DIVE Biology Quarterly Exam 4

hormone

Chemicals messengers, mostly proteins, 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.

thyroxine

hormone produced by the thyroid gland, which increases the metabolic rate (i.e. increases oxygen use) of cells throughout the body, indirectly affecting growth

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 is controlled by the sympathetic nervous system to help the body react in stressful situations.

epinephrine (adrenalin)

A hormone produced by the adrenal medulla 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.

pineal gland

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

placenta

An organ that connects the embryo (beginning at the blastocyst stage) to the uterine wall of the mother. The placenta transfers nutrients and wastes between mother and child.

endocrine

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

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. After 3 days, has divided into 16 cells.

gestation

The length of time that it takes an embryo to develop; directed by genes which are regulated by epigenetic factors

blastocyst

During first week of 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, in the second week (about 12 days) of gestation.

amniotic fluid

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

umbilical cord

The membrane-covered bundle of blood vessels that connects a baby to the placenta providing nutrients (aka dissolved chemicals).

fetus

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

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 the third week of gestation, in which the embryo is a hollow, sac-like structure composed of the ectoderm, mesoderm, and endoderm.

embryo

Unborn offspring in the stage of development from implantation of the zygote to the end of the eighth week of pregnancy (1st trimester).

amnion

A fluid filled sac that surrounds and cushions the embryo.

neuron

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

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.

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 such as body temperature and fluid balance by controlling 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.

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.

taste buds

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

olfactory receptors

Modified 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 dynamic equilibrium and balance.

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.

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.

pulmonary circulation

The flow of oxygen-depleted blood from the right ventricle of the heart, to the lungs where it absorbs oxygen and releases carbon dioxide, and then back to the left ventricle of the heart.

systemic circulation

The flow of freshly oxygenated blood out of the left ventricle of the heart, throughout the body, and then back to the right ventricle of the heart.

renal circulation

The circulation of blood to and from the kidney, where waste materials are removed.

portal circulation

The flow of nutrient-rich blood from the digestive organs, along with oxygenated blood from the hepatic artery, to the liver.

lymph

Fluid that is absorbed by lymph capillaries from the spaces between cells, then returned to the blood stream.

lymph vessel

Vessels that are fed by lymph capillaries, and carry lymph back through lymph nodes, and eventually back into the blood stream.

lymph node

Small organs located along the lymph vessels that filter out foreign particles, and fight infections; contain primarily lymphocyte cells and macrophage cells.

antibody

Proteins produced by the immune system which are used to bind to and neutralize bacteria, viruses, and other foreign particles.

antigen

Foreign cells, usually proteins, that prompt a response by the immune system.

B cell

Lymphocytes, or white blood cells, whose main function is to produce antibodies.

cell-mediated immunity

The use of a variety of T cells to fight an infection, instead of antibodies.

allergy

A disorder of the immune system in which it treats harmless substances as pathogens, and attempts to fight them off.

allergen

A normally harmless substance that provokes an allergic reaction.

autoimmune disease

A disease in which the immune system attacks the body's own cells.

kidney

Organs that filter waste from the blood, forming urine.

External respiration

The step of respiration in which oxygen is transferred from air inside the alveoli, into the blood.

internal respiration

The step of respiration in which oxygen is transferred from the blood, into body cells.

breathing

The process of pulling air into the alveoli, the small spherical chambers in the lungs where gas is exchanged, and then pushing the air back out of the body.

expiration

The emptying of air from the lungs.

tidal volume

The amount of air that enters the lungs through inspiration, and then leaves through respiration during sleep.

inspiratory reserve volume

The extra amount of air that a person can inhale, in addition to the tidal volume.

expiratory reserve volume

When exhaling, it is the amount of air a person can force out of their lungs, after the tidal volume.

residual volume

The amount of air left in a person's lungs after forced expiration.

vital capacity

The total amount of air that a person can forcefully exchange with the environment, which is the sum of the inspiratory volume, tidal volume, and expiratory reserve volume.

total lung capacity

The total amount of air that can fit in a person's lungs, which is the vital capacity, plus the residual capacity.

hemoglobin

The red pigment found in blood cells that carries oxygen.

pharynx

Known as the throat, it is the tube that connects the mouth and nose to the larynx, and the mouth to the esophagus.

larynx

An organ found in the necks of mammals that contains the vocal cords.

glottis

The vocal folds, or chords, and the space between them.

trachea

1) A tube that connects the lungs to the mouth or throat.

bronchi

Two tubes that branch out from the trachea to the lungs.

alveoli

Small spherical chambers in the lungs where gas is exchanged.

absorption

The process in which soluble food molecules are diffused, and pass into the blood stream, mostly in the small intestine.

enzyme

Proteins that serve as catalysts. They can help synthesize a new compound, or break down a compound.

calorie

A unit of energy, usually used to measure the energy content of food.

inspiration

The filling of the lungs with air.

epithelial tissues

It is composed of layers of cells that form the outer and inner surfaces of organs and structures throughout the body, including blood vessels.

matrix

The nonliving component of tissue that forms a network or frame that other cells are supported or suspended by.

integumentary system

The protective covering of a body, primarily made up of skin, but also includes appendages such as hair, feathers, scales, and nails.

epidermis

The outer, visible, layer of skin.

dermis

The thicker layer of skin just under the epidermis, that contains nerve endings, sweat glands, hair follicles, and blood vessels.

subcutaneous layer

A layer of fatty connective tissue that connects the dermis to the muscle that lies under it.

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.

sebaceous gland

Produces an oily substance called sebum, that is used to lubricate the skin. They are usually attached to hair follicles.

melanocyte

Melanin-producing cells located at the bottom of the epidermis.

melanin

The pigment that produces color in skin.

sweat gland

Used for temperature regulation by releasing water, salt, and other organic substances onto the surface of the skin.

osteocytes

Living bone cells that are fed by fluid from the Haversian blood vessels.

cartilage

Stiff but flexible connective tissue. Found in humans and many animals, it forms the skeleton of sharks.