Unit 1- Physiology and Health Flashcards
In the reproductive system what do hormones control?
The onset of puberty
Sperm production
The menstrual cycle
What is the function of testosterone?
To stimulate sperm production and activate the accessory glands
What arteries are most commonly affected by PVD?
The arteries in the legs
What is the pituitary gland?
A gland hanging from the base of the brain.
Describe the process of fertilisation
A mature ovum is released into the oviduct where it is fertilised by sperm
Describe the process of puberty onset.
The hypothalamus decreases a released hormone targeting the pituitary.
The pituitary the produces 2 hormones
FSH and LH in women
And
FSH and ICSH in men
What is ICSH
Interstitial cell stimulating hormone
Stimulates testosterone production
What is the function of the pituitary gland?
To secrete hormones that control many other glands in the body.
What does haploid mean?
1 single set of chromosomes
Sex cells
How is sperm production controlled hormonally?
Negative feedback of FSH and ICSH
What is FSH?
Follicle Stimulating Hormone.
Develops follicle in women
And
Stimulates sperm production in men
Approximately how long is the average menstrual cycle?
28 days
What marks the first day of the menstrual cycle?
The first day of menstruation
What are the 2 phases of the menstrual cycle called?
Follicular and luteal phase
Describe the stages of the follicular phase of the menstrual cycle
FSH is released, stimulating the development of the follicle in the ovary.
The follicle secretes oestrogen, which stimulates the proliferation of the endometrium and affects the consistency of the cervical mucus making it more easily penetrated by sperm
Hugh levels of oestrogen trigger a surge in LH which is the direct cause of ovulation
What’s different about the end of the luteal phase of the menstrual cycle of fertilisation occurs?
The corpus luteum doesn’t degenerate and progesterone levels remain high to maintain the foetus.
What is the name given to a male fertility?
Continuous
What 2 ways can a female fertile period be calculated?
0.5 degree temperature increase
Thinning of the cervical mucus
What are the 4 types of infertility treatments?
Stimulating ovulation drugs
Artificial insemination
Intra-cytoplasmic sperm injection (ICSI)
In vitro fertilisation (IVF)
Why does diastole mean?
The chambers of the heart relax
What does diploid mean?
2 sets of chromosomes
Describe how stimulating ovulation drugs work
Drugs given to prevent negative feedback of oestrogen on FSH or drugs given to mimic FSH and LH to cause super ovulation
Describe the process of artificial insemination
Semen samples are collected over a period of time and inserted into the female reproductive tract
Describe the process of ICSI
Head of sperm is drawn into a needle and injected directly into the ova
Describe the process of IVF
Done in conjunction with ovulation drugs
Several eggs are removed, mixed with sperm.
Fertilised zygotes are incubated till around 8 cells and implanted into the uterus
What is the use fo PGD
To identify single gene disorders and chromosomal abnormalities
How do barrier methods of contraception work?
Cause a physical barrier between sperm and egg
How does an IUD work?
I steered into the uterus by a doctor and changed the lining of the uterus and oviduct stopping the movement of sperm and eggs
Where do the SL valves sit?
Between the ventricles and arteries
What is the morning after pill and how does it work?
An emergency contraceptive containing a high dose of progesterone preventing ovulation or implantation if ovulation has already occurred
What triggers the pituitary gland?
The hypothalamus
What does antenatal screening do?
Identifies risks of a disorder so further tests can be carried out and prenatal diagnosis can be given.
What is the main antenatal screening?
Ultrasound
What are the 2 types of ultrasound scan?
Dating scan and anomaly scan
What does a dating scan check for?
Babies due date
What is the name given to female fertility?
Cyclical- lasting about 1-2 days
When can a dating scan take place?
8-14 weeks
What does an anomaly scan check for?
Physical abnormalities with the foetus
Describe the luteal phase of the menstrual cycle
The empty follicle develops into the corpus luteum which secretes progesterone
Progesterone promotes further vascularisation of the endometrium
High levels of oestrogen and progesterone have a negative feedback control on the pituitary, inhibiting FSH and LH production so no new follicles
Lack of LH causes the corpus luteum to degenerate
Low levels of progesterone cause menstruation to occur because the endometrium can’t be maintained
What is a dating scan done in conjunction with?
Testing for chemical markers
Apart from ultrasound scans what’s the other type of antenatal screening?
Blood and urine tests
How does the combined contraceptive pill work?
By containing synthetic progesterone and oestrogen mimicking negative feedback preventing FSH and LH release
What do blood and urine tests do ?
Check levels of chemical markers in the blood or urine to indicate the possibility of a condition.
What can happen if blood and urine tests are done too early
It can result in a false positive
What can an irregular chemical marker concentration lead to?
A diagnostic test
What happens to expectant parents before diagnostic tests are done?
The risk factors are discussed and also their decisions they’re likely to make if the results are positive.
Describe the process of amniocentesis
A sample of amniotic fluid is taken using a fine needle through the belly and uterine wall. The cells are then cultured and karyotyped to check for chromosomal disorders.
How would you identify autosomal recessive inheritance?
Relatively rare
May skip generations
Males and females affected in equal number.
What is a diagnostic test?
A definitive test used to establish whether or not a person has a certain condition
Name 2 types of diagnostic test
Amniocentesis
Chorionic villus sampling (CVS)
What is a karyotype?
Individual chromosomes arranged as homologous pairs.
What happens if an atheroma ruptures?
The damage releases clotting factors that activate the formation of a blood clot/thrombus
What is cardiac output?
Volume of blood pumped through the ventricle per minute
Compare amino and cvs
Amniocentesis has a Lower risk of miscarriage but is carried out later in pregnancy whereas cvs is a slightly higher risk of miscarriage but can be carried out earlier.
How would you identify sex linked recessive inheritance?
Usually:
Many more males affected than females
Shown as X^h X^h or X^h Y
How is PKU tested for?
Heel prick test
How would you identify autosomal incomplete dominant inheritance?
Usually:
Full expression is rare
Partial expression is more common
Full sufferer has both parents with partial
Males and females affected in equal number
What causes plasma to be forced out of the capillaries into the fluid surrounding the cells?
High pressure blood coming from the arterioles
What is screened for in post natal screening?
Phenylketonuria (PKU)
What is PKU?
Phenylketonuria
A substitution mutation which causes the enzyme which converts phenylalanine into tyrosine to be non functional
What does systole mean?
The chambers of the heart contract
How is PKU treated?
A restricted diet low in phenylalanine
What is the heart rate?
Number of heart beats per minute
What hormone increases heart rate when stressed or during exercise?
Adrenaline
Where do the AV valves sit?
Between the atria and ventricles
What is PGD
Preimplantation genetic diagnosis
How do you calculate cardiac output?
Heart rate x stroke volume
Where is the SAN located?
The wall of the right atrium
How do the SL and AV valves open and close?
Due to pressure changes
How can you listen to the heart sounds?
With a stethoscope
What sets the rate of cardiac contraction?
The SAN(sinoatrial node) or pacemaker
Where does the heart beat originate?
Within itself
How does the mini contraceptive pill work?
Contains a high dose of progesterone which causes the thickening of the cervical mucus, stopping sperm
What is the order of blood circulation?
Heart——>Arteries——>capillaries——>veins——>heart
What causes ventricular systole?
Electrical impulses travelling down the centre of the heart and up the ventricle walls
What is the SAN made of?
Auto rhythmic cells
What causes atrial systole?
Electric leg impulses sent from the SAN across the atria to the AVN
Where is the AVN located?
The base of the atria
What is the wave on an ECG called?
PQRST wave
What does a T wave represent?
Recovery of ventricle walls
What is cholesterol?
Type of lipid found in cell membranes
Is cholesterol on its own soluble or insoluble?
Insoluble
What do the electrical impulses generate in the heart?
A current that can be detected by an electrocardiogram (ECG)
What is LH
Lutenising hormone
Stimulates ovulation and the development of the corpus luteum
How would you identify autosomal dominant inheritance?
In every generation
Each sufferer has an affected parent
Will die out and then not reappear
Males and females affected in equal number
What would a doctor do if glucose was present in the urine(positive indicator test)?
Do a glucose tolerance test
What are the names of the 2 types of nerves that secrete neurotransmitters to control heart rate?
Sympathetic accelerator nerves
Slowing parasympathetic nerves
What does a QRS wave represent?
Ventricular systole
What alters the heart rate?
Hormonal and nervous activity
What is the name given to the nervous system the heart is supplied by?
The autonomic nervous system
What regulates the SAN?
Control centres in the medulla through antagonistic action
What do the sympathetic accelerator nerves release and what does it do?
Noradrenaline to increase heart rate
What is blood pressure?
Friction between the blood and the blood vessel
What happens to blood pressure during ventricular systole?
Increases
What happens to blood pressure during diastole?
Decreases
What is blood pressure measured using?
A sphygmomanometer
Describe the process of blood pressure being taken
The cuff inflates to stop blood flow in the upper arm
First reading taken when cuff starts to deflate and blood starts to flow (pulse detected) — systolic pressure
Second reading taken when cuff continues to deflate and blood flows freely (no pulse detected) — diastolic pressure
What is a typical blood pressure reading?
120/80 Mmhg (millimetres of mercury)
What name is given to chronic high blood pressure?
Hypertension
What does hypertension increase the risks for?
CVD (cardiovascular disease)
Why happens to blood pressure as blood moves away from the heart?
Decreases
What is a lumen?
Central canal of blood vessels
Name the structures in an artery
Outer layer of connective tissue Containing elastic fibres
Thick smooth muscle layer
Narrow lumen
Inner endothelial lining
What do the elastic fibres in it’s walls allow it to do?
Stretch and recoil to accommodate for the surge of blood after each contraction of the heart
What does the smooth muscle in an artery allow it to do?
Contract and relax to allow it to Vasoconstrict and vasodilate to control blood flow
What do veins do?
Carry blood back to the heart
Name the structures in a vein?
Outer layer of connective tissue containing elastic fibres
Much thinner smooth muscle layer
Wide lumen
Inner endothelial lining
Valves
What do the valves in veins do?
Prevent back flow of blood
Why causes heart sounds?
The opening and closing of the AV and SL valves
What are capillaries?
Exchange vessels where materials are exchanged with tissues due to 1 cell thick walls
What is fluid called that surrounds cells?
Tissue fluid
Where is cholesterol synthesised?
In all cells but 25% of it is made in the liver from saturated fats
What is the process of plasma being forced out of capillaries into tissue fluid called?
Pressure filtration
How does tissue fluid differ from blood plasma?
There is no proteins in tissue fluid due to them being too big to fit through capillary walls
When can an anomaly scan be done?
Between 18-20 weeks
Describe the process of CVS
A sample of placental cells is removed through the vagina. These cells are then cultured and then karyotyped to check for chromosomal disorders.
What is diffusion?
Movement of molecules from a high concentration to a low concentration
What happens to soluble food molecules,oxygen and ions in the tissue fluid?
Diffuse into nearby cells
What do cells diffuse into the tissue fluid?
Carbon dioxide and urea
What happens to tissue fluid after exchange of materials?
Much of it returns to the blood through osmosis
What is the excess tissue fluid that is absorbed into lymphatic vessels called?
Lymph
What does the lymphatic system do with the lymph absorbed from excess tissue fluid?
Return it to the circulatory system
What is atherosclerosis?
Formation of an Atheroma
What is an atheroma?
Build up of fatty material beneath the endothelium
What happens as an atheroma grows?
The artery thickens and loses its elasticity
The diameter of the lumen becomes reduces and blood flow is restricted
Raises blood pressure
What is a thrombus?
Blood clot in a blood vessel
What is thrombosis?
The formation of a thrombus
What is atherosclerosis the food cause of?
Angina
Heart attack
Stroke
PVD
What does the fatty material that forms an atheroma consist of?
Mainly cholesterol, fibrous material and calcium
What is blood clotting?
Protective device triggered by damage to cells in order to prevent blood loss.
What does thrombin do?
Turn fibrinogen (soluble protein) into fibrin (insoluble protein)
What do the parasympathetic nerves release and what does it do?
Acetylcholine to decrease heart rate
What happens if an embolus blocks a blood vessel?
Reduced blood flow or cut it off completely
What do fibrin threads do?
Form a mesh work structure that clots blood, seals the wound and provides a scaffold for the formation of scar tissue
What what would thrombosis in an artery in the brain cause?
A stroke
What would thrombosis in a coronary artery lead to?
A myocardial infarction(heart attack)
What is it called if an embolus blocks an artery?
Embolism
Where does the SAN send electrical impulses?
Across the atria to the AVN (atrioventricular node)
Where does the electrical impulse go after the AVN?
Down the centre wall of the heart and up the walls of the ventricles
What do arteries do?
Carry blood away from the heart
What is an embolus?
A thrombus that breaks loose from the blood vessel wall
What happens to blood glucose levels when a person is experiencing a fight or flight response?
Adrenaline inhibits insulin secretion and promotes glucagon secretion which raises the blood glucose levels giving the body the added energy it may need
What is a use for cholesterol?
Used to make sex hormones
Basic component in cell membranes
What is an indicator for diabetes?
Glucose in urine found by testing with clinistix
What is CVD?
Cardiovascular disease
What is PVD?
Peripheral vascular disease is narrowing of the arteries due to atherosclerosis in arteries other than those to the hear of brain
What’s is stroke volume?
Volume of blood expelled by each ventricle on contraction
What would a diet high in cholesterol result in?
Higher blood cholesterol levels and a higher risk of heart disease.
Why do PVD sufferers experience pain?
Due to a limited supply of oxygen which causes cells to undergo anaerobic respiration, resulting in a build up of lactic acid.
What can be the result of a thrombus breaking free in vein?
It could become lodged in the Lungs and cause a pulmonary embolism.
How does cholesterol travel around the body?
Attached to proteins to make soluble lipoproteins.
What are the 2 major transport lipoproteins?
High density lipoproteins (HDL)
Low density lipoproteins (LDL)
What are HDL’s?
High density lipoproteins (good cholesterol)
What do HDL’s do?
Transport transport excess cholesterol from body cells to liver for elimination
Preventing a build up of cholesterol in the blood stream
How is obesity caused most commonly?
A high in fat diet and a lack of exercise
What are LDL’s?
Low density lipoproteins (bad cholesterol)
What do LDL’s do?
Transport cholesterol from liver to body cells
To LDL receptors where it is taken in and the cholesterol is used
What happens to the the LDL’s after body cells have an efficient store of cholesterol?
Negative feedback is triggered to stop the production of new LDL receptors
Excess LDL’s are left circulating
Endothelial cells take in the LDLs and cholesterol is deposited into the artery walls
Resulting in the formation of an atheroma
How do statins work?
Inhibit the enzyme essential for cholesterol synthesis
Name 3 ways to treat high cholesterol
Regular exercise
Low saturated fat diet
Medications known as statins
What ratio of HDLs to LDL’s result in?
A lower blood cholesterol and reduced chance of atherosclerosis
What is DVT?
Deep vein thrombosis- formation of a thrombus in a deep vein, usually in the calf muscle causing pain and swelling.
Describe what happens when a rise in blood glucose is detected
The rise is detected by pancreatic receptor cells
These increase the secretion of insulin which converts glucose into glycogen
Glycogen is stored in the liver and decreases blood glucose levels
Describe what happens if a drop in blood glucose levels is detected
The drop is detected by pancreatic receptors cells
These increase the secretion of glucagon by the pancreas which converts glycogen to glucose
This increases blood glucose levels
What’s more common type 1 diabetes or type 2?
Type 2
When does type 1 diabetes usually occur?
Childhood
Name at least 3 benefits of exercise
Increases energy expenditure and preserves lean tissue
Reduces the risk of CVD
Keeps weight under control
Minimises stress
Reduces hypertension
Increased the number of HDL’s in the blood therefore reducing cholesterol levels
When does type 2 diabetes usually occur?
Later in life
What is the biology of type 1 diabetes?
The patients pancreatic cells do not produce insulin but they’re cells still have normal insulin receptors.
How are the chances type 2 diabetes heightened?
Being over weight or having a bad diet
What is a treatment for type 2 diabetes?
Regular exercise and diet changes
What is a treatment for type 1 diabetes?
Regular doses of insulin
What would a glucose tolerance test diagnose?
Diabetes
Why BMI is considered obese?
Over 30
Name 3 types of physical contraceptive methods
Barrier methods- condoms, diaphragm
IUD
Sterilisation
What is the biology of type 2 diabetes?
The patients pancreatic cells still produce sufficient insulin but they’re pancreatic receptors have become less sensitive to insulin.
Describe how a glucose tolerance test works
The patient would fast for 8 hours to limit the initial level of glucose in the blood
They would consume a known mass of glucose
They’re glucose levels would be monitored over 2 hours and interpreted to determine if their body is handling glucose appropriately.
What can obesity lead to?
CVD or type 2 diabetes
What is BMI?
Body mass index, ideal weight for an individual person
How is BMI calculated?
BMI= body mass/height^2
Why is BMI not always reliable or accurate?
Can wrongly identify muscular people as obese as it doesn’t distinguish between muscle tissue and fat
What happens to blood glucose concentration after a meal for diabetics?
It will rise rapidly
What does chronic elevation of blood glucose lead to?
Endothelial cells taking in more glucose than normal, damaging the blood vessels
Risk of atherosclerosis
Haemorrhaging of blood vessels in the retina
Renal failure
Peripheral nerve dysfunction
What happens to the excess tissue fluid that does not return to the capillaries?
Absorbed by thin walled lymphatic vessels
What does a P wave represent?
Arterial systole
What do clotting factors do?
Turn prothrombin (inactive enzyme) into thrombin (active enzyme)
