Comprehensive Study Guide: Articulations, Muscle Tissue, Digestive, Respiratory, and Urinary Systems

Articulations

Classification and Types of Joints

Joints, or articulations, are the connections between bones that allow for movement and provide structural support. They are classified based on their structure and function.

• Structural Classification: Joints are classified as fibrous, cartilaginous, or synovial based on the material joining the bones.

• Functional Classification: Joints are classified as synarthroses (immovable), amphiarthroses (slightly movable), or diarthroses (freely movable).

• Synovial Joints: These are the most movable type, characterized by a synovial cavity and articular cartilage.

Example: The shoulder joint is a synovial ball-and-socket joint, allowing a wide range of motion.

Synovial Joint Components and Movements

Synovial joints have several key components that facilitate movement:

• Articular Cartilage: Covers bone surfaces to reduce friction.

• Synovial Membrane: Secretes synovial fluid for lubrication.

• Ligaments: Connect bone to bone, providing stability.

• Types of Movements: Include flexion, extension, abduction, adduction, rotation, and circumduction.

Example: The knee joint allows flexion and extension, while the hip joint allows rotation and circumduction.

Major Ligaments and Functions

Ligaments are crucial for joint stability and function.

• Shoulder Joint Ligaments: Glenohumeral, coracohumeral, and transverse humeral ligaments.

• Hip Joint Ligaments: Iliofemoral, pubofemoral, and ischiofemoral ligaments.

• Knee Joint Ligaments: Anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial and lateral collateral ligaments.

Additional info: Ligaments prevent excessive movement and dislocation.

Muscle Tissue

Types and Characteristics of Muscle Tissue

Muscle tissue is specialized for contraction and movement. There are three main types:

• Skeletal Muscle: Voluntary, striated, attached to bones.

• Cardiac Muscle: Involuntary, striated, found in the heart.

• Smooth Muscle: Involuntary, non-striated, found in walls of hollow organs.

Common Characteristics: Excitability, contractility, extensibility, and elasticity.

Functions and Structure of Muscle Tissue

• Main Functions: Movement, posture maintenance, joint stabilization, heat generation.

• Connective Tissue Layers: Epimysium (surrounds entire muscle), perimysium (surrounds fascicles), endomysium (surrounds individual fibers).

Example: Skeletal muscles contract to move limbs.

Sarcomere Structure and Muscle Contraction

The sarcomere is the functional unit of muscle contraction.

• Main Protein Molecules: Actin (thin filament), myosin (thick filament).

• Muscle Contraction: Involves sliding of actin and myosin filaments.

• T-tubules and Triads: Structures that help transmit action potentials for contraction.

Equation: $\text{Force} = \text{Cross-sectional area} \times \text{Tension}$

Neuromuscular Junction and Contraction Stages

• Neuromuscular Junction: Site where motor neuron stimulates muscle fiber.

• Stages of Contraction: Excitation, contraction, relaxation.

Additional info: ATP is required for both contraction and relaxation.

Motor Units, Twitch, and Tetanus

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

• Twitch: A single, brief contraction.

• Tetanus: Sustained contraction due to rapid stimulation.

Digestive System

Main Organs and Accessory Organs

The digestive system breaks down food for nutrient absorption and waste elimination.

• Main Organs: Mouth, pharynx, esophagus, stomach, small intestine, large intestine.

• Accessory Organs: Teeth, tongue, salivary glands, liver, gallbladder, pancreas.

Functions and Layers of Digestive System

• Main Functions: Ingestion, digestion, absorption, excretion.

• Layers of Alimentary Canal: Mucosa, submucosa, muscularis externa, serosa.

Oral Cavity, Teeth, and Salivary Glands

• Borders of Oral Cavity: Lips, cheeks, palate, tongue.

• Teeth: Deciduous (baby) and permanent teeth; formula for permanent teeth: $2\text{I}, 1\text{C}, 2\text{P}, 3\text{M}$ per quadrant.

• Salivary Glands: Parotid, submandibular, sublingual.

Stomach and Intestines

• Stomach Parts: Cardia, fundus, body, pylorus.

• Functions: Mechanical and chemical digestion.

• Small Intestine Parts: Duodenum, jejunum, ileum.

• Large Intestine Parts: Cecum, colon, rectum, anal canal.

Liver, Pancreas, and Bile

• Liver Functions: Metabolism, detoxification, bile production.

• Bile Storage: Stored in gallbladder, released into duodenum via bile duct.

• Pancreas Functions: Produces digestive enzymes and hormones.

Respiratory System

Stages and Functions of Respiration

The respiratory system enables gas exchange and maintains acid-base balance.

• Stages: Pulmonary ventilation, external respiration, transport, internal respiration, cellular respiration.

• Respiratory Mucosa: Pseudostratified ciliated columnar epithelium.

Pharynx, Larynx, and Bronchial Tree

• Pharynx Parts: Nasopharynx, oropharynx, laryngopharynx.

• Larynx Cartilages: Thyroid, cricoid, arytenoid, epiglottis.

• Bronchial Tree: Trachea, bronchi, bronchioles, alveoli.

Lungs and Ventilation

• Lung Parts: Apex, base, lobes, hilum.

• Pleura: Visceral and parietal layers.

• Ventilation Phases: Inspiration and expiration.

Respiratory Disorders

• Major Disorders: Asthma, COPD, emphysema, chronic bronchitis.

Urinary System

Main Organs and Functions

The urinary system removes waste and regulates fluid balance.

• Main Organs: Kidneys, ureters, bladder, urethra.

• Kidney Functions: Filtration, reabsorption, secretion.

Kidney Structure

• Location: Retroperitoneal, hilum is entry/exit for vessels and ureter.

• Renal Pyramids: Cone-shaped tissue in medulla.

• Renal Calyces: Collect urine from pyramids.

Renal Corpuscle and Tubules

• Renal Corpuscle Components: Glomerulus and Bowman's capsule.

• Podocytes: Specialized cells in Bowman's capsule aiding filtration.

• Renal Tubules: Proximal convoluted tubule, loop of Henle, distal convoluted tubule.

Urine Production and Filtration

• Stages: Filtration, reabsorption, secretion.

• Filtration Membrane Components: Endothelium, basement membrane, podocytes.

• Renal Filtrate: Fluid filtered from blood into Bowman's capsule.

Urethra and UTI

• Male Urethra Parts: Prostatic, membranous, spongy.

• UTI: Urinary tract infection, more common in women due to shorter urethra.

System	Main Organs	Main Functions
Articulations	Joints, ligaments	Movement, stability
Muscle Tissue	Skeletal, cardiac, smooth muscle	Contraction, movement
Digestive System	Mouth, stomach, intestines, liver, pancreas	Digestion, absorption
Respiratory System	Lungs, trachea, bronchi	Gas exchange
Urinary System	Kidneys, ureters, bladder, urethra	Waste removal, fluid balance