Physiology Flashcards
(76 cards)
1
Q
What are tissues?
A
- a group of cells with similar structure and specialised function
2
Q
What are body organs?
A
- two or more types of primary tissues that function together to perform a specialised function
3
Q
What are body systems?
A
- group of organs that perform related functions, to achieve a common goal
4
Q
Define homeostasis
A
- the maintance of steady states within our bodies, by coordinated physiological mechanisms
- maintance of a constant internal environment
5
Q
Describe the 3 stages that make a control center?
A
- sense
- integrate
- make
6
Q
Explain intrinsic control
A
- local controls that are within the organ
7
Q
Explain extrinsic control
A
- regulatory mechanisms initated outside an organ
- use of nervous and endocrine system
8
Q
Explain feedforward control
A
- responses made in anticipation of a change
9
Q
Explain feedback control
A
- responses made after a change has been detected
10
Q
Explain positive feedback and an example
A
- amplifies an inital change
- labour contraction
11
Q
Explain negative feedback and an example
A
- opposes inital change
- temperature regulation
12
Q
Define blood pressure
A
- outwards hydrostatic pressure exerted by the blood on the walls of blood vessels
13
Q
Systolic is when the heart _____
A
- contracts
14
Q
Define hypertension
A
- clinical BP of 140/90mmHg or higher
- day time average of 135/85mmHg or higher
15
Q
What is the pulse pressure? and what are its normal ranges?
A
- the difference between systolic and diastolic pressures
- usually between 30-50
16
Q
Define mean arterial blood pressure?
A
- the average blood pressure during a single cardiac cycle
17
Q
Diastolic is ______ as long as systolic
A
- twice
18
Q
what is the usual value for mean arterial pressure?
A
- 70-105mmHg
19
Q
Equations to calculate MAP
A
MAP = (2 x diastolic + systolic ) / 3
MAP = diastolic + 1/3 pulse pressure
MAP = CO X SVR
20
Q
____mmHg is the minimum MAP needed to perfuse organs
A
60
21
Q
What are baroreceptors?
A
- recognise the differences in MAP
- located in carotids and aortic arch
22
Q
What happens to the firing of baroreceptors if MAP increases?
A
- firing increases
23
Q
Define cardiac output?
A
- the volume of blood pumped out by each ventricle per minute
24
Q
Define stroke volume?
A
- volume of blood pumped out of each ventricle per beat
25
3 ways in which MAP can be regulated?
- heart rate
- systemic vascular resistance
- stroke volume
26
How is systemic vascular resistance regulated?
- vascular smooth muscle
27
Define vasomotor tone
- when the vascualr smooth muscle is partially constricted at rest
- due to tonic discharge of sympathetic nerves
28
There is no significant parasympathetic innervation on arterial smooth muscle?
true/false?
- true
| - only exceptions are the penis and clitoris
29
What are the 7 main vital signs recorded?
- pulse (60-100bmp)
- bp (<140/90mmHg - hypertensive)
- temperature (core- 37.8)
- capillary refill (>2secs)
- resp rate (12-20)
- consciousness
- oxygen saturation (<95%)
30
What is the core body temperature? and what are the normal range?
- the temperature deep within the body
| - 37.8
31
Ear drum temperature range?
35.5 - 37.5
32
Rectal temperature range?
36.7 - 37.5
33
4 ways in which heat can be lost or gained in the body?
- radiation
- conduction
- convection
- evaporation
34
The bodys temperature is kept at a constant by _______ feedback control?
- negative
35
Where are the central thermoreceptors located?
- hypothalamus
| - organs
36
Where are the peripheral thermoreceptors located?
- skin
37
What is the control center of body temperature?
- hypothalamus
38
the _____ end of the hypothalamus is activated by cold
- posterior
39
the ______ end of the hypothalamus is activated by warmth
- anterior
40
Explain how a fever is produced in response to infection
- macrophages release endogenous pyrogen chemicals in response to an infection
- these stimulate the hypothalamus to release prostaglandin
- this resets the body thermostat to a higher temperature
- imitates a cold response
41
what temperature represents hyperthermia?
>40
42
what temperature represents hypothermia?
<35
43
What is the role of a membrane?
- forms a outer boundary of every cells
- selectively permeable
- controls entry of nutrients, and exit of waste products
44
Explain the role of phospholipids in a membrane
- hydrophilic head
- hydrophobic tail
- constantly moving --> fluid like appearance
45
What is the role of cholestrol in the plasma membrane?
- to provide stability
46
What are peripheral membrane proteins?
- loosely associated
| - lie on the top of the membrane
47
What are integral proteins?
- closely associated
- may be transmembranal
- may act as pores, channels, pumps and enzymes
48
Name given to the layer formed by
| glycoproteins + glycolipids?
- glycocalyx
49
What is used as a self-recognition marker on plasma membranes?
- carbohydrate molecules
| - different cells have different carbohydrate markers
50
Another name for tight junctions?
- occluding junctions
51
Another name for desmosomes?
- anchoring junctions
52
Another name for gap junctions?
- communicating junctions
53
Role of tight junctions?
- prevents diffusion
54
Role of desmosomes?
- anchor cells together
55
Role of gap junctions?
- all the movement of ions
56
The plasma membrane is ____ permeable
- selectively permeable
57
What are the 2 main factors that influence membrane transport?
- size and solubility of ion
58
Explain unassisted membrane transport
- movement is either down a concentration gradient
| - or along a electrical gradient
59
What are the 5 factors of Ficks law of diffusion?
- magnitude of concentration gradient
- surface area of membrane
- lipid solubility
- molecular weight
- diffusion distance
60
What does electrochemical gradient mean?
- both chemical (concentration) and electrical gradients play a role in diffusion
61
define osmolarity
- concentration of osmotically active ions in a solution
62
define tonicity
- the effect of a solution on the the cell volume
63
carrier mediated transport involves____ changes-
- conformational changes
64
What does Tm mean in relation to carrier mediated transport?
- transport maximum
| - saturation kinetics
65
Define primary active transport
- energy is required to move an ion against its concentration gradient
66
Define secondary active transport
- energy isn't used directly
| - couple to an ion transport
67
2 different types of secondary transport?
- symport (together)
| - antiport (opposite)
68
Energy is required for vesicular transport
| - True or false?
- TRUE
69
2 Different types of vesicular transport?
- endocytosis
| - exocytosis
70
Define membrane potential?
- separation of opposing charges across a membrane (Em)
71
The membrane of a cell is charged.
True or False?
- FALSE
| - the membrane itself isnt charged
72
What is the concentration gradient for K+?
- outward
| - Ek = -90mV
73
What is the concentration gradient for Na+?
- inward
| - Ena= +60mV
74
What is the resting membrane potential? and why is it this value?
- = -70mV
| - Close to Ek (=-90) but slightly more positive due to the inward leakage of Na+
75
How many more times permable is the membrane to K+ over Na+?
- 100 times more permeable
76
What directions does the Na/K+ pump work?
- 3 Na+ outward
| - 2 K+ inward
