Overview of Human Physiology and Immune System Concepts

Anatomy

Study of the structure of the human body.

Physiology

Study of body functions related to structure.

Cells

Basic building blocks of all living organisms.

Tissues

Groups of similar cells performing specific functions.

Organs

Structures formed from multiple tissue types.

Organ Systems

Groups of organs working together for functions.

Homeostasis

Stable internal environment maintained by the body.

Feedback Loops

Mechanisms regulating homeostasis through responses.

Gradients

Differences in concentration or electrical charge.

Cell-Cell Communication

Interaction between cells for coordination.

Extracellular Matrix

Material outside cells providing structural support.

Chemical Gradients

Concentration differences of substances across membranes.

Electrical Gradients

Charge differences across cell membranes influencing activity.

Organism

A living entity made of multiple organ systems.

Building Blocks

Progressively larger structures forming the body.

Organ Formation

Combination of tissues creating recognizable organ shapes.

Disease

Disturbances in homeostasis leading to health issues.

Regulated Variables

Factors manipulated to maintain homeostasis.

Stable Environment

Condition where internal variables remain constant.

Disturbances

Changes that disrupt homeostasis and can cause harm.

Physiological Processes

Activities or rates that maintain body functions.

Chemical Communication

Molecular signals exchanged between cells for function.

Homeostasis

Stable internal environment maintained by regulatory mechanisms.

Regulated Variable

Variable controlled to stay near a set point.

Negative Feedback Loop

Process that counteracts changes to maintain stability.

Stimulus

Change that disrupts homeostasis in a variable.

Control Center

Brain or gland that processes stimulus information.

Effector

Organ or cell that responds to restore balance.

Positive Feedback Loop

Amplifies response to a stimulus until an endpoint.

Chemotaxis

Movement of cells towards a chemical stimulus.

Blood Clotting

Example of positive feedback in response to injury.

Childbirth

Labor initiated by positive feedback mechanisms.

Nervous System

Transmits stimulus information to the control center.

Endocrine System

Releases hormones to regulate body functions.

Set Point

Desired value for a regulated variable.

Cervix

Structure that stretches during childbirth.

Uterine Contractions

Muscle contractions triggered by hormonal feedback.

Oxytocin

Hormone that stimulates uterine contractions during labor.

Temperature Regulation

Example of homeostasis through negative feedback.

Vasodilation

Widening of blood vessels to cool the body.

Sweating

Cooling mechanism activated by increased body temperature.

Cellular Metabolism

Chemical reactions that sustain life in cells.

Cell Membrane

Barrier that controls entry and exit of substances.

Cytoplasm

Fluid inside the cell where organelles reside.

Nucleus

Cell structure housing DNA and controlling functions.

Nuclear Envelope

Double-membrane enclosing the nucleus.

Nucleoplasm

Gel-like substance within the nucleus.

Nucleolus

Site for RNA types and ribosome assembly.

Mitochondria

ATP-producing organelles with double membranes.

Oxidative Catabolism

Process breaking down fuels to produce ATP.

Outer Membrane (Mitochondria)

Contains channels for cytosol substance entry.

Inner Membrane (Mitochondria)

Selective membrane transporting specific substances.

Mitochondrial Matrix

Contains DNA, proteins, enzymes for ATP production.

Rough Endoplasmic Reticulum (RER)

Membrane with ribosomes, synthesizes proteins.

Polypeptide Folding

RER enzymes fold proteins into 3-D shapes.

Glycoproteins

Proteins with carbohydrates, often exported from cells.

Transport Vesicle

Membrane-enclosed structure for protein transport.

Smooth Endoplasmic Reticulum (SER)

Lacks ribosomes, involved in lipid synthesis.

Calcium Ion Storage

SER stores calcium ions for cellular use.

Detoxification

SER processes harmful substances in liver cells.

Lipid Synthesis

SER synthesizes cell membrane components and hormones.

Ribosomes

Sites of protein synthesis, composed of subunits.

Free Ribosomes

Ribosomes suspended in cytosol.

Bound Ribosomes

Ribosomes attached to organelle membranes.

Golgi Apparatus

Modifies, sorts, and packages proteins and lipids.

Secretory Vesicles

Transport proteins outside or within the cell.

Peroxisome

Membrane-bound vesicle containing oxidative enzymes.

Cristae

Folds of the inner mitochondrial membrane.

Rough Endoplasmic Reticulum

Modifies and folds proteins; studded with ribosomes.

Smooth Endoplasmic Reticulum

Synthesizes lipids and detoxifies substances; no ribosomes.

Lysosome

Vesicle containing digestive enzymes for waste breakdown.

Adenosine Triphosphate (ATP)

Main energy source for cellular processes.

ATP Synthesis

Formed from ADP and inorganic phosphate; energy-intensive.

Glycolysis

First step in glucose catabolism; occurs in cytosol.

Pyruvate

End product of glycolysis; can convert to lactate.

Mitochondrion

Site of ATP production; involved in aerobic respiration.

Citric Acid Cycle

Series of reactions in mitochondrial matrix; produces ATP.

Electron Transport Chain (ETC)

Transfers electrons to generate ATP via a proton gradient.

NADH

Electron carrier; produced during glycolysis and citric acid cycle.

FADH2

Another electron carrier; produced in the citric acid cycle.

Substrate-Level Phosphorylation

Direct ATP production during glycolysis and citric acid cycle.

Hydrogen Ion Gradient

Created by ETC; drives ATP synthesis.

Calcium Ion Storage

Function of smooth ER; regulates cellular calcium levels.

Detoxification

Process of neutralizing harmful substances; occurs in smooth ER.

Ribosomes

Molecular machines that synthesize proteins from amino acids.

Plasma Membrane Components

Proteins and lipids synthesized by the endoplasmic reticulum.

Energy Catabolism

Breakdown of glucose, amino acids, or fatty acids for ATP.

Oxidative Phosphorylation

Final stage of ATP production; occurs in mitochondria.

ATP Replenishment

Cells continuously regenerate ATP; requires oxygen.

Membranous System

Network of membranes involved in cellular functions.

Saclike Membranes

Structure of rough ER; encloses the ER lumen.

Cyanide

Almond-scented poison affecting ATP production.

Oxidative Phosphorylation

Process utilizing oxygen to produce ATP.

Cellular Hypoxia

Condition of insufficient oxygen in cells.

Metabolic Acidosis

Increased acidity in body fluids due to metabolism.

Antidotes for Cyanide

Hydroxocobalamin, sodium nitrite, sodium thiosulfate.

Phospholipid Bilayer

Two-layer structure forming cell membrane barrier.

Hydrophilic Regions

Polar phosphate heads interacting with water.

Hydrophobic Regions

Nonpolar fatty acid tails repelling water.

Intracellular Space

Fluid space within cells containing cytosol.