Untitled Flashcards Set

Role of anatomy in body model

Anatomy is involved in creating a model that represents the organization and structure of body systems.

Homeostasis

The maintenance of a stable internal environment despite changes in external conditions.

Negative feedback

A process that counteracts a change in a physiological system, preventing extremes; an example is the regulation of body temperature.

Positive feedback

A process that amplifies changes in a system, leading to a greater response; it differs from negative feedback in that it enhances rather than dampens changes.

Set point

The ideal value that a physiological parameter attempts to maintain.

Error signal

The difference between the current state and the set point in physiological regulation.

Body Mass Index (BMI) calculation

Calculated using weight in kilograms divided by height in meters squared.

Signs and symptoms of diabetes

Common signs include excessive thirst, frequent urination, extreme fatigue, and blurred vision.

Diagnosis tests for diabetes

Include fasting blood glucose test, oral glucose tolerance test, and HbA1c test to measure blood sugar levels over time.

Total body water

The total amount of water in the body, crucial for physiological processes.

Body fluid compartments

Include intracellular fluid (inside cells) and extracellular fluid (outside cells), differing in composition and function.

Passive transport

Movement of substances across cell membranes without energy input.

Active transport

Movement of substances across cell membranes requiring energy input.

Chemical driving force

The force that drives the movement of ions or molecules across a membrane based on concentration gradients.

Positive value in chemical driving force

Indicates movement toward a region of lower concentration.

Negative value in chemical driving force

Indicates movement toward a region of higher concentration.

Selective permeability of membranes

Determined by the chemical properties of substances and the lipid bilayer.

Substances that cross the membrane easily

Small, nonpolar molecules like oxygen and carbon dioxide.

Substances that do not cross the membrane easily

Large, polar molecules and ions.

Membrane potential calculation

Determined by the difference in charge across the membrane.

Chemical forces

Influence the movement of substances based on concentration gradients.

Electrical forces

Influence the movement of charged particles across the membrane.

Equilibrium potential

The membrane potential at which the chemical gradient and electrical gradient for an ion are balanced.

Sodium/potassium pump function

Maintains the electrochemical gradient by actively transporting sodium out and potassium into the cell.

Glucose transport mechanisms

Include facilitated diffusion via GLUT transporters and secondary active transport with sodium.

Simple diffusion

Movement of small molecules across the membrane without assistance.

Facilitated diffusion

Transport of molecules across the membrane via protein channels or carriers.

Primary active transport

Direct use of ATP to move substances against their concentration gradient.

Secondary active transport

Movement of substances down their gradient to transport another substance against its gradient.

Osmosis

Diffusion of water across a selectively permeable membrane.

Osmolarity

Concentration of solute particles in a solution (iso-, hypo-, hyper- refer to relative concentrations compared to another solution).

Tonicity

Describes how a solution affects cell volume based on its osmotic pressure.

Endocytosis

Process by which cells internalize substances from the extracellular environment.

Exocytosis

Process by which cells expel materials into the extracellular space.

Transcytosis

The transportation of proteins across a cell via vesicles.

Paracrine chemical messenger

A signaling molecule that acts on nearby cells within the same tissue.

Lipophobic and lipophilic ligands differences

Lipophobic ligands do not readily cross cell membranes, while lipophilic ligands can easily diffuse through lipid membranes.

Chemical classification of messengers

Based on solubility, mechanism of action, and receptor types.

Messenger half-life

Time taken for half of a messenger to be degraded; impacts duration of its action.

Receptor affinity

The degree to which a receptor and its ligand bind; higher affinity means stronger binding.

Transport proteins role in signaling

Facilitate the movement of ligands across membranes, impacting signaling processes.

Magnitude of target response

Determined by receptor binding, density of receptors, and presence of signal transduction pathways.

Up-regulation vs down-regulation

Up-regulation increases receptor numbers in response to low hormone levels, while down-regulation decreases receptor numbers in response to high hormone levels.

Agonists

Molecules that activate receptors to produce a biological response.

Antagonists

Molecules that block receptors and inhibit responses.

G Protein–Coupled Receptors function

Transduce signals from extracellular stimuli through the activation of G proteins.

Second messenger systems function

Amplify the signal from an extracellular messenger, often leading to a cellular response.

Signal amplification

Process by which a single signaling molecule produces a large response in the cell.

Endocrine glands

Glands that secrete hormones directly into the bloodstream, regulating various body functions.

Primary endocrine organs

Organs like the pituitary, thyroid, and adrenal glands, producing key hormones.

Secondary endocrine organs

Organs that produce hormones but are not primarily responsible for endocrine function, like the kidneys.

Regions of the adrenal gland

Include the adrenal cortex (producing corticosteroids) and adrenal medulla (producing catecholamines).

Abnormal hormone secretion effects

Can lead to disorders such as hypersecretion or hyposecretion of hormones, affecting various bodily functions.

Types of hormone interactions

Include synergistic, permissive, and antagonistic interactions between hormones.