Comprehensive Review Notes: Anatomy & Physiology (Chapters 1–17)

I Major Themes of Anatomy & Physiology

Methods to Study the Human Body

• Inspection: Observing the body for any visible abnormalities or features.

• Palpation: Feeling body structures with the hands (e.g., feeling for a pulse).

• Auscultation: Listening to body sounds (e.g., heart, lungs) using a stethoscope.

• Percussion: Tapping on the body to listen for sounds indicating underlying structures.

Concepts of Anatomy, Physiology, and Histology

• Anatomy: Study of the structure of body parts and their relationships.

• Physiology: Study of the function of body parts and systems.

• Histology: Study of tissues at the microscopic level.

Hierarchy of Complexity

• Order: Atoms → Molecules → Organelles → Cells → Tissues → Organs → Organ Systems → Organism

Feedback Mechanisms

• Negative Feedback: A process that reverses a change to maintain homeostasis (e.g., body temperature regulation).

• Positive Feedback: A process that amplifies a change (e.g., blood clotting, childbirth contractions).

Anatomical vs Physiological Variations

• Anatomical Variation: Differences in physical structure (e.g., number of ribs).

• Physiological Variation: Differences in function (e.g., metabolic rate).

Histology

Concept of Tissue

• Tissue: A group of similar cells performing a common function.

Four Primary Tissue Classes

Tissue Type	Function	Common Location
Epithelial	Protection, secretion, absorption	Skin, lining of GI tract
Connective	Support, binding, protection	Bone, blood, fat
Muscle	Movement	Skeletal muscles, heart
Nervous	Communication, control	Brain, nerves

Types of Epithelia

• Simple: One cell layer (e.g., simple squamous in alveoli).

• Stratified: Multiple layers (e.g., stratified squamous in skin).

• Specialized types: Pseudostratified, transitional, etc.

Basement Membrane and Brush Border

• Basement Membrane: Thin layer anchoring epithelium to connective tissue.

• Brush Border: Microvilli-covered surface for absorption (e.g., small intestine).

The Integumentary System

Layers of the Skin

• Epidermis: Outermost, avascular, stratified squamous epithelium.

• Dermis: Middle, connective tissue, contains nerves and blood vessels.

• Hypodermis (subcutaneous): Deepest, adipose tissue for insulation.

Factors Affecting Skin Color

• Physiological: Melanin, carotene, hemoglobin.

• Pathological: Cyanosis (blue), jaundice (yellow), erythema (redness).

Bone Tissue, Skeletal System, and Joints

Types and Characteristics of Bone Cells

• Osteogenic cells: Stem cells that differentiate into osteoblasts.

• Osteoblasts: Bone-forming cells.

• Osteocytes: Mature bone cells maintaining bone tissue.

• Osteoclasts: Bone-resorbing cells.

Compact vs Spongy Bone

• Compact Bone: Dense, forms outer layer.

• Spongy Bone: Porous, contains red marrow, found at ends of long bones.

Bone Marrow Types

• Red Marrow: Hematopoietic (blood cell formation).

• Yellow Marrow: Fat storage, found in adults.

Long vs Flat Bones

• Long Bones: Longer than wide (e.g., femur), contain marrow cavity.

• Flat Bones: Thin, often curved (e.g., skull, ribs).

Features of a Long Bone

• Diaphysis: Shaft.

• Epiphyses: Ends.

• Marrow Cavity: Central cavity containing marrow.

Mineralization vs Resorption

• Mineralization: Deposition of minerals into bone matrix.

• Resorption: Removal of minerals by osteoclasts.

Hormonal Control of Calcium Homeostasis

• Calcitonin: Lowers blood calcium by stimulating bone deposition.

• Calcitriol (Vitamin D): Increases blood calcium by promoting absorption in intestines.

• Parathyroid Hormone (PTH): Raises blood calcium by stimulating resorption.

Hypercalcemia vs Hypocalcemia

• Hypercalcemia: High blood calcium; stimulates calcitonin release.

• Hypocalcemia: Low blood calcium; stimulates PTH release.

Most Common Bone Disease

• Osteoporosis: Loss of bone density, increased fracture risk.

Axial vs Appendicular Skeleton

Skeleton Part	Main Components
Axial	Skull, vertebral column, rib cage
Appendicular	Limbs, pectoral and pelvic girdles

Sutures

• Sutures: Immovable joints between skull bones.

Bones Forming Joints

• Atlantoaxial Joint: Atlas (C1) and axis (C2) vertebrae.

• Glenohumeral Joint: Humerus and scapula (glenoid cavity).

• Jaw Joint: Mandible and temporal bone.

Concept of Joints (Articulations)

• Joint: Where two bones meet.

• Examples: Acetabulum (hip), proximal radioulnar joint (elbow), multiaxial (shoulder), least movable (sutures).

Muscular System and Tissue

Types of Muscles and Characteristics

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

• Cardiac Muscle: Involuntary, striated, heart only.

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

Muscle Fiber and Sarcoplasmic Reticulum

• Muscle Fiber: Single muscle cell.

• Sarcoplasmic Reticulum: Specialized endoplasmic reticulum storing calcium.

Connective Tissue Layers

• Endomysium: Surrounds individual muscle fibers.

• Perimysium: Surrounds bundles (fascicles) of fibers.

• Epimysium: Surrounds entire muscle.

Rotator Cuff Muscles

• Stabilize the shoulder joint; covered at all sides except inferior.

Prime Mover, Synergist, Antagonist

• Prime Mover (Agonist): Main muscle causing movement (e.g., biceps brachii for elbow flexion).

• Synergist: Assists the prime mover (e.g., brachialis).

• Antagonist: Opposes the prime mover (e.g., triceps brachii).

Structural Hierarchy of Skeletal Muscle

Level	Structure
Muscle	Organ
Fascicle	Bundle of fibers
Fiber	Cell
Myofibril	Contractile elements
Myofilament	Actin, myosin, etc.

Prime Mover for Inhalation

• Diaphragm: Main muscle for inhalation.

Actin vs Myosin and Myofilaments

• Actin: Thin filament.

• Myosin: Thick filament.

• Three Types: Thick (myosin), thin (actin), elastic (titin).

Threshold

• Threshold: Minimum stimulus needed to elicit a muscle contraction.

Location of Smooth Muscle

• Walls of hollow organs (e.g., intestines, blood vessels).

Nervous Tissue

Dermatome

• Dermatome: Area of skin supplied by a single spinal nerve.

Nerve Fiber

• Nerve Fiber: Axon of a neuron.

Opening Na Channels

• Leads to depolarization and initiation of action potential.

Cells of Nervous Tissue

• Central Nervous System: Neurons, astrocytes, oligodendrocytes, microglia, ependymal cells.

• Peripheral Nervous System: Neurons, Schwann cells, satellite cells.

The Spinal Cord, Brain, and Cranial Nerves

Tracts Information

• Tracts are bundles of axons in the CNS carrying specific information (e.g., sensory, motor).

Meninges in Order

• Dura mater (outermost), arachnoid mater (middle), pia mater (innermost).

Mixed Nerve

• Contains both sensory and motor fibers.

Location of Cardiac, Vasomotor, and Respiratory Centers

• Located in the medulla oblongata of the brainstem.

Equilibrium and Motor Coordination

• Cerebellum: Responsible for equilibrium and coordination.

Brain Functions and Related Structures

• Sex drive, body temperature, food/water intake: Hypothalamus.

• Planning, motivation, social judgment: Prefrontal cortex (frontal lobe).

• Vision accommodation: Occipital lobe.

Visceral Reflex and Reflex Arc Steps

• Visceral Reflex: Involuntary response of internal organs.

• Reflex Arc Steps: Receptor → Sensory neuron → Integration center → Motor neuron → Effector.

Cranial Nerves

• 12 pairs, each with specific functions (e.g., optic nerve for vision).

• Decussation: Crossing over of fibers (e.g., optic nerve at optic chiasm).

The Autonomic Nervous System and Sensory System

"Fight-or-Flight" Reaction

• Sympathetic division; increases heart rate, dilates pupils, inhibits digestion.

"Rest and Digest" Reaction

• Parasympathetic division; decreases heart rate, stimulates digestion.

Nociceptors

• Receptors for pain; found in skin, muscles, joints, and some internal organs.

Endocrine System and Hormones

Anterior and Posterior Pituitary Hormones

Lobe	Hormone	Main Function
Anterior	Growth Hormone (GH)	Stimulates growth
Anterior	ACTH	Stimulates adrenal cortex
Posterior	ADH	Water retention in kidneys

Pineal Gland and Melatonin

• Pineal Gland: Secretes melatonin, regulates sleep-wake cycles.

Pancreatic Hormones

• Glucagon: Raises blood glucose by stimulating glycogen breakdown.

• Insulin: Lowers blood glucose by promoting uptake into cells.