Artificial Pancreas 1

Cells

Cells are basic building blocks of living things.

Tissues

A tissue is a group of cells that have similar structure and function together as a unit

Organs

An organ is a group of tissues which collectively perform a specific function

System

An organization of varying numbers and kind of organs so arranged that together they can perform complex functions for the body

Homeostasis

A state of balance among body systems needed for the body to survive and function correctly

What responds to changes inside and outside the body when in homeostasis

In homeostasis, body levels of acid, blood pressure, blood sugar, electrolytes, energy, hormones, oxygen, proteins and temperature are constantly adjusted to respond to changes inside and outside the body, to keep them at a normal level

What do we need to do to maintain homeostasis

• Desirable “set point/range”

• Awareness of change

  • receptors

  • processor: feedback-negative/positive

• Mechanism to restore set point

  • effectors

• Consider the components needed for homeostatic control system

  • challenge to homeostasis requires complex algorithms to cope

What are the two functions of the pancreas

exocrine and endocrine

Exocrine Function

Produces enzymes to help digestion (<98% acini)

Endocrine Function

Small round clusters of cells-”Islets (<2%0 produce hormones to regulate blood sugar

(also produces hormones for local processes)

What is I,A,D and C

I- Islets of Langerhans

A- Acini

D- Duct System

C- Connective Tissue

Beta Cells of Islets of Langerhans

Insulin decreases blood glucose levels

Alpha Cells of Islets of Langerhans (what do the do)

Glucagon increases blood glucose levels

What is the feedback loop to maintains glucose levels

Glucose is 1 fuel for (nearly) all our cells

Blood glucose concentration must be maintained even when fasting

• So access from stored form or de novo synthesis needed

Metabolism

The reactions that occur throughout the body within cells to provide energy.

This energy is used for vital processes and synthesis of new cells: C6H12O6 + 6O2 → 6CO2 + 6H2O

Why a set point is important

Because your body works best when blood glucose stays in a fairly narrow range as too low will not have enough energy. Then too high will cause tissue damage

What is the diabetic reference range for fasting

>7.0 mmol/l

When is HbA1c useful

Its useful as an overall marker of glucose levels over a period of 2-3 months

Diabetes mellitus

a group of metabolic disorders in which persistent hyperglycaemia is caused by deficient insulin secretion and/or resistance to the action of insulin

Type 1 Insulin Dependent Diabetes Mellitus

• autoimmune destruction of b cells

  • may be via T cell or antibody mediated mechanism

• typically juvenile onset

• treatment attempts to correct deficiency through insulin injections

Type 2 Non Insulin Dependent Diabetes Mellitus

• insulin resistance and later deficiency

• associated with obesity and ageing

  • normal decrease in beta cell mass with ageing interacts with other causal mechanisms

• age profile changing rapidly in West

• control via diet, later oral agents (metformin), then finally insulin injection

What is good control mean

reduction in complications of diabetes