Terminology: 23-27 Flashcards
Frick’s Law of Diffusion
Describes the rate of diffusion of a gas between two areas separated by a barrier.
Rate of diffusion increases when
* Area of gas exchange is larger
* Thickness of barrier is smaller
* Larger difference in gas pressure
Which epithelium type are Alveoli covered with?
Squamous epithelium
Ventilation
Movement of medium (air/water) over the respiratory surface to ensure the pressure difference between gasses on either side of the barrier is as high as possible
Gas exchange
Exchange of gas (oxygen/Carbon dioxide) at a respiratory surface between medium (air/water) and blood.
Countercurrent Flow
The gas exchange system used in fish gills.
The flow of water runs the opposite direction of the flow of blood.
Tracheal System
A system of tubes through which air travels to provide gas exchange for insects.
Insects have spiracles which are valves that open to the exoskeleton.
Some flying insects use their wing muscles to push air in and out of their tracheal system as they flap.
Ventilation method of Mammals
Ribs & Diaphragm
Inhalation by negative pressure
Ventilation method of Birds & Reptiles
Ribs & NO Diaphragm
Inhalation by negative pressure
Ventilation method of Frogs
Inhalation by positive pressure
Cutaneous respiration (skin)
Diaphragm contracts
negative or positive pressure?
Negative pressure
Diaphragm relaxes
negative or positive pressure?
Positive pressure
Albumin
A major constituent of plasma that helps keeping blood fluids from leaking into the tissues.
- Maintenance of osmotic pressure
- Binding and transport of substances
- Neutralization of free radicals
Hemoglobin
- A protein in red blood cells that carries oxygen.
- Each hemoglobin protein has four heme groups each with their own iron ion (Fe²+).
- Each iron ion can carry one O₂ molecule, thus a single hemoglobin protein can carry four O₂ molecules.
Cooperative Binding (Hemoglobin)
Muscles that are depleted of oxygen will saturate faster than muscles that are full of oxygen.
The oxygen unloading rate of hemoglobin is most efficient where oxygen levels are low.
Bohr Shift (Hemoglobin)
During exercise:
PCO₂ (Pressure CO₂) is high
pH is low.
Temperature increases
These conditions induce increased rate of oxygen unloading.
Carbonic Anhydrase
An enzyme in red blood cells that converts CO₂ and water into bicarbonate and vice versa.
PCO₂ in tissues favor CO₂ -> Bicarbonate
PCO₂ in lungs favor Bicarbonate -> CO₂
Bicarbonate is transported in plasma
Ventilation rate & Homeostasis
Chemoreceptors in the brain & carotid arteries detect pH changes.
Low pH triggers increased ventilation rate through medulla respiratory control.
Closed Circulation
Blood travels within heart & blood vessels. Allows for greater control of material distribution.
Open Circulation
Hemolymph (blood equivalent) is not confined within vessels, it is held in large cavities called hemocoels where the hemolymph is in direct contact with tissues and organs.
Blood or hemolymph fluid may serve as hydrostatic skeleton.
Hemocoels
Cavities in which hemolymph is held
Hemolymph
Blood equivalent fluid in open circulatory systems
Arteries
- Impermeable walls
- Oxygenated blood transport (except for pulmonary arteries)
- Heart -> Body
- Smooth muscle
Veins
- Impermeable walls
- Deoxygenated blood transport (except for pulmonary veins)
- Body -> Heart
- Smooth muscle
Capillaries
Permeable walls that allow material diffusion.
Interior wall composed of simple squamous epithelium
Interstitial Fluid
Fluid found in the space between cells. It comes from substances that leak from the capillaries. Helps bring oxygen and nutrients to cells and take away waste products from them.
New interstitial fluid replaces old, which drains towards lymph vessels.
Fish have how many heart chambers?
Two chambers of the heart
One circuit
Difference between one and two blood circuits
Dual circuit systems have separate blood vessels from the heart going to the lungs and the body. Pulmonary Circuit, Systemic Circuit.
Single circuit systems go between the lungs and the body before returning to the heart.
Sinoatrial Node (SA Node)
Pacemaker
Generates nerve impulses (depolarizations) that spread over atria.
Located in the right atrium
Atrioventricular Node (AV Node)
Picks up the nerve impulses from the Sinoatrial node (SA) and passes it to the ventricles.
Located in the right atrium
Blood Pressure
Systole/Diastole
Diastole
Semilunar valves: Closed
Atrioventricular valves: Open
All chambers relaxed
Blood flows passively into the chambers
Atrial Systole
Semilunar valves: Closed
Atrioventricular valves: Open
Atrium Contracts
Blood is pushed into the ventricles to fill them up fully
Ventricular Systole
Semilunar valves: Open
Atrioventricular valves: Closed
Ventricle Contracts
Blood is squirted out of the ventricles to the pulmonary artery and the aorta artery.
Hypertension
Abnormally elevated blood pressure
Can lead to damage to blood vessels, especially in conjunction with high blood cholesterol levels.
Blood
Blood is a fluid connective tissue
Composed of 55% Plasma & 45% cellular elements
Cellular elements of blood
- Red blood cells (Erythrocytes)
- White blood cells (Leukocytes)
- Platelets
What are the components of Plasma?
- Water (92%)
- Ions
- Nutrients
- Proteins (Especially albumin)
Erythrocytes
Red blood cells
5-6 million per mm³ of blood
Leukocytes
White blood cells
5,000-10,000 per mm³ of blood
Monocytes
White blood cell (Leukocyte)
Help break down bacteria
Lymphocytes
White blood cell (Leukocyte)
Create antibodies to fight against bacteria and viruses
Neutrophils
White blood cell (Leukocyte)
Kill and digest bacteria and fungi. First line of defense and the most numerous type of white blood cell.