Unit 2 Flashcards
(252 cards)
1
Q
Name parts of the male reproductive system
A
Seminal vesicle Prostate gland Sperm duct Testis Scrotum Penis Urethra
2
Q
Name parts of the testes
A
Seminiferous tubule
Sperm duct
3
Q
Name parts of the seminiferous tubule
A
Germline cell
Sperm
Interstitial cell
Blood capillary
4
Q
What do the testes do?
A
Sperm produced in the seminiferous tubules
Testosterone produced in interstitial cell
5
Q
Sperm
A
Male gametes (motile (able to move))
Need fluid for motility
Need source of energy to move
6
Q
Semen
A
Milky fluid containing sperm and liquid secretions from seminal vesicles and prostate gland
Gives sperm energy and helps them to swim
7
Q
Seminal vesicle
A
Produces a liquid rich in fructose (energy source for sperm)
Contains hormone like compounds to simulate contractions of female reproductive tract (helps sperm reach oviduct faster)
8
Q
Prostate gland
A
Produces liquid with enzymes so sperm can move easily
Keeps semen at optimum viscosity
9
Q
Where do testes produce sperm?
A
The seminiferous tubules
10
Q
Where do testes produce testosterone?
A
The interstitial cells
11
Q
What do the prostate gland and the seminal vesicles do?
A
Secret fluids that maintain the viability and mobility of the sperm
12
Q
Name parts of the female reproductive system
A
Oviduct Ovary Uterus Endromentrium Uterus Cervix
13
Q
What cycle does the follicle go through?
A
Immature follicle >
Ovulation of mature ovum > Corpus luteum
14
Q
Ovum
A
Female gamete (ova (plural))
15
Q
Follicle
A
protects developing ova and secretes oestrogen
16
Q
Corpus luteum
A
Structure that forms after ovulation and secretes progesterone
17
Q
Oviduct
A
Site of fertilisation
18
Q
Uterus
A
Site of implantation and development of zygote
19
Q
Endometrium
A
Lining of uterus
20
Q
Ova are formed from….
A
Germline cells in the female ovaries
21
Q
What do ovaries contain
A
Immature eggs at various stages of development
22
Q
What is ovulation?
A
A mature ova is released from the ovary from the oviduct
23
Q
What does the follicle secrete after ovulation
A
Progesterone and oestrogen
24
Q
What is fertilisation
A
Mature ova are released into the oviduct where they may be fertilised by sperm to form a zygote
25
What are hormones
Chemical messengers in the blood what are released by endocrine glands
26
Hormones only affect the target tissue because...
Hormones are complementary in shape to specific receptions on the target cell
27
What controls the onset of puberty, sperm production and the menstrual cycle
Hormones
28
The hypothalamus releases a releaser hormone which...
Stimulates the pituitary gland to produce and release 2 hormones
29
What are the two hormones released by the pituitary gland in males
FSH (Follicle stimulating hormone)
| ICSH (interstitial cell stimulating hormone)
30
What are the two hormones released by the pituitary gland in females
FSH (Follicle stimulating hormone)
| LH (luteinising hormone)
31
The release of these hormones at puberty sparks...
The production of sperm in males and the menstrual cycle in females
32
The pituitary gland releases FSH which stimulates...
Sperm production in the seminiferous tube
33
ICSH stimulates...
the interstitial cells to release testosterone
34
Testosterone stimulates...
Sperm production and stimulates the prostate gland and seminal vesicle to secret fluids
35
Testosterone further stimulates....
Sperm production
36
At high concentrations testosterone...
Inhibits the release of FSH and ICSH by the pituitary gland
| This self-regulation mechanism is known as negative feedback control
37
How long is the mensural cycle
28 days
38
What is the first day of the cycle?
The first day of menstruation
39
What phases can menstruation be divided into
```
Follicular phase (aprox day 1-14)
Inteal phase (approx. Day 15-28)
```
40
Describe the follicular phase
The pituitary releases FSH which stimulates the development of a follicle inside the ovary
Stimulates the production of oestrogen by the follicle
41
Oestrogen stimulates
The proliferation of the endromentrium preparing it for implementation
Alters the consistency of the cervical mucus making it more easily penetrated by sperm
42
High levels of oestrogen stimulates ...
The pituitary to release LH
43
LH stimulates
Ovulation
44
Luteal phase
The follicle developes into corpus luteum which secrets progesterone
45
Progesterone
Promotes further development and vascularisation of the endometrium preparing it for implantation if fertilisation occurs
Inhibits the pituitary gland from releasing FSH and LH which prevents further follicles from developing
This is called negative feedback
46
Describe negative feedback during menstruation
Eventually the lack of LH leads to the degeneration of the corpus luteum
Progesterone levels drop leading to menstruation
Pituitary gland is no longer inhibited
47
What effect does FSH have on the follicle
Stimulates development and production of oestrogen
48
What effect does LH have on the corpus luteum
Causes development of corpus luteum stimulates production of progesterone
49
Describe the structure that releases it, Function, target tissue and function of FSH in males
Released by the pituitary gland
Target tissue: seminiferous tubules
Stimulates sperm production
50
Describe the structure that releases it, Function, target tissue and function of ICSH in males
Released by pituitary gland
Targets interstitial cells
Stimulates testosterone production
51
Describe the structure that releases it, Function, target tissue and function of Testosterone in males
```
Released by interstitial cells
Targets prostate gland and testes
Stimulates sperm production
Stimulates prostate gland and seminal vesicle to secrete fluids
Inhibits pituitary
```
52
Describe the structure that releases it, Function, target tissue and function of FSH in females
Released by pituitary gland
Targets the follicle within the ovaries
Stimulates development of the follicle
Stimulates production of oestrogen by the follicle
53
Describe the structure that releases it, Function, target tissue and function of LH in females
Released by pituitary gland
Targets the follicle and corpus luteum
Stimulates ovulation
Stimulates development of corpus luteum
54
Describe the structure that releases it, Function, target tissue and function of Progesterone in females
Produced by ovaries
Targets endometrium and pituitary gland
Causes proliferation of the endometrium and release of the LH
55
Describe the structure that releases it, Function, target tissue and function of Oestrogen in females
Released by the corpus luteum
Targets endometrium
Stimulates proliferation of the endometrium
Alters consistency of the cervical mucus
High levels of oestrogen stimulates the pituitary to release LH
Drop in levels leads to menstruation
56
What can the biology of fertility help create
Infertility treatments
| Contraception
57
What is fertility like in women
Cyclical fertility leading to a fertile period
58
What is fertility like in men
Continuous
59
What can a womens fertile period be identified by?
An increase in body temperature (after ovulation approx. Increase of 0.5°c-0.2°c
The production of thin watery mucus
60
What can be used to treat issues such as a failure of the pituitary gland to secret enough FSH and LH
Drugs that mimic the normal action of FSH and LH
| Drugs that prevent the negative feedback effect of oestrogen
61
What is artificial insemination
The insertion of semen into the female tract by a method other than sexual intercourse
62
Why would someone use artificial insemination
If a man has a low sperm count
| To insert the semen of a donor if a donor is required
63
Describe artificial insemination
Several samples of the mans semen can be taken over a period of time and frozen.
They can then be defrosted and released together into his partners cervical region at the time when she is most likely fertile
64
What is in vitro fertilisation
Fertilising the gametes of the would be parents outside of the body in a culture dish
65
What can in vitro fertilisation treat
Attempts to solve the problem of infertility caused by a blockage of the oviducts
66
Describe in vitro fertilisation
The woman is given hormonal treatment to stimulate multiple ovulation
The eggs are then surgically removed and mixed with sperm in a culture dish of nutrient medium or alternatively the sperm may be injected directly into an egg. The eggs are incubated for 2-3 days and then the embryos are chosen and inserted via the vagina into the mothers uterus
The remaining embryos are then frozen incase a second attempt is required
67
What is intracytoplasmic used to treat
In cases where a mans sperm count is low or many of his mature sperm are defective in some way ICSI can be employed
68
Describe intracytoplasmic sperm injection
A healthy sperm is drawn into a syringe needle and injected into an egg to bring about fertilisation
The egg is held in place by a holding tool
This procedure is part of IVF
69
What is contraception?
The intentional prevention of conception or pregnancy by natural or artificial means
70
What is physical contraception
Stops gametes from meeting
71
What is chemical contraception
Usually involves hormones
72
Name some physical methods of contraception
```
Avoiding intercourse (during fertile periods)
Barrier methods (condom, diaphram, cervical cap)
IUD- alters cervical mucus and prevents implantation of fertile egg
Sterilisation procedures (vasectomy, tying tubes)
```
73
Name some chemical methods
Oral contraceptive pills
Progesterone only pills (mini pills)
Morning after pills
74
Describe oral contraceptive pills
Contain a combination of synthetic oestrogen and progesterone hormones that mimic negative feedback preventing the development and maturation of a follicle
75
Describe mini pills
Work by thickening the cervical mucus therefore reducing sperm access to the uterus
76
Describe morning after pills
Emergency contraceptive pills. They are taken after intercourse to prevent implantation of a fertilised egg
77
Describe sterilisation procedures in males
Involves cutting and tying 2 sperm ducts, preventing the realise of sperm during intercourse
78
Describe sterilisation procedures in females
Involves cutting and tying 2 oviducts to prevent eggs from reacting with sperm
79
The health of a pregnant woman and her fetus cab be monitored using....
A variety of techniques and tests
80
What can antenatal screening be used to identify???
The risk of the fetus developing a genetic disorder or chromosomal abnormality
If necessary further tests and prenatal diagnosis can be offered
81
What are the two types of ultrasound
Dating scans and abnormality scans
82
What do abnormality scans detect?
Serious physical problems in the fotus
83
Anomaly scans are carried out at...
18-20 weeks
84
What are dating scans used to do?
Determine the stage of development and the due date
85
When are date scans carried out
8-14 weeks
86
What are dating scans used in conjunction with?
Biochemical tests
| Which vary normally during pregnancy
87
When are biochemical tests carried out
At 16-18 weeks
88
How are they carried out
By sampling blood and urine
89
Routine blood and urine tests are carried out throughout pregnancy...
to monitor the concentrations of marker chemicals
90
What could measuring a chemical at the wrong time lead to
A false positive result
91
An Atypical chemical concentration can lead to...
Diagnostic testing to determine if the fetus has a medical condition
92
What is diagnostic testing
A definitive test to detect if a person is suffering from a particular condition
Particularly offered to "high risk women (Age/ health condition)
93
What does diagnostic testing involve
A karyotype of the fetus chromosomes arranged as homogenous pairs must be viewed
94
How are foetal chromosomes obtained
Amniocentesis- (lower risk to foetus
| Chronic villus sampling (CVS) carried out earlier in pregnancy
95
What can post natal screening detect
Phenylketonuria (PKU)
96
What is PKU
An error of metabolism caused by a substitution mutation
| The enzyme which converts phenylalanine to tyrosine does not function
97
How do you test for PKU
A blood test is taken from the baby within a few days of birth to test for the presence of excess phenylalanine
If the baby suffers from PKU a restricted diet is prescribed
98
Gene
A sequence of DNA that codes for a particular protein
99
Allele
Different forms of a gene
100
Phenotype
The appearance of an organism
101
Genotype
The set of genes an organism has
102
Dominant
A dominant allele will always be expressed
103
Recessive
A gene that can be masked
104
Homozygous
Two of the same allele
105
Hertozygous
Two different alleles
106
Describe the chromosomes in a human cell
23 pairs
The first 22 Are called autosomes
The last are called sex chromosomes (XX= female XY=male)
107
Describe a pedigree chart
A pattern of inheritance about a characteristic can be obtained and used to construct a pedigree chart
Once the phenotypes are determined, the genotypes can also be formed
108
Why is a pedigree chart needed
Its construction would be carried out by a genetic counsellor who can advise of the chances of them passing on a genetic disorder to the children
109
Name the types of inherited gene disorders
```
Autosomal recessive
-Cystic fibrosis
Autosomal dominant
-Huntington's disease
Incomplete dominance
- sickle cell disease and sickle cell trait
Sex-linked recessive
-haemophilia/ ducheune muscular dystrophy
```
110
Explain sex-linked recessive
Females who
carry two recessive alleles suffer from the disease
Females who carry one recessive allele are known as carriers
Males only need one recessive allele to suffer from the disease
111
What are sex linked genes
Genes that are found on the exclamation but have no homoglous allele on the Y chromosome
112
Why do sex linked genes always show in the phenotype of males
There are no genes on the Y chromosome to counteract them
113
How is the genotype of sex linked conditions written
With x or Y chromosomes with the allele as a subscript letter
114
Explain the sex linked rules
Always include the X and Y chromosomes with the allele as a subscript letter
Males are affected more than females
Mothers pass X chromosomes to the doctors and sons
Males received a sex linked alleles from the mother
Fathers only pass X chromosomes to daughters
Affected father always passes alleles to daughter
115
Describe the pattern of autosomal recessive conditions
Rare
May skip generations
Trait expressed amongst cousins in family trees
116
Describe the pattern of autosomal dominant conditions
Appears in every generation
Each sufferer also has an affected parent
Males and females express trait equally
If one branch does not express the trait, it will not reappear in future generations
117
Describe the pattern of autosomal incomplete dominance conditions
Fully expressed form of disorder rarely/ partly expressed form occurs more frequently
Each fully expressed sufferer has 2 parents that shows partial expression
Males and females express trait equally
118
Describe the pattern of Sex-linked recessive conditions
More males effected than females
None of the sons of an affected male show the trait
Carried on the X chromosome
119
What are the 3 main types of blood vessel
Arteries, capillaries and veins
120
What order does blood circulate in
From the heart, through the arteries, to the capillaries, to the veins and back to the heart
121
There is a decrease in blood pressure as...
...it moves away from the heart
122
Between the veins and the capillaries there is...
The venule
123
Between the arteries and the capillaries there is...
The arteriole
124
Arteries
```
Arteries carry blood away from the heart
Has:
Central lumen
Endothelium
Smooth muscle
Connective tissue
The elastic walls of the arteries stretch and recoil to accommodate the sunge of blood after each contraction of the heart
```
125
Central lumen
Is the empty space in the middle of a blood vessel
126
Endothelium
The lining of the cental lumen
127
Veins
```
Veins carry blood towards the heart
Has:
Central lumen
Endothelium
Smooth muscle
Connective tissue
Veins also have valves. Valves prevent the back-flow of blood
```
128
Capillaries
Have a narrow central lumen
| Endothelium is one cell thick
129
Arteries carry...
High pressure blood away from the heart
130
Why is the wall of a capillary one cell thick?
Allows for the exchange of substances such as glucose and oxygen with the body tissues
131
Veins carry
Low pressure blood back to the heart
132
Vasodilation
This is the widening of blood vessels
Caused by smooth muscle cells relaxing
This results in the lumen becoming wider and blood flow increasing
(To parts of the body such as skeletal muscle during exercise)
133
Vasoconstriction
The narrowing of blood vessels
Caused by smooth muscle cells contracting
This results in the lumen becoming narrower and blood flow decreasing
-(to parts of the body such as the small intestine during exercise)
134
Blood plasma
A watery yellow fluid that contains many dissolved substances:
- glucose
- Amino acid
- plasma proteins
- ions
135
Describe the first stage in the exchange of blood materials
Blood is transported from the arteries at high pressure, then through the arteriole and and enters the narrow capillaries
136
Describe the second stage in the exchange of blood materials
Pressure filtration squeezes the blood plasma through the capillary wall and into the surrounding cells. As a result, the blood plasma loses its plasma proteins and becomes tissue fluid instead
This is because plasma proteins are too large to pass through the capillary wall
137
Describe the third stage in the exchange of blood materials
Glucose/ oxygen diffuses out of the tissue fluid and into the surrounding cells. At the same time, carbon dioxide diffuses out of the surrounding cells and into the tissue fluid to be excreted
138
Describe the fourth stage in the exchange of blood materials
Most of the tissue fluid is then absorbed back into the capillary (by osmosis) and leaves the capillary bed via the venule
139
Describe the fifth stage in the exchange of blood materials
Some of the tissue fluid does not return to capillaries. Instead this excess fluid is absorbed by lymph vessels
140
Describe the sixth stage in the exchange of blood materials
The tissue fluid at this point is called lymph, and is taken away by the lymph vessels, where it is transported around the lymphatic system
141
Describe the path of blood through the heart
```
Vena cava (from the body)
Right atrium
Atrio-ventricular valve
Right ventricle
Semi-lunar valve
Pulmonary artery (to the lungs)
Pulmonary vein (from the lungs)
Left atrium
Atrioventricular value
Left ventricle
Semi-lunar valve
Aorta (to the body)
```
142
What is the function of valves
Prevent the backflow of blood
143
Av valves prevent...
Blood from flowing back into the atrium
| Force the blood into the ventricules
144
Sl valves prevent...
Blood from flowing back into the ventricles
| Force the blood to leave the heart
145
What causes the "Lub-Dub" sound?
The opening and closing of the AV and SL valves
146
The pulmonary vein
Pumps oxygenated blood from the lungs to the left atrium
147
Aorta
Pumps oxygenated blood from the left ventricle to the body
148
Vena cava
Pumps deoxygenated blood from the body to the right atrium
149
Pulmonary artery
Pumps deoxygenated blood from the right ventricle to the lungs
150
Heart rate (Pulse) HR
Number of heart beats per minute
151
Stroke volume
Volume of blood expelled by each ventricle on contraction (the stronger the contraction the stronger the stroke volume)
152
Cardiac output
The volume of blood pumped through each ventricle per minute (creates the pulse)
153
The left and right ventricles pump....
The same volume of blood through the aorta and pulmonary artery
154
How do you calculate cardiac output?
CO=HRxSV
155
What is the cardiac cycle?
The name of the pattern of contraction (systole) and relaxation (diastole) in one complete heartbeat
156
What is systole
Contraction in the heart
157
What is diastole
Relaxation in the heart
158
Atrial systole
When the atria contract to transfer blood through the open atrio-ventricular valves to the ventricles
159
Ventricular systole
Closes the Av valves. The ventricle contract and pump the blood out through the open semi-lunar valves to the aorta and pulmonary artery
160
Diastole
During diastole blood returning to the relaxed atria flows into the relaxed ventricles
In diastole the higher pressure in the arteries closes the SL valves
161
Summarise the cardiac cycle
Diastole
/ \
Ventricular ---artial systole Systole
162
The events of the cardiac cycle are brought about by...
The activity of the hearts pacemaker, or sino-arterial node (SAN)
163
Where is the sino-arterial node located
The wall of the right atrium
164
What is the SAN
A small region of specialised tissues that contain auto rhythmic cells
165
What do the auto rhythmic cells in the SAN do
Initiate electrical impulses that make the cardiac muscle contract at a certain rate
166
The timing of cardiac cells is controlled by....
Impulse from the SAN
167
Describe the path of the impulses from the SAN
They spread through the atria and then travel to the atrial ventricular node then through the ventricles
168
The impulses from the SAN generate....which can be detected by...
Currents
| Electrocardiogram (ECG)
169
The events of the cardiac cycle are brought about by...
The activity of the hearts pacemaker, or sino-arterial node (SAN)
170
Where is the sino-arterial node located
The wall of the right atrium
171
What is the SAN
A small region of specialised tissues that contain auto rhythmic cells
172
What do the auto rhythmic cells in the SAN do
Initiate electrical impulses that make the cardiac muscle contract at a certain rate
173
The timing of cardiac cells is controlled by....
Impulse from the SAN
174
Describe the path of the impulses from the SAN
They spread through the atria and then travel to the atrial ventricular node then through the ventricles
175
The impulses from the SAN generate....which can be detected by...
Currents
| Electrocardiogram (ECG)
176
Electriocardiogram
Measures the electrical changes that take place in the heart
177
P wave (electrocardiogram)
The wave of electrical impulses spreading over the atrium from the SAN
178
Q R S complex (electrocardiogram)
The electrical impulses through the ventricle
179
T wave (electrocardiogram)
The electrical recovery of the ventricles at the end of the ventricular systole
180
The medulla regulates the....
Rate of the sinotrial node through the antagonistic action of the autonomic nervous system (ANS)
181
Heart rate is controlled by...
The actions of sympathetic and parasympathetic nerves
182
Impulses can be sent from....along both of the sympathetic and parasympathetic nerves
Medulla
183
The heart rate depends on which system exerts a greater influence over the heart. Explain this
A sympathetic nerve releases noradrenaline which increases the heart rate whereas the parasympathetic nerve releases acetylcholine which decreases the heart rate
184
The conduction system of the heart is controlled by the...
Autonomic nervous system
185
What is the autonomic nervous system made up of
Sympathetic and parasympathetic nerves
186
The sympathetic and parasympathetic nervous can be described as...
Antagonistic systems in action
187
Impulses originate in the
Control centres of the medulla
188
With what instrument is blood pressure measured?
A sphygmomanometer
189
How is the first pressure reading obtained
After an inflatable cuff stops the blood flow and deflates gradually, causing the blood to start to flow, detected by a pulse at systolic pressure)
190
How is the second pressure reading obtained
Taken when the blood flows freely through the artery (and a pulse is not detected) at diastole in pressure
191
A typical blood pressure reading is...
120/80 mmHG (mm of mercury)
192
Hypertension AKA high blood pressure
Hypertension is a major risk for many diseases such as coronary heart disease
193
The hormone nor-adrenaline is released by
Sympathetic accelerator nerves
194
The hormone Acetylcholine is realeased by
The slowing parasympathetic nerves
195
The pacemaker or SAN is located in the
Right atrium
196
Once stimulated, the SAN...
Produced impulses and contracts
197
The impulses from the AVN are carried by
Conductive nerves spread out in the ventricle
198
Impulses from the SAN cause
Contraction of ventricles (ventricular systole) followed by relaxation (diastole)
199
The atheroma/plaque
is a build up of fatty material under the endothelium
200
Atherosclerosis
The accumulation of fatty material (consisting mainly of cholesterol) fibrous material and calcium forming an atheroma/ plaque beneath the endothelium
201
As the atheroma grows...
The artery thickens and looses its elasticity. The diameter of the artery becomes reduced and blood flow becomes restricted resulting in increased blood pressure
202
Atherosclerosis is the root cause of....
Various cardio vascular disease including angina, heart attack, stroke and peripheral vascular disease
203
Clotting factors activate..
Prothrombin (which is always present in the blood) into its active form called thrombin
204
Thrombin promotes....
The conversion of fibrinogen (a soluble plasma protein) into threads of fibrin
205
Fibrin threads are interwoven to allow...
Platelets to adhere forming a blood cloth (thrombus)
206
Thrombosis
The formation of a clot
207
Describe the formation of a clot (thrombosis)
Atheroma's may rupture, damaging the endothelium
The damage releases clotting factors that activate a cascade of reactions resulting in the conversion of the enzyme prothrombin to its active form thrombin
Thrombin then causes molecules of the plasma protein fibrinogen to form threads of fibrin
The fibrin threads forms a mesh work that clots the blood, seals the wound and provides a scaffold for the formation of scar tissue
208
In some cases a thrombus may break loose forming an...
Embolism and traveling through the blood stream until it blocks a narrow blood vessel
209
A thrombosis in a coronary artery may lead to
A heart attack (MI or myocardial infarction)
210
A thrombosis in an artery in the brain may lead to
Stroke
211
Why does thrombosis cause damage
Cells are deprived of oxygen which leads to tissue death
212
PVD (Peripheral Vascular Disease)
A narrowing of the artery due to atherosclerosis of the arteries other than those of the heart or brain
213
What is the most commonly effected artery of PVD
Legs
214
With PVD, why is pain experienced in the leg
Limited supply of oxygen
215
DVT (Deep vein Thrombosis)
a blood clot that forms in a deep vein most commonly in the leg and can break off and result in a pulmonary embolism
216
Pulmonary embolism
Blood clot in the lungs
217
Cholesterol
A type of lipid molecule found in the cell membrane
218
Why is cholesterol good?
Component of the cell Membrane
| Component of the sex hormone (oestrogen, progesterone and testosterone )
219
Why is cholesterol so bad?
Higher blood cholesterol level = higher risk of heart disease
Too much cholesterol contributes to the formation of atheromas
220
What are LDLs and HDLs
Essentially they are transporters
| Insoluble cholesterol must combine with proteins to form soluble lipoproteins to be transported in blood
221
The two major transport lipoproteins are...
High density lipoprotein (HDLs)
| Low density lipoprotein (LDLs)
222
High density lipoproteins
Transport cholesterol from body tissues to liver to be broken down
Prevents high level of cholesterol build up in blood stream
Known as good cholesterol
223
Low density lipoprotein
Main cholesterol carriers in blood
Transports cholesterol made by liver to body cells
Body cells have LDL receptors
When LDL cholesterol complex attaches it is engulfed and then used by the cell
224
When there is sufficient cholesterol in the cell....
Negative feedback inhibits the production of LDL receptors on the cell membrane
Resulting in more LDL circulating tho blood where it may be deposited in the endothelium of arteries forming atheromas
225
A.... of HDL and LDL is required
Balance
226
Percentage of Cholesterol carried by HDL
20%-30%
227
Percentage of Cholesterol carried by LDL
60-70%
228
A higher ratio of HDL to LDL will result in...
Lower blood cholesterol and a reduced chance of atherosclerosis
229
How can diet and exercise help high cholesterol
Regular physical activity tends to raise HDL levels and dietary changes aim to reduce the levels of total fat in the diet to replace saturated fat with unsaturated fat
230
How can medication help high cholesterol
Drugs such as statins reduce blood cholesterol by inhibiting the synthesis of cholesterol by liver
231
Chronic elevated blood glucose levels lead to...
atherosclerosis and blood vessel damage
232
At high blood glucose levels
Insulin is released converting glucose into glycogen
233
At low blood glucose levels
Glucagon is released converting glucose into glycogen
234
When adrenaline is released glucagon ...
Is secreted and insulin is inhibited
235
Blood glucose concentration is maintained within tolerable limits by...
Negative feedback control involving the hormones insulin, glucagon and adrenaline
236
Blood glucose is monitored by...
Receptors in the pancreas
237
The pancreas controls blood glucose with two hormones...
Insulin and glucagon, which act antagonisticlly
238
People who suffer diabetes are...
Unable to control their blood glucose level
239
How is diabetes diagnosed
Blood glucose concentrations rise rapidly after a meal and the kidneys are unable to reabsorb all the glucose, resulting in glucose being excreted in the urine
Testing urine for glucose is often used as an indicator of diabetes
240
Type 1 diabetes
Usually occurs in childhood
Pancreatic cells cannot produce insulin
Treatment is insulin injections and careful diet
Role of insulin- cells have normal levels of insulin so respond to insulin treatment
241
Type 2 diabetes
Usually occurs in adulthood
Pancreatic cells can produce insulin
Treatment is exercise, weight loss, diet control
Role of insulin- cells have decreased number of insulin receptors making them less sensitive to insulin
242
Obesity is a major risk factor for..
Cardiovascular disease and type 2 diabetes
243
Obesity is characterised by...
Excess body fat in relation to lean muscle.
244
body mass index (BMI) is
A measurement of body fat based on height and weight
245
The formula for BMI is
body weight (kg)
BMI= ------------------
Height (m^2)
246
BMI can be used to identify those who are....
Overweight, obese, underweight and normal
247
A body mass index greater than what is used to identify obesity
30
248
BMI can wrongly class..... and obese
Muscular individuals
249
Obesity is linked to....
High fat diets and a decrease in physical activity
250
Exercise increases...
Energy expenditure and preserves lean muscle tissue
251
Exercise can help...
Reduce Risk factors for CVD by keeping weight under control, minimising stress reducing hypertension and improving HDL:LDL ratios
252
What are the mainstream treatments of obesity and reduction of CVD
A reduction in energy intake (eat less) and an increase in energy expenditure (exercise more)
