Welcome to Block 6

INTRODUCTIONBasic Medical Science III

HOMEOSTASIS AND METABOLISM

MetabolismMetabolism•The set of chemical reactions that happen in living organisms to maintain life.

•These processes allow organism to :▫Grow and reproduce▫Maintain their structures▫Respond to their environments.

MetabolismMetabolism•Metabolism is divided into two catagories : catabolism and anabolism

•Catabolism: degradative pathways▫Usually energy-yielding!

•Anabolism: biosynthetic pathways▫energy-requiring!

Organization in PathwaysOrganization in Pathways

•Pathways consist of sequential steps•The enzymes may be separate•Or may form a multienzyme complex

•Or may be a membrane-bound system•New research indicates that

multienzyme complexes are more common than once thought

Nutrition•Protein is a rich source of nitrogen and

also provides essential amino acids•Carbohydrates provide needed energy

and essential components for nucleotides and nucleic acids

•Lipids provide essential fatty acids that are key components of membranes and also important signal molecules

Organ Systems Interrelationships

•Nutrients and oxygen are distributed by the blood

•Metabolic wastes are eliminated by the urinary and respiratory systems

Figure 1.2

Homeostasis•Homeostasis = The maintenance of a

stable internal environment. •Maintaining a stable internal environ-

ment requires constant monitoring and adjustments as conditions change.

•This adjusting of physiological systems within the body is called homeostatic regulation.

•Homeostatic regulation involves three parts or mechanisms: ▫1) the receptor, ▫2) the control center and ▫3) the effector.

Homeostatic SystemsHomeostatic Systems

Three Basic Components:

1. Receptor ▫ detects change in a

variable (stimulus/stress)

▫ sends input (information) to a control center

2. Control Center▫ assesses input; sends

output to effector(s)

3. Effector ▫ causes response, i.e.,

an “effect” which is triggered by output

For example :

Our bodies control body temperature in a similar way.

The brain is the control center

The receptor is our body's temperature sensors,

And the effector is our blood vessels and sweat glands in our skin.

Homeostasis

▫System Communications (feed back, transduction, etc)

▫Homeostasis & Disturbance of Homeostasis

▫Physiological adaptation

BLOCK OBJECTIVEExplain structure, function and

composition of human body from cellular level and its role in homeostasis to solve health problem.

Understand the pathophysiology and management of metabolic and nutrition disorder.

Understand how to perform physical and laboratory examination relevant to metabolic and nutrition disorder.

Block 6Homeostasis and Metabolism

•Lectures : 24 ITs•Practical and skill lab (11 topics):

▫Practical : 8 topics▫Skill lab : 3 topics

•Tutorial (4 times) ▫Homeostasis : 1 topics▫Metabolism : 2 topics▫Adaptation : 1 topics

Block 6Homeostasis and Metabolism

Assessment:- Individual assignment (10%)- Written test (40%)- SOCA (30%)- OSCE and Practical (20%)

Rules of Lecture

WHEN LECTURE IS GOING ON:

•Don’t play internet. •Turn off your laptop. •Concentrate on the lesson.•Don’t play your hand-phone.•Don’t walking in and out of the

classroom without permission.

COME TO CLASS AND READ THE BOOK BEFORE LECTURE

Rules in Labs

•General rules:▫Using lab coat and name tag▫Authorized persons only can access labs▫Using lab tools or materials carefully

(microscope; chemical material, etc.)▫Eating, drinking, smoking NOT

ALLOWED▫Be seriously