Chapter 11 Flashcards
what are the four main functions of the circulatory system
- Transportation of water, oxygen and carbon dioxide
- Distribution of nutrients and removal of wastes
- Maintenance of body temperature
- circulation of hormones
what are the three main components of the circulatory system
Blood, Blood vessels and the heart
what are the components of blood
Red blood cells, white blood cells, Plasma and platelets
What are red blood cells and what is another name for them
Erythrocytes contain haemoglobin to carry oxygen
What are white blood cells and what is another name for them
Leucocytes and they protect our body from disease
what are platelets and what is another name for them
Also called thrombocytes, block damage of wounds causing a clot to form
what is plasma
liquid component of the blood that holds blood cells, proteins and nutrients
explain the blood clotting process
platelets are irregularly shaped and move easily through smooth blood vessels when resting. They activate when they encounter a sharp edge caused by a cut. Release a substance which create a mesh of fibres. Fibres begin to close the wound
what characteristics of Erythrocytes make them ideal to transport oxygen
They contain haemoglobin, have no nucleus so there is more room for haemoglobin and they are shaped like biconcave discs which increases surface area
describe the uptake of oxygen in the lungs
When there is a high concentration of oxygen, the oxygen combines with haemoglobin to form oxyhemoglobin. Where there is a low concentration of oxygen, the oxygen molecules dissociate from the haemoglobin.
How is carbon dioxide carried in blood
7% carried in plasma
23% attaches to haemoglobin
70% is carried as carbonic acid
what are the three types of blood vessels
Arteries, Veins and capillaries
what are the characteristics of arteries
Thick, carry blood away from heart, high blood pressure and oxygenated blood
what are the characteristics of veins
Thin, carries blood towards heart, low blood pressure, deoxygenated blood and have veins to prevent back flow
what are the characteristics of capillaries
Very thin (one cell), blood flows from artery to vein
What is the blood circulation pathway within the body
Right atrium —> tricuspid valve —> Right Ventricle —> Pulmonary valve —> Pulmonary Artery —> The Lungs —> Pulmonary Vein —> Left Atrium —> mitral valve —> Left Ventricle —> Aortic valve —> Aorta —> Body tissues —> Superior/inferior vena cava
what is pulmonary circulation
system of blood vessels that lead to and from the lungs
what is systemic circulation
the general body system of blood vessels
what is systole
The pumping phase of the cycle, when the muscle contracts
what is diastole
The filling phase, as the heart muscle relaxes
what is the main function of the lymphatic system
To collect some of the fluid that escapes from the blood capillaries and return it to the circulatory system.
what does the lymphatic system consist of
A network of lymph capillaries and lymph nodes
What is an open circulatory system
the circulatory system in which transport liquid washes freely over the internal organs. less efficient
what is a closed circulatory system
type of circulatory system in which blood is always closed within vessels at all times
Explain the circulatory system in a fish
Two chambered heart with one atrium and ventricle, oxygenated blood proceeds directly from the gills to the tissues
Explain the circulatory system in amphibians
Two atria, one ventricle. blood doesn’t mix. Deoxygenated blood is sent to the lungs, oxygenated is delivered to the brain
what are the four characteristics needed for gas exchange
- Moist (gases dissolve in water)
- Thin + permeable (quick and easy diffusion)
- Large surface area to volume ratio (easy to meet requirements)
- Maintain concentration gradient (ensure continuous movement)
define endothermic
use internal processes to maintain body temp
What is the pathway of oxygen in the body
Air —> mouth —> Trachea —> Bronchi —> Bronchioles —> Alveoli
what is the alveoli
Air sac at the end of the bronchioles that provide a moist surface for oxygen to dissolve into.
what is the epiglottis
small flap that closes off the trachea when eating
what is the diaphragm
organ that contracts to moves air into and out of lungs Moves down when air comes in, up when air comes out
what is the trachea
carries gases to the lungs via bronchi and bronchioles. Strengthened by rings of cartilage
what is the bronchi
two branches of trachea that lead into lungs
what are the bronchioles
Smaller tubes of bronchi
how is our breathing rate controlled
by the amount of co2 in the blood
what are the alveoli
tiny air sac located at the end of the bronchioles
what happens if fish are taken out of water
Their gills will collapse as air cannot provide as much support as water does. The surface area available to exchange gases decrease dramitcally and the gills are no longer kept mpist
define digestion
When large complex molecules are broken down into simple substances that are small enough to move across cell membranes
what are the two types of digestion
Mechanical (chewing/muscle movements) and Chemical (enzymes)
what is mechanical digestion
Food broken down into smaller pieces via physical means. Increases surface area for chemical digestion
what is chemical digestion
when enzymes break down substances into simplest forms (eg carbs to glucose)
what organs make up the digestive system
Mouth, Oesophagus, Stomach, Small intestine, large intestine
What are the four main roles of the digestive system
- Ingestion: Taking in of nutrients. Occurs in mouth and oesophagus
- Digestion: breakdown of complex molecules into smaller ones. occurs in Stomach and small intestine
- Absorption: The taking up of digested molecules into cells. Occurs in small intestine
- Egestion: Removal of wastes from the body (Large Intestine)
Describe ingestion in the mouth
Mechanical: teeth grind food into smaller pieces which increases surface area
Chemical: Amylase secreted from salivary glands break down complex carbs
Describe Ingestion in the Oesophagus
Mechanical: Tongue pushes bolus into oesophagus
Chemical: Some amylase continues to break down starch
Describe digestion in the stomach
Mechanical: Walls of stomach relax and contract, muscles churn food
Chemical: presence of food stimulates gastric juice to be secreted. Contains HCl (lowers pH of stomach for optimum enzyme efficiency), Pepsin (Break down proteins into smaller chains), Mucus (protects lining of stomach)
what are the three parts of the small intestine
Duodenum, Jejunum, ileum
describe digestion in the small intestine
Pancreatic juice enters duodenum. contains bicarbonate (neutralises acid from stomach), Bile (Breaks fats into smaller pieces to increase SA), Lipase (Breaks down fat into fatty acid), trypsin (breaks down polypeptides into smaller chains), Erepsin (completes breakdown of proteins into Amino acids)
Describe absorption in the small intestine
Lining moist + thin with rich supply of Blood vessels, villi project from surface which increases SA
describe egestion in the large intestine
Compact undigested food, absorb water + some salts back into body, push wastes through rectum
what are three parts of the large intestine
transverse colon, Ascending colon, Descending colon
what are the four unique parts of a cows stomach
Reticulum, Omasum, Abomasum and the Rumen
what is the reticulum
the first chamber of the four chambered stomach of cud chewing animals. Where grass forms ball of cud that is regurgitated and chewed again
what is the omasum
the fourth chamber of the four chambered stomach of cud chewing animals. contents of rumen empty into here
what is the abomasum
the true stomach of cud chewing animals
what is the rumen
the largest chamber of the four chambered stomach of cud chewing animals. where cud goes after being swallowed again, here is mixes with cellulose digesting bacteria
what is the main function of the lymphatic system
To collect some of the fluid that escapes from the blood capillaries and return it to the circulatory system.
What does the lymphatic system consist of
A network of lymph capillaries and lymph nodes
what is lymph
Colourless fluid that circulates through the lymphatic vessels to be returned to blood
