cardiovascular system #1

week 6

briefly describe role of DNA

carries instructions for growth development, functioning & reproduction

• enables inheritance & passing genetic info

explain basic structure of DNA

• 2 phosphate molecule

• 1 deoxyribose sugar

• double stranded helix

• 4 bases

• chromosome= 1 long DNA molecule

• joined by hydrogen bonds

briefly explain/describe relo b/w DNA sequence & corresponding protein sequence

1. transcription

   • DNA transcribed into messenger RNA sequence

   • sequence of bases used as template to create complementary mRNA strand

2. translation

   • mRNA translated into protein sequence

   • at ribosome, codons (3 bases) matched with corresponding amino acids

   • each code assembles specific protein

describe human chromosomes with respect to

• number

• autosomes & sex chromosomes

• homozygous/heterozygous

• homologous pairs

• gene, phenotype, genotype

1. number: 46 total, 23 pairs of chromosomes

2. autosomes: 1-22 chromosomes (male & female)

3. sex chromosones: 23rd pair (XX, XY)

4. homozygous: 2 alleles identical

5. heterozygous: 2 alles different

6. homologous pairs: 2 chromosomes, 1 from mum, 1 from dad, similar in size, shape, genetic content

7. gene: seml section of DNA that carries instructions for protein

8. phenotype: observable traits from genotype/ environment

9. genotype: 2 alleles for a gene, genetic makeup

define allele

• alternate DNA sequence version of a gene

explain relo b/w phenotype &genotype

• genotype provides instructions for building proteins, which influence organism traits

• phenotype not solely determined by genotype, also environment (diet, climate, lifestyle)

describe dominant vs recessive alleles

dominant:to express only 1 allele dominant needs to be present

recessive: to express must be 2 recessive alleles

• homozygous

• small lettered

sex linked vs autosomal alleles

codominance:

• 2 allies are dominant over recessive allele

• when both dominant allele present = both phenotypes expressed

sex lined:

• when disease allele on X chromosomes

• most X linked are recessive

• males commonly affected

what happens in mitosis

• replaces romantic/ body cell

• interphase: cell grows, performs normal functions

• before division DNA must be replicated

  1. prophase

  2. pre metaphase

  3. metaphase

  4. anaphase

  5. telophase

  6. cytokinesis

describe prophase

• chromosomes become condensed & visible

• spindle fibres emerge from centrosomes

• centrosomes move towards opposite poles

describe pre metaphase

• miotic spindle microtubules attach to kinetochores

• chromsones continue to condense

• kinetochores appear at centromeres

describe metaphase

chromosomes lined up at metaphase plate

each sister chromatid attached to spindle fibre

describe Anaphase

• centromeres split in 2

• sister chromatids (now chromosomes) pulled towards opposite poles

• some spindle fibres elongate cell

describe telophase

• chromosomes arrived at opposite poles & become to decompose

• nuclear envelope materials surround each set of chromosomes

• biotic spindle breaks down

describe cytokinesis

• animal cells: a cleavage furrow separates the daughter cells

• plant cells: precursor to a new cell wall separates daughter cells

what different in steps for meiosis

prophase, metaphase, anaphase and telophase/ cytokinesis repeated

number chromosomes, number daughter cell, if genetically identical, function of meiosis/mitosis

mitosis:

• 46

• 2

• yes

• grow tissue, replace body cells

meiosis:

• 23

• 4

• no

• proud gametes

descrive L, orientation, St & F of heart

• location: thoracic cavity, mediastinum

• orientation: with apex

2/3 heart mass on left of midline

• structure: 4 chambers (2 atria, 2 ventricles)

• function: pump, circulatory oxygenated/deoxy blood

distinguish between/w 3 layers of heart

1. epicardium

   • outermost layer

   • provides protection & decrease friction b/w surrounding structures

   • doubles as a inner layer of pericardium

2. myocardium

   • middle layer

   • composed of cardiac tissue & responsible for pumping action of heart

3. endocardium

   • inner layer

   • layer ofnendothelium with connective tissue

   • forms lining of chambers & covers valves

   • smooth = decrease friction as blood passes through heart

roles of 2 AV vales

1. tricuspid vales

   • b/w right atrium & right ventricle

   • during ventricular contraction

2. bicuspid valve

   • b/w left atrium & left ventricle

roles of 2 SV valves

1. pulmonary

   • b/w right ventricle & pulmonary artery

   • prevents back flow after pumped in lungs

2. aortic valve

3. b/w left ventricle & aorta

4. opposite prevention of blood flow

explain how heart itself receives blood & return it to blood supply and systemic vs pulmonary pumps

• pulmonary: send blood to lungs'

• systemic: delivers blood to/from body

• receiving blood: canary arteries, branch off aorta, oxygenated blood

• returning blood: deoxygenated blood

• cardiac veins

• conary sinus

• empties to right atrium

name major vessels attached to heart & explain where they receive blood from & carry to

1. bring blood to heart =

   • vena canna (superior & inferior): deoxygenated blood to right atrium from body

   • pulmonary veins: bring oxygen blood from lungs to left atrium

2. vessels blood away heart

   • pulmonary artery: deoxygenated blood from right ventricle to lungs for oxygen

   • aorta: carries oxygen from L ventricle to rest of body

outline path blood takes for a complete circuit around body

1. superior/inferior venacava

2. right atrium

3. tricuspid valve

4. right ventricle

5. right semilunar valve (pulmonary valve

6. pulmonary trunk

7. pulmonary arteries

8. lungs pulmonary veins

9. left atrium

10. bicuspid valve

11. left atrium

12. bicuspid valve

13. left ventricle

14. left semilunar valve (aortic valve)

15. aorta

16. peripheral circulation

location and function of SA node

L: upper wall right atrium

F: hearts natural pacemaker, innate electrical pulses

location and function of AV node

L: lower part right atrium

F: receives & slows down electrical impulses from SA node, allows ventricles fill with blood before contradicting

location and function of AV bundle (bundle of his)

L: Av node into inter ventricular septum

F: transmits impulses from AV node to L&R bundle branches

location and function of L&R bundle branches

L: through inter ventricular septum

F: carry electrical impulses to apex of heart

location and function of purkinje fibres

L: walls of ventricles

F: distribute electrical impulses throughout ventricular myocardium, synchronised contractions ventricles

describe atrial conduction

• once SA node fires electrical impulses spread through atria

• contraction

• blood into ventricles

3 roles of SA sinoatrial node

1. acts as a pacemaker

   • generate electrical impulses that innate each heartbeat

2. determines heart rate

   • rate of impulse dictates frequency the heart beats

3. synchronous contraction of atria

   • coordinating blood flow into ventricles

relate depolarisation to contraction & repolarisation to relax of muscle

1. depolarisation

2. electrical conduction

3. calcium release

4. muscle contraction

1. depolarisation

2. restoring resting potentail

3. calcium removal

4. muscle relaxation

describe role of blood pressure in blood flow

driving force:

• blood flow areas increase pressure to decrease pressure

• generates pressure gradient during systole & diastole

systemic & pulmonary circulation:

• in systemic - L ventricle: pumps to aorta in increase pressure

• in pulmonary - R ventricle pumps in decrease pressure into pulmonary artery

describe role of blood pressure in closing of heart valves

AV valve:

• open when pressure in atria increase more than ventricle

• during diastole

• close when systole & pressure exceeds atrial pressure, prevent back flow into aorta

Semilunar valve:

• open when ventricular pressure more than pulmonary artery & aorta

• during systole

• blood flow out of ventricles

• close when diastole& pressure in arteries more than ventricles

relate p-wave to electrical, mechanical/ physical events of normal cardiac cycle

E: depolarisation of atria

M/P: systole, pushes blood into ventricles

relate PR interval to mechanical/ physical events of normal cardiac cycle

E: time taken for impulse to travel from atria to AV node ventricles

M/P: allows atria to fully contract & fill ventricles b/f ventricular contraction begins

relate QRS segment to mechanical/ physical events of normal cardiac cycle

E: depolarisation of ventricles

M/P: systole, blood out of right ventricle & body (L ventricle), atrial depolarisation, diastole

relate ST segment to mechanical/ physical events of normal cardiac cycle

E: period b/w ventricular depolarisation & beginning of depolarisation & beginning of depolarisation

M/P: ventricles remain contracted, actively ejecting blood into arteries

relate T-wave to mechanical/ physical events of normal cardiac cycle

E: depolarisation of ventricles

M/P: diastole, ventricles fill with blood for next cycle

ECG in relation to cardiac cycle

• depolarisation corresponds to contraction (systole)- drive blood forward

• depolarisation corresponds to relaxation (diastole), prepare for next HB