Integrated Physiology for Human Nutrition: Homeostasis, Tissues, and Neural Signaling

Flashcards covering body levels of organization, cell structure, tissues, fluid compartments, homeostatic control loops, resting membrane potential, graded potentials, action potentials, and neural conduction velocity.

Atoms such as oxygen, carbon, hydrogen, and nitrogen make up approximately __________ of the human body.

$$99\%$$

Calcium, phosphorous, and potassium combined make up approximately __________ of the human body.

$$1\%$$

The smallest unit capable of carrying out life processes in an organism is the __________.

cell

Three primary components of a homeostatic control system

Sensor, integrator, effector

The fluid matrix of the cell excluding organelles is called the __________.

cytosol

In a human cell, lipid synthesis occurs at the __________.

smooth endoplasmic reticulum

Organelles that package and sort proteins within the cell are known as the __________.

Golgi apparatus

Organelles containing digestive enzymes that break down waste are called __________.

lysosomes

Epithelial tissue consists of closely packed cells specialized for exchange or __________.

protection

Epithelial tissue located in the airways that protects against debris and mucus is classified as __________ epithelial tissue.

ciliated

Connective tissue is characterized by having few cells dispersed within an abundance of __________ material.

extracellular

Dense connective tissue includes structures such as ligaments and __________.

tendons

Adipose tissue is a type of connective tissue specialized for storing __________.

fat

The two types of excitable tissues capable of generating and propagating electrical activity are muscle tissue and __________ tissue.

nervous

An organ consists of __________ or more primary tissue types functioning together to perform specific tasks.

two

Intracellular fluid contains approximately __________ of total body fluid.

$$\frac{2}{3}$$

Extracellular fluid is divided into interstitial fluid and blood __________.

plasma

The three components of a homeostatic control system in sequential order are sensor, integration centre, and __________.

effector

A homeostatic mechanism that opposes an original change to maintain internal stability is called __________ feedback.

negative

A homeostatic mechanism that amplifies an initial physiological change is known as __________ feedback.

positive

A control mechanism that initiates responses in anticipation of a change in a regulated factor is called __________.

feedforward

Abnormal functioning of the body associated with disease is termed __________.

pathophysiology

The central nervous system consists of the brain and the __________.

spinal cord

The resting membrane potential of a typical nerve cell is __________.

$$-70\,mV$$

The equilibrium potential for potassium ($E_{K^+}$) is __________.

$$-90\,mV$$

The equilibrium potential for sodium ($E_{Na^+}$) is __________.

$$+60\,mV$$

When the membrane potential becomes less negative or more positive than the resting potential, the cell undergoes __________.

depolarization

A return of the membrane potential to resting potential following depolarization is called __________.

repolarization

When the membrane potential becomes more negative than the resting potential, the cell is in a state of __________.

hyperpolarization

An ion channel that opens in response to the binding of a chemical messenger is a __________ channel.

ligand-gated

Ion channels that open in response to physical stretch or pressure are called __________ channels.

mechanically gated

Graded potentials decrease in magnitude as they travel away from the initial site due to current loss through __________ channels.

leak

When a graded potential reaches threshold potential, rapid opening of voltage-gated __________ channels generates an action potential.

$$Na^+$$

The rising phase of an action potential is primarily caused by an influx of __________ ions.

$$Na^+$$

The falling phase of an action potential is caused by the efflux of __________ ions.

$$K^+$$

The principle stating that an action potential fires at full amplitude once threshold is reached or does not fire at all is the __________ law.

all-or-none

Neurons encode stronger signal intensity by increasing the __________ of action potentials.

frequency

The period following an action potential during which a neuron cannot be restimulated because sodium channels are inactivated is the __________ refractory period.

absolute

Action potential propagation in unmyelinated nerve fibers where the impulse spreads across every portion of the membrane is called __________ conduction.

contiguous

In myelinated nerve fibers, action potentials jump from node to node via __________ conduction.

saltatory

In saltatory conduction, electrical signals jump between unmyelinated gaps known as nodes of __________.

Ranvier

Action potential conduction speed is greatest in fibers that are large in diameter and __________.

myelinated

Based on the levels of organization diagram, level 2 corresponds to a cell in the stomach lining, representing the __________ level.

Cellular

According to the action potential waveform shown, the 'Falling phase' is caused by __________ efflux.

$$K^+$$