WEEK 3: CIRCULATION SYSTEMS Flashcards
What constituents the body?
*Cells with their contents (water, electrolytes, nutrients, gases)
*Tissues (soft and hard)
*organs
The total amount of fluids and solids in the human body is approximately how many % of the human body weight in MALES and FEMALES and BABIES?
MALES
60% of body fluids, 40% solids
FEMALES
55% of body fluids, 45% solids
BABIES
80%
How much % does each of the 2 compartments make of the body fluids?
ICF: 2/3
ECF:1/3
The Body fluid has been divided into two compartments.
a. Name them.
b. How much body water ifs found in the ECF and ICF?
1.Intracellular fluid (ICF)
Inside the cells
55% of total body water
2.Extracellular fluid (ECF)
Outside the cells
45% of total body water
The ECF is divided into several compartments.
State them.
State the % each component holds of the ECF.
Extracellular fluid includes:
1.Interstitial fluid
-Present between the cells
-Approximately 80% of ECF
2.Plasma
-Present in blood
-Approximately 20% of ECF
3.Also includes:
-Lymph
-synovial fluid
-aqueous humor
-cerebrospinal fluid
State the barriers which separate:
1. ICF from surrounding interstitial fluid
2.Interstitial fluid from plasma
*Plasma membrane
Separates ICF from surrounding interstitial fluid.
*Blood vessel wall
Separate interstitial fluid from plasma.
State the Organic substances found in body fluids.
Glucose
Amino acids
Fatty acids
Hormones
Enzymes
State the Inorganic substances found in body fluids.
Sodium
Potassium
Calcium
Magnesium
Chloride
Phophate
Sulphate
Name the ions abundant in the ECF.
What are their functions?
ECF
Most abundant cation - Na+,
-muscle contraction
-Impulse transmission
-fluid and electrolyte balance
Most abundant anion - Cl-
-Regulates osmotic pressure
-Forms HCl in gastric acid
Name the ions abundant in the ICF.
What are their functions?
ICF
Most abundant cation - K+
-Resting membrane potential
-Action potentials
-Maintains intracellular volume
-Regulation of pH
-Anion are proteins and phosphates (HPO42-)
What plays a major role in keeping K+ high inside cells and Na+ high outside cell?
Na+ /K+ pumps play major role in keeping K+ high inside cells and Na+ high outside cell
State the 7 Specialized Fluids of the Body.
Lymph
Milk
Cerebrospinal fluid
Amniotic fluid
Aqueous humor
Sweat
Tears
Where is the CSF found?
How many times is it replaced in a day?
How much of it is present in the system?
Characteristics
Clear, colorless liquid formed within the cavities of brain and around spinal cord
At any given time, there is 120-150ml CSF in the system
CSF is completely replaced about three times a day
State the functions of CSF.
Functions
*Hydraulic shock absorber
*Regulation of intracranial pressure
*Influences the hunger sensation and eating behaviors.
Where is the aqueous humor found?
What secretes it?
Fluid that fills the interior chamber of eye
Secreted by ciliary body, enters anterior chamber.
Blockade in the flow of aqueous humor causes glaucoma due to increased intraocular pressure.
Posterior chamber of eye is filled with vitreous humor which contains a gel (vitreous body of hyaluronic acid secreted by retina)
Where does fluid exchange mainly occur?
In capillaries.
What make capillaries efficient in exchange of fluid?
-Capillaries are efficient in the exchange of fluid due to their small diameter and the thinness of their walls.
-The walls of capillaries consist of a single layer of endothelial cells.
-To maximize the area available for diffusion, there are many capillaries supplying the same tissue.
-Moreover, a constant blood flow through the capillaries maintains a large concentration gradient to allow the molecules to be rapidly exchanged with the tissue.
Name the outward pressures and inward pressures at the arteriole end of the capillary.
1.Outward pressure (total 37 mm Hg)
*Capillary hydrostatic pressure (37 mm Hg)
*Interstitial colloid osmotic pressure ( 0 mm Hg)
2.Inward pressure (Total 26 mm Hg):
*Plasma colloid osmotic pressure (25 mm Hg)
*Interstitial hydrostatic pressure (1 mm Hg)
Net OUTWARD PRESSURE = 11 mm Hg i.e. (37 – 26 mm Hg) ultra-filtration pressure)
Name the outward and inward pressures at the venous end of the capillary.
1.Outward pressure (total 17 mm Hg
*Hydrostatic pressure (17 mm Hg)
*Interstitial colloid osmotic pressure (0 mm Hg)
2.Inward pressure (Total 26 mm Hg)
*Plasma colloid osmotic pressure (25 mm Hg)
*Interstitial hydrostatic pressure 1 mm Hg)
Net INWARD PRESSURE = 9 mm Hg i.e. (26 – 17 mm Hg) re-absorption pressure
NOTE: The plasma hydrostatic pressure in the venous blood is less than in the arteriolar blood.
17mmHg and 35 mmHg respectively.
The rest of the pressures are the same.
What is oedema?
Accumulation of excess fluid in the interstitial space/body cavities.
State the possible causes of oedema. (4)
Possible causes
*Reduced concentration of plasma proteins (Starling forces) e.g. kidney failure
*Increased permeability of capillary wall (Inflammation, allergic etc)
*Increased venous pressure (Block)
*Impaired lymph flow (Blockage)
State the components of lymph.
*Clear and colorless fluid
*96% water and 4% solids
SOLIDS
*Proteins
2-6% of solids
albumin, globulin, fibrinogen, prothrombin, clotting factors, antibodies, enzymes
*Lipids
5-15%
Chylomicrons, lipoproteins
*Carbohydrates: Glucose mainly
*NPN
Urea and creatinine
*Electrolytes
Sodium, calcium, potassium, chloride, bicarbonates
State the functions of lymph.
Return protein from tissue spaces into blood
Redistribution of fluid
Removal of bacteria, toxins and other foreign bodies from tissues
Maintain structural and functional integrity of tissue
Route for intestinal fat absorption
Transport lymphocytes
