Organisation in animals Flashcards
What is a tissue
Group of similar cell that work together to carry out a particular function. It can include more than one type of cell
What is an organ
A group of different tissues that work together to perform a certain function.
Give 3 types of tissues in mammals
- Muscular tissue: contracts to move whatever it’s attached to e.g. moves stomach walls to churn food
- Glandular tissue: makes and secretes chemicals like enzymes and hormones e.g. makes digestive juices to digest food
- Epithelial tissue: covers some parts of the body e.g. inside of the gut, and outside and inside of the stomach
How does gas exchange happen in the alveoli?
- alveoli surrounded by blood capillaries. This is where gas exchange happens
- blood passing next to the alveoli has **returned to the lungs from the rest of the body by the pulmonary artery.
- blood coming from body contains lots of carbon dioxide and very little oxygen
-
oxygen diffuses out of the alveolus (higher concentration area) to the blood (lower concentration)
-carbon dioxide diffuse out of the blood(high concentration) into the **alveolus **(low concentration) to be breathed out
What 3 components make up the circulatory system?
- Heart: heart muscle contracts to generate force to move the blood
- Blood vessels: tubular structures that carries blood through all organs and tissues of the body
- Blood: the transport medium that carries nutrients and chemical Messenger molecules(hormones) to the tissues and removes waste products for them
What is a double circulatory system?
The blood passes through the heart twice per complete circuit around the body.
What are the 2 routes in a double circulatory system?
- Pulmonary circuit: deoxygenated blood passes from the left ventricle to the lungs and then returns as oxygenated blood to the left atrium
- Systemic circuit: oxygenated blood passes for the left ventricle to the rest f the body and then returns as deoxygenated blood to the right atrium
Where are the lungs?
Thorax
What is the order in which air travels to the lungs after being inhaled?
trachea, bronchus, bronchiole, alveolus
A blood cell enters the heart through the Vena Cava. Make a flow chart of its journey from there, ending at the aorta. Name the valves in your answer.
vena cava, right atrium, through tricuspid valve, right ventricle, semi-lunar valve, pulmonary artery, lungs, pulmonary vein, left atrium, through bicuspid valve, left ventricle, semi-lunar valve, aorta
What is the heart made of?
- Cardiac muscle tissue
- Nervous tissue
Around the heart, arteries called _____ arteries branch off the _____ and surround the __________ muscle tissue.
coronary, aorta, cardiovascular
What does the pacemaker do?
Controls the natural rate of the heartbeat
Where is the pacemaker located?
The electrical impulses are generated in specialised patch of cells that are located on the right atrium wall
What can be used if a patient has an irregular heartbeat?
an artificial pacemaker
What do artificial pacemakers do?
Artificial pacemakers are electrical devices used to correct irregularities in the heart rate by sending electrical impulses to the heart muscle
Name the three types of blood vessels.
arteries, veins, capillaries
Blood in the arteries is under high pressure, so they need valves. True or False?
False
Veins have valves. True or False?
True
Why do veins need valves?
blood in the veins flows at low pressure and often against gravity, so valves are needed to prevent backflow and pooling
Describe and explain the layers of a vein.
- Thin walls with elastic fibres and muscle: blood pressure is low so valves are present to prevent back flow and pooling of blood
- Wide lumen: reduce resistance between the blood and the walls of the vein
- Irregular lumen
Describe the layers and their functions of the artery wall (including the lumen).
- Walls are made of elastic fibres and smooth muscle
- Thick walls: to withstand high pressure
- Elastic tissue: allows walls to stretch when blood is forced through and recoil when pressure drops
- Narrow lumen- maintain high blood pressure
- Regular and round lumen