7.13 Lecture Homeostasis Final

8/12/2019 7.13 Lecture Homeostasis Final

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Homeostasis,and the Contribution of

Digestive System toHomeostasis

Andreanyta Meliala, Dr., PhD (Clin Nutr)

Dept of Physiology


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physiology

The science of the functions and phenomena of living things

about how cells (fundamental unit of all living things) are kept alive and

about how their environment is maintained so that the integrity of the cells is p

Cells need continuous supplies of matter and energy to maintain their form

Metabolism

will mainly be the topic of bichemistry Physiology deals with

Getting supplies to the cells at suitable rates and

Removing waste products


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Level of Organisation


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ECF*read: Claude Bernard (1813-1878)

Every cell is surrounded by fluid (ECF)The medium through which all exchangesbetween cells and external environment occur

For normal function the composition of thisbathing fluid must be maintained constant

The constancy of the ECF is maintained byhomeostatic-mechanisms

Which monitor and regulate its

TemperatureOsmotic pressure

pH

Composition


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Homeostatic Mechanisms

Are triggered by: alteration in someof physiological property or quantity

Act to produce a compensatingchange in the opposite direction

To return the system as close aspossible to the normal situation

Is called: negative feed backcontrol


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Minimum Requirements

Receptors

To detect alterations in particular variables

Effectors

the circulatory system carries nutrients and O2 to cells and remove metabolic waste pro(CO2);

alimentary system provide nutrients to the body;

respiratory system that carries out exchange of gases with the external environment;

renal system allows losses of unwanted solutes and water from body;

musculoskeletal system

Coordinating and integrating mechanisms

Nervous and Hormonal


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Factors homeostatically regulated

1. Concentration of nutrient molecule

2. Concentration of O2 and CO2 to carry energy yielding chemicareactions

3. Concentration of waste productsanticipating toxic effect

4. pH

5. Concentration of water, salt, other electrolytes

6. Temperature

7. Volume and Pressure


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The Interdependency


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The integration betweensystems of the body


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Homeostasis

The body ability to maintain internal stability

(homeosimilar;stasis, status,condition)


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Homeostatic Control Systems

Intrinsic / Extrinsic Control

Intrinsicoperate locally

Extrinsicoperate bodywide

Feedback / Feed Forward

Feedback - response made after a change

Feedforwardresponse made in anticipation of a change

Intrinsic: operate on the basis of feedback mechanism

Extrinsic: operate on the basis of feedback but also use feedforward me


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Internal Failure

Abnormal growth of cells

Cancer, benign tumours

Production of antibodies by the body against its own tissues (autoimmudisease)

Premature death of cells or the failure of cell processes

Inherited disorders


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External Causes

Toxic chemicals

Physical trauma

Foreign invaders (viruses & bacteria)


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Contribution of Body Systems to Homeos


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FOOD

BRAINHORMONHORMONHORMONHORMONHORMONHORMONHORMONHORMON

VOLUNTAR

INVO

THE GI SYSTEM

TRACHEA

STOMACH

PANCREAS

SMALL INTE

LAR

ANUSRECTUM

GALLBLADDER

SUBMANDIBULARSALIVARY GLANDS

SUBLINGUALAND

MOUTH PAROTIDSALIVARY GLAN

Dr. And

LIVER


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DIGESTIVE SYSTEM

The three fundamental processes that takeplace are:

Secretion: Delivery of enzymes, mucus, ions and

like into the lumen, and hormones into blood.

Absorption: Transport of water, ions and nutrien

from the lumen, across the epithelium and into blo

Motility: Contractions of smooth muscle in the wa

the tube that crush, mix and propel its contents.


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Human Nutritional NeedsAll animals are heterotrophs

They must obtain energy and nourishment from molecules made borganisms

Remember: The Thermodynamic Law

Conversion of food energy onto heat, movement, etc

Food is used for two purposes:

1. as fuel (to provide energy for cellular metabolism) and

2. as a source of building blocks (monomers for cellular biosynth

Basic nutrients: carbohydrates, lipids, proteins,minerals, vitamins


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FOOD PROCESSING

THE PROCESS OF ENERGY CONVERSION INCLUDES:

1. Ingestion

2. Digestion

3. Absorption

4. Elimination


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----- + H2O ----------- -----OH + H-

MACROMOLECULES: MONOMERS:Carbohydrates

polysaccarides Monosaccharidesmaltose 2 glucoselactose glucose + galactose

sucrose glucose+fructosestarch maltoseProteins Amino Acids (AA)

peptidesFats

Tryglycerides Monoglycerides + FFAPhospholipids Lysophospholipids + FFA


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Preserve The Oldies

Genuine and Last Forever

avoid pure memory get a deep understanding

7.13 Lecture Homeostasis Final

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