Anatomical Position & Terminology

Anatomical Position & Terminology

• Anatomical Position is a standardized posture used as a reference point that includes standing upright, facing forward, arms at sides with palms forward, and feet flat
• It is essential for consistent communication
• Anterior means front
• Posterior means back
• Superior means toward the head
• Inferior means away from the head
• Medial means toward the midline
• Lateral means away from the midline
• Proximal means toward the trunk
• Distal means away from the trunk
• Deep means away from the surface
• Superficial means toward the surface
• The nose is inferior to the eyes
• The shoulder is proximal to the elbow
• The nose is medial to the ears

Human Body Systems & Sections

• The 11 body systems include Integumentary, Endocrine, Skeletal, Muscular, Digestive, Respiratory, Urinary, Nervous, Reproductive, Circulatory, and Lymphatic
• The Integumentary system consists of skin, hair, and nails
• The Endocrine system consists of hormones and the thyroid
• The Skeletal system consists of bones
• The Muscular system consists of muscles
• The Digestive system consists of the esophagus and stomach
• The Respiratory system consists of lungs
• The Urinary system consists of the bladder
• The Nervous system consists of the brain and nerves
• The Reproductive system consists of testes and ovaries
• The Circulatory system consists of the heart and blood
• The Lymphatic system consists of lymph nodes
• The head includes the nervous, sensory, and endocrine systems, such as the brain, eyes, ears, and pituitary gland
• The trunk includes the respiratory, cardiovascular, digestive, and lymphatic systems, such as the lungs, heart, and stomach
• The upper limbs include the musculoskeletal and nervous systems, such as bones, muscles, and nerves
• The lower limbs include the musculoskeletal and circulatory systems, such as bones, muscles, and blood circulation

Anatomical Planes & Movements

• The Sagittal plane divides the body into left and right
• Movements in the sagittal plane include flexion, extension, dorsiflexion, and plantarflexion
• Examples of sagittal plane movements are bicep curls, squats, and crunches
• The Coronal (Frontal) plane divides the body into front and back
• Movements in the coronal plane include adduction, abduction, and lateral flexion
• Examples of coronal plane movements are cartwheels and jumping jacks
• The Transverse plane divides the body into upper and lower sections
• Movements in the transverse plane include rotation, such as twisting the torso

Bone Structure, Development & Function

• Types of bones include long, short, flat, irregular, and sesamoid
• Bone functions include support, protection, movement, mineral storage, blood cell production, and fat storage
• Compact bone is a dense outer layer providing strength and protection
• Spongy bone is porous, lightweight, and supports blood cell production
• The epiphysis is spongy bone at the ends and houses red marrow
• The metaphysis is the growth plate area
• The diaphysis is the shaft containing the medullary cavity, which has yellow marrow in adults
• Intramembranous ossification is direct development from connective tissue, such as the skull and clavicle
• Endochondral ossification replaces a cartilage template, such as the femur
• Bone remodeling is a continuous process involving osteoclasts (breakdown) and osteoblasts (building)
• Nutrition, hormones, and physical activity influence bone remodeling

Joints & Movement

• Fibrous joints are immovable, such as skull sutures
• Cartilaginous joints are slightly movable, such as intervertebral discs
• Synovial joints are freely movable, such as the knee and shoulder
• Synarthroses joints are immovable
• Amphiarthroses joints are slightly movable
• Diarthroses joints are freely movable

Lever Systems in the Body

• In a first-class lever, the fulcrum is between the effort and load, such as neck movements
• In a second-class lever, the load is between the fulcrum and effort, such as a calf raise
• In a third-class lever, the effort is between the fulcrum and load, such as a bicep curl

Connective Tissues & Muscles

• Tendons connect muscle to bone
• Ligaments connect bone to bone
• Hyaline cartilage reduces friction and is found in joints and the nose
• Elastic cartilage provides flexibility and is found in ears
• Fibrocartilage is strong, shock-absorbing, and is found in intervertebral discs

Muscle Structure & Contraction

• Skeletal muscle is voluntary, striated, and multinucleated, like the biceps
• Smooth muscle is involuntary, non-striated, and found in organs, like the digestive tract
• Cardiac muscle is involuntary, striated, and found in the heart
• Muscle properties include excitability, contractility, extensibility, and elasticity
• Convergent muscles include the pectoralis major
• Circular muscles include the orbicularis oris
• Fusiform muscles include the biceps brachii
• Parallel muscles include the sartorius
• Unipennate muscles include the extensor digitorum
• Bipennate muscles include the rectus femoris
• Multipennate muscles include the deltoid
• The origin is the fixed point of a muscle
• The insertion is the moving point of a muscle
• Muscle hierarchy: Muscle > Bundle of Fibers (Perimysium) > Single Fiber (Endomysium) > Myofibril > Sarcomere
• Isometric contraction is tension without length change
• Isotonic contraction is tension with length change
• Concentric contraction is when the muscle shortens
• Eccentric contraction is when the muscle lengthens
• Isokinetic contraction is at a constant speed

Factors Influencing Bone & Muscle Health

• Calcium, Vitamin D, and Vitamin C are essential for bone health
• Growth hormone, testosterone, and estrogen influence bone growth and density
• Mechanical stress promotes bone remodeling, according to Wolff's law

Divisions of the Nervous System and Their Roles in Movement Control

• The Central Nervous System (CNS) consists of the brain and spinal cord
• The CNS processes sensory information, initiates responses, controls voluntary movement, and reflexes
• The Peripheral Nervous System (PNS) consists of nerves outside the CNS
• The PNS is divided into the somatic nervous system (controls voluntary muscles) and autonomic nervous system (controls involuntary functions)
• The Somatic Nervous System controls skeletal muscle movements consciously and reflexively
• The Autonomic Nervous System is divided into sympathetic (fight or flight) and parasympathetic (rest and digest) systems, regulating involuntary functions

Major Anatomical Structures in the CNS and PNS

• CNS structures include the brain (cerebrum, cerebellum, brainstem) and spinal cord
• PNS structures include cranial nerves, spinal nerves, ganglia, and sensory receptors
• The brain processes sensory data, coordinates motor output, and regulates cognitive functions
• The spinal cord transmits signals between the brain and the rest of the body and is responsible for reflex actions
• Nerves are bundles of axons that transmit information to and from the CNS

Structure and Function of Neurons

• Neurons are fundamental units of the nervous system responsible for receiving, processing, and transmitting information
• Parts of a neuron: Cell Body (Soma), Dendrites, Axon, Myelin Sheath, and Axon Terminals
• The cell body (soma) contains the nucleus and organelles
• Dendrites receive incoming signals
• The axon transmits electrical signals away from the cell body
• The myelin sheath is an insulating layer around axons that speeds up signal transmission
• Axon terminals release neurotransmitters to communicate with other neurons

Mechanisms Involved in Signal Propagation and Movement

• Resting Potential: Neurons maintain a negative charge inside the cell when at rest
• Action Potential: A rapid change in electrical charge across the neuron’s membrane, allowing signal transmission
• Depolarization: Sodium ions enter the neuron, making the inside more positive
• Repolarization: Potassium ions exit the neuron, restoring the negative charge
• Synaptic Transmission: When the action potential reaches the axon terminal, neurotransmitters are released across the synapse to bind to receptors on the adjacent neuron
• Movement Control: Signals from the CNS travel through motor neurons to initiate muscle contractions, while sensory neurons provide feedback to the CNS for coordination