DIVE Biology Quarterly Exam 4

hormone

hormone

Chemical messengers produced in the endocrine glands, which then travel through the blood stream to interact with certain areas or organs.

feedback mechanism

The method of hormone regulation in which hormones produced in one gland control the hormone production of another gland.

hyposecretion

The production of too little of a substance.

hypersecretion

The production of too much of a substance.

thyroxine

A hormone produced by the thyroid gland.

goiter

A swelling in the thyroid gland, caused by iodine deficiency, or a problem with the thyroid.

parathyroid gland

Structures located behind the thyroid that are part of the endocrine system, controlling calcium and phosphorous levels.

glucagon

A hormone that stimulates the production of glucose, to raise the blood sugar level.

adrenal glands

Part of the endocrine system, one is located on top of each kidney.

adrenal medulla

The inner region of the adrenal gland, which works which the sympathetic nervous system to prepare the body to react in stressful situations.

adrenal cortex

The outer portion of the adrenal gland, which helps regulate stress response through mineralocorticoid and glucocorticoid production.

epinephrine (adrenalin)

A hormone produced by the adrenal medulla in response to stress.

norepinephrine

A hormone produced by the adrenal medulla, that works with epinephrine in response to stress.

diabetes mellitus

A condition in which the body cannot produce enough insulin, resulting in high glucose levels in the blood.

hypoglycemia

A condition in which the body produces too much insulin, resulting in a drop in glucose levels in the blood.

glucocorticoid

A hormone produced by the adrenal cortex that plays a role in regulating the metabolism of carbohydrates, fats, and proteins.

mineralcorticoid

A hormone produced by the adrenal cortex that plays a role in regulating salt and water balance in the body.

anabolic steroid

A synthetic form of testosterone used to stimulate tissue growth.

gonad

The organ that produces gametes; reproductive organ.

pineal gland

A small endocrine gland that produces melatonin, which helps regulate waking and sleeping patterns.

thymus gland

An organ located in the chest that plays a role in the production of T cells.

placenta

An organ that connects the embryo to the uterine wall of the mother, and provides nutrients to the embryo.

puberty

A step in the maturation process in which hormones trigger the development of secondary sex characteristics.

pheromones

Hormones that send chemical signals from one organism to a different organism, provoking a response from the one receiving.

endocrine

Ductless glands that secrete hormones directly into the bloodstream, where they are transported to cells containing specific receptor cites.

exocrine

Glands such as sweat, sebaceous, and mammary glands that transport secretory products to the surface of the body through ducts.

Embryology

A branch of science that focuses on the study of the development of an embryo.

follicle

1) A hair follicle contains the hair root, and forms hair by packing dead cells together. 2) Tiny structures found in the ovary that each contain a single immature ovum.

ovum

A female reproductive cell, or gamete.

sperm

Male reproductive cells, or gametes.

zygote

The initial cell that is produced by the fusion of two gametes in sexual reproduction.

gestation

The length of time that it takes an embryo to develop.

cleavage

The dividing of cells as the zygote undergoes mitosis.

blastocyst

During pregnancy, it is a mass of cells produced during cleavage that forms a fluid-filled sphere.

implantation

The attachment of the blastocyst to the inner wall of the uterus, during which the placenta forms.

womb

A term for the uterus.

amniotic fluid

A clear liquid that surrounds the fetus, and serves to nourish and protect it.

uterus

Female organ that a baby develops in during gestation.

placenta

An organ that connects the embryo to the uterine wall of the mother, and provides nutrients to the embryo.

ectoderm

The outermost embryonic germ layer that eventually forms the nervous system, hair, nails, and tooth enamel.

mesoderm

The middle embryonic germ layer, that eventually forms bones, muscle, and connective tissue.

endoderm

The innermost embryonic germ layer, that eventually forms the lining of the digestive system, the bladder, and urethra.

umbilical cord

The membrane-covered bundle of blood vessels that connects a baby to the placenta.

fetus

The stage in which the embryo starts to develop recognizable features, which is approximately 8 weeks after fertilization in humans.

labor

A term used to describe the birthing process.

birth canal

The channel formed by the vagina and cervix during childbirth.

foramen ovale

An opening between the right and left atrium that closes as soon as a baby is born.

ductus arteriosus

A human blood vessel connecting the pulmonary artery and aorta that closes as soon as a baby is born.

gastrula

An embryonic stage following the blastula, in which the embryo is a hollow, sac-like structure composed of the ectoderm, mesoderm, and endoderm.

neural tube

A tube made of ectodermal cells in the embryo, which eventually develops into the spinal cord.

embryo

Unborn offspring in the stage of development from implantation of the zygote to the end of the eighth week of pregnancy.

neurulation

A process in the development of the central nervous system in an embryo, in which the neural plate develops and then forms the neural tube.

hox genes

Important genes in the development of embryonic segment structures.

amnion

A fluid filled sac that surrounds and cushions the embryo.

decidua basalis

The part of the uterine lining that interacts with the outer layer of a blastocyst, and develops into the maternal portion of the placenta.

neuron

Also known as nerve cells, they process and distribute impulse, and are the core components of the nervous system.

potential

The electrical charge difference between two different areas.

central nervous system

Made up of the brain and spinal cord.

peripheral nervous system

The components of the nervous system that extend from the central nervous system, connecting it to limbs and organs.

ventricle

1) Chambers in the heart that pump blood. 2) Cavities in the brain.

meninges

The system of protective membranes that covers the brain and spinal cord.

dura mater

The tough outer layer of the meninges that lines the inner surface of the cranium.

arachnoid membrane

The thin, delicate middle layer of the meninges covering the brain and spinal cord.

pia mater

The thin lower layer of the meninges that lines the surface of the brain and spinal cord.

cerebrospinal fluid

The fluid that fills any spaces between the arachnoid membrane and pia mater, and in the ventricles.

cerebrum

The section of the brain that controls voluntary muscle movement.

cerebral cortex

The outermost layer of the cerebrum, the gray matter.

thalamus

A pair of oval structures near the center of the brain that is responsible for receiving general sensations and relaying them to different parts of the cerebral cortex.

hypothalamus

Located below the thalamus, it controls many involuntary functions, and controls hormones released by the pituitary gland.

midbrain

The region of the brain between the thalamus and the pons, it contains the centers for body movement, and relays impulses related to movement.

pons

A rounded region of the lower brain that relays information between different sides of the brain. Paired with the medulla oblongata, it controls heart rate, respiration, and digestion.

medulla oblongata

Located at the tip of the spinal cord, it is the lower part of the brainstem. It regulates functions such as heart rate, breathing, and blood pressure. It also transmits impulses to and from the spinal cord.

cerebellum

The section of the brain that deals with fine motor skills. It does not initiate movement, but helps coordinate it. It also plays a role in some involuntary movement.

spinal cord

A bundle of nerve tissue that extends from the brain down just past the first lumbar vertebrae. Its main function is the transmission of neural signals between the brain and the rest of the body.

cranial nerves

Nerves that emerge directly from the brain, are mainly associated with sensation and movement related to the head and neck.

spinal nerve

Nerves that emerge directly from the spinal cord, branching out to either side of the body.

autonomic nervous system

Part of the peripheral nervous system that controls automatic, or unconscious functions.

sympathetic nervous system

A part of the autonomic nervous system that functions to help the body relax, so that processes such as digestion can proceed.

parasympathetic nervous system

A part of the autonomic nervous system that functions to help the body relax, so that processes such as digestion can proceed.

referred pain

Pain that is perceived in one area, but originates from another area. This can happen when damage to an internal organ is perceived as pain in an unrelated body part.

taste buds

Small structures on the surface of the tongue that contain the cells that perceive taste.

olfactory receptors

Neurons located in the sinus cavities that are responsible for detecting odors.

conduction deafness

When vibrations are prevented from being transmitted to the inner ear.

nerve deafness

Caused by malfunction of, or damage to the cochlea, auditory nerve, or brain.

semicircular canal

A structure composed of three interconnected tubes located in the inner ear that is involved in equilibrium and balance.

brain

The central organ of the nervous system.

Blood

A bodily fluid that delivers oxygen and nutrients to the body's cells, and then transports carbon dioxide and waste away from them.

plasma

The yellow liquid component of blood.

globulin

One type of protein found in blood plasma.

erythrocyte

Also known as red blood cells. Important in transporting oxygen through the body.

leucocyte

Cells used by the immune system to fight infection, also known as white blood cells.

hemocytoblast

Stem cells found in the bone marrow that develop into all different types of blood cells as needed.

platelet

Small, irregularly shaped cell fragments that play a role in reducing blood loss and forming blood clots.

coagulation

The process by which blot clots are formed.

thrombus

A blood clot that forms within a healthy blood vessel, causing a blockage that results in further damage.

embolus

A freely-floating thrombus, or blood clot, that can become lodged in an artery and cause major damage by blocking the vital flow of blood.

agglutinate

The clumping together of particles or substances. This reaction can occur if blood of different types is mixed together.

systole

When the heart muscle contracts, pumping blood out of the heart.

diastole

When the heart muscle relaxes, allowing the heart to fill with blood.

pulse

The temporary expansion of an artery caused by the force of a heartbeat, which can be used to measure the heart rate.