Week 11 - Pregnancy, Menopause, Ageing

Question 1

Fertilization steps

Answer 1

1. Sperm enters corona radiata
2. Sperm cell contacting zona pellucida (depolorization so other sperm cells cannot enter)
3. Sperm enters oocyte
4. Sperm and Oocyte nucleus undergo transformation to make Male and Female pronucleus (23 chromosones each)
5. Pronucleus combine and form a Zygote (46 chromosomes)

Question 2

What does the Zygote become a Blastocyst?

Answer 2

~Day 7 in the uterus

Question 3

What day does the blastocyst burrow into the uterine wall?

Answer 3

Around day 7

Question 4

Name all of the arrows on the left of this picture from top to bottom and what do these structures form?

Answer 4

Syncytiotrophoblast, Cytotrophoblast, Lacuna filled with maternal blood. They form a protective layer between the maternal arterioles and the embryonic vessels

Question 5

Stages of pregnancy and the time

Answer 5

Zygote - once male and female nucleus combine

Blastocyst - first 2 weeks

Embryo - 2-8 weeks

Foetus - week 9 to birth

Pregnancy lasts 40 weeks

Question 6

Human chorionic gonadotropin (hCG)

Answer 6

Secreted by blastocyst and placenta

Found in urine provides indication of pregnancy

Stimulates growth of the corpus luteum x2 in size

= increased amounts of oestrogen and progesterone

Question 7

Relaxin

Answer 7

Secreted by the corpus luteum and placenta

Relaxes the ligaments of the body

Question 8

What does the placenta secrete?

Answer 8

Oestrogen: increase water retention and protein synthesis

Progesterone: smooth muscle relaxation, raises body temp

Question 9

Why do the physiological changes occur during pregnancy?

Answer 9

To provide a suitable environment for the growth, nutrition and development of the foetus

To protect and prepare the mother for the process of pregnancy and support the newborn

Question 10

Maternal cardiovascular alterations

Answer 10

Blood volume +45-50%

Heart rate +15-25% at rest

Stroke volume increases 30%

Cardiac Output increases 40-50%

Question 11

When can blood pressure decrease during pregnancy and why?

Answer 11

1st and 2nd Trimester, returns 3rd trimester

Increased progesterone causes vasodilation, heart is pushed upwards and to the side, which increases the size of the heart 70-80ml

Question 12

Maternal respiratory alterations

Answer 12

Increases in Tidal volume (30-50%)

Minute volume (20-50%)

Decreases in Expiratory reserve volume and residual volume

Question 13

Why does inspiration increase, but expiration doesn’t during pregnancy?

Answer 13

More oxygen is needed for the foetus, therefore more oxygen is breather in and used.

Question 14

Maternal renal alterations

Answer 14

Kidneys enlarge - Rengal blood flow (30-50%)

Glomerular filtration rate (50%)

Increased urination

Question 15

Why can glucosuria occur during pregnancy?

Answer 15

More urination occuring, meaning more glucose may be secreted into the filtrate and not reabsorbed

Question 16

Thermoregulation during prengnacy

How does the body dissipate additional heat load?

Answer 16

Increase ventilation, increased skin blood flow.

Pregnant women should stay hydrated and avoid high environmental temperatures

Question 17

Meternal endocrine changes

Answer 17

Anterior pituitary: Increased plasma concentrations of Prolactin

Placenta produces CRH and ACTH

GH, LH, FSH are supressed

Posterior Pituitary: Increased number of oxytocin receptors

Thyroid function increases

Question 18

Physical changes during pregnancy

Answer 18

Weight gain to the anterior, ligament laxity - Relaxin, Joint mobility, COG moves forward, increased weight of uterus and breasts

Question 19

Function of pelvic floor

What can happen when these muscles weaken?

Answer 19

Support the pelvic organs: uterus, bladder, bowel

Urinary incontinence, organ prolapse

Question 20

Menopause occurs when and why and symptoms?

Answer 20

Between ages 40-60 years

Remaining number of follicles is small, Follicles left are less sensitive to FSH and LH, reduced amounts of oestrogen and progesterone

Uncomfortable sweating (hot flushes), anxiety, fatigue, emotional disturbances

Question 21

Post-menopausal osteoporosis

Answer 21

1 in 3 women, reduction in bone mineral density due to hormonal factors = reduced oestrogen = increased bone loss, increased risk of fractures

Question 22

Senescence

Answer 22

The process of deterioration with age

Question 23

Causes of ageing

Answer 23

Complex and multifactorial

Question 24

What occurs to our cardiovascular system when we age? (4)

Answer 24

Reduction in arterial elasticity - blood pressure can rise quickly due to less room in arteries, out of breath quickly as increased pulmonary capillary pressure

Cardiac tissue - accumulation of lipids and collagen stiffens the heart and makes it less compliant

Heart valves become less flexible

SA node cells decrease altering electrical activity

Question 25

What happens to HR, SV, CO and VO2?

Answer 25

Declines

Question 26

Ageing and the respiratory system? (5)

Answer 26

Vital capacity decreased, residual volume increases as we don’t have the power in our lungs to expire, decreased gas exchange across respiratory membrane, gradual rise in tidal volume, mucus builds up

Question 27

Ageing and urinary system? (6)

Answer 27

Kidneys decrease in size, renal blood flow decreases, glomeruli are destroyed, ability to secrete and absorb declines, loss of responsiveness to ADH and aldosterone, decrease in renin secretion

Question 28

Ageing and the digestive system? (5)

Answer 28

Thinning of mucosa and submucosa, decrease in blood supply, decrease in smooth muscle cells, less secretions from major secretory organs, muscles of mastication are weakened.

Question 29

Ageing and the endocrine system (5)

Answer 29

Gradual decrease in secretory activity in some glands, GH levels decrease, Thyroid hormones decrease slightly, Increase in parathyroid hormone but reduced levels of Ca2+ makes bone matrix waste away, Thymosin decreases with age leading to easier infection

Question 30

Ageing and thermoregulation (3)

Answer 30

Sweat gland secretions decrease, reduced peripheral blood flow = reduced ability to regulate temperature, increased risk of heat exhaustion and illness