Health & Disease Flashcards
(52 cards)
1
Q
Fibroblasts
A
Cells that produce collagen during proliferative stage of wound healing
2
Q
What are the stages of wound healing?
A
- Haemostasis (blood clotting - involves platelets, fibrin)
- Inflammation (clear debris/infection - neutrophils, macrophages)
- Proliferation (rebuild tissue - fibroblasts, keratinocytes, endothelial cells)
- Maturation (strengthen tissue - collagen remodeling)
3
Q
Osteoblasts
A
- Bone-building cells
- Have PTH receptors - when PTH binds, stimulates osteoclast formation which increases bone resorption (break down) —> increased [Ca2+] in blood
4
Q
Osteoclast
A
- Bone resorbing cells (break down bone to release calcium and phosphate)
5
Q
Chondrocyte
A
Cartilage cells
6
Q
Chondroblast
A
Cartilage forming cells
7
Q
Endochondral ossification
A
Formation of long bones from a cartilage model
8
Q
What are the different classifications of bone (based on shape)?
A
Long, short, flat, irregular, semisolid (bone embedded within tendon)
9
Q
Examples of long bones:
A
Tibia, femur, humorus
10
Q
What is Fatty B-oxidation?
A
- Fatty acids are broken down in the mitochondria for energy
- Uses CoA intermediates
- Uses NAD+ and FAD as cosubstrates
11
Q
Endospores
A
Resistant structures that bacteria (usually gram-positive) form in response to harsh conditions —> allow them to survive/be dormant within them
12
Q
Differences between Gram Positive and Gram Negative bacteria?
A
13
Q
Slime-layer
A
- Loose layer of polysaccharides outside of bacterial cell wall
- Aid attachment + provide (a bit of) protection
14
Q
Capsule
A
- Thick layer of polysaccharides outisde cell walls of bacteria
- Aid with (more) protection, attachment + evasion/hiding from body’s immune system
15
Q
Type 1 diabetes
A
Autoimmune disease where immune system attacks insulin-producing cells in the pancreas (born with).
16
Q
Type 2 diabetes
A
Metabolic disorder where body either has insulin-resistance or does not produce enough insulin (caused by lifestyle)
17
Q
IgE antibodies
A
Released in response to harmless substances like pollen (cause allergies)
18
Q
IgA antibodies
A
Protect against infection
19
Q
How to calculate # of generations (n)?
A
20
Q
“Optical density” method
A
- Indirect method to measure bacterial number
- Measures how cloudy a bacteria culture looks using a spectrophotometer
21
Q
Human microbiota
A
- The indigenous micro-organisms (not just bacteria) that exist on some of our body surfaces.
- Can be harmful, non-harmful, neutral
22
Q
Obligate vs Facultative anaerobe
A
- Obligate = only can live WITHOUT oxygen
- Facultative = can live with OR without oxygen
23
Q
Importance of iron for bacteria
A
- Iron = involved in energy generation (via helping with e- transport + metabolism in bacteria)
24
Q
Helminths
A
- Parasitic worms that infect humans and animals
- I.e. Nematodes (roundworms), Cestodes (tapeworms), Trematodes (flukes)
25
Siderophores
- Low MW compounds with high affinity to iron
- Bacteria release these to capture iron to then absorb themselves
26
How are PTH and Calcitonin involved in calcium homeostasis?
- PTH acts on PTH receptors on osteoblasts, indirectly activating osteoclast formation —> increases bone resorption (extraction of minerals from bones), increasing [Ca2+] in blood
- Calcitonin directly acts on receptors on osteoclasts —> decreases bone resorption, decreasing [Ca2+] in blood
(Calcitonin = calci-tone-it-down!)
27
Effect of decrease in pH on haemoglobin’s affinity for oxygen:
Increased [H+] causes for conformation change in haemoglobin —> new form has decreased affinity for oxygen —> haemoglobin releases more O2
28
What causes for blood pH to drop during/after exercise?
- Cells produce more CO2 —> CO2 combines with water to form carbonic acid which dissociates to form H+ ions
(CO2 + H2O <—> H2CO3 <—> **H+** + HCO3-)
29
Residual capacity (of the lungs)
The amount of air that remains in the lungs after normal expiration/exhalation
30
Capillary Net Filtration Pressure (NFP)
- The balance of forces that determines whether fluid moves out of the capillaries —> tissues (filtration), or back into the capillaries (reabsorption).
- Positive NFP = filtration
- Negative NFP = reabsorption
31
ECG
- Electrocardiogram
32
What does the P wave measure in an ECG?
Atrial depolarisation
33
What does the QRS wave measure in an ECG?
Ventricular depolarisation
34
What does the QT segment meaure in an ECG?
Ventricular contraction
35
What does the T wave represent in an ECG?
Ventricular repolarisation
36
Total Peripheral Resistance (TPR)
The overall resistance to blood flow in the systemic circulation.
37
What is Total Peripheral Resistance mainly affected by?
- The diameter of small arteries + arterioles
38
Korotkoff sounds
- Sounds heard through stethoscope during blood pressure measurement using a cuff (sphygmomanometer).
- Produced as a result of turbulent blood flow in an artery as the cuff pressure changes.
39
Baroreceptors
- Pressure-sensitive nerve endings found in carotid sinuses (at neck) and aortic arch
- They detect changes in blood pressure and send signals to the brain stem to adjust **cardiac output** (heart rate + stroke volume) and therefore **regulate blood pressure**.
40
Peptide hormones
- Synthesised as larger, inactive precursors called **prohormones**
- Stored in secretory vesicles in the cell, released via exocytosis in response to stimulus.
- Water soluble, therefore travel freely in blood (not protein-bound) + cannot enter cell membrane via diffusion
41
42
Explain insulin’s secretion mechanism
1. Glucose enters via GLUT channels
2. ATP produced from glycolysis - raises ATP : ADP ratio
3. Causes for **K-ATP channels** to close - causing membrane depolarisation
4. **Ca2+ channels** open - leading to Ca2+ influx
5. Ca2+ triggers vesicles containing insulin to fuse with cell membrane —> releasing insulin
43
Direct actions of Growth Hormone (GH)
GH acts directly on fat and muscle tissues to:
- Stimulate lipolysis (fat breakdown for energy)
- Promote protein synthesis
- Decrease glucose uptake
44
45
Somatomedins
- Peptide hormones that mediate the growth-promoting effects of Growth Hormone.
- I.e. Insulin-like Growth Factor 1 (IGF-1)
46
Describe the steps of Vitamin D metabolism and how it affects Calcium Homeostasis?
1. **Cholecalciferol** (Vitamin D3) is produced in the **skin** upon exposure to sunlight.
2. In the **liver**, cholecalciferol is converted to **calcidiol**. This is the form that circulates the blood.
3. In the **kidneys**, upon binding by **PTH**, calcidiol is converted to **calcitriol**.
4. Calcitriol acts to increase blood calcium levels
47
Hypocalcaemia symptoms
- Increased neuromuscular excitability <— as Ca2+ stabilises nerve membranes, when Ca2+ conc is decreased, nerves fire more easily.
- Bone pain/fragility
- Hypotension (low blood pressure)
48
Hypercalcaemia symptoms
- Fatigue
- Muscle weakness <— due to decreased neuromuscular excitability
- Hypertension (increased blood pressure, sometimes)
- Osteoporosis/too high bone resorption
49
Thyroid hormones…
- Bind to nuclear receptors
- Increase protein synthesis and growth
- Increase the synthesis of NA-K ATPase
- Stimulate ATP production
50
Aldosterone
- **Steroid hormone** produced by adrenal cortex of the **adrenal glands**
Actions:
- Increase sodium and water reabsorption in kidneys —> raising blood volume + pressure
- Increase potassium excretion via urine
51
Androgens (TBC)
52
Progesterone (TBC)
