Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Body Logistics > Homeostasis > Flashcards

Homeostasis Flashcards

1
Q

Define homeostasis

A

Homeo=sameness stasis=standing still

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

Detailed homeostasis definition

A

Ability of a living organism to keep the internal conditions at dynamic equilibrium, despite intrinsic and extrinsic changes

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

What fundamental technique does homeostasis use?

A

Feedback loops

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

State the four components of a feedback loop

A

Stimulus/variable, sensor, control centre, effector

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

When does a negative feedback loop stop

A

When the effector ceases

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

When does a positive feedback stop

A

When the stimulus ceases

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

What does each feedback loop do to the stimulus? - give an example

A

Negative - removes it, insulin removing glucose
Positive - exaggerates or enhances it, oxytocin causing the uterus to stretch

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

What is the normal range of human body temperature?

A

36-38 degrees

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

SSCcE for temperature

A

S - change in temp
S - skin, hypothalamus
Cc - hypothalamus (in the thermostat)
E - fat, hair, blood vessels, sweat glands

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

What is the range of pH for humans?
And why?

A

7.35-7.45
Normal cellular metabolism happens in this range

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

Organs responsible for maintaining acid base balance

A

Lungs and kidneys

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

Range of acidosis and alkalosis

A

7-7.35
7.45-7.8

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

What is the pH of stomach acid?
What can it cause if it enters the oesophagus
Or through the stomach lining?

A

1.5-3.5
Oesophagitis and stricture (closes)
Gastric ulceration

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

What is the limit of human tissue survival for pH?

A

6.8 - 7.8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the normal plasma pH?

A

7.35-7.45

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the [H+] for pH of 7.4?
So what is 7.1, 6.8 and 7.7

A

40nM
80, 160, 20

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

What colour is arterial blood in comparison to venal and why?

A

Bright red, more O2 bonded to haemoglobin to make oxyhaemoglobin - more alkali
Venal blood has more CO2 -more acidic

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

Symptoms of acidosis

A

Headaches, confusion, tired, tremors, coma

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

What compounds in the blood are used to control treat acidosis?

A

Bicarbonate solution - increases pH
Mechanical ventilation - drives CO2 out (dissolved CO2 is acidic)

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

What percentage water is for a standard adult?

A

60%

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

Proportion of water that is extra cellular and intracellular

A

1/3
2/3

22
Q

How is extra cellular water divided?

A

Interstitial - 3/4
Plasma - 1/4 - 0.5L in the transmembrane space

23
Q

What happens if there is not enough or too much water, in general?

A

Dehydration

Toxicity, metabolic failure

24
Q

Comparison of total body water between elderly, man, woman, child?

A

Elderly and women - lower proportion of muscle and higher proportion of fat
Man - higher muscle
Child - high sa:mass so high total body water

More muscle - higher total body water (muscle is mainly made of water)

25
Q

Describe a hypotonic SOLUTION
Inc description of osmotic pressure

A
  • higher conc of water - more dilute
  • lower conc of solutes
  • lower osmotic pressure
26
Q

What is osmolality?

A

Conc of a solution, expressed as the total number of solute particles per kg

27
Q

Osmolality calculation when positive metal ions are involved
E.g. Sodium 140

A

You must double the amount with each metal, as it dissociates with Cl- (the Cl- are osmotically active)
So Na 140 + Cl 140 = 280

28
Q

Summarise what happens when there is not enough water (outside of the cell)

A

Shift in osmotic pressure
Cells and tissue give up their water into the interstitial fluid compartment
They shrink

29
Q

Summarise what happens when there is too much water consumed

A

Reduction in Na+ conc in the extracellular fluid
Shift in osmotic pressure
Water osmoses into the cells
Cells and tissue swell (oedema)

30
Q

What kind of solutions do patients need?

A

Isotonic
IV = 0.9% NaCl

31
Q

What controls bulk water flow?

A

Via integral aqua protein

32
Q

What is oedema?

A

Fluid retention - ‘dropsy’

33
Q

What is an equation that explains how odeomas form?

A

Hydrostatic pressure>osmotic pressure
(Out>in)

34
Q

What is hydrostatic pressure?

A

Force exerted by fluid on the vessel wall

35
Q

What is osmotic pressure?

A

Force applied by the solute to prevent osmotic movement across the membrane

36
Q

What is the control centre?

A

Something that retains the desired value of the variable/stimulus and can compare it to the current value - which is provided by the sensor

37
Q

What happens to the body at high or low temperatures?

A

High - enzymes denature
Low - insufficient energy to maintain metabolic processes

38
Q

What are the two sensors in humans

A

Skin
Hypothalamus

39
Q

What happens to the temperature when infected with bacteria?
Why?

A

Toxins from bacteria and chemicals produced by the immune system
Increase the set point in the hypothalamus
Initiating shivering and increased metabolic rate
Higher temperature

40
Q

What is pyrexia?

A

A fever
Abover 38 degrees

41
Q

Why is a fever good when you are infected?

A

Immune system works optimally

42
Q

Equation of pH in relation to [H+]

A

pH=-log10[H+]

43
Q

Two general causes of acidosis
Where are they controlled?

A

Metabolic - kidneys
Respiratory - lungs

44
Q

How is stomach protected by gastric juice?

A

Special issued epithelial cells that secrete substances, like mucus

45
Q

What is the movement of water across semi permeable membranes dependent on? (2)
Define both

A

Hydrostatic pressure - pumping of heart
Osmotic pressure - conc of solute particles

46
Q

Describe the protective mechanism, to prevent over consumption of water

A

Increase in plasma osmolality detected by the hypothalamus
Before fluids absorbed from the GI tract
Feeling of thirst is quenched

47
Q

Symptoms of dehydration

A

Dry mouth, thirst, low urine output, fever, dizziness

48
Q

What does a loss of blood plasma volume lead to

A

Increased conc of blood components (viscosity)
^ so an increased workload of the heart
Tachycardia

49
Q

What is the name of the condition when the body temp is above 38 degrees?

A

Pyrexia

50
Q

What is rigor?
What triggers it?

A

An episode of shaking or exaggerated shivering which can occur with a high fever

Triggered by pyrogens

51
Q

What are febrile seizures?

A

Seizure of an infant between 6 months-3 years
Response to high temp

52
Q

What molecule is the highest contributor to oncotic pressure?

A

Albumin

Body Logistics (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions