Download 4.3 review ppt - Huber Heights City Schools

Unit 4.3 Review PBS
What is cholesterol? What roles does
cholesterol play in our cells and in the body
• Cholesterol is an important
lipid that is made in the liver
• It acts as a stabilizer for cell
membranes and used for cell
to cell communication.
•It is a precursor to steroid
hormones and Vitamin D
•It helps for bile acids, which are
important in fat digestion.
•It also makes up the myelin
sheath around nerve cells to
improve the speed of nerve
impulses
What are LDL and HDL?
• HDL – High Density Lipoprotein (made of mostly protein).
– Job is to carry cholesterol from the arteries to the liver
to be digested
• LDL – Low Density Lipoprotein (made of mostly lipids).
– Job is to carry cholesterol to the cells
How are LDL, HDL, and cholesterol related to
heart disease? How do doctors interpret the
results of a cholesterol test?
• High LDL levels carry too
much cholesterol to the
cells, which then builds up
in the arteries.
• Low HDL levels means not
enough HDL to clear the
arteries of the excess LDL.
• Build of LDL causes
Atherosclerosis, which
reduces blood flow and
can cause high blood
pressure and heart attacks
What is familial hypercholesterolemia and
how is it inherited?
• Mutation of the LDL
receptors on the cell
membrane, which leads
to a build of LDL in the
blood stream.
• Autosomal dominant
trait: heterozygotes will
still be affected and will
express the trait.
• Homozygous individuals
suffer with extremely
high cholesterol values
due to mutations of
even more receptors.
Using molecular biology to analyze DNA
for the presence of the FH mutation.
• PCR – is used to make many
copies of the FH gene
• Restriction Enzymes are used to
cut the FH Gene. Depending on
the bases the enzyme will cut at
different places, making different
sized fragments, called RFLPs
• Gel electrophoresis is used to
separate the fragments by size.
The negatively charged DNA
moves towards the positive end
and shorter fragments move
farther.
• The bands from each person can
be compared to controls to
identify the genotype that person
has.
Lifestyle changes
to lower
cholesterol levels?
• Limit Trans and Saturated
Fat as they increase LDL
• Eat unsaturated fats to
increase HDL
• Exercise daily
• Maintain healthy weight
• Manage stress and do
not smoke
• Take medications, like
statins if needed
Pros and Cons of cholesterol
lowering medications?
• Statins (Common cholesterol medication) will
decrease LDL, triglycerides, and even CRP (involved
in strokes), while slightly elevating HDL
• Side effects
– Muscle weakness and pain, even in the heart
– Amnesia for minutes to hours
– Headaches
– Dizziness
– Liver dysfunction
How does the heart
work as a pump ?
• As the heart
contracts it pushes
on the blood, causing
enough pressure to
push it through the
arteries.
What is atherosclerosis?
• Atherosclerosis is the
build up of plaque, which
can be due to excess LDL
along the arterial walls,
reducing blood flow
• Atherosclerosis of the
coronary artery can cause
lack of oxygen to fuel the
heart.
How can cholesterol
plaques affect the
overall function of
the heart?
•It can cause lack of blood
flow to the extremities,
including the brain, causing
strokes