Science Section II: nitty gritty details

What animals lack a nervous system?

Sponges and some specific species of aquatic worms

What animal has a "nerve net" structured nervous system?

Cnidarians

What animals have a centralized location in the middle of the body as their nervous system?

Sea stars

What animals have ganglia (central clusters of nerves) as a central nervous system?

Flatworms and bees

Of all invertebrates, which animal has the most complex nervous system?

Octopus

How fast can neurons transmit information?

Milliseconds

What is the range of size of neurons?

Millimeters to meters

How do neurons within the central region communicate?

Through projections: releasing specific chemical cues to attract or repel other neurons. THEY ARE NOT CONNECTED like neurons in the peripheral region.

Do neurons in the central nervous system regrow?

No

Do neurons in the peripheral nervous system regrow?

Yes

How does the nervous system work?

Nerves transmit sensory information (touch, taste, hear, smell, sight) to the brain which then perceives the information (making us realize what it is, or whatever the case)

[btw this happens very fast, you reading this right now is an example of that]

Which animals do not have the nerves needed to smell?

Toothed whales such as orcas and dolphins

Mice and human comparison in terms of hearing:

1) Mice and humans can hear sounds at the same frequency

2) Mice have abilities to sense sounds at ultrasonic frequencies that are too high for humans

What are the specialized neurons in the eyes called?

Rods and cones

How does visual information get transmitted into the brain region?

By going through nerve fibers

What is perception based on? (List of 3)

1) Experiences

2) Current emotions

3) Types of sensory neurons each animal has

Do vertebrate animals or invertebrate animals hold the most complex nervous system?

Vertebrate animals

When did the vertebrate nervous system evolve?

500 million years ago

From what animals did the vertebrate nervous system evolve from?

Worms and insects

Depending on the animal, there are other types of sensory neurons that can detect things such as... (list of 3)

Electrical fields, polarized light, and magnetic fields.

What is the end of the neuron called?

Axon

What animals have the eye blink reflex?

Animals such as mammals and birds that have eyelids.

How many millimeters apart at LEAST do two points have to be on the tongue in order to perceive the feelings as being in different locations?

1.1 millimeters

How many millimeters apart at LEAST do two points have to be on the hand in order to perceive the feelings as being in different locations?

3-8 millimeters

How many millimeters apart at LEAST do two points have to be on the back in order to perceive the feelings as being in different locations?

36-75 millimeters

When an animal has long-term sympathetic nervous system activation, it... (list of 4)

Prevents the body from correctly absorbing nutrients, disrupts social behavior, and affects the animal's ability to reproduce

+ autoimmune diseases

What protects the vertebrates' central nervous system?

The backbone, cerebrospinal fluid, and the blood-brain barrier

What is allowed into and from the blood-brain barrier?

Waste products can leave, oxygen and nutrients are allows inside

What is a downside to the blood-brain barrier?

It makes it difficult for medications to get in the brain.

To what extent does the brain have a blood-brain barrier?

Most, not all, as some parts of the brain release molecules that need to enter the bloodstream to reach other parts of the body (ex. HPA axis)

Compared to vertebrates, invertebrate nerves are...

Larger and fewer in number

Which animal has neurons large enough to be visualized?

Sea slugs

What animals don't have a central nervous system yet are able to have behaviors complex than most, including foraging and sexual reproduction?

Jellyfish

The simplest neural organization is...

The nerve net.

The simplest linear-type nervous system of two nerves connected to a complex neuronal network.

Flatworm system

The annelid (worms) nervous system is organized into...

...a bilobed (1) brain and ventral (2) cord with segmental ganglia (3)

definitions:

1) bilobed: 2 regions

2) ventral: abdominal or underside of an animal

3) ganglia: central clusters of nerves

An arthropod's nervous system has...

Large ganglia (1) and sensing organs

definitions:

1) ganglia: central clusters of nerves

Which genre of invertebrates has the most complex nervous system in invertebrates?

Cephalopods such as squid and octopus

What are cephalopods related to?

Mollusks like snails and clams

How many neurons do cephalopods have?

Hundreds of millions

Why do cephalopods have the most complex neural system of all invertebrates?

1) To control their multiple arms

2) to rapidly learn optimal hunting strategies

Why haven't other invertebrates developed complex nervous systems?

No evolutionary pressure

Hormones were first thought of to be only related to...

Reproductive behaviors

Do invertebrate or vertebrate animals produce additional hormones specific only to them?

Invertebrates

What can a hormone binding with its receptor be compared to?

A key entering a lock

Which molecule acts as a neurotransmitter in the brain but as a hormone when binded with other organs in the body?

Oxytocin

Where are hormones released from? (List of 3)

1) The brain

2) Peripheral nervous system

3) Other tissue in the body

Which organs most commonly release hormones? (List of 3)

1) Adrenal glands

2) Reproductive organs

3) Pituitary gland

Where are the adrenal glands located?

On top of the kidneys

Where is the pituitary gland?

In the brain

All animals have these organs (list of 3)...

1) Adrenal glands

2) Reproductive organs

3) Pituitary gland

Hormones can interact with each other by triggering a release of other hormones or control bodily functions to regulate... (list of 4)

1) Mood

2) Blood sugar

3) Metabolism

4) Sleep-wake cycle

In the brain region of a human, which endocrine is found?

Hypothalamo-hypophyseal system

In the neck region of a human, what endocrine gland is found?

Thyroid

In the neck region of a human, aside from the thyroid, what endocrine gland is found?

Parathyroid

In a human, used to digest food, what endocrine gland is found as a whole?

Gastrointestinal tract

In the upper portion of the human torso, below the gastrointestinal tract, what endocrine gland is found?

Pancreas islets

In humans, below the pancreas islets, above each kidney, what endocrine gland is found?

Adrenal cortex (interrenal gland)

In humans, above each kidney, other than the adrenal cortex, what endocrine gland is found?

Adrenal medulla (stores chromaffin cells)

In humans' reproductive system, what endocrine gland is found?

Gonads

In fish's kidneys, what endocrine glands are found?

Stannius corpuscles

In the posterior of a fish, what endocrine gland is found?

Caudal neurosecretory

Endogenous and exogenous hormones from _____ help aid in fetal development.

The mother and other offspring in the womb.

This hormone signals that the body needs more nutrients.

Ghrelin

This hormone signals the animal to stop seeking food.

Leptin

What hormone can increase aggression?

Testosterone

What hormone is vital for male reproduction?

Testosterone

What hormone helps develop muscle mass?

Testosterone

What hormone contributes to bone density?

Testosterone

Social behavior can increase concentrations of these hormones through feedback loops.

Oxytocin and serotonin

Why is the sympathetic nervous system used to cope with stress and return to homeostasis?

It increases heart rate which can cause the animal to fight or flight and get away from stressors to come back to homeostasis.

How do animals act in predictable ways to alleviate stress? (List of 3)

1) Using hormonal signaling from the sympathetic nervous system

2) Processing sensory information in the brain

3) Using the perception of the threat

Animals determine the behaviors needed to alleviate stress by relying on...? (List of 3)

1) Past experiences

2) Social environment

3) Unique physiology

Long term exposure to stressors can cause, in humans...

Mental illnesses such as generalized anxiety disorder or depression

These animals chew on bars and objects to stimulate their tongue...

Dairy cattle

How long is the daily cycle of behavior?

A 24 hour period

Birds and mammals use what to predict the most optimal time to breed and raise young?

Temperature and the length of daylight

Chickens require exposure what to produce eggs...

A certain amount of time exposed to sunlight

Animals in the water use what to coordinate behavior...

Lunar rhythms based on the phases of the tides

What animal did the 1950s chronobiology study have?

Drosphila (fruit fly)

Why did the 1950s chronobiology study have fruit flies?

They have a short lifespan and reproduce fast

What was the conclusion of the 1950s chronobiology study?

Genes such as period (per) in fruit flies and fequency (frq) in Neurospora crassa were discovered

Groups of genes in mammals regulating circadian rhythms

Clock genes

Where is the SCN located?

Midbrain

What do animals underground use to determine their biological rhythm?

Temperature or specialized light-detecting cells

These animals fly at night and feed during the day, and sleep by resting half of their brain at a time

Migratory birds during migration

These animals depend on their roles to change their circadian rhythm... for example workers have a daily rhythm but nurses only rest when tired

Honeybees

A startle reflex is an example of what type of behavior?

Instinctual

These animals dig to make nests to bury their eggs as an innate behavior, meaning it will always happen no matter the condition (even if the floor is concrete)

Turtles

Suckling to get milk is an example of which type of behavior?

Instinctual

Who observed geese engaging in fixed-motor patterns regarding eggs escaping the nest?

Konrad Lorenz

Who studies the instinctual behavior of herring gull chicks?

Ethologist Nikolaas Tinbergen

What did Tinbergen notice herring gull chicks were stimulated by for food?

A red dot on the beak

What was the relative pecking response of a fake model of an adult gull?

100

What was the relative pecking response of a fake model of an adult gull without the eyes?

92

What was the relative pecking response of a beak without a red dot?

35

What was the relative pecking response of a red pencil?

126

Which animals are half of an inch long and live in dry arid climates of Australia?

Australian jewel beetles

What was causing the population of Australian jewel beetles to decline?

Brown beer bottles were mistaken for a female beetle, and male beetles kept perishing by continuing to try to reproduce.

Who studied dogs and classical conditioning?

Ivan Pavlov