L1- Homeostasis Flashcards

1
Q

what does homeo mean

A

sameness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what does stasis mean

A

standing still

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

definition of hoemostasis

A

the process by which cells, tissues and organisms maintains its parameters within a normal range of values

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what needs to be kept constant (8)

A
  • oxygen
  • carbon dioxide
  • salts
  • nutrients
  • pH
  • electrolytes
  • temp
  • volume and pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what maintain homeostasis

A

feedback loops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

negative feedback loops

A

stops when effector ceases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

examples of negative feedback loop

A

temperature control and glucose control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

when you are hot

A

1) vasodilation
2) sweating
3) pilorection
4) stretching out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

vasodilation

A

arterioles dilate so more blood enters skin capillaries and heat is lost

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

sweating

A

sudorific glands secrete sweat which removes heat when water changes state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

pilorelaxation

A

hair lies flat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

when you are cold

A

1) vasoconstriction
2) shivering
3) pilorection
4) curling up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

shivering increase body temp

A

rapid contraction and relaxing of skeletal muscles produces heat via respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

negative feedback loop of blood glucose control

A
  1. Eats meal and blood sugar goes up
  2. Pancreas produces insulin which acts on the liver and muscle cells to increase uptake of sugar from blood
  3. Glucose stored as glycogen or used by body (e.g. muscle cells)
  4. Blood sugar lowered
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

give three examples of a positive feedback loop

A
  • coagulation
  • sepsis
  • birth process- Ferguson relex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Ferguson reflex

A

baby head pressing on cervix causes it to stretch, Cervix nerves feedback got the pituitary which releases oxytocin.

Oxytocin causes the cervix to contract which stretches it even more etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

in simple positive feedback loops occur when

A

output enhances or exaggerates original stimulus- stops when the initiator ceases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Core body temperature

A

36.5- 37.5 degrees celsius

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

core temperature..

A

fluctuates throughout the day and shows circadian rhythm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

where should core temp be measured from

A

head and neck

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

where is body temp controlled

A

the hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

hypothermia temp

A

35

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

symptoms of mild hypothermia

A
  • shivering
  • fatigue
  • slurred speech
  • confusion
  • forgetfulness
  • muscle stiffness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

fever

A

37.5 - 40 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

fever symptoms

A

place sweaty skin, cramps in stomach arms and legs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

heat stroke

A

40 to 46

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

heat stroke symptoms

A

flushed dry skin, hot to touch, bounding pulse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

heat exhaustion

A

46+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

heat exhaustion symptoims

A

unconsciousness/ fitting/seizures, confused, headache, dizzy, uncomfortable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

severe hypothermia

A

26-32 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

severe hypothermia symptoms

A

shivering stops, muscle are right, very slow weak pulse

  • serve reduction in response level
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

no vital signs

A

below 28

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

with body temp remember

A

NOT DEAD UNTIL WARM AND DEAD

Warm patient up before declaring death

34
Q

normal pH

A

7.35 to 7.45- very narrow range which is safe

35
Q

organs responsible for acid use balance

A
  • lungs- respiratory

- kidneys- metabolic

36
Q

alkalosis

A

above 7.45

37
Q

acidosis

A

below 7.35

38
Q

death below

A

7 and above 7.8

39
Q

gastric acid pH can damage

A

oesophagus- causing oesophagitis

40
Q

if stomach loses mucus

A

acid can cause ulcers and perforation

41
Q

limit of tissue survival in terms of pH

A

6.8 to 7.7

42
Q

name some buffering systems of ICF

A
  • phosphate buffer system

- protein buffer systems (haemoglobin buffer system and amino acid buffers)

43
Q

what use haemoglobin buffer system

A

RBC

44
Q

buffer systems of ECF

A

carbonic acid0bicarbonate buffer system

45
Q

sodium phosphate buffering system used to

A

regulate intracellular pH

46
Q

carbonic acid

A

bicarbonate important in blood- uses RBC as an intermediary

47
Q

antacids and give an example

A

used to neutralise acids by virtue of their alkalinity and its insolubility
e.g. aluminium hydroxide

48
Q

how are pH and blood gases classified

A

using arterial blood gas test

49
Q

too much water is

A

toxic

- metabolic failure

50
Q

how much water do we need everyday

A

2.5 litres

51
Q

in men how much of body weight is made up of water

A

60% and in elderly

52
Q

in women how much of body weight is made up of water

A

5–55% (more fat)

53
Q

how much of water is held extraceulllarly

A

1/3

54
Q

how much water is held intracellularly

A

2/3

55
Q

interstitial fluid volume

A

80% of ECF volume

56
Q

plasma volume

A

20% of EC volume

57
Q

worked out body fluid question

A
  • Intracellular Fluid Volume is 2/3 of total body water = 2/3 x 42L = 28 Litres
  • Extracellular Fluid Volume is 1/3 of total body water = 1/3 x 42L = 14 Litres
  • Interstitial Fluid Volume is 80% of ECF volume = (80/100%) x 14L = 11.2 Litres
  • Plasma volume is 20% of ECF volume = (20/100%) x 14L = 2.8 Litres
  • But, in practice numbers are rounded up and down, so:
  • ICF volume = 11 litres and plasma = 3 litres
58
Q

who have the highest percentage of total body water

A

infants

59
Q

the higher the percentage body fat

A

the lower percentage total body water

60
Q

three classes of tonicity

A

isotonic
hypertonic
hypotonic

61
Q

isotonic

A

concentration of solutes int he cell is the same as outside

62
Q

hypertonic

A

concentration of solutes int he cell is higher than outside the cell

63
Q

hypotonic

A

the concentration of solutes int he celll is lower than outside the cell

64
Q

tonicity is maintained by

A

plasma proteins such as Albumun

65
Q

osmolality

A

uses tonicity to stop too much water leaving the blood (using albumin)

66
Q

tonicity and osmalility work

A

in the opposite way to hydrostatic pressure

67
Q

if too much water

A

cell will swell

  • enzymes stop working
  • cell will lyse
68
Q

patients need what sort of IV drips

A

isotonic solution

69
Q

what concentration of saline is giving

A

0.9% NaCl

70
Q

definition of tonicity

A

The relative [solutes] dissolved in solution which determine the direction and extent of diffusion

71
Q

how is tonicity different to osmotic pressure

A

Unlike osmotic pressure, tonicity is influenced by solutes that cannot cross the membrane

72
Q

solutes able to cross the membrane

A

do not affect tonicity because they will always equilibrate with equal concentrations on both sides of the membrane without net movement

73
Q

what happens when their isn’t enough water?

A
  • coagulation problems
  • cells initially absorb water from interstitial places
  • then from each other
  • then tissues die
  • increases osmolality
  • -> ADH increases
  • -> stopping urine production- tissue dies
74
Q

as organs die of dehydration water is absorbed from the

A

brain, liver kidney and finally the heart

75
Q

osmolality is not dependent on

A

temperature and pressure

76
Q

osmolarity is

A

dependent on temp and pressure

77
Q

where is osmotic pressure taken from

A

plasma and urine

78
Q

oedema

A

fluid retention in interstitial tissue

79
Q

peripheral oedema results in

A

swollen annkles

80
Q

oedema caused by

A
  • presence of plasma proteins in the interstitial space
  • lymphatics blocked or damage

e.g. in heart failure and kidney failure

81
Q

when does oedema occur

A

when hydrostatic pressure is higher than osmotic pressure