Overview
This lecture provides a comprehensive overview of human anatomy and physiology for the ATI TEAS 7 exam, covering all major body systems, key physiological processes, and vital terminology relevant to exam success.
Respiratory System
- Air enters through the nasal cavity, where it is warmed, humidified, and filtered.
- The pharynx directs food to the esophagus and air to the larynx; the epiglottis prevents food from entering the trachea.
- Trachea is supported by cartilage rings, divides into bronchi, which branch into bronchioles and alveoli.
- Gas exchange occurs at the alveoli, with oxygen entering blood and COâ‚‚ removed.
- Conducting zone (nose, trachea, bronchi) moves air but has no gas exchange; respiratory zone (respiratory bronchioles, alveoli) is where gas exchange happens.
- Breathing is controlled by the diaphragm and intercostal muscles; pH changes regulate breathing rate.
Circulatory System
- Blood is always red; arteries carry blood away from the heart, veins return blood to the heart.
- Pulmonary arteries carry deoxygenated blood; pulmonary veins return oxygenated blood.
- The heart has four chambers; valves prevent backflow.
- Blood: plasma (liquid), red blood cells (Oâ‚‚/COâ‚‚ transport), white blood cells (immune defense), platelets (clotting).
- Flow through the heart: body → right atrium → right ventricle → lungs → left atrium → left ventricle → body.
- Heart's conduction system: SA node → AV node → Bundle of His → bundle branches → Purkinje fibers.
Nervous System
- Central nervous system (CNS): brain and spinal cord; Peripheral nervous system (PNS): nerves.
- Brain divided into hindbrain (vital functions), midbrain (alertness, movement), forebrain (cognition, sensory/motor cortex).
- Neuron structure: cell body, dendrites, axon (carries signals away).
- Gray matter = cell bodies; white matter = myelinated axons.
- Somatic nervous system (voluntary muscle control), autonomic (involuntary: sympathetic/fight-or-flight, parasympathetic/rest-and-digest).
- Sensory (afferent) neurons carry info to CNS; motor (efferent) neurons carry signals to muscles.
Digestive System
- Four main functions: ingestion, digestion, absorption, elimination.
- Mouth initiates digestion (mechanical and chemical); epiglottis prevents choking.
- Stomach uses acid/enzymes to break down food; sphincters regulate entry/exit.
- Small intestine absorbs nutrients; divided into duodenum (enzyme digestion), jejunum (absorption), ileum (vitamins/final absorption).
- Large intestine absorbs water; segments: ascending, transverse, descending colon.
- Accessory organs: liver (produces bile), gallbladder (bile storage), pancreas (enzymes).
Muscular System
- Three muscle types: cardiac (involuntary, striated), smooth (involuntary, non-striated), skeletal (voluntary, striated).
- Muscle contraction: sliding filament model—actin (thin) and myosin (thick) filaments slide past each other; ATP required.
- Skeletal muscle is multinucleated and under conscious control.
Reproductive System
- Male: testes produce sperm/testosterone; ducts transport sperm; glands add fluids to semen.
- Female: ovaries produce eggs/estrogen/progesterone; oogenesis in ovaries; fertilization occurs in fallopian tubes.
- Hormonal control via hypothalamus and pituitary (FSH, LH): regulate gamete production and sexual cycles.
Integumentary System (Skin)
- Layers: epidermis (outer, keratinized), dermis (connective tissue), hypodermis (fat).
- Functions: protection, temperature regulation, sensation, vitamin D synthesis.
- Accessory structures: sweat/sebaceous glands, hair, nails.
- Common issues: skin cancer (basal cell, squamous cell, melanoma), burns (1st-4th degree).
Endocrine System
- Endocrine glands: pituitary, thyroid, parathyroid, adrenal, pancreas, gonads.
- Hormones regulate metabolism, growth, stress, sugar, calcium, reproduction.
- Endocrine (ductless, hormones into blood) vs. exocrine (ducts to surface/cavities).
Urinary System
- Kidneys filter blood; nephrons are the functional units.
- Filtration, reabsorption, secretion, and excretion produce urine.
- Water and solute balance, waste removal (urea, creatinine).
Immune System
- First line: physical/chemical barriers (skin, mucous membranes).
- Second line: non-specific responses (inflammation, phagocytes).
- Third line: adaptive responses—cell-mediated (T cells) and humoral (B cells/antibodies).
- Immunity types: active (own antibodies), passive (antibodies given).
Skeletal System
- Functions: support, protection, movement, blood cell production, mineral storage.
- Types of bones: long, short, flat, irregular, sesamoid.
- Bone structure: compact (outer), spongy (inner, marrow).
- Cells: osteoblasts (build), osteocytes (maintain), osteoclasts (break down).
- Bone remodeling and healing process after fractures.
Key Anatomical Terms & Planes
- Anterior (front), posterior (back), medial (toward midline), lateral (away from midline), proximal (near origin), distal (far from origin), superior (above), inferior (below).
- Anatomical planes: sagittal (left/right), frontal (front/back), transverse (upper/lower).
Key Terms & Definitions
- Alveoli — air sacs in lungs where gas exchange occurs.
- SA node — heart’s primary pacemaker.
- Neuron — nerve cell that transmits electrical impulses.
- Hormone — chemical messenger regulating body functions.
- Nephron — kidney’s functional unit for urine production.
- Osteoblast/Osteoclast/Osteocyte — bone-building, bone-resorbing, and bone-maintaining cells.
- Immunity — body’s defense against disease (innate and adaptive).
Action Items / Next Steps
- Review all key terms and definitions.
- Memorize blood and air flow pathways.
- Practice labeling diagrams of major organs and systems.
- Complete any assigned textbook readings on body systems.
- Study anatomical terms, planes, and positions for the exam.