Health Science - Endocrine & Brain

Central nervous system (CNS)

The brain and spinal cord; it collects, processes, and acts on info.

Peripheral nervous system (PNS)

The nerves that run from the spine to the rest of the body.

Somatic nervous system (SNS)

Carries messages between the CNS and the body for conscious control.

Autonomic nervous system (ANS)

Sympathetic and parasympathetic systems controlling involuntary body functions and keeping homeostasis (fight or flight).

Afferent (or sensory) nerves

Carry messages from the body to the brain and spinal cord.

Efferent (or motor) nerves

Carry messages from the brain/spinal cord out to the muscles and glands.

Neuron

A nerve cell made up of dendrites, a cell body, an axon, and a myelin coating.

Action potential

The electric impulse or signal that travels down the length of the neuron.

Synapse

The gap between two neurons.

Neurotransmitters

The chemicals that carry messages across the synapse to the next neuron.

Reflex arc

A fast, immediate response where a message is carried only to the spinal cord (not the brain), and a response is sent right back to the body.

Glia cells

Cells that nourish and protect the neurons; they outnumber neurons 10 to 50 to 1.

Cerebrum

The largest part of the brain handling higher functions like memory, logic, speech, and senses; divided into four lobes.

Cerebellum

The part of the brain that coordinates motor movements, posture, and balance.

Brain Stem

Connects the brain to the spinal cord and acts as a relay center (midbrain, pons, and medulla).

Corpus callosum

Bundles of fibers that send messages between the right and left hemispheres of the brain.

Frontal lobe

Controls personality, judgment, speech, body movement, and intelligence.

Parietal lobe

Interprets the sense of touch, pain, temperature, and handles spatial/visual perception.

Occipital lobe

Interprets vision.

Temporal lobe

Understands language, memory, hearing, sequencing, and organization.

Broca's area

Located in the left frontal lobe; if damaged, it makes it hard to move the tongue and face muscles to speak.

Wernicke's area

Located in the left temporal lobe; if damaged, a person talks with long sentences that have no meaning and creates new words.

Meninges

Three protective membranes (dura mater, arachnoid mater, pia mater) that cover the brain and spinal cord.

Cerebrospinal fluid

Acts as a shock absorber protecting the brain and spinal cord, carries nutrients, and removes wastes.

Homeostasis

A stable state of balance in the body, maintained by endocrine glands working antagonistically with each other.

Hypothalamus

Controls body temperature, thirst, hunger, metabolism, and the ANS; causes the pituitary to release hormones.

Pituitary Gland

The pea-shaped "master gland" that controls other endocrine glands and makes growth hormone.

Pineal gland

Regulates the body's internal clock by secreting melatonin.

Thyroid gland

Blocks calcium absorption; a deficiency causes an increase in weight.

Adrenal glands

Found on top of the kidneys; make adrenaline which causes the fight or flight response.

Pancreas

Controls blood sugar levels by making insulin (converts glucose to glycogen) and glucagon (converts glycogen back to glucose).

Testes

Makes testosterone and develops male physical characteristics.

Ovaries

Produce estrogen and progesterone to maintain female physical characteristics and sustain pregnancy.

Endorphins (opiates)

Nature's pain killers formed by the endocrine system.

Pheromones

Airborne hormones whose odor can influence other people who smell it.

Alzheimer's

A progressive disease beginning with mild memory loss due to decreased production of acetylcholine.

Parkinson's

A brain disorder causing unintended movements, shaking, and stiffness due to inadequate production of dopamine.

Multiple Sclerosis

A potentially disabling disease where the immune system attacks the protective myelin sheath covering nerve fibers.

ALS (Lou Gehrig's disease)

A fatal neurodegenerative disease that destroys motor neurons in the brain and spinal cord.

Diabetes

The inability to convert glucose into glycogen; Type 1 = can't make insulin, Type 2 = can't use insulin properly.

Meningitis

A condition where the meninges become inflamed and swollen, pressing into the brain (can be fatal).

Aphasia

A brain injury affecting speech, comprehension, reading, and writing, usually due to a stroke or trauma.

Gigantism

A rare condition caused by excessive production of growth hormone by a pituitary tumor during childhood.

Dwarfism

Short stature caused by a genetic mutation or a growth hormone deficiency.

What is an action potential?

The electric impulse or signal that travels down the length of the neuron.

In a neuron, what is the function of dendrites?

They are the branches that pick up messages from other nerve cells and pass them on to the axon.

What are glia cells and what is their ratio to neurons?

Glia cells nourish and protect neurons, and they outnumber neurons 10 to 50 to 1.

What are the three parts of the brain stem?

The midbrain, pons, and medulla.

What are the specific names of the three layers of the meninges?

Dura mater (outer), arachnoid mater (middle), and pia mater (inner).

What is the purpose of cerebrospinal fluid?

It acts as a shock absorber, carries nutrients, and removes wastes from the brain and spinal cord.

Which lobe controls personality, judgment, intelligence, and body movement?

The frontal lobe.

Which lobe understands language, memory, and hearing?

The temporal lobe.

What happens if Broca's area is damaged?

It becomes hard to move the tongue and face muscles to speak.

What is the function of the thyroid gland, and what happens if there is a deficiency?

It blocks calcium absorption; a deficiency causes an increase in weight.

Which gland increases calcium uptake in the body?

The parathyroid gland.

What are endorphins?

Hormones formed by the endocrine system that act as nature's pain killers.

What are "taxes" in the context of the nervous system?

Responses to stimuli.

What is cephalization?

The evolutionary importance and development of a head region in an organism.

Describe the nervous system of a Planaria (flatworm).

It has two main nerves down either side joined in a ladder-like structure, and eye spots that respond to light.

What is ALS (Lou Gehrig's disease)?

A fatal neurodegenerative disease that destroys motor neurons, causing progressive muscle weakness.

What mental disorder involves hallucinations, delusions, and disordered thinking?

Schizophrenia.

What is Tourette's?

A nervous system condition causing sudden twitches, movements, or sounds ("tics") that repeat involuntarily.

What brain injury is caused by a bump or jolt making the brain move rapidly back and forth?

A concussion.

What inherited disease causes progressive nerve cell breakdown, first appearing in the 30s or 40s?

Huntington's Disease.