Integumentary and Respiratory Systems

Integumentary System

• Skin Layers:
  • Epidermis: Outermost, protective layer containing keratin and melanocytes.
  • Dermis: Middle layer with blood vessels, nerves, and hair follicles.
  • Hypodermis (Subcutaneous): Deepest layer, composed of fat and connective tissue for insulation and cushioning.
• System Functions:
  • Protection, sensation, temperature regulation, vitamin D synthesis, and excretion.
• Temperature Regulation:
  • Heat Loss: Sweating, vasodilation (blood vessel widening).
  • Heat Gain: Shivering, vasoconstriction (blood vessel narrowing), piloerection (goosebumps).

Respiratory System

• Gas Exchange: Occurs in the alveoli of lungs where oxygen enters blood and carbon dioxide is expelled.
• Lung Anatomy:
  • Right lung: 3 lobes.
  • Left lung: 2 lobes.
  • Surrounded by pleura.
• Airways (Anatomy):
  • Upper: Nose, nasal cavity, pharynx, larynx.
  • Lower: Trachea, bronchi, bronchioles, alveoli.
• Surfactant: A lipoprotein that reduces surface tension in alveoli, preventing lung collapse.
• Respiration:
  • External: Gas exchange between alveoli and blood.
  • Internal: Gas exchange between blood and tissues.
• Oxygenation vs. Ventilation:
  • Oxygenation: Oxygen binding to hemoglobin.
  • Ventilation: Physical air movement in/out of lungs.
• Airway Functions:
  • Upper: Warms, filters, and humidifies air.
  • Lower: Conducts air to lungs for gas exchange.

Musculoskeletal System

• Bone Anatomy: Composed of compact and spongy bone, with periosteum, marrow, and growth plates.
• Muscle Types:
  • Skeletal: Attached to bones, voluntary.
  • Smooth: Internal organs (e.g., intestines, blood vessels), involuntary.
  • Cardiac: Heart, involuntary.
• Muscle Tissue Differences:
  • Skeletal: Striated, voluntary, multinucleated.
  • Smooth: Non-striated, involuntary, single nucleus.
  • Cardiac: Striated, involuntary, intercalated discs (synchronized contractions).

Cardiac System

• Blood Pressure Control: Regulated by cardiac output, blood volume, and vascular resistance (controlled by baroreceptors and hormones like ADH and epinephrine).
• Blood Pathway (Through Heart):
  • Vena Cavae → Right Atrium → Tricuspid Valve → Right Ventricle → Pulmonary Valve → Pulmonary Arteries → Lungs (Oxygenation) → Pulmonary Veins → Left Atrium → Mitral Valve → Left Ventricle → Aortic Valve → Aorta → Body.
• Heart Anatomy/Contraction: Four chambers (2 atria, 2 ventricles). Systole (contraction), Diastole (relaxation).
• ECG (Electrocardiogram):
  • P wave: Atrial depolarization.
  • QRS complex: Ventricular depolarization.
  • T wave: Ventricular repolarization.
• Electrical Impulse Pathway: SA Node → AV Node → Bundle of His → Purkinje Fibers (contraction).
• Cardiac Output: Heart Rate × Stroke Volume. Affected by preload, afterload, and contractility.
• Blood Components: Red blood cells, white blood cells, platelets, plasma.
• Blood Clotting: Intrinsic and extrinsic pathways form fibrin clot via thrombin activation.

Nervous System

• System Functions: Controls bodily functions, processes sensory input, and initiates motor responses.
• Action Potential Speed: Increased by myelination and larger axon diameter.
• Sensory vs. Motor Systems:
  • Sensory (Afferent): Body to brain.
  • Motor (Efferent): Brain to muscles/glands.
  • Spinal nerves carry both.
• Central Nervous System Layers:
  • Dura Mater: Tough outer layer.
  • Arachnoid Mater: Middle layer with cerebrospinal fluid (CSF).
  • Pia Mater: Inner layer, adheres to brain/spinal cord.
• Autonomic Nervous System:
  • Sympathetic: Fight-or-flight (increased heart rate, dilated pupils).
  • Parasympathetic: Rest-and-digest (lowered heart rate, increased digestion).
• Vagus Nerve (Cranial Nerve X): Parasympathetic functions (heart rate, digestion).
• Hypothalamus: Regulates homeostasis, hormone release, body temperature, and emotions.

This quiz explores the Integumentary and Respiratory systems, focusing on their structures, functions, and processes. Topics include skin layers, temperature regulation, and gas exchange in the lungs. Test your knowledge on these essential human body systems.