Obesity (Causes and Effects)

Question 1

state what it is meant by the key term - obesity

Answer 1

obesity is the condition in which excess fat gas accumulated in the body

Question 2

Obesity can also be defined as …

Answer 2

BMI = BW (Kg) / Height (m^2)

Question 3

state 4 ranges of BMI (from normal up)

Answer 3

1. normal range = 20 - 25 Kg/m^2
2. grade 1 obesity = 25 - 30 Kg/m^2
3. grade 2 obesity = 30 - 40 Kg/m^2
4. grade 3 obesity = 40+ Kg/m^2

Question 4

state the 3 main causes of obesity

Answer 4

1. genetic disorders (rare)
2. pathological conditions
3. Increased food consumption and decreased energy expenditure

Question 5

what is the main hormone concerned with appetite regulation ?

Answer 5

Leptin

Question 6

what is leptin ?

Answer 6

a 167 amino acid chain protein

Question 7

what is the gene which codes for leptin ?

Answer 7

Ob gene

Question 8

talk about mutations of the Ob gene (2 facts)

Answer 8

1. mutated ob genes don’t produce / produce very little leptin
2. homozygous mutations (ob/ob) do not become satiated after a meal and develop obesity and diabetes

Question 9

explain how leptin regulates appetite (4 points)

Answer 9

1. adipocytes produce and release leptin into blood
2. binds to leptin receptor in the ‘feeding centre’ in the ‘hypothalamus’
3. decreases neuropeptide Y (NPY) - a 36 amino acid protein
4. decreased NPY causes: 1) increased energy expenditure, and 2) decreased food intake

Question 10

what is ‘Cushing’s Disease’ ?

Answer 10

Cushing’s disease is a pathological disease associated with obesity

Question 11

state 3 symptoms of Cushing’s disease

Answer 11

1. psychiatric effects
2. fat trunk / abdomen
3. muscle wasting and weakness
4. moon face
5. striae (stretch marks on the abdomen)
6. diabetes
7. thin extremities

Question 12

state the 2 causes of Cushing’s disease

Answer 12

1. a pituitary adenoma (benign tumour of the epithelial origin)
2. adrenal tumour

Question 13

state the two types of pituitary adenomas (benign tumour of the epithelial origin)

Answer 13

1. micro-adenoma = < 10 mm

2. macro-adenoma = > 10 mm

Question 14

what are the 3 layers of the adrenal cortex ?

Answer 14

1. zona glomerulosa (outer layer)
2. zona fasciculata (middle layer)
3. zona reticularis (inner layer)

Question 15

what 3 things does the adrenal cortex secrete ?

Answer 15

1. glucocorticoids
2. sex steroids
3. mineralocorticoids

Question 16

what does the medulla secrete ?

Answer 16

catecholamines (epinephrine and norepinephrine)

Question 17

briefly explain what the ‘hypopituitary-adrenal axis’ is

Answer 17

anterior pituitary gland secreted ACTH, stimulates cortisol secretion from adrenal cortex, inhibits ACTH secretion - negative feedback mechanism

Question 18

state the 4 clinical presentations of Cushing’s disease

Answer 18

1. obesity
2. headaches
3. visual field deficits
4. hypercortisolaemia

Question 19

what causes headaches in Cushing’s disease ?

Answer 19

due to stretching of the dura mater (meninges - surround the brain and the spinal column)

Question 20

what are the 3 layers of the dura matter ?

Answer 20

1. dura (outer layer)
2. arachnoid (middle layer)
3. pia (inner layer)

Question 21

explain how ‘visual field deficits’ occur in Cushing’s disease (2 points)

Answer 21

1. bi-temporal hemianopia

2. pituitary gland sits below optic chiasma. swelling of adenoma causes reduced peripheral vision

Question 22

what is hemianopia ?

Answer 22

hemianopia = absence of half of the normal field of vision

Question 23

explain the 3 effects of ‘hypercortisolaemia’ in Cushing’s disease

Answer 23

1. increased gluconeogenesis
2. redistributes body fat (mechanism unknown)
3. causes muscle wasting

Question 24

Cushing’s-like symptoms can be known to be iatrogenic. what does iatrogenic mean ?

Answer 24

iatrogenic - condition resulting from treatment with unforeseen side effects

Question 25

state 3 obesity health risks

Answer 25

1. increased risk of death from surgery 2. insulin resistance and diabetes 3. coronary heart disease (CHD) 4. gallstones 5. arthritis 6. varicose veins and haemorrhoids

Question 26

state 3 reasons to why those with obesity have an increased risk of death during surgery

Answer 26

1. surgery takes longer 2. anaesthesia more difficult to control (veins aren't visible, anaesthetic soluble in fat) 3. obese people have reduced lung function due to inc^ adipose tissue in the thoracic cavity (can dec^ by approx. 60%)

Question 27

explain how those who have obesity are more likely to develop insulin resistance and diabetes

Answer 27

fatty acid increase causes a decrease in glucose uptake in muscle and decreases glucose utilisation

Question 28

what is insulin resistance ?

Answer 28

insulin resistance = the inability of cells to respond to insulin

Question 29

explain why those who have obesity are more likely to develop arthritis

Answer 29

increased weight bearing load on the hips and knees (weight bearing joints)

Question 30

state what it is meant by the key term - haemorrhoids

Answer 30

the enlargement of the normal spongy blood-filled cushions around the anus

Question 31

state the 2 causes of haemorrhoids

Answer 31

1. increased intra abdominal pressure | 2. decreased fibre intake (increases the strain of deification)

Question 32

haemorrhoids are divided into what 3 things ?

Answer 32

1. 1st class bleeding at the end of defecation 2. 2nd protrude and return 3. 3rd remain outside

Question 33

state the 2 main treatments for haemorrhoids

Answer 33

1. if bleeding persists, inject an irritant fluid so the anus shrivels up 2. application of elastic bands or surgery

Question 34

what two types of cells are located in the anterior pituitary glands ?

Answer 34

1. Basophilic cells | 2. Acidophilic cells

Question 35

what 4 hormones are produced by Basophilic cells ?

Answer 35

FSH, LH, TSH, ACTH

Question 36

what two hormones are produced in the posterior pituitary gland ?

Answer 36

oxytocin, vasopressin

Question 37

what 2 hormones are produced by the Acidophilic cells ?

Answer 37

GH, Prolactin

Question 38

decreased lung function due to obesity can lead to infections. state 2 examples

Answer 38

1. bronchitis | 2. pneumonia

Question 39

what type of glucose transporter is insulin sensitive ?

Answer 39

GLUT 4

Question 40

what are glucose transporters called ?

Answer 40

GLUTS