Lecture 12 Flashcards
Blood and hemolymph carry
- Oxygen
- CO2 produced by mitochondria
- Glucose
- Hormones
- Immune Cells
What are the components of vertebrate blood?
- Plasma (55%)
- Erythrocytes (45%)
- Other blood cells (<1%)
What is the plasma?
Liquid part of blood containing water and substances (glucose, ions and hormones)
Erythrocytes function to
Carry O2 and CO2
What are mechanisms to move blood in veins back to the heart?
- Skeletal muscle pump
- Respiratory Pump
The skeletal muscle pump functions to
Use the normal contraction of striated muscle to help push blood back towards the heart
Normal walking involves muscle contractions that
Squeeze veins and assist in returning venous blood back to the heart
The Respiratory Pump functions to
Use muscle contractions associated with breathing, specifically by the diaphragm
What happens during Inhalation?
Diaphragm muscles contract and move blood through the veins towards the heart
The variation of blood pressure in different parts is important for the
Correct circulatory system function and blood pressure needs to be controlled
Primary means of circulatory system regulation is via
Vasoconstriction and vasodilation
Baroreceptor Reflex is used to make sure that
Heads of animals receive a continual supply of blood during changes in body position, which have a strong influence on blood pressure
Orthostatic Hypotension is
Fainting due to low blood pressure
Orthostatic Hypotension is prevented by
Baroreceptor reflex
What are Baroreceptors?
Pressure sensitive neurons found in the walls of arteries
What happens when Baroreceptors are activated by a decrease in pressure?
They send APs to the adrenal glands to release hormone to cause vasoconstriction, which increases the BP, keeps blood in the head and prevents fainting
Strategies to overcome limitations of slow diffusion:
- Circulating external medium throughout the body
- Diffusion of gases across all or most of body surface by transporting gas in an internal circulatory system
- Diffusion across a specialized respiratory surface accompanied by circulatory system transport
