Exercise - Overdoing It Flashcards
What is apoptosis?
Death of a cell and all of it’s contents
Why is the cell apoptosis likely to have a better outcome than cell lysis in the case of cells infected by virus, such as one that causes VRTIs?
- Apoptosis destroys the virus inside the cell
- Cell lysis would split open the cell, releasing any virus inside
Describe and explain the effects of moderate exercise on immunity
- Increases number and activity of a lymphocyte called Natural Killer Cells
- These are found in blood and lymph
- Provide non-specific immunity against cells invaded by viruses and cancerous cells
- They are activated by cytokines and interferons
- Release the protein perforin which forms pores in the target cell’s membrane
- These pores allow other molecules, such as proteases, to enter the infected cell and cause apoptosis
Describe and explain the effect of vigorous exercise on immunity
- The number of natural killer cells, B cells, phagocytes and T helper cells decreases
- Decrease in T helper cells reduces the amount of cytokines available to active lymphocytes
- This results in less antibodies being produced
What are the main features of the non-specific immune response to infection?
- Inflammation
- Phagocytosis
- Antimicrobial proteins
How will the action of T killer cells be affected by vigorous exercise?
- Fewer T-helper cells due to exercise
- Less cytokines produced
- Cytokines activate T-Killer cells
- Less T-Killer cells will be activated
Explain the idea that moderate exercise enhances immunity, while excessive exercise suppresses it
- Moderate exercise increases the number of natural killer cells
- Intense exercise reduces the amount of natural killer cells, B cells, phagocytes and T-Killer cells
What is arthroscopy?
Key hole surgery
Give advantages of key hole surgery over regular surgery
- Less bleeding due to smaller incisions
- Less scarring
- Less pain and quicker recovery time as less damage is done
- Shorter stay in hospital
How can cruciate ligaments be repaired using key hole surgery?
- Damaged cruciate ligament can be removed and replaced with a graft of ligament
- This is done through a small incision in the knee
Describe the normal role of a tendon
-Tendons connect muscle to bone
Suggest two reasons why a tendon used to repair a ligament is taken from the same injured joint
- Only one operation required
- No immune response as the tendon is from the same person
Ligaments are more elastic than tendons. Suggest what advice a footballer who has has a torn ligament in her knee replaced with one of her tendons might be given to help her get fit again
- Tendon less elastic than ligament
- So knee must be gently exercised to stretch the tendon
- Avoid overstretching
Suggest why removing a tendon to use as a ligament would not cause any problems
- Muscles usually have more than one attachment to bones
- Removal of one tendon means there are still other tendons attaching the muscle to the bone
- The remaining tendons get stronger so the tendon that was removed does not cause any weakness
What is a prosthesis?
An artificial body part used by someone with a disabilities to enable them to regain some degree of normal function/appearance
What are articulated prostheses?
Prosthetics that contain joints
When might using an articulated prosthesis be better than using a non-articulated prosthesis?
-On uneven surfaces
Explain how a damaged knee joint can be replaced by a prosthetic joint
- Surgeon makes an incision in the knee
- The patella is moved out of the way and the ends of the femur and tibia are trimmed to fit the prosthesis
- The metal, usually Titanium, prosthesis is placed on the end of the femur and attached to the tibia and patella
Give the benefits of enough exercise
- Increased arterial vasodilation lowers blood pressure - this reduces risk of CHD and strokes
- Increases the level of HDLs in the blood - more cholesterol is transported to the liver to be broken down
- Reduces LDLs in the blood which reduces the risk of CHD and strokes
- Use of energy maintain a healthy weight
- Improved glucose regulation due to muscles being more sensitive to insulin - reduces the risk of type 2 diabetes
- Increases bone density - reduces chances of osteoporosis
- Reduces the risk of some cancers
- Improves metal well-being
What are the risks of not doing enough exercise?
- CHD
- Strokes
- Cancer
- Obesity
- Type 2 diabetes
- Osteoporosis
When is a person considered obese?
When their BMI is over 30
How can not doing enough exercise lead to type II diabetes?
- High blood glucose levels due to glucose not being used up in exercise
- This reduces sensitivity of cells to insulin
- Less insulin produced
- Body cells do not respond to insulin produced
- Blood sugar levels cannot be controlled
Why might type II diabetes, developed from not doing enough exercise, might result in weight loas
- Body cells become less sensitive to glucose in the blood
- As a result there is a decreased absorption of glucose from the blood
- Cells break down fatty acids and proteins for energy instead
- Muscles are made from proteins
Where are your cruciate ligaments?
- Middle of the knee
- Connect your thigh bone to your lower leg bone
What are hormones?
Chemical messengers, released directly into the blood from endocrine glands
What is the difference in structure of endocrine glands and exocrine glands?
-Endocrine glands don’t have ducts
Why are hormones produced in an inactive form or packaged within vesicles in the Golgi apparatus?
So the cells producing the hormone is not affected by it
eg a cell that produces the human growth hormone would not want to be continuously growing
How would a hormone be released from a vesicle inside a cell?
- The vesicle would fuse with the cell surface membrane
- The contents, the hormone, is released by exocytosis
Which hormones are produced in the pituitary gland?
- Growth hormones
- Follicle-stimulating hormone
- Antidivetic hormones
Which hormone is produced in the thyroid gland? What does it do?
- Thyroxine
- Raises basal metabolic rate
Where is adrenaline produced?
The adrenal gland
What effects does the adrenaline hormone have on the body?
- Raises basal metabolic rate
- Dilates blood vessels
- Prepares body for action
Which hormone is produced in the pancreas?
Insulin
Give the two methods a hormone used to modify a cell
- Enter the cells directly
- Bind to complementary receptor molecules on the outside of the cell membrane
What brings about change in a cell?
The activation or inhibition of enzymes
What are peptide hormones?
Protein chains, varying from about 10-300 amino acids in length
Why can’t peptide hormones pass through cell membranes, despite being small in size?
They are charged
Explain how a hormone can still affect a cell when it cannot enter it
- Peptide hormones binds to a complimentary receptor on the cell membrane
- This activates a second messenger located in the cytoplasm of the cell
- The second messenger activates enzymes or transcription factors
- This directly or indirectly affects gene transcription and brings about chemical change in a cell
Name three peptide hormones
- EPO
- Human growth hormone
- Insulin
Why do steroid hormones pass through the cell membrane?
- They are lipid-based
- So they dissolve
Most hormones travel all round the body in the blood, and will come into contact will many cells. Why do hormones only produce a response within cells of the target organs?
- Hormone binds to complementary receptor to bring about response
- Only the correct cells will have the correct receptors
Explain how a gene can be activated
- Transcription factors bind to promotor region
- This forms a transcription initiation complex
- RNA Polymerase then binds to the complex
- Transcription takes place and mRNA is synthesised
Suggest how fungal genes may be expressed and effect behaviour
- Transcription factors bind to promotor region
- This forms a transcription initiation complex
- RNA Polymerase binds
- Gene activated
- mRNA produced by transcription
- Translation on ribosomes produce proteins which effect behaviour
What can testosterone act as when referring to transcription factors?
An activator molecule
How would testosterone, an activator molecule, enable transcription?
- Enters cell through membrane
- Binds to transcription factor which removes the inhibitor
- The transcription factor is now active and can bind to the promotor region along with RNA Polymerase
Name three performance enhancing hormones, where they are produced and what effect they have
- Human growth hormone - pituitary gland - stimulates growth which increases muscle mass
- EPO - Adrenal glands - Stimulates red blood cell production
- Testosterone - Testis in men, adrenal gland in both men and women - produces male characteristics/increases muscle mass
What is testosterone an example of?
A steroid hormone
What is the steroid hormone testosterone made from?
Cholesterol (lipid)
How does testosterone increase muscle mass?
- Testosterone binds to receptors in the cell’s cytoplasm
- Modifies gene expression
- This increases protein synthesis, an anabolic reaction, in muscle cells
- More proteins made, increasing size and strength of muscles
Why are anabolic steroids such as nandrolone used by body builders instead of injecting testosterone?
- Testosterone breaks down quickly
- This means it is not effective at muscle development
- Anabolic steroids are modified to not break down as quickly
How does EPO enhance performance?
- Stimulates the formation of new red blood cells in the bone marrow
- Increased red blood cell count means more oxygen can be transferred to muscle cells
- Longer period of aerobic respiration possible
Suggest how EPO might stimulate formation of new blood cells
- Unspecialised stem cells in bone marrow divide and differentiate to form red blood cells
- EPO binds to receptors on target cells
- This alters gene expression
- Altered gene expression can lead to transcription forming enzymes that are involved in the synthesis of haemoglobin
Why is EPO not taken by sprint athletes?
- Sprinting involves anaerobic respiration
- EPO increases aerobic respiration as it increases red blood cell count
What is meant by thrombosis?
Blood clots in arteries and veins
EPO is a natural substance but can also be taken by an athlete. Why would it be important to distinguish between synthetic and natural EPO?
-To determine if athletes are taking EPO as a performance enhancing drug
What are the dangers of taking EPO?
- Red blood cell concentration increases which leads to thicker blood
- This can lead to thrombosis which could lead to heart attacks or strokes
What are the dangers of taking anabolic steroids?
- Cause high blood pressure
- Liver damage
- Kidney damage
- Decreased sperm production
- Heart disease
Provide arguements for and against using performance enhancing drugs
Against:
- Some drugs illegal
- Drugs provide an unfair advantage to those who take them over those who don’t
- Serious health risks
- Athletes may not be fully aware of the dangers
For:
- Its down to the individual to decide if the risks are worth the benefits
- Sport is unfair anyway as some athletes have access to better facilities/equipment
- Some people may not be good enough to compete without them
Name a substance that is performance enhancing but is not banned. Where is it naturally found?
- Creatine
- In meat and fish
How is creatine performance enhancing?
- Increases the amount of creatine phosphate (CP) in muscles
- When CP is hydrolysed, it releases energy which is used to regenerate ATP from ADP, the phosphate coming from the CP
- Decreases recovery time
What type of system would a javelin thrower rely on for energy?
ATP/PC system
What is myoglobin?
- Globular protein
- Binds to oxygen
- Found in muscles only
