University:
Sam Houston State University
Course:
BIOL 1406 | General Biology I
Academic year:

2020
Views:

199

Pages:

13
Author:

StellarStrategist

BLOOD VESSELS  Three kinds: arteries, capillaries, veins  Arteries: carry blood away from the heart  Divide into arterioles, which are small arteries that are controlled by the nervous system to regulate blood pressure microscopic blood vessels with a wall formed of one layer of simple squamous cells  Capillaries:    Beds of capillaries are very prevalent in the body When an animal eats, capillary beds of the digestive system open So narrow that red blood cells must pass through in single file BLOOD VESSELS vessels that take blood from capillaries and join to form a vein  Veins: transport blood toward the heart  Venules:    Walls are much thinner than arteries No blood pressure One-way valves open in the direction of the heart and close to prevent back flow BLOOD the liquid in the circulatory system of an animal organism  Organisms cannot live without it  All animals have it, but its nature varies from one species to another  Amount varies with the species and size of animal  Blood: BLOOD  An average adult human weighing 160 pounds has about 5 quarts of blood  Animals in high altitudes have more blood than those at lower altitudes because air at higher altitudes has less oxygen  What do you think will happen if animals from higher altitudes are moved to lower altitudes? BLOOD CONSISTS OF: the liquid substance in which various solid materials are suspended and moved about  Plasma: 90% water  10% = dissolved substances including hormones, wastes, minerals, vitamins, and proteins  BLOOD CONSISTS OF: blood cells: responsible for carrying oxygen from the lungs throughout the circulatory sysem  Red      Oxygen carried by hemoglobin: a protein part of the blood Do not repair themselves New cells are made in bone marrow Dead cells are removed by the spleen and liver One animal may have a trillion blood cells! BLOOD CONSISTS OF: blood cells: responsible for fighting disease and removing harmful substances from the body  White Four different kinds found in blood  Some cells surround and digest infectious bacteria  Produce antibodies: a kind of protein that destroys bacteria, viruses, and other invasive substances   WBC counts go up if there is an infection BLOOD CONSISTS OF: the structures in blood that are responsible for clotting  Platelets:    Disk-like shape Creates scabs Without them, an animal might bleed to death from a wound THE ACTUAL PROCESS:  Heart pumps blood into the body through arteries and capillaries  Blood returns in the veins  Circulation includes moving blood: through the lungs by receiving oxygen and giving off carbon dioxide  by the liver and spleen for cleaning  throughout the entire body to support life processes  BLOOD’S ROLE AS A TRANSPORT  Carries oxygen to all areas of the body and acquires carbon dioxide from the respiration process in the cells  Protects against disease (white blood cells)  Transport hormones  Transport nutrients and wastes  Heat regulation  Skin uses some of the liquid in blood as sweat MAINTAINING BLOOD SUPPLY  Regulation  Amount of blood and proportions of materials in blood is regularly being adjusted to meet demands of the body  Replacing   worn cells Blood cells and platelets produced in bone marrow Marrow: the soft substance in the middle of bones, can be red or yellow MAINTAINING BLOOD SUPPLY  Controlling bleeding Coagulation: a complex process initiated by injured tissues giving off signals indicating bleeding is occuring  Clotting factors result in formation of fibrin: creates a blockage that stops the loss of blood from the wound  Blood also has substances that dissolve clots where they are not needed (example: arteries)  MAINTAINING BLOOD SUPPLY  Organisms that lose blood may be given blood taken from another animal with the same blood type, which is called a blood transfusion  More common in humans and domesticated animals  Can transmit disease  Should only be done by trained individuals