Metaboism And Endocrine Contrl During Special Circumstances

Question 1

What are the fuel sources of the body?

Answer 1

normal - Glucose + fatty acids
in special circumstances - amino acids, ketone bodies + lactate

Question 2

Body energy stores + their weight in a 70kg man

Answer 2

Glucose ~ 400g
Fat - TAGs 10-15kg
Muscle protein ~ 6kg

Question 3

What amino acids are glucogenic?

Answer 3

Alanine
Valine

Question 4

What amino acids are ketogenic?

Answer 4

Lysine
Leucine

Question 5

What amino acids are both glucogenic and ketogenic?

Answer 5

Tyrosine
Phenylalanine

Question 6

What are the key features of metabolic control?

Answer 6

Feeding:
up to 2 hours - glucose and fat absorption from gut fuels metabolism and prompts storage
2-10 hours - absorption stopped - fatty acids and glycogen stores used to preserve blood glucose for brain
8+ hours - glycogen stores deplete - gluconeogenesis occurs

Starvation:
No glycogen - body breaks down fatty acids into ketone bodies

Question 7

Anabolic control of metabolism

Answer 7

Promote fuel storage

insulin
Growth hormone- increase protein synthesis + gluconeogenesis

Question 8

Catabolic control of metabolism

Answer 8

promote release from stores

Glucagon
Adrenaline
Cortisol
GH - increases lipolysis + glycogenolysis
Thyroid hormones

Question 9

What process are inhibited by insulin?

Answer 9

Gluconeogensis
Glycogenolysis
Lipolysis
Ketogenesis
Proteolysis

Question 10

What process are stimulated by insulin?

Answer 10

Glucose uptake into muscle +adipose (GLUT4)
Glycolysis
Glycogen synthesis
Protein synthesis

Question 11

Outline the feeding-fasting cycle

Answer 11

Feeding releases insulin
Fasting releases glucagon

Question 12

How much weight does woman gain during pregnancy?

Answer 12

~8kg

Question 13

Outline the 2 phases of metabolic adaptation in pregnancy

Answer 13

1- anabolic phase:
- increased fat + nutrient stores
- increases in level of insulin sensitivity

2- catabolic phase
- decreased insulin sensitivity
- increase in maternal glucose free fatty acid conc.

Changes occur due to fetoplacetal unit

Question 14

Wha can maternal resistance to insulin lead to?

Answer 14

Gestational diabetes

Question 15

Outline placental transfer

Answer 15

Mainly via diffusion down conc. gradient
Glucose via GLUT1 transporter

Question 16

What is gestational diabetes?

Answer 16

Disease where pancreatic B cells do not produce enough insulin to meet increased demand in late pregnancy

Question 17

What are the 3 main causes of gestational diabetes?

Answer 17

1- autoantibodies in blood
2- genetic susceptibility
3- chronic insulin resistance + obesity - most common

Question 18

Clinical implications of gestational diabetes

Answer 18

• increases chance of miscarriage
• increases risk of congenital malformation
• increased chance of macrosomia - large baby
• increases chance of gestational hypertension + pre-ecamplsia

Question 19

What is macrosomia?
What can it cause?

Answer 19

Large baby
Can cause shoulder dystocia - shoulder of baby gets caught in birth cancel
Can cause Erb’s palsy

Question 20

What is pre-eclampsia?

Answer 20

Condition characterised by proteinuria + hypertension in a other
Caused by placenta not being able to supply enough blood to fetus

Question 21

Management of gestational diabetes

Answer 21

Dietary modification
Insulin injections
Regular fetal monioring

Question 22

Risk factors of gestational diabetes

Answer 22

Maternal age >25
Maternal BMI >25 overweight or obese
Family history of diabetes
Family history of macrosomia - potential undiagnosed gestational diabetes

Question 23

Hormonal changes during extreme exercise

Answer 23

• decrease insulin
• increase glucagon, adrenaline, GH and cortisol

Question 24

What does the magnitude and nature of the metabolic response to exercise depend on?

Answer 24

Type of exercise - muscle used
Intensity + duration
Physical control + nutrition