Chap 27 The Circulatory and Respiratory Systems Flashcards
What are the respiratory and circulatory systems for?
they work together to provide the body with oxygen
What does the respiratory system do?
exchanges CO2 for O2
What does the circulatory system do?
delivers the O2 to the rest of the body’s cells
What travels through the circulatory system?
blood
How does blood move throughout the circulatory system?
the heart pumps the blood through vessels
What carries blood to respiratory surfaces?
blood vessels
What happens with blood at the respiratory surface?
the blood exchanges gases with the environment
Blood vessels also carry blood to where?
body tissues
What happens with blood in body tissues?
blood exchanges gases and nutrients
Blood is closely connected to other…?
organ systems
What is the step by step way that blood interacts with organs?
blood carries gases that are exchanged in the respiratory system
nutrients enter the blood from the digestive system
blood circulates through the kidneys, which eliminate many wastes
blood carries hormones from the endocrine system and participants in immune reactions
What is blood made of?
cells in suspended plasma
Blood consists of what?
red blood cells
white blood cells
platelets
The cells in blood produce what?
a liquid extracellular matrix called plasma
What is plasma made of?
mostly water
contains some antibodies
many other dissolved substances
Red blood cells do what?
carry oxygen
Red blood cells are the only cells in the body that express what?
hemoglobin
What is hemoglobin?
a protein that binds to oxygen
Where do red blood cells originate?
from stem cells in red bone marrow
What happens to red blood cells as they mature?
they lose all their organelles and fill up with as much hemoglobin as possible
What do white blood cells do?
fight infection
Blood contains How many types of white blood cells?
5
What are white blood cells called?
leukocytes
White blood cells are part of what system?
immune system
How do white blood cells fight infection?
they provoke inflammation and destroy microbes, among many other functions
What do platelets do
help blood clot
What are platelets?
small, colorless cell fragments that initiate blood clotting when there is a wound
Platelets do what to stop bleeding?
form a clump that temporarily plugs the leak
After temporarily plugging the leak what so platelets do?
they attract plasma proteins called clotting factors that trap blood cells and platelets forming a blood clot
What are the many function of blood in the body?
gas exchange nutrient transport waste transport hormone transport formation of interstitial fluid maintenance of homeostasis protection
Cells depend on what to maintain homeostasis in their levels of water, salts, and other nutrients?
the exchanges made by plasma
What is the main function of plasma?
to exchange water and dissolved substances with fluid that surrounds the body’s cells
How are blood vessels classified?
by direction of blood flow
What carries blood away from the heart?
arteries
arterioles
What carries blood back to the heart?
veins
venules
What are the tiniest blood vessels?
capillaries
What happens to water and dissolved substances at capillaries?
they diffuse between each capillary and the interstitial fluid that bathes body cells
What is the heart?
a muscular pump
How many chamber s the the heart have?
4
What part of the heart receives blood from veins?
atria
What part of the heart pumps blood into arteries?
ventricles
The heart needs what?
a blood supply
What branches off from the aorta and brings O2-rich blood to the heart?
coronary arteries
A vein entering the right atrium returns blood that has been doing what?
circulating within the walls of the heart
What is the most common cause of a heart attack?
blockage of a coronary artery
Where does blood get oxygen from?
the lungs
Blood brings oxygen to what?
the body
What is the fist step of blood flow through the body?
O2-poor blood enters the right atrium and is pumped into the right ventricle
What is the second step of blood flow through the body?
blood moves through the pulmonary arteries to the lungs, where it picks up O2 and unloads CO2
What is the third step of blood flow through the body?
the pulmonary veins carry O2-rich blood from the lungs back to the left atrium of the heart
What is the fourth step of blood flow through the body?
O2-rich blood enters the left atrium and is pumped into the left ventricle
What is the fifth step of blood flow through the body?
contraction of the left ventricle sends blood into the aorta, the largest artery in the body
What is the sixth step of blood flow through the body?
the blood circulates throughout the body before returning through the veins to the right ventricle
What strengthens the heart?
exercise
What is cardiac output?
the amount of blood pumped each minute
What determines cardiac output?
by the heart rate and the strength of the heart
WHO recommends what for exercise?
150 minutes of moderate exercise per per week
What is blood pressure?
the force blood exerts on the vessel walls
What is used to measure blood pressure?
sphygmomanometer
What does negative feedback regulate?
short term blood pressure
What detects blood pressure and passes that information to the medulla in the brainstem?
pressure receptors in the walls of major arteries
What adjusts both heart rate and the diameter of arterioles to maintain homeostasis?
the medulla, via the autonomic nervous system
What regulates blood pressure?
arteriole diameter
What is vasoconstriction?
narrowing of blood vessels
When does vasoconstriction occur?
when smooth muscle in arteriole walls contracts
What happens to blood pressure when arteriole diameter decreases?
blood pressure increases
What is vasodilation?
widening of blood vessels
When does vasodilation occur?
when the same muscle relax, decreasing pressure
What does altering arteriole diameter allow the body to do?
increase blood delivery to regions that need it most
Where does breathing start?
in the upper respiratory system
Air enters the respiratory system through what?
nose and mouth
After air enters the body it passes through what?
the pharynx
The pharynx and mouth are part which systems?
digestive and respiratory systems (since both food and air pass through them)
What are the main human respiratory organs?
lungs
The trachea branches into what?
two bronchi
Where do the bronchi lead?
one to each lung
The bronchi branch repeatedly into what?
bronchioles
The autonomic nervous system controls what to adjust airflow?
the contraction of muscles in the bronchioles
Where does gas exchange occur?
alveoli
Each alveolus is what?
a tiny sac with a wall of epithelial tissue that is one cell layer thick.
What happens in each alveolus?
oxygen and CO2 diffuse through the thin walls of the alveoli and the neighboring capillaries
Breathing requires what?
pressure changes
Air flows from what to what?
areas of high pressure to areas of low pressure
What happens in the lungs when we inhale and exhale?
air pressure changes
How does air flow through the human respiratory system?
- ) contraction of the diaphragm expands chest cavity
- ) air floes into the body through nose/mouth
- ) gas exchange occurs at alveoli
- ) relaxation of diaphragm shrinks cavity
- )air flows out of the body
What are the steps of airflow when entering the body?
air enters through nose/mouth
then goes to trachea
then to bronchus
then to bronchiole
finally to alveoli
O2 and CO2 diffuse in…?
opposite directions
Gas exchange in the alveoli and at the body’s other tissues relies on what?
simple diffusion
Where does O2 enter the blood?
O2 diffuses into the blood at alveoli
Where does O2 exit the blood?
diffuses out of the blood at tissue cells
Where does CO2 enter the blood?
at tissue cells
Where does CO2 exit the blood?
diffuses into the environment at alveoli
Breathing is controlled by what?
negative feedback of blood pH
What happens to blood as CO2 levels rise?
it becomes more acidic
What detects change in blood pH?
receptors in the arteries and in the medulla of the brain
In response to increasing blood acidity, what does the brain do?
the brain stimulates an increase in the breathing rate
What happens when the breathing rate increases?
the body acquires additional O2 and releases excess CO2, maintaining homeostasis in blood gas concentrations