Obesity (Causes and Effects) Flashcards
state what it is meant by the key term - obesity
obesity is the condition in which excess fat gas accumulated in the body
Obesity can also be defined as …
BMI = BW (Kg) / Height (m^2)
state 4 ranges of BMI (from normal up)
- normal range = 20 - 25 Kg/m^2
- grade 1 obesity = 25 - 30 Kg/m^2
- grade 2 obesity = 30 - 40 Kg/m^2
- grade 3 obesity = 40+ Kg/m^2
state the 3 main causes of obesity
- genetic disorders (rare)
- pathological conditions
- Increased food consumption and decreased energy expenditure
what is the main hormone concerned with appetite regulation ?
Leptin
what is leptin ?
a 167 amino acid chain protein
what is the gene which codes for leptin ?
Ob gene
talk about mutations of the Ob gene (2 facts)
- mutated ob genes don’t produce / produce very little leptin
- homozygous mutations (ob/ob) do not become satiated after a meal and develop obesity and diabetes
explain how leptin regulates appetite (4 points)
- adipocytes produce and release leptin into blood
- binds to leptin receptor in the ‘feeding centre’ in the ‘hypothalamus’
- decreases neuropeptide Y (NPY) - a 36 amino acid protein
- decreased NPY causes: 1) increased energy expenditure, and 2) decreased food intake
what is ‘Cushing’s Disease’ ?
Cushing’s disease is a pathological disease associated with obesity
state 3 symptoms of Cushing’s disease
- psychiatric effects
- fat trunk / abdomen
- muscle wasting and weakness
- moon face
- striae (stretch marks on the abdomen)
- diabetes
- thin extremities
state the 2 causes of Cushing’s disease
- a pituitary adenoma (benign tumour of the epithelial origin)
- adrenal tumour
state the two types of pituitary adenomas (benign tumour of the epithelial origin)
- micro-adenoma = < 10 mm
2. macro-adenoma = > 10 mm
what are the 3 layers of the adrenal cortex ?
- zona glomerulosa (outer layer)
- zona fasciculata (middle layer)
- zona reticularis (inner layer)
what 3 things does the adrenal cortex secrete ?
- glucocorticoids
- sex steroids
- mineralocorticoids
what does the medulla secrete ?
catecholamines (epinephrine and norepinephrine)
briefly explain what the ‘hypopituitary-adrenal axis’ is
anterior pituitary gland secreted ACTH, stimulates cortisol secretion from adrenal cortex, inhibits ACTH secretion - negative feedback mechanism
state the 4 clinical presentations of Cushing’s disease
- obesity
- headaches
- visual field deficits
- hypercortisolaemia
what causes headaches in Cushing’s disease ?
due to stretching of the dura mater (meninges - surround the brain and the spinal column)
what are the 3 layers of the dura matter ?
- dura (outer layer)
- arachnoid (middle layer)
- pia (inner layer)
explain how ‘visual field deficits’ occur in Cushing’s disease (2 points)
- bi-temporal hemianopia
2. pituitary gland sits below optic chiasma. swelling of adenoma causes reduced peripheral vision
what is hemianopia ?
hemianopia = absence of half of the normal field of vision
explain the 3 effects of ‘hypercortisolaemia’ in Cushing’s disease
- increased gluconeogenesis
- redistributes body fat (mechanism unknown)
- causes muscle wasting
Cushing’s-like symptoms can be known to be iatrogenic. what does iatrogenic mean ?
iatrogenic - condition resulting from treatment with unforeseen side effects
state 3 obesity health risks
- increased risk of death from surgery
- insulin resistance and diabetes
- coronary heart disease (CHD)
- gallstones
- arthritis
- varicose veins and haemorrhoids
state 3 reasons to why those with obesity have an increased risk of death during surgery
- surgery takes longer
- anaesthesia more difficult to control (veins aren’t visible, anaesthetic soluble in fat)
- obese people have reduced lung function due to inc^ adipose tissue in the thoracic cavity (can dec^ by approx. 60%)
explain how those who have obesity are more likely to develop insulin resistance and diabetes
fatty acid increase causes a decrease in glucose uptake in muscle and decreases glucose utilisation
what is insulin resistance ?
insulin resistance = the inability of cells to respond to insulin
explain why those who have obesity are more likely to develop arthritis
increased weight bearing load on the hips and knees (weight bearing joints)
state what it is meant by the key term - haemorrhoids
the enlargement of the normal spongy blood-filled cushions around the anus
state the 2 causes of haemorrhoids
- increased intra abdominal pressure
2. decreased fibre intake (increases the strain of deification)
haemorrhoids are divided into what 3 things ?
- 1st class bleeding at the end of defecation
- 2nd protrude and return
- 3rd remain outside
state the 2 main treatments for haemorrhoids
- if bleeding persists, inject an irritant fluid so the anus shrivels up
- application of elastic bands or surgery
what two types of cells are located in the anterior pituitary glands ?
- Basophilic cells
2. Acidophilic cells
what 4 hormones are produced by Basophilic cells ?
FSH, LH, TSH, ACTH
what two hormones are produced in the posterior pituitary gland ?
oxytocin, vasopressin
what 2 hormones are produced by the Acidophilic cells ?
GH, Prolactin
decreased lung function due to obesity can lead to infections. state 2 examples
- bronchitis
2. pneumonia
what type of glucose transporter is insulin sensitive ?
GLUT 4
what are glucose transporters called ?
GLUTS
