Unit 9 - Human Biology

Tissue Rejection

Tissue rejection occurs when the recipient's immune system makes antibodies against the protein markers on the donor's tissue.

Organ System

Two or more organs working in a coordinated way form an organ system.

Ureter

Ureter is a tube that carries urine from each kidney to the bladder.

Urinary Bladder

Urinary bladder is a saclike organ that can store up to half a liter of urine at one time.

Vas Deferens

Vas deferens is a duct that carries spermatozoa from the epididymis to the ejaculatory duct.

Vein

Veins are blood vessels that carry blood from the rest of the body back to the heart.

Villie

Villi are small fingerlike projections, covered with epithelial cells, that absorb nutrients.

Vitamins

Vitamins are organic molecules that work with enzymes to regulate cell functions, growth, and development.

Tolerance

When someone has tolerance, it takes larger doses of the drug to produce the same effect.

White Blood Cells

White blood cells, which contain no hemoglobin, are cells that defend the body against infection and that remove foreign material and dead cells.

Neurotransmitter

neurotransmitters are the chemical signals of the nervous system.

Blastocyst

A blastocyst is the blastula of mammals.

Fetus

A fetus is an unborn or unhatched vertebrate in the later stages of development showing the main recognizable features of the mature animal.

Follicle

A follicle is any small spherical group of cells containing a cavity.

Ligament

A ligament is a sheet or band of tough fibrous tissue connecting bones or cartilages or supporting muscles or organs.

Menstrual Cycle

A menstrual cycle is a recurring cycle (beginning at menarche and ending at menopause) in which the endometrial lining of the uterus prepares for pregnancy.

Neuron

A neuron is a specialized cell that stores information and carries messages within the nervous system and between other body systems.

Phagocyte

A phagocyte is a cell that destroys pathogens by surrounding and engulfing them.

Sexually Transmitted Disease

A sexually transmitted disease is a communicable disease transmitted by sexual intercourse or genital contact.

Stimulus

A stimulus is defined most broadly as something that causes a response.

Tendon

A tendon is a cord or band of inelastic tissue connecting a muscle with its bony attachment.

Trimester

A trimester is a period of three or about three months; especially: any of three periods of approximately three months each into which a human pregnancy is divided.

Uterus

A uterus is a hollow muscular organ in the pelvic cavity of females.

Vaccine

A vaccine is substance that contains the antigen of a pathogen.

Vector

A vector is anything that carries a pathogen and transmits it into healthy cells.

Vertebrae

A vertebrae is 26 small bones that make up your backbone.

Zygote

A zygote is the cell resulting from the union of an ovum and a spermatozoon (including the organism that develops from that cell).

Absorption

Absorption is the process by which nutrients move out of the digestive organs into the circulatory and lymphatic system.

Acquired Immune Deficiency Syndrome

Acquired immune deficiency syndrome is the final stage of the immune system's decline due to HIV.

Actin

Actin is one of the proteins into which actomyosin can be split.

Active Immunity

Active immunity is immunity that your body produces in response to a specific pathogen that has infected or is infecting your body.

Addiction

Addiction is the physiological need for a substance.

Adolescence

Adolescence is the time period between the beginning of puberty and adulthood.

Adulthood

Adulthood is the period of time in your life after your physical growth has stopped and you are fully developed.

Allergen

Allergens are antigens that cause an allergic reaction.

Embryo

An Embryo is an animal organism in the early stages of growth and differentiation that in higher forms merge into fetal stages but in lower forms terminate in commencement of larval life.

Allergy

An allergy is an oversensitivity to a normally harmless antigen.

Amniotic Sac

An amniotic sac is the thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals).

Circulatory System

the circulatory system is the body system that transports blood and other materials.

Opportunistic Infection

An opportunistic infection is an infection caused by a pathogen that a healthy immune system would normally be able to fight off.

Ovary

An ovary is the organ that bears the ovules of a flower.

Umbilical Cord

An umbilical cord is membranous duct connecting the fetus with the placenta.

Anaphylaxis

Anaphylaxis is a condition that occurs when the immune system releases a large amount of histamine, which causes airways to tighten and blood vessels to become porous.

Axon

And axon is a long extension that carries electrical messages away from the cell body and passes them to other cells.

Rh Factor

Another blood protein, known as the Rh factor, is also critical in making a successful transfusion.

Antibiotic Resistance

Antibiotic resistance occurs when bacteria mutate so that they are no longer affected by antibiotics.

Antibodies

Antibodies are proteins made by B cells.

Antigen

Antigens are protein markers on the surfaces of cells and viruses that help the immune system identifying a foreign cell or virus.

Antiseptic

Antiseptics are chemicals, such as soap, vinegar, and rubbing alcohol, that kill pathogens.

Artery

Arteries are blood vessels that carry blood away from the heart to the rest of your body.

Esophagus

As you swallow, the food moves into the esophagus, a tube that connects the mouth to the stomach.

asthma

Asthma causes the bronchioles to constrict due to muscle spasm.

Plasma

At the top of the tube is plasma, a clear pale-yellow fluid that makes up about 55 percent of the blood.

B Cells

B cells produce proteins that inactivate pathogens that have not yet infected a body cell.

Synapse

Before an action potential moves into the next neuron, it crosses a tiny gap between the neurons called a synapse.

Blood Pressure

Blood pressure is the force with which blood pushes against the wall of an artery.

Desensitization

Brain cells undergo desensitization when there is more neurotransmitter present in the synapse than usual.

Calcification

Calcification is a process that impregnates something with calcium (or calcium salts).

Capillary

Capillaries are the tiny blood vessels that transport blood to and from the cells of the body.

Cartilage

Cartilage is tough elastic tissue.

Cellular Immunity

Cellular immunity is an immune response that depends on T cells.

Childhood

Childhood is the state of a child between infancy and adolescence.

Cone Cell

Cone cells detect color.

Corpus Luteum

Corpus Luteum is a yellow endocrine tissue that forms in a ruptured Graafian follicle following the release of an ovum.

Dendrites

Dendrites are branch like extensions of the cytoplasm and the cell membrane that receive messages from neighboring cells.

Depressants

Depressants are drugs that make a person feel relaxed and tired.

Determination

Determination occurs in which most stem cells become committed to develop into only one type of cell.

Dialysis

Dialysis is a treatment in which a patient's blood is cleaned and chemically balanced through a mechanical process.

Organ

Different types of tissue that function together form an organ.

Differentiation

Differentiation is the process by which committed cells acquire the structures and functions of highly specialized cells.

Digestion

Digestion is the process by which the large complex molecules in food are broken down into smaller molecules that can be used by the body.

Chyme

Digestive juices and enzymes turn your partly digested sandwich into a semi-liquid mixture called chyme.

Pathogens

Disease-causing agents are pathogens.

Glomerulus

Each nephron is supplied with blood through an after iole, a venule, and a tangled ball of capillaries that is known as the glomerulus.

Emphysema

Emphysema is a lung disorder caused mainly by smoking.

Endometrium

Endometrium (pregnancy), is the mucous membrane that lines the uterus.

Estrogen

Estrogen is a general term for female steroid sex hormones that are secreted by the ovary and responsible for typical female sexual characteristics.

Microvilli

Every epithelial cell on the villi has thousands of tiny projections.

Excretory System

Excretory system is the body system that eliminates non solid wastes through sweat, urine, and exhalation to help maintain homeostasis.

Feedback

Feedback is information from sensors that allows a control center to compare current conditions to a set of ideal values, in a feedback loop, information moves continuously among sensors, a control center, and a target.

Node

From the vessels, lymph collects in small rounded structures called lymph nodes.

Germ Theory

Germ theory of proposed that specific microorganisms caused diseases.

tissues

Groups of similar cells that work together to perform a specialized function are known as tissues.

Hair Cell

Hair cells are specialized cells in the inner ear that contain mechanoreceptor that detect vibrations.

Homeostasis

Homeostasis is the regulations and maintenance of the internal environment - temperature, fluids, salts, pH, nutrients, and gases - within the narrow ranges that support human life.

Glands

Hormones are made in organs called glands, which are found in many different areas of the body.

Humoral Immunity

Humoral immunity is a type of immune response that depends on antibodies.

Hemoglobin

In red blood cells, most of the O2 molecules bind to an iron-rich protein called hemoglobin.

Infancy

Infancy is the earliest state of immaturity.

Infertility

Infertility is the state of being unable to produce offspring.

Inflammation

Inflammation is a nonspecific response that is characterized by swelling, redness, pain, itching, and increased warmth at the affected site.

Integumentary System

Integumentary system is the skin and its appendages.

Interferons

Interferons are proteins produced by body cells that are infected by a virus.

Keratin

Keratin is a fibrous scleroprotein that occurs in the outer layer of the skin and in horny tissues such as hair feathers nails and hooves.

Kidney

Kidneys are organs that eliminate wastes by filtering and cleaning the blood to produce urine.

Leukemia

Leukemia is cancer of the bone marrow.

Lymph

Lymphatic circulation begins when the fluid between the cells enters the lymphatic capillaries, where it becomes known as lymph.

memory Cell

Memory cells are specialized T and B cells that provide acquired immunity because they "remember" an antigen that has previously invaded your body.

Menopause

Menopause is the time in a woman's life in which the menstrual cycle ends.

Mineral

Minerals are organic materials the body uses to carry out processes in cells and to build or repair tissues.

Muscle Fiber

Muscle fiber is an elongated contractile cell that forms the muscles of the body.

Myofibril

Myofibril is one of many contractile filaments that make up a striated muscle fiber.

Myosin

Myosin is the commonest protein in muscle.

Negative Feedback

Negative feedback is when a control system counteracts any change in the body that moves conditions above or below a set point.

Calorie

One calorie from food equals one kilocalorie, or 1000 calories.

Ovulation

Ovulation is the expulsion of an ovum from the ovary (usually midway in the menstrual cycle).

Passive Immunity

Passive Immunity is immunity that occurs without the body's undergoing an immune response.

Peristalsis

Peristalsis is the rhythmic, involuntary contraction of the smooth muscles in the walls of digestive organs.

Platelet

Platelets are cell fragments, produced in bone marrow, that help in blood clotting.

Positive Feedback

Positive Feedback is when a control center uses information from sensors to increase the rate of change away from the set points.

Puberty

Puberty is the time of life when sex glands become functional.

Pulmonary Circulation

Pulmonary Circulation occurs only between the heart and the lungs.

Reflex Arc

Reflex arcs are nerve pathways that need to cross only two synapses before producing a response.

Releasing Hormones

Releasing hormones are hormones that stimulate other glands to release their hormones.

Sphincter

Rings of muscle called sphincters, separate one section from another.

Rod Cell

Rod cells detect light intensity and are used in black and white vision.

Sarcomere

Sarcomere is one of the segments into which a myofibril is divided.

Semen

Semen is the thick white fluid containing spermatozoa that is ejaculated by the male genital tract.

Sensitization

Sensitization occurs when low amounts of a neurotransmitter are in the synapses.

Skeletal Muscle

Skeletal muscle is a muscle that is connected at either or both ends to a bone and so move parts of the skeleton.

Smooth Muscle

Smooth muscle is a muscle that contracts without conscious control and found in walls of internal organs such as stomach and intestine and bladder and blood vessels (excluding the heart).

Sodium-potassium pump

Sodium-potassium pump uses energy to actively transport Na+ ions out of the cell and bring K+ ions into the cell.

Stimulants

Stimulants are drugs that increase the number of action potentials that neurons generate by increasing the amounts of neurotransmitter in the synapses.

Systemic Circulation

Systematic Circulation occurs between the heart and the rest of the body, except for the lungs.

T Cells

T cells destroy body cells that are infected with pathogens.

Testis

Testis is one of the two male reproductive glands that produce spermatozoa and secrete androgens.

Testosterone

Testosterone is a potent androgenic hormone produced chiefly by the testes.

Pacemaker

The SA node is known as the heart's pacemaker because the cells in this node generate an electrical signal that starts the wave of contractions.

Appendicular Skeleton

The appendicular skeleton is the part of the skeleton that includes the pectoral girdle and the pelvic girdle and the upper and lower limbs.

Autonomic Nervous System

The autonomic nervous system is the division of the PNS that controls automatic functions that you do not have to think about.

Axial Skeleton

The axial skeleton is the part of the skeleton that includes the skull and spinal column and sternum and ribs.

Terminal

The axon terminal, the part of the axon through which the impulse leaves that neuron, contains chemical-filled vesicles.

Bile

The bile helps to digest fat.

Red Blood Cell

The blood in the capillaries contain red blood cells, a type of cell that picks up oxygen in the lungs and delivers it to all of the body's cells.

Diastolic Pressure

The bottom, and lower, number is known as the diastolic pressure.

Brain Stem

The brain stem connects the brain to the spinal cord and controls the most basic activities required for life, such as breathing and heartbeat.

Cardiac Muscle

The cardiac muscle is the muscle tissue of the heart.

Central Nervous System

The central nervous system includes the brain and spinal cord.

Cerebellum

The cerebellum is the part of the brain that coordinates your movements.

Cerebrum

The cerebrum is the part of the brain that interprets signals from your body and forms responses such as hunger, thirst, emotions, motion, and pain.

Hormones

The chemical signals made by the endocrine system are called hormones.

Dermis

The dermis is the deep vascular inner layer of the skin.

Diaphragm

The diaphragm is a dome-shaped muscle at the base of the rib cage.

Resting Potential

The difference in charge across the membrane is called the resting potential, because it contains the potential energy needed to transmit an impulse.

Endocrine System

The endocrine system is a collection of physically disconnected organs that helps to control growth, development, and responses to your environment, such as body temperature.

Epidermis

The epidermis is the outer layer of the skin covering the exterior body surface of vertebrates.

Epididymis

The epididymis is a convoluted tubule in each testis.

Fallopian Tube

The fallopian tube is either of a pair of tubes conducting the egg from the ovary to the uterus.

Hair Follicle

The hair follicle is a small tubular cavity containing the root of a hair.

Heart

The heart is a muscular pump, about the size of your fist, that keeps the blood moving to every part of the body.

Valves

The heart valves are flaps of tissue that prevent blood from flowing backward.

Human Immunodeficiency Virus

The human immunodeficiency virus is a retrovirus that attacks and weakens the immune system.

Hypothalamus

The hypothalamus is a small area of the middle of the brain. It makes hormones that stimulate the pituitary gland to release hormones.

Immune System

The immune system is the body system that fights off infection and pathogens.

Joint

The joint is (anatomy) the point of connection between two bones or elements of a skeleton (especially if the articulation allows motion).

Lung

The lungs are the organs that absorb O2 from the air you inhale.

Lymphatic System

The lymphatic system consists of a complex network of organs, vessels, and nodes throughout the body.

ABO Blood Group

The most common markers are A and B, which produce four blood types: A, B, AB, and O, also known as ABO Blood Group.

Muscular System

The muscular system enables movement of the body and internal organs.

Nephron

The nephron is the individual filtering unit of the kidney.

Nervous System

The nervous system is a physically connected network of cells, tissues, and organs that controls thoughts, movements, and simpler life processes such as swallowing.

Cerebral Cortex

The outer layer of the cerebrum, called the cerebral cortex, interprets information from your sensory organs and generates responses.

Ovum

The ovum is the female reproductive cell.

Parasympathetic Nervous System

The parasympathetic nervous system is the division of the autonomic nervous system that calms the body and helps the body to conserve energy.

Peripheral Nervous System

The peripheral nervous system is a network of nerves that transmits messages to the CNS and from the CNS to other organs in the body.

Pituitary Gland

The pituitary gland is also in the middle of the brain. It makes and releases hormones that control cell growth as well as osmoregulatory hormones that regulate the concentration of water in the blood.

Placenta

The placenta is the vascular structure in the uterus of most mammals providing oxygen and nutrients for and transferring wastes from the developing fetus.

Thermoregulation

The process of maintaining a steady temperature under a variety of conditions is known as thermoregulation.

Reproductive System

The reproductive system is organs and tissues involved in the production and maturation of gametes and in their union and subsequent development as offspring.

Respiratory System

The respiratory system is the body system in which gas exchange takes place.

Scrotum

The scrotum is the external pouch that contains the testes.

Skeletal System

The skeletal system is the hard structure (bones and cartilages) that provides a frame for the body of an animal.

Small Intestine

The small intestine is a long, narrow tube in which most digestion takes place.

Alveoli

The smallest branches, the branchioles, end in clusters of tiny air sacs called alveoli.

Somatic Nervous System

The somatic nervous system is the division of the PNS that regulates all of the movements over which toy have voluntary control.

Stomach

The stomach is a muscular sac that can stretch to nearly twice its original size and holds up to two liters of food.

Action Potential

The stretching causes a change in charge distribution that triggers a moving electrical impulse called an action potential.

Sympathetic Nervous System

The sympathetic nervous system is the part of the autonomic nervous system that prepares the body for action and stress.

Lymphocyte

The thymus, located behind the breastbone, is important in developing certain types of white blood cells known as lymphocytes.

Systolic Pressure

The top, and higher, number is known as the systolic pressure.

Trachea

The trachea is a long structure made of soft tissue reinforced with C-shaped rings of cartilage.

Ventricles

The two larger chambers are the right and left ventricles.

Atrium

The two smaller chambers are the right atrium and left atrium.