Physiology Lab Midterm Study Guide

This set of flashcards covers key concepts, definitions, and examples from the physiology lab midterm study guide, helping students prepare for their exam.

Independent Variable

The variable intentionally changed in an experiment

Dependent Variable

The measured outcome of the experiment.

Standardized Variables

Conditions kept constant so they do not affect results.

Confounding Variable

An uncontrolled factor that affects results.

Positive Control

A sample known to produce a positive result.

Negative Control

A sample known to produce no reaction.

Bar Graph

Used to compare groups.

Line Graph

Shows change across time or conditions.

Mean Definition

average value of a set of numbers.
found by adding all the numbers together and then dividing by how many numbers there are.

Mean (x̄) equation

Σx / n.

Range

The difference between the highest and lowest values.

Range equation/set up

(highest value-lowest value)answer

Percent Change

A way to measure change in percentage.

percent change equation

((new value - old value)/old value) x 100

Delta (Δ)

Means change in a variable.

Enzyme

A biological catalyst that speeds up chemical reactions.

Substrate

The molecule an enzyme acts on.

Active Site

The region where substrate binds.

Product

The molecules produced by a reaction.

Enzyme–substrate complex

Temporary structure formed when enzyme binds substrate.

Activation Energy

Energy required to start a chemical reaction.

Denaturation

Loss of enzyme shape and function.

Amylase

An enzyme that breaks starch into maltose.

Benedict’s Reagent

Chemical indicator to detect reducing sugars.

Lugol’s Iodine

Chemical indicator to detect starch.

Diffusion

Movement of molecules from high concentration to low concentration.

Osmosis

Movement of water across a selectively permeable membrane.

Selectively Permeable Membrane

Allows some molecules to pass but blocks others.

Hypotonic Solution

Has lower solute concentration than cell; water enters cell.

Hypertonic Solution

Has higher solute concentration than cell; water leaves cell.

Isotonic Solution

Equal solute concentration; no net water movement.

Isotonic Point

Solution concentration where there is no net change in mass.

Thyroxine (T4)

A hormone produced by the thyroid gland that increases metabolic rate.

TSH (Thyroid Stimulating Hormone)

Stimulates thyroid gland to release T4.

Propylthiouracil (PTU)

Blocks thyroid hormone production and decreases metabolic rate.

Normal rat

Has normal endocrine function.

Thyroidectomized rat

Thyroid removed; cannot produce T4.

Hypophysectomized rat

Pituitary removed; cannot produce TSH.

Metabolic Rate

Measured by oxygen consumption.

Olfactory Nerve (CN I)

Sensory nerve associated with smell.

Optic Nerve (CN II)

Sensory nerve associated with vision.

Oculomotor Nerve (CN III)

Motor nerve controlling pupil reflex.

Trochlear Nerve (CN IV)

Motor nerve controlling eye movement.

Trigeminal Nerve (CN V)

Both sensory and motor functions related to facial touch and chewing.

Abducens Nerve (CN VI)

Motor nerve for lateral eye movement.

Facial Nerve (CN VII)

Both sensory and motor nerve for facial expression.

Vestibulocochlear Nerve (CN VIII)

Sensory nerve for hearing and balance.

Glossopharyngeal Nerve (CN IX)

Both sensory and motor nerve involved in gag reflex.

Vagus Nerve (CN X)

Both sensory and motor nerve involved in gag reflex.

Accessory Nerve (CN XI)

Motor nerve for shoulder shrug.

Hypoglossal Nerve (CN XII)

Motor nerve controlling tongue movement.

Peripheral Vision

Occurs due to rods concentrated in outer retina.

Blind Spot

Occurs at optic disc; no photoreceptors present.

Afterimage

Occurs due to photoreceptor fatigue after staring at an object.

Reflex Arc

Pathway for reflex action including receptor, sensory neuron, integration center, motor neuron, and effector muscle.

Patellar Reflex

Involves a stimulus tap at the patellar ligament causing leg extension.

Reaction Time Experiment

Measures time taken to respond to a stimulus.

Motor Unit

One motor neuron and all muscle fibers it controls.

Recruitment

Increasing contraction force by activating more motor units.

Tonus

Constant slight muscle contraction.

Tetany

Sustained contraction caused by rapid stimulation.

EMG Amplitude

Height of signal; represents strength of contraction.

EMG Duration

Length of signal; represents time of contraction.

Muscle Fatigue

Defined as force dropping to 50% of maximum force.