INTERNAL ENVIRONMENT

INTERNAL ENVIRONMENT - i) Interstitial Fluid (except cellular components of blood and plasma protein)   ii) Blood plasma
Internal Environment must kept constant (homeostasis)
There is two factor to keep the internal environment constant a) physical factor ( i - blood pressure, ii- osmotic pressure, iii - temperature) b) chemical factor ( i - pH value, ii - salt & sugar)
MAINTAINING AN OPTIMAL INTERNAL ENVIRONMENT
1. TEMPERATURE
2. pH VALUE
3. OSMOTIC PRESSURE
4. GLUCOSE LEVEL



Temperature 
1. The Blood Circulatory System ( low temperature-vasoconstriction,  high temperature - vasodilation)

2. The Integumentary System (sweating)

3. The Muscular System (shivering)

4. The Endocrine System


pH Value

1. Nervous System

    a) partial pressure of carbon dioxide increase
    b) pH level drop
    c) blood acidity increase
    d) chemoreceptor cells are stimulated to send impulses to the respiratory center and cardiovascular centre in brain via afferent nerves

2. Circulatory System

Cardiovascular centre, impulses are sent via afferent nerves to a) stimulate the heart to increase cardiac frequency  b) increase rate of circulation of oxygenated blood to tissues

3. Respiratory System

Impulses are sent via afferent nerves to stimulate the lung in order to increase the ventilation rate (breathing rate- remove carbon dioxide and increase oxygen uptake)


Osmotic pressure
Regulated by ( i) Nervous System, ii) Circulatory System, iii) Endocrine System, iv) Excretory System)
i) Nervous System 
a) blood osmotic pressure increase
b) detected by the osmoreceptors in the hypothalamus 
c) Nerve impulse are generated and sent to the posterior pituitary gland to stimulate the release of ADH hormone


ii) Circulatory System
a) ADH is transported by the bloodstream
b) to its target organ (kidney)


iii) Endocrine System
a) ADH increase the permeability of the distal convoluted tubules and collecting ducts
b) more permeable to water
c) facilitates the reabsorption of water from the filtrate into surrounding blood vessels


iv) Excretory System
a) more concentrated urine are excreted
b) decrease in ADH 
c) decrease in water removal
d) large volume of dilute urine is excreted


Glucose Level
Regulated by ( i) Endocrine System, ii) Circulatory System, iii) Digestive System)


i) Endocrine System
a) detected by pancreas (function - as endocrine gland to secrete the hormone insulin)
b) blood sugar level rises - insulin is secreted into the blood and sent to the liver 
c) Insulin cause the liver cells to speed up the oxidation of glucose to carbon dioxide and water through cell respiration
d) Liver also speed up the conversion of glucose to glycogen and fat for storage


ii) Circulatory System
- glucose is sent to the liver by the hepatic portal vein


iii) Digestive System
a) heavy meal - rich in carbohydrates
b) digestive system hydrolyses it into glucose
c) absorbed into the ileum (small intestine)


Please make your own note in form of mind mapping. I will ask you tomorrow. Tq

BIOLOGY FORM 4 (EXERCISES)

Here is your assignment
1. Please write down 7 characteristic of living process

2. Meristematic Tissue in Plants (1. Epidermal Tissue, 2. Ground Tissue, 3. Vascular Tissue)
EPIDERMAL TISSUE - coated with cuticle, they are specialised to prevent water loss through evaporation, infection and mechanical injury
GROUND TISSUE - a) Parenchyma tissue ( specialised in storing starch, primary cell wall only)   b) Collenchyma tissue (thickened cell wall)     c) Sclerenchyma tissue ( appears as clusters of stone-like cells)
VASCULAR TISSUE - a) xylem ( to transport water and dissolved minerals)    b) phloem ( to transport nutrients to all parts of plants)
Please write this note inform of mind mapping.
Wish you all the best.