Bio Exam 1

What’s a scientific hypothesis?

A testable, educated guess that explains an observation

Characteristics of a good hypothesis?

Testable, specific, based on evidence, and falsifiable (can be proven wrong).

What do dendrites do

Receive info

What does the cell body do

processes info

Inductive reasoning

Going from specific observations → general conclusion

Example of inductive reasoning

Timothy got a new car, maybe he got a promotion

Deductive reasoning

Going from general idea → specific prediction.

Example of deductive reasoning

Timothy got a promotion, maybe he’ll get a new car

How can scientists reduce bias?

Using random samples, blind studies, large sample sizes, clear methods

Primary sources

Original research

Secondary sources

Summaries or reviews of research

How do you evaluate secondary sources?

Check author credibility, sources cited, date, and bias.

What is a controlled experiment?

An experiment where you only change one thing (variable) at a time.

Why are controlled experiments important?

So you know what caused the result.

What are the main parts of the nervous system?

CNS (brain + spinal cord) and PNS (all other nerves).

Difference between CNS and PNS?

CNS is the “control center” and processes info while PNS transmits to and from CNS

What do sensory neurons do?

detect external/internal stimuli (touch, light, sound, temperature, chemicals) and transmit electrical signals to the CNS

Motor neurons

Carry signals from the CNS to muscles or glands, triggering movement or secretion

Interneurons

“middlemen” of sensory and motor neurons, integrate information to coordinate responses, and help regulate neural activity

General senses

detect touch, pressure, pain, temperature

Special senses

detect vision, hearing, taste, smell, and balance with specialized organs

Cerebrum function

Controls conscious thought, voluntary movement, memory, reasoning, and sensory perception.

Thalamus function

Acts as a sensory relay station, directing incoming signals to the correct cortical area for processing

Hypothalamus function

maintains homeostatsis, control center for sex drive/pleasure/pain/hunger,

Cerebellum

Coordinates balance, posture, fine motor control, and smooth, precise movements

Brain stem function

Controls involuntary functions such as heartbeat, breathing, and reflexes; connects brain to spinal cord.

Structure of a neuron

Dendrites (receive info), cell body (processes info), axon (transmits signals to other neurons or muscles)

Mechanoreceptors is one of the 5 sensory receptors. What does it detect?

pressure, vibration, stretch

Thermoreceptors is one of the 5 sensory receptors. What does it detect?

detect temp changes

Chemoreceptors is one of the 5 sensory receptors. What does it detect?

detects chemicals (taste, smell, blood chemistry)

Photoreceptors is one of the 5 sensory receptors. What does it detect?

Light (vision)

Taste

Senses basic chemical flavors via taste buds

Smell

detects a wide variety of airborn chemicals

How do reflexes work?

Sensory signals are processed in the spinal cord to produce a fast, automatic response.

Structure of a neuron?

Dendrites receive signals, the cell body processes them, and the axon sends them onward.

Action potential

A brief electrical signal that travels down a neuron

How does a signal cross a synapse?

Neurotransmitters pass the signal from one neuron to the next.

What do otoliths detect?

Sense head position and linear movement by using tiny crystals in the inner ear

Semicircular canals detect what?

Senses head rotation when fluid movement bends hair cells in the inner ear

What is the biggest part of the brain

Cerebrum

Gyri

ridges on the brain

Sulci

groove on the brain

cerebral cortex

integrate sensory info, participates in intellectual activities and emotions, and generates motor responses

what is the cerebral cortex made of

gray matter

what is gray matter made of

neuron cell bodies, dendrites, and unmyelinated fibers

pituitary gland

endocrine gland that secretes hormones that signals puberty

pineal gland

endocrine gland that secretes melatonin and regulates day-night cycle

mamillary lobes

has centers for reflex coordination involved in eating like chewing/licking/swallowing

What are the three parts of the brain stem

pons, medulla oblongata, midbrain

pons

contains the reflex centers that help medulla in regulating respiration, facilitating the relay of sensory and motor messages

medulla oblongata

contains the respiratory and cardiovascular control centers / reflex centers in coughing, sneezing and vomiting

frontal lobe

function of planning, problem-solving, judgement, impulse control, voluntary movement, personality, memory

temporal lobe

processing auditory information, understanding language, memory formation, recognizing faces and objects, and processing emotions

What does the cornea do

refracts light

Aqueous and vitreous humors

are fluids in the eye that provide nutrient / waste transport and regulate the amount of light passing through the pupil

Rods in the eye

allow us to see images in low light

Near-sightedness

focusing an image behind your retina

Three bones of the human ear

malleus, incus, stapes

Prolonged exposure to loud noises or aging can cause

sensorineural hearing loss and permanent hearing loss

Where are chemoreceptors found on the tongue

front tip

Pupillary reflex

autonomic

first step of reflex arc pathway

stimulus

second step of reflex arc pathway

sensory neuron

third step of reflex arc pathway

spinal cord

fourth step of reflex arc pathway

motor neuron

fifth step of reflex arc pathway

response

first step path of light

cornea

second step of path of light

pupil

third step of path of light

lens

fourth step of path of light

retina

fifth step of path of light

optic nerve

sixth step of path of light

brain…

first step of path of sound

outer ear

second step of path of sound

eardrum

third step of path of sound

ossicles

fourth step of path of sound

cochlea

fifth step of path of sound

auditory nerve

sixth step of path of sound

brain