Download Biology 101: An Introduction to Tissues, Organs, and the Human Circulatory System and more Quizzes Human Biology in PDF only on Docsity!
Tissue
A group of cells of the same type that performs a particular functionThere are four general classes of tissues Epithelial Connective Muscle Nerve TERM 2
Organs
DEFINITION 2 Body structures comprised of several different tissues grouped together into a larger structural and functional unitAn organ system is a group of organs that work together to carry out an important function TERM 3
Epithelium
DEFINITION 3 The epithelium functions in three ways: To protect the tissues beneath them from dehydration To provide a sensory surfaces to secrete materials TERM 4
Connective tissue
DEFINITION 4 Connective tissue cells fall into three functional categories: Defense (Cells of the immune system) Support (cells of the skeletal system) Transport and storage (blood and fat cells) All connective tissues share a common structural feature-they have an abundant extra-cellular material, called the matrix, between widely spaced cells. TERM 5
Types of Skeletons
DEFINITION 5 Animals are able to move because the opposite ends of their muscles are attached to a rigid scaffold, or skeleton3 types of skeletons in animals: Hydraulic skeletons are fluid-filled cavities encircled by muscles that raise the pressure of the fluid when they constrict exoskeletons surround the body as a rigid hard case to which muscles attach internally endoskeletons are rigid internal skeletons to which muscles are attached
Basics of
muscles
Muscles can only pull because myofibrils contract rather than expand-the muscles in the movable joints of vertebrates are attached in opposing pairs called flexors and extensors-when contracted they move the bones in different directions TERM 7
Muscles
DEFINITION 7 Skeletal muscles move the bones of the skelton tendons are straps of dense connective tissue that attach muscles to bone the origin of the muscle is the end of the muscle attached to a bone that remains stationary during a contraction the insertion of the muscle is attached to a bone that moves if the muscle contracts TERM 8
Open circulatory systems
DEFINITION 8 In this system, there is no distinction between the circulating fluid (blood) and the extra cellular fluid of the body tissues- fluid is called hemolymph TERM 9
Closed circulatory system
DEFINITION 9 the circulating fluid (blood) is always enclosed within blood vessels that transport blood away from from and back to heart TERM 10
Cardiovascular system
DEFINITION 10 The functions of the circulatory system can be divided into three areas:- transportation : grass, nutrients, wastes, and hormones are transported by the circulatory system -regulation: to the cardiovascular can retain heat in a cold environment using counter-current heat exchange -protection: the circulatory system protects against injury and foreign microbes or toxins introduced into the body
Respiration
The uptake of oxygen and release of carbon dioxide-Most primitive animal phyla obtain oxygen directly from their environments through diffusion.-More advanced phyla have specific respiratory organs: grills, tracheae, and lungs TERM 17
Aquatic Respiration
DEFINITION 17 Water always moves past a fish's gills in one direction- moving the water past the gills in the opposite direction as the blood flows permits counter-currentflow *This process is an extremely efficient way of extracting oxygen TERM 18
Lungs
DEFINITION 18 Lungs, although less efficient than gills, are adaptations to a terrestrial habitat-In mammals, a pair of lungs is housed in the thoracic cavity TERM 19
Breathing
DEFINITION 19 The active pumping of air in and out TERM 20
Inhalation
DEFINITION 20 Muscular contraction cuases the chest cavity to expand-when the air pressure outside the lungs exceeds that within the lungs, air flows inward, filling the lungs
Exhalation
The ribs and diaphragm return to their original position-this puts pressure on the lungs and causes air pressure to become greater inside the lungs than outside the body TERM 22
Hormone
DEFINITION 22 A chemical signal produced in the body-It is stable enough to be produced in glands that are completely enclosed in tissue TERM 23
Endocrine glands
DEFINITION 23 Most hormones are produced in glands that are completely enclosed in tissue, called endocrine glands TERM 24
Exocrine glands
DEFINITION 24 Like sweat glands, have ducts TERM 25
3 big advantages of using chemical signal
DEFINITION 25 Chemical molecules can spread to all tissues via the blood Chemical signals can persist much longer than electrical ones Many different kinds of chemical can act as hormones
Adrenal glands
The adrenal glands are located just above the kidney and each is comprised of two parts-the medulla is the inner core and produces epinephrine and norepinephrine-The cortex is the outer regions and produces the steroid hormones cortisol and aldosterone
