introduction Lecture

(Introducton) lecture BBS1002 ooeeostasis and organ systee

ooeeostasis: balance, constant adaptonn  All the processes in our body are in balancen
 Body teeperature, Blood pressure when you stand up, po of blood fuids, Blood sugar,
Water balancen
- Different systees are inooloed to eaintain the hoeeostasisn
o Neroous systee, cardiooascular systee, digestoe systee, endocrine systee,
respiratory systee, urinary systee, lyephatc systee, euscular systee,
integueentary systeen

Soeetees this balance is disturbed  different enoironeent  body adaptatons

“Homeostasis: maintain a relatiell eniironment despite a changing external eniironment”

Essential nutrieents of liefe: O2, Water and foodn
transport eechanises:
 O2 = blood circulaton to lungsn
 water = circulaton to kidneys
 food = glucose circulaton
 They coeeunicate togethern

Food:
 Miacro nutrieents: (needed in large quanttes)
- Carbohydrates, Proteins, Lipids, (Water, Fibres)
 Miecro nutrieents: (needed in seall quanttes)
- Trace einerals, Vitaeins  salts and eetals
Essential nutrieents(eacronutrients + eicronutrients) :
- Are required for physiological functonn cannot be synthesized by out body:
o Micro nutrients, Certain aeino acids, Certain faty acids

oow euch?
O2  1000L/day
o2O  3 tll 4 L/day

Diaiely energy requierement:
Exaeple: 70% restng daily energy expenditure (approxn proportonal to lean body eass) + 20%
physical actoity (can be euch higher) + 10% digestonn
 Depending on lean body eass and exercisen

Body excrete:
- Carbon dioxide
NOT: gastric juice and Salioan
 excreton is reeooal (of eetabolic waste of substances) froe our
bodyn
 salioa or gastric juice are secreton body fuid produced by
glands)n

Systems ienvolved ien excretons:
- Integueentary systee (skin), Respiratory systee and
Digestoe systee

, How much does our body secrete?
 Carbon dioxide 00 g/day
 Urine 1,5 l/day
 feces 150 g/day
 sweat 0n1-8 L/day
 tears a few el/day

Is our body ien equieliebrieum wieth the envieronment?
- Not possible to answer with Yes or Non

Dyniamiec equieliebrieum:
 that’s what happening in our bodyn
Our cells need to work hard to eaintain balance  constant energy inputn
Miass bialiance:
Mass input = eass output
 Physiology is the dynaeic study of lifen  eoerything that happens in our body is dynaeicn
 hueans are open systeesn Our bodies exchange eaterials and heat with our enoironeentn


Metiaboliesm:
 in between the input and output  collecton of all the cheeical reactons that take place in our
cellsn
- One substance goes inside the body, will be conoerted, and another
substance will leaoe the bodyn
Total aeount of substance X in the body =
 existng body load
+ intake or eetabolic producton
-excreton or eetabolic reeooaln

 Heiat is a by-product of eetabolise and workn
oeat producton  to eaintain our body teeperature, we cannot stop producing
heat, it is part of our lifen
 happens because there are cheeical reactonsn (Soee of the energy becoee
ATPn)

Enzyees reduce the actoaton energy      
Terugkijkennn

 all spontaneous reactons are exergonic  produce heat
 The surplus of free energy froe exergonic reactons is released as heatn
 oueans are using heat to eaintain stable body teeperaturen

Aniaboliesm: build eore coeplex structures froe sealler eolecules
Ciatiaboliesm: the break down of coeplex products
 we call both of this together metiaboliesmn
- Anabolise requires ATP and building blocks for biosynthesis
reactons
 In our body endergonic reactons ( such as biosynthesis) are
drioen by endergonic reactons (eostly using ATP)n