Chapter 5 – Membrane Dynamics

Important Concepts

Membrane dynamics refer to the movement of solutes and water across cell membranes, which is essential for maintaining cellular homeostasis.

• Cell membrane structure: Facilitates selective movement of solutes in and out of the cell.

• Types of permeability: Differences between permeable, semi-permeable, and non-permeable membranes.

• Osmolarity vs. tonicity: Osmolarity measures solute concentration; tonicity describes the effect of a solution on cell volume.

• Penetrating vs. non-penetrating solutes: Penetrating solutes can cross the membrane; non-penetrating cannot.

• Concentration gradients: Drive passive transport processes.

Example: Red blood cells placed in a hypotonic solution will swell due to water influx.

Important Terminology

• Solution

• Solute

• Solvent

• Permeable

• Semi-permeable

• Osmolarity

• Isosmotic

• Hyperosmotic

• Hyposmotic

• Tonicity

• Facilitated diffusion

• Active transport

• Endocytosis

• Exocytosis

• Vesicle

• Paracellular transport

• Transcellular transport

• Diffusion

Formula:

Where J is flux, D is the diffusion coefficient, and is the concentration gradient.

Chapter 6 – Cell Communication

Important Concepts

Cells communicate via chemical and electrical signals to coordinate physiological processes.

• Specificity: Signal molecules bind only to specific receptors.

• Nature, speed, and duration of signals: Electrical signals are fast and short-lived; chemical signals are slower and longer-lasting.

• Hormone vs. cytokine: Hormones are secreted by glands; cytokines are secreted by many cell types.

• Signal transduction: Conversion of a signal from outside the cell to a functional change inside the cell.

• Ion channels vs. G proteins: Ion channels allow ions to pass; G proteins activate second messenger pathways.

Example: Epinephrine binding to a beta-adrenergic receptor activates a G protein, leading to increased heart rate.

Important Terminology

• Signal

• Ligand

• Receptor

• Specificity

• Affinity

• Competition

• Saturation

• Autocrine

• Paracrine

• Endocrine

• Hormone

• Neurotransmitter

• Cytokine

• Lipophilic

• Tonic

• Phasic

• Cascade

• Amplification

• Agonist

• Antagonist

• Upregulation

• Downregulation

Chapter 7 – Endocrine System

Important Concepts

The endocrine system regulates physiological processes through hormones.

• Types of hormones: Peptide, steroid, and amine hormones differ in synthesis, transport, and action.

• Lipophilic vs. lipophobic hormones: Lipophilic hormones cross membranes; lipophobic bind to surface receptors.

• Hormone synthesis and clinical significance: Disorders can arise from abnormal hormone synthesis or secretion.

• Anterior vs. posterior pituitary: Anterior releases hormones via portal system; posterior stores and releases neurohormones.

• Feedback loops: Negative and positive feedback regulate hormone levels.

• Diagnosis of endocrine pathology: Primary, secondary, and tertiary disorders are classified by the origin of dysfunction.

Example: Diabetes mellitus results from insufficient insulin production or response.

Important Terminology

• Cholesterol

• Testosterone

• Estradiol

• Aldosterone

• Half-life

• Catecholamine

• Dopamine

• Epinephrine

• Thyroid hormone

• Vasopressin/Antidiuretic hormone (ADH)

• Synergism

• Permissiveness

• Antagonism

• Hyposecretion

• Hypersecretion

Chapter 8 – Neurons

Important Concepts

Neurons are specialized cells for transmitting electrical and chemical signals in the nervous system.

• Neuron structure: Includes body, dendrite, axon hillock, axon, and varicosities.

• Types of neurons: Sensory, motor, and interneurons have distinct functions.

• Action potential: Rapid change in membrane potential that propagates along the axon.

• Resting membrane potential: Maintained by ion gradients and membrane permeability.

• Synaptic transmission: Neurotransmitters released at synapses transmit signals to other neurons or effectors.

• Refractory periods: Absolute and relative refractory periods prevent overlapping action potentials.

Example: The sodium-potassium pump maintains the resting membrane potential by moving Na+ out and K+ into the cell.

Important Terminology

• Neuron

• Sensory neuron

• Interneuron

• Effector neuron

• Somatic motor division

• Autonomic division

• Repolarization

• Hyperpolarization

• Sympathetic branch

• Parasympathetic branch

• Nodes of Ranvier

• Sodium

• Voltage gated Na channels

• Acetylcholine

• Convergence

• Divergence

• Synaptic plasticity

• Spatial summation

• Temporal summation

• Presynaptic facilitation

• Presynaptic inhibition

• Global inhibition

• Selective inhibition

Formula:

Nernst equation for membrane potential.

Chapter 9 – The Central Nervous System

Important Concepts

The central nervous system (CNS) integrates sensory information and coordinates responses.

• Brain regions: Each region has specialized functions (e.g., cerebrum for cognition, cerebellum for coordination).

• Gray vs. white matter: Gray matter contains neuron cell bodies; white matter contains myelinated axons.

• Blood-brain barrier: Protects the CNS from toxins and pathogens.

• Brainstem: Controls vital functions such as breathing and heart rate.

• Hypothalamus: Regulates homeostasis, including temperature and hunger.

• Sensation vs. perception: Sensation is detection; perception is interpretation.

Example: The hippocampus is essential for forming new memories.

Important Terminology

• Plasticity

• Affective behaviors

• Gray matter

• White matter

• Choroid plexus

• Ventricles of the brain

• Blood brain barrier

• Thalamus

• Hypothalamus

• Pituitary gland

• Hippocampus

• Amygdala

• Medulla

• Cerebellum

• Cingulate gyrus

• Somatic motor nuclei

• Cerebral localization

• Circadian rhythm

• Retrograde amnesia

• Declarative (explicit) memory

• Wernicke’s area

• Broca’s area

Chapter 10 – Sensory Physiology

Important Concepts

Sensory physiology studies how the body detects and processes stimuli from the environment.

• Somatic senses: Touch, pain, temperature, proprioception.

• Receptors: Specialized cells that detect specific types of stimuli.

• Transduction: Conversion of stimulus energy into electrical signals.

• Properties of sensory coding: Includes modality, location, intensity, and duration.

• Pathways: Sensory information travels via specific neural pathways to the brain.

Example: Photoreceptors in the retina convert light into electrical signals for vision.

Important Terminology

• Chemoreceptor

• Mechanoreceptor

• Thermoreceptor

• Photoreceptor

• Receptive field

• Primary sensory neuron

• Convergence

• Habituation

• Tonic receptor

• Phasic receptor

• Nociceptor

• Withdrawal reflex

• Referred pain

• Cochlea

• Tympanic membrane

• Organ of Corti

• Semicircular canal

• Macula

• Optic disk

• Fovea

• Rods

• Cones

• Retina

Chapter 11 – Autonomic and Somatic Divisions of the Nervous System

Important Concepts

The nervous system is divided into autonomic (involuntary) and somatic (voluntary) branches.

• Autonomic vs. somatic: Autonomic controls smooth muscle, cardiac muscle, and glands; somatic controls skeletal muscle.

• Sympathetic vs. parasympathetic: Sympathetic prepares for 'fight or flight'; parasympathetic for 'rest and digest'.

• Antagonistic control: Most organs receive input from both branches, which have opposite effects.

• Neurotransmitters: Acetylcholine, norepinephrine, and epinephrine are key in autonomic signaling.

• Varicosities: Swellings along autonomic axons that release neurotransmitters.

Example: The heart rate increases via sympathetic stimulation and decreases via parasympathetic stimulation.

Important Terminology

• Afferent

• Motor

• Preganglion neuron

• Postganglion neuron

• Ganglion

• Varicosity

• Acetylcholine

• Acetylcholinesterase

• Nicotinic

• Muscarinic

• Adrenergic

• Neuromuscular junction

• Motor endplate

Chapter 12 – Muscles

Important Concepts

Muscles generate force and movement through contraction.

• Types of muscle: Skeletal, cardiac, and smooth muscle differ in structure and function.

• Sliding filament theory: Muscle contraction occurs when actin and myosin filaments slide past each other.

• Excitation-contraction coupling: Electrical signals trigger muscle contraction via calcium release.

• Motor unit: A motor neuron and all the muscle fibers it innervates.

Example: Skeletal muscle contraction enables voluntary movement.

Important Terminology

• Actin

• Myosin

• Sarcomere

• Tropomyosin

• Troponin

• Calcium

• ATP

• Motor unit

• Isotonic contraction

• Isometric contraction

Chapter 13 – Integrative Physiology (Motor Control)

Important Concepts

Motor control involves the coordination of muscles and neural circuits to produce movement.

• Motor pathways: Descending tracts from the brain to the spinal cord control voluntary movement.

• Reflexes: Automatic responses to stimuli.

• Central pattern generators: Neural circuits that produce rhythmic movements.

Example: Walking is controlled by central pattern generators in the spinal cord.

Important Terminology

• Reflex arc

• Motor cortex

• Basal ganglia

• Cerebellum

• Descending tract

Chapter 14 – Cardiovascular Physiology

Important Concepts

The cardiovascular system transports nutrients, gases, and wastes throughout the body.

• Heart structure and function: Four chambers pump blood through pulmonary and systemic circuits.

• Blood flow: Governed by pressure gradients and vessel resistance.

• Cardiac cycle: Sequence of events in one heartbeat.

• Electrical conduction: SA node initiates heartbeat; signals spread via conduction system.

Example: Blood pressure is highest in arteries and lowest in veins.

Important Terminology

• Artery

• Vein

• Capillary

• SA node

• AV node

• Cardiac output

• Stroke volume

• Blood pressure

Formula:

Chapter 15 – Blood Flow and the Control of Blood Pressure

Important Concepts

Blood pressure is regulated to ensure adequate tissue perfusion.

• Vascular resistance: Determined by vessel diameter and blood viscosity.

• Baroreceptor reflex: Maintains blood pressure via autonomic adjustments.

• Hypertension vs. hypotension: High vs. low blood pressure, with distinct clinical implications.

Example: Vasoconstriction increases blood pressure; vasodilation decreases it.

Important Terminology

• Baroreceptor

• Vasoconstriction

• Vasodilation

• Mean arterial pressure

Formula:

Chapter 16 – Blood

Important Concepts

Blood is a connective tissue that transports oxygen, nutrients, and waste products.

• Components: Plasma, red blood cells, white blood cells, platelets.

• Hemostasis: Process of stopping bleeding via clot formation.

• Blood types: Determined by antigens on red blood cells.

Example: Type O blood is the universal donor.

Important Terminology

• Hemoglobin

• Hematocrit

• Platelet

• Coagulation

• Antigen

• Antibody

Chapter 17 – Mechanics of Breathing

Important Concepts

Breathing involves the movement of air into and out of the lungs.

• Inspiration and expiration: Driven by changes in thoracic volume and pressure.

• Diaphragm: Main muscle of respiration.

• Compliance and resistance: Affect ease of breathing.

Example: Asthma increases airway resistance, making breathing difficult.

Important Terminology

• Alveoli

• Diaphragm

• Tidal volume

• Vital capacity

• Compliance

• Resistance

Chapter 18 – Gas Exchange and Transport

Important Concepts

Gas exchange occurs in the lungs and tissues to supply oxygen and remove carbon dioxide.

• Partial pressures: Drive diffusion of gases.

• Hemoglobin: Binds oxygen for transport.

• CO2 transport: Dissolved, bound to hemoglobin, or as bicarbonate.

Example: Oxygen diffuses from alveoli into pulmonary capillaries.

Important Terminology

• Partial pressure

• Hemoglobin

• Bicarbonate

• Oxyhemoglobin

Formula:

Chapter 19 – The Kidneys

Important Concepts

The kidneys regulate fluid balance, electrolyte levels, and waste excretion.

• Nephron structure: Functional unit of the kidney.

• Filtration, reabsorption, secretion: Key processes in urine formation.

• Regulation of blood pressure: Via renin-angiotensin system.

Example: Antidiuretic hormone increases water reabsorption in the kidneys.

Important Terminology

• Nephron

• Glomerulus

• Bowman's capsule

• Proximal tubule

• Loop of Henle

• Distal tubule

• Collecting duct

• Renin

• Angiotensin

Chapter 20 – Fluid and Electrolyte Balance

Important Concepts

Fluid and electrolyte balance is vital for cellular function and homeostasis.

• Water balance: Regulated by intake and output.

• Electrolytes: Sodium, potassium, calcium, and chloride are key ions.

• Acid-base balance: Maintained by buffers, respiration, and renal function.

Example: Dehydration leads to increased plasma osmolarity and thirst.

Important Terminology

• Osmolarity

• Buffer

• Acidosis

• Alkalosis

Chapter 21 – The Digestive System

Important Concepts

The digestive system breaks down food, absorbs nutrients, and eliminates waste.

• Digestive tract: Mouth, esophagus, stomach, intestines.

• Enzymatic digestion: Enzymes break down macromolecules.

• Absorption: Nutrients are absorbed into the bloodstream.

• Motility: Movement of food via peristalsis.

Example: Amylase in saliva begins carbohydrate digestion.

Important Terminology

• Peristalsis

• Enzyme

• Villi

• Microvilli

• Chyme

Chapter 22 – Metabolism and Energy Balance

Important Concepts

Metabolism encompasses all chemical reactions in the body, including energy production and storage.

• Anabolism vs. catabolism: Anabolism builds molecules; catabolism breaks them down.

• ATP production: Cellular respiration generates ATP from glucose.

• Energy balance: Intake vs. expenditure determines body weight.

Example: During fasting, the body uses stored glycogen and fat for energy.

Important Terminology

• ATP

• Glycolysis

• Krebs cycle

• Electron transport chain

• Basal metabolic rate

Formula: