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chromosomes

rod shaped cell structures that direct the activities of a cell and passes on the traits of a cell to new cells

cytokinesis

division of the cytoplasm, usually at the end of nuclear division.

cytoplasm

gel-like substance in which all cellular components outside the nucleus are immersed.

daughter cell

one of two cells resulting from the division of a single cell.

diploid

a cell that contains two of each type of chromosome, such as a human somatic cell.

chromatin

The loose and uncoiled form of DNA seen during interphase

G1 stage

first stage in interphase, during which cellular growth and development takes place

G2 stage

third stage of interphase during which organelle replication and protein synthesis takes place

gametes

reproductive cells; sperm and egg cells in animals.

hereditary material

the information which is passed from one cellular generation to the next (encoded in DNA in humans).

homologous chromosome

A member of a chromosome pair, both of which are similar in shape, size, and the genes they carry

interphase

the portion of the cell cycle where the cell is not dividing; includes G1, S and G2 stages.

metaphase

the stage in mitosis or meiosis in which the replicated chromosomes line up along the equatorial plate of the cell

mitosis

process of cellular division in which the daughter cells are genetically identical to themselves and to the parent cell.

nucleus

organelle in the center of the cell which contains the chromosomes.

prophase

the first stage of mitosis /meiosis in cell division; characterized by the condensation of the chromosomes and the dissolution of the nuclear envelope

replicated chromosomes

chromosomes which have undergone DNA replication and contain two sister chromatids.

S-phase

second stage of interphase ; period of DNA replication.

sister chromatids

two identical copies of a parent chromosome which are attached to one another at the centromere.

somatic cell

any cell in the body that is not a germ cell (reproductive cell).

spindle fibers

protein structures which move the chromosomes during cell division.

telophase

the final stage of mitosis or meiosis, during which a nuclear membrane forms around each set of new chromosomes

clones

A group of cells derived from a single ancestor.

histones

protein molecules around which DNA is tightly coiled in chromatin

anaphase

the stage of meiosis or mitosis when chromosomes move toward opposite ends of the poles

centrioles

specialized organelles that facilitate cell division

centromere

the region of the chromosome that holds the two sister chromatids together during mitosis

cleavage furrow

contractile ring of microfilaments in animal cell where the cell membrane is divided

cell plate

the precursor of a new plant cell wall that forms during cell division and divides a cell into two

cancer

any malignant growth or tumor caused by abnormal and uncontrolled cell division

radiation therapy

treatment using x-rays to destroy cancerous tissue

chemotherapy

the use of chemical agents to treat or control some types of cancer (destroys cells or prevents them from dividing)

binary fission

a form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size

budding

a process of asexual reproduction in which a new individual develops from an outgrowth of the parent

spore formation

single, specialized cells that are units of reproduction that can be formed asexually or sexually (ex. bread mold)

regeneration

the ability for an organism to regrow and replace a body part

meiosis

cell division that occurs in sex cells in which the number of chromosomes is reduced by half.

synapsis

the pairing of homologous chromosomes during meiosis

disjunction

The separation of homologous chromosomes during meiosis

crossing over

exchange of genetic material between homologous chromosomes during prophase I of meiosis

gametogenesis

The formation of haploid gametes (sperm or ova) via meiosis.

oogenesis

the meiotic process that results in the formation of eggs

spermatogenesis

the meiotic process that results in the formation of sperm cells

endocrine system

a collection of glands and groups of cells that secrete hormones that regulate growth,development, and homeostasis

hormones

chemical "messengers" of the endocrine system that are released into the blood

protein hormones

class of hormones that cannot pass through the cell membrane; less likely to be stored in the body

steroid hormone

class of hormones that can pass through the cell membrane; can be stored in the body

prostaglandins

local hormones that do not enter the bloodstream

positive feedback

Process that amplifies a small change (Reinforce change)

negative feedback

a response that opposes the original stimulus

one messenger model

mechanism of hormone action used by steroid hormones which bring their message directly into the cell

two messenger model

mechanism of hormone action used by protein hormones; attach to cell membrane receptors which activate enzymes in the cell to produce the desired effect

hypersecretion

excessive hormone production by an endocrine gland

hyposecretion

deficient hormone production by an endocrine gland

pituitary gland

the master gland of the endocrine system

growth hormone

hormone secreted by anterior pituitary gland that stimulates growth of bones

luteinizing hormone

A protein hormone secreted by the anterior pituitary that stimulates ovulation in females and androgen production in males.

Prolactin

Peptide hormone released by anterior pituitary which promotes lactation.

follicle stimulating hormone

secreted in increasing amounts during puberty, by the anterior pituitary gland, to stimulate development of reproductive cell follicles

adrenocorticotropic hormone

A peptide hormone released from the anterior pituitary, it stimulates the production and secretion of steroid hormones by the adrenal cortex.

oxytocin

A hormone produced by the hypothalamus and released from the posterior pituitary. It induces contractions of the uterine muscles during labor.

antidiuretic hormone

hormone secreted by the posterior pituitary gland which aids in water reabsorption by the kidney

hypothalamus

part of the brain which links the endocrine and nervous system, and controls the pituitary gland.

acromegaly

Hypersecretion of the GH in adults which causes an overgrowth of bones in the hands, feet, and face

thyroid gland

gland found in neck that regulates rate of metabolism; produces thyroxine

calcitonin

Produced by the thyroid gland and decreases the blood calcium levels by stimulating calcium deposit in the bones. The antagonist of the parathyroid hormone.

parahormone

secreted by parathyroid glands and controls calcium and phosphate metabolism

tetany

condition affecting nerves causing muscle spasms as a result of low amounts of calcium in the blood caused by a deficiency of the parathyroid hormone

osteoporosis

a condition in which the body's bones become weak and break easily; may be caused by hypersecretion of parahormone

adrenal gland

one of a pair of ductless glands, located above the kidneys, consisting of a cortex, which produces steroidal hormones, and a medulla, which produces epinephrine and norepinephrine.

cortex

outer part of kidney which produces corticosteroids; helps body deal with long term stress

medulla

inner part of kidney which produces epinephrine and norepinephrine

cortisol

secreted from the adrenal cortex, aids the body during stress by regulating glucose, carbohydrates, and fat levels

aldosterone

a corticosteroid hormone that is secreted by the cortex of the adrenal gland, regulates mineral balance in blood and controls fluid volumes

Cushing syndrome

excessive production of cortisol by adrenal cortex with symptoms of abnormal fat deposits and wasting away of muscle

pancreas

located partially behind the stomach in the abdomen, and it functions as both an endocrine and exocrine gland. It produces digestive enzymes as well as insulin and glucagon

insulin

a hormone secreted by the beta cells of the Islets of Langerhans of the pancreas responsible for regulating the metabolism of glucose

glucagon

hormone secreted by alpha cells of the pancreas; raises blood glucose levels

diabetes

a condition in which the pancreas fails to produce enough insulin or the body's cells cannot use it properly, characterized by excessive thirst, weight loss/gain, frequent urination.

estrogen

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

progesterone

A hormone produced by the ovaries which acts with estrogen to bring about the menstrual cycle.

testosterone

The male sex hormone produced by the testes which promotes the maturation of the reproductive system accessory structures, and development of the male secondary sex characteristics.

pineal gland

A small mass of tissue near the center of the brain; it secretes the hormone melatonin.

melatonin

Hormone secreted by the pineal gland, used to regulate sleep patterns.

Thymus gland

Gland located near the heart; it aids in the body's defense against infection by making antibodies

neuron

a nerve cell; the basic building block of the nervous system.

brain

specialized group of nerve cells that controls & coordinates activities of the nervous system

cns

the portion of the vertebrate nervous system consisting of the brain and spinal cord

pns

subdivision of the nervous system that brings information to the cns

autonomic nerves

serves the internal organs of the body

nerve impulse

message that travels from the dendrites of a neuron to the axon

axon

long nerve fiber that conducts away from the cell body of the neuron

dendrite

the branching extensions of a neuron that receives messages and conducts impulses toward the cell body

schwann cell

large nucleated cells that form myelin around the axons of neurons

node of ranvier

small gap between myelinated segments where axonal membrane is exposed; increase speed of impulses

synapse

the space between two neurons through which neurotransmiters travel

receptor

receives information about changes in the environment (stimuli)

effector

muscles or glands that respond to impulses

stimulus

something that causes a response

cell body

contains major concentration of the cytoplasm and the nucleus of the neuron

myelin

an electrically-insulating phospholipid (fat) layer that surrounds the axons of many neurons

reflex

A relatively simple, involuntary response to a stimulus.

resting potential

the potential difference between the two sides of the membrane of a nerve cell when the cell is not conducting an impulse

action potential

change in electrical potential that occurs between the inside and outside of a nerve or muscle fiber when it is stimulated

refractory period

the time after a neuron fires during which a stimulus will not evoke a response

saltatory conduction

transmission of an impulse by jumping

neurotransmitter

a chemical messenger that travels across the synapse from one neuron to the next and influences whether a neuron will generate an action potential(impulse)

spinal cord

part of central nervous system, links brain to rest of body

cerebellum

responsible for balance and coordination, routine movement

cerebrum

the largest part of the brain, controls thinking, reasoning, and memory

corpus callosum

connects the hemispheres; found deep inside cerebrum; allows hemispheres to share information

pons

relay link between brain and spinal cord

medulla oblongata

Regulates ♥ heart rhythm, blood flow, breathing rate,etc.

endorphins

natural neurotransmitters linked to pain control

sclera

Tough, white outer layer of the eye

autonomic nervous system

The part of the nervous system that controls involuntary action and responses.

Parkinson's Disease

a progressive disease that destroys brain cells and is identified by muscular tremors, slowing of movement, and partial facial paralysis

Alzheimer's Disease

a disease that results in the progressive loss of an individual's memory and mental capacity.

ALS

"Lou Gherig's Disease" - progressive neurological disease in which the motor neurons degenerate to the point of total loss of motor function. The intelligence, memory, and personality is unaffected.

Multiple Sclerosis

disorder in which myelin is destroyed causing loss of motor activity

sclera

Tough, white outer layer of the eye

choroid coat

middle layer of the eye; contains blood vessels

retina

The light sensitive layer of the eye which is composed of receptors (rods and cones).

aqueous humor

anterior cavity of the eye filled with clear, watery fluid

vitreous humor

the clear colorless transparent jelly that fills the posterior chamber of the eyeball

nearsightedness

a condition in which nearby objects are seen more clearly than distant objects

farsightedness

condition in which vision for distant objects is better than for near objects

rods

rod-shaped receptor in the retina of the eye that is sensitive to dim light but not color

cones

Receptor cells in the retina that are sensitive to bright light and produce color vision.

pinna

visible part of the outer ear. It collects sound and directs it into the auditory canal

eardrum

the membrane that separates the outer ear from the middle ear and that vibrates when sound waves strike it (tympanic membrane)

hammer

the bone attached to the eardrum

anvil

the bone between the hammer and the stirrup

stirrup

a tiny U shaped bone that passes vibrations from the anvil to the cochlea

oval window

membrane that covers opening between middle ear and inner ear

cochlea

a coiled tube that is found in the inner ear and that is essential to hearing

semicircular canal

3 loops of fluid filled tubes that that are attached to to the cochlea; maintains equilibrium

olfactory cells

sensitive nerve cells in nasal passages.

eustachian tubes

tube connecting ear to throat; helps to equalize pressure

menstruation

monthly shedding of the lining of the uterus when fertilization does not occur

follicle stage

the stage of the menstrual cycle where the pituitary gland produces FSH which starts the maturation of an egg

corpus luteum

name given to the follicle after ovulation, secretes progesterone

luteinizing hormone

secreted by pituitary; regulates estrogen secretion and ovum development in the female and testosterone production in the male

estrogen

Hormone produced by the ovaries which controls the development of eggs and adult female characteristics.

progesterone

hormone produced by the corpus luteum which promotes uterine lining growth

follicle stimulating hormone

secreted by the anterior pituitary gland to stimulate development of reproductive cell follicles

ovulation

The process by which a mature egg is released from the ovaries into the fallopian tubes.

zygote

the cell resulting from the union of an egg and sperm

embryo

a developing human, from fertilization through the first 8 weeks of development

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