Introduction to Anatomy & Physiology

This study guide summarizes foundational concepts in human anatomy and physiology, focusing on the integumentary, skeletal, muscular, and nervous systems. Each topic is expanded with definitions, examples, and key facts to support exam preparation.

Integumentary System

Layers of the Skin

The skin consists of multiple layers, each with distinct functions and structures.

• Stratum basale: Deepest epidermal layer, responsible for cell division and regeneration.

• Stratum corneum: Outermost layer, composed of dead keratinized cells providing protection.

• Stratum lucidum: Present only in thick skin (palms, soles); not distinguishable in thin skin.

• Stratum granulosum: Contains granules important for keratin formation.

• Hypodermis: Subcutaneous layer storing lipid reserves.

Example: The hypodermis stores energy in the form of fat and provides insulation.

Skin Appendages and Glands

• Arrector pili muscle: Smooth muscle that raises hair, causing 'goosebumps.'

• Sudoriferous (eccrine) glands: Produce watery sweat for thermoregulation.

• Sebaceous glands: Secrete sebum for lubrication and protection.

Example: Eccrine glands are most active during exercise to cool the body.

Skin Protection and Healing

• Melanin: Pigment that absorbs UV radiation and reduces DNA damage.

• Skin tension lines: Cuts made parallel to these lines heal more efficiently due to alignment with collagen fibers.

Formula:

Skeletal System

Bone Structure and Function

• Osteoclasts: Bone cells responsible for bone resorption.

• Epiphyseal plate: Growth plate; fractures here can affect bone growth.

• Periosteum: Membrane covering bone; important for bone health and repair.

Example: Vitamin D deficiency can lead to poor bone mineralization and conditions like rickets.

Axial and Appendicular Skeleton

• Axial skeleton: Includes skull, vertebral column, and thoracic cage.

• Appendicular skeleton: Includes limbs and girdles.

Example: The thoracic cavity is separated from the abdominal cavity by the diaphragm.

Cartilage Types

• Articular cartilage: Hyaline cartilage found in joints, providing smooth surfaces for movement.

• Fibrocartilage: Found in intervertebral discs, providing strength and shock absorption.

• Elastic cartilage: Found in structures like the ear, providing flexibility.

Muscular System

Muscle Tissue Types

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

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

• Smooth muscle: Involuntary, non-striated muscle found in organs.

Muscle Fiber Types

• Fast glycolytic fibers: Fatigue quickly, used for short bursts of power.

• Slow oxidative fibers: Resistant to fatigue, used for endurance activities.

• White fibers: Fast-twitch, less myoglobin, fatigue rapidly.

Muscle Structure and Function

• Myofibril: Contractile unit of muscle cell.

• Sarcoplasmic reticulum: Stores calcium ions necessary for muscle contraction.

• Epimysium, perimysium, endomysium: Connective tissue layers surrounding muscle fibers and bundles.

Example: The shoulder joint is more prone to dislocation than the hip due to its shallow socket and greater mobility.

Nervous System

Neurons and Neuroglia

• Neuron: Functional unit of the nervous system, transmits impulses.

• Neuroglia: Support cells in the nervous system (e.g., microglia, oligodendrocytes, Schwann cells).

• Axon: Transmits impulses away from the neuron cell body.

• Dendrite: Receives signals from other neurons.

Peripheral Nervous System Structure

• Myelin sheath: Insulating layer formed by Schwann cells in the peripheral nervous system, increasing impulse speed.

• Perineurium: Connective tissue surrounding bundles of nerve fibers (fascicles).

Brain Regions and Functions

• Cerebrum: Responsible for higher cognitive functions.

• Cerebellum: Controls balance and coordination.

• Medulla oblongata: Regulates vital autonomic functions.

• Pons: Relays signals between different parts of the brain.

Example: Damage to the cerebellum can result in loss of coordination and balance.

Body Organization and Anatomical Terms

Body Planes and Sections

• Sagittal section: Divides body into left and right parts.

• Transverse section: Divides body into superior and inferior parts.

• Coronal section: Divides body into anterior and posterior parts.

Anatomical Directions and Regions

• Superior: Above; Inferior: Below.

• Medial: Toward the midline; Lateral: Away from the midline.

• Quadrants: Abdominal regions used to localize pain or organs (e.g., left upper quadrant for spleen).

Hormones and Homeostasis

Hormonal Regulation

• Calcitonin: Lowers blood calcium levels by inhibiting osteoclast activity.

• Parathyroid hormone: Increases blood calcium levels by stimulating osteoclasts.

• Thyroxine: Regulates metabolism and energy production.

HTML Table: Types of Cartilage

Additional info:

• Some anatomical terms and regions were inferred based on standard curriculum.

• Hormonal regulation and muscle fiber types were expanded for clarity.