66 terms

IB Biology Topic 6

Humans as organisms SL

Terms in this set (...)

any disease-producing agent (especially a virus or bacterium)
any surface protein that may elicit an immune response or cell recognition
the process where food is converted into smaller molecules that can be absorbed into the body
globular proteins that speed up chemical reactions in the body
enzyme found in saliva and pancreatic juice that breaks the chemical bonds in starches
enzyme that speeds up the breakdown of proteins into amino acids. produced by the stomach, small intestine, and pancreas.
an enzyme secreted by the pancreas that catalyzes the breakdown of fats into individual fatty acids
An organ of the digestive system that contains acid, protease enzymes and churns food.
small intestine
organ that completes the chemical digestion of food and absorbs the nutrients
large intestine
the last section of the digestive system, where water is absorbed from food and the remaining material is eliminated from the body
the process of absorbing nutrients into the body after digestion
the process where cells absorb nutrients and use them for what the body needs
fingerlike projections of the small intestine (illeum) that helps it absorb nutrients
multi-chambered, muscular organ that pumps blood throughout the body
coronary arteries
arteries that supply oxygen-rich blood to the heart muscle
Describes muscle tissue (heart muscle) that generates its own contractions.
a specialized bit of heart tissue that controls the heartbeat
any bundle of fibers belonging to the nervous system that transmits sensations and messages between the brain and other parts of the body
part of the brain nearest the spinal cord (base of brainstem) which controls breathing, heart rate and blood pressure.
affect sympathetic nervous system in stress response
thick walled, elastic blood vessels that carry blood away from the heart
the smallest blood vessels which connect the smallest arteries with the smallest veins.
Diffusion can easily occur through the thin walls of capillaries
blood vessels with valves, that carry blood back to the heart
liquid portion of blood made up of water, dissolved salts, proteins, hormones, etc.
A red blood cell;
with hemoglobin, carries oxygen in the blood.
white blood cell
involved in immune response
a blood cell fragment that is important in forming blood clots
chemicals that inhibit the growth of microorganisms (bacteria and fungi)
a nonliving, infectious particle composed of a nucleic acid and a protein coat.
Prokaryotic, single celled organisms.
a type of endocytosis in which substances are taken up by a cell, forming a vesicle.
Protein that is produced by lymphocytes that attaches to a specific antigen which aids in destroying infectious diseases
the virus that causes acquired immune deficiency syndrome (AIDS); it replicates and kills Helper T-cells
a syndrome caused by the human immunodeficiency virus (HIV) that renders immune cells ineffective, permitting opportunistic infections.
the bodily process of inhalation and exhalation; of air - containing oxygen and carbon dioxide.
gas exchange
exchange of gases between air in alveoli and blood.
O2 for respiration and its waste product, CO2
tiny sacs of lung tissue specialized for the movement of gases between air and blood
The windpipe; a passage through which air moves in the respiratory system.
two spongy organs, located in the thoracic cavity enclosed by the diaphragm and rib cage.
two short branches located at the lower end of the trachea that carry air into the lungs.
progressively smaller tubular branches of the airways
Large, flat muscle at the bottom of the chest cavity that helps with breathing
Central Nervous System
the brain and spinal cord;
Peripheral Nervous System
the sensory and motor neurons that connect the central nervous system to the rest of the body
branching extensions of a neuron that receive messages and conduct impulses toward the cell body
the extension of a neuron, which conducts impulses away from the cell body
myelin sheath
a layer of fatty tissue surrounding the fibers of many neurons;
motor end plates
Terminal filaments of motor neurons that form a synapse with a muscle cell
nerve impulse
the electrical discharge that travels along a nerve fibre
relay neuron
a neuron which connects sensory neurons to motor neurones in neural pathways
motor neuron
this carries impulses from the CNS to the muscles.
resting potential
the potential difference between the two sides of the membrane of a nerve cell when the cell is not conducting an impulse, -70mV
action potential
a neural impulse; the local voltage change across the membrane as a nerve impulse is transmitted.
endocrine system
collection of glands that secrete hormones into the blood which regulate growth, development, and homeostasis
process by which organisms maintain a relatively stable internal environment
negative feedback
a mechanism where the change in a physiological state triggers a response that reverses the initial change.
a condition in which the pancreas fails to produce enough insulin or the body's cells cannot use insulin properly,
male reproductive system
Produces male sex cells (sperm) and mail hormones (e.g. testosterone), transfers sperm to the female
female reproductive system
produces female sex cells (oocytes) and female hormones (e.g. estrogen and progesterone); recieves sperm from male; site of fertilization of an oocyte; site of growth and development of an embryo and fetus.
Follicle Stimulating Hormone; a gonadotropic hormone that is secreted by the anterior pituitary and stimulates growth of Graafian follicles in female mammals, and activates sperm-forming cells in male mammals
Luteinizing Hormone, a gonadotropic hormone that is secreted by the anterior pituitary; stimulates ovulation in female mammals and androgen release in male mammals
female sex hormone, secreted by the ovary and responsible for typical female sexual characteristics
A hormone produced by the ovaries which acts with estrogen to bring about the menstral cycle; prepares and maintains uterus for pregnancy
the mucous membrane that lines the inner wall of the uterus
In Vitro Fertilization
The most common assisted reproduction procedure, in which a woman's eggs are mixed with sperm in culture dishes (in vitro) and then carefully inserted into a woman's uterus.
the male sex hormone. testosterone in males stimulates the growth of the male sex organs in the fetus and the development of the male sex characteristics during puberty