrease in A-a gradients?

A
  • causes blood to bypass gas exchange locations
  • can occur as a result of intrapulmonary shunts
  • often a result of the opening up of small ducts present between the right and left atria (patent foramen ovale PFO)
370
Q

How does the opening of shunts contribute to the decrease in A-a gradients?

A
  • causes blood to bypass gas exchange locations
  • can occur as a result of intrapulmonary shunts
  • often a result of the opening up of small ducts present between the right and left atria (patent foramen ovale PFO)
371
Q

As cardiac output doesn’t change, the main driver for a-v gradient changes at high altitude is

A

increasing the oxygen carrying capacity in the blood

372
Q

Does hypoxia influence the creatinine phosphate ATP system? Why?

A

Research has shown no. Likely because oxygen respiration and fermentation do not contribute significantly to the energy necessary during such explosive short efforts

373
Q

A reduction in power output during explosive exercises at high output could be caused by:

A
  • motor command efficiency is decreased

- muscle wasting

374
Q

As we acclimatize to high altitude, glucose uptake by muscles ______________

A

increases

375
Q

What is produced in higher than normal amounts at high altitude during exercise? Is this always the case?

A

lactate. once acclimatized, the level of lactate produced for a given workload will be greatly reduced

376
Q

Lower production of lactate after acclimatization at altitude can be attributed to what?

A
  • alteration to epinephrine levels (decrease)
  • increased uptake of lactate by brain
  • loss of muscle mass
377
Q

What happens to VO2max as we gain altitude?

A

VO2max decreases about 1% per 100m elevation gain above 1500m.

378
Q

What are proposed methods for the reduction in VO2max at altitude?

A
  • alterations to lung function
  • decreased peak heart rate
  • alterations to central nervous system
379
Q

What role does the central nervous system play at high altitude during exercise?

A

When the somatosensory and motor cortex perceive a sense of effort and exercise is volitionally terminated when the sense of effort and other sensations like muscle pain become more intense than is tolerable

380
Q

What are some strategies for avoiding AMS?

A
  • ascend no more than 400m per day and after every 1000m gained, take an extra rest day
381
Q

AMS develops above heights of

A

2400m

382
Q

Objects in low Earth orbit are subjected to about ___________% of the Earth’s ground-level gravity

A

90

383
Q

What should be considered regarding radiation exposure in space?

A
  • on Earth, the atmosphere acts as a natural shield to a lot of the radiation that bombards the earth on a daily basis
  • astronauts are exposed to heavy ions and proton fluxes far more than those on earth
384
Q

What are some of the immediate cardiovascular changes we see in astronauts?

A
  • reduction in intrathoracic pressure through blood shifting towards head
  • head swells and legs get thinner
  • causes space motion sickness
  • imbalance in expected and actual sensory vestibular inputs which causes motion sickness
  • heart does not require as much contractility to pump blood to head, hence heart becomes atrophied
385
Q

Higher blood pressure in space is compensated for by what:

A

increased level of urine production and reduced thirst

386
Q

What happens to hematocrit levels of astronauts?

A

It increases

387
Q

What musculoskeletal changes do we see in space?

A
  • bone mineral loss

- muscle wasting

388
Q

Why would astronauts experience bone mineral loss?

A

due to microgravity environment, weight bearing bones like spine, neck, legs lose their density because they are no longer weight bearing

389
Q

Why would astronauts experience muscle wasting?

A
  • Antigravity muscles (supporting muscles) are not used to counter gravity and therefore begin to atrophy
  • skeletal muscle protein degradation
390
Q

what are the causes of concussions

A

direct blow to the head face neck or elsewhere on the body with an impulsive force transmitted to the head

391
Q

early management & treatment of concussion

A
  • remove from play
  • not left alone
    medically evaluated following the injury
  • Return to play should be medically advised
  • players should not return to play while symptomatic
392
Q

Children vs Adult concussions

A
  • adults recover faster than kids
  • children often present with different symptoms; more emotional and more cognitive based symptoms
  • adults have more physical symptoms
393
Q

What is a concussion

A

traumatic brain injury induced by biomedical forces

KNES 323 (2 decks)

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