BSC2085 Final Exam Review: Anatomy & Physiology Study Notes

Chapter 6: Bones and Bone Structure

Functions and Structure of Bone

Bones are dynamic organs that provide support, protection, and facilitate movement. They also play a role in mineral storage and blood cell production.

• Function of Bone: Support, protection, movement, mineral storage (especially calcium and phosphate), and hematopoiesis (blood cell formation).

• Ligament vs Tendon: Ligaments connect bone to bone; tendons connect muscle to bone.

• Compact vs Spongy Bone: Compact bone is dense and forms the outer layer of bones; spongy bone is porous and found at the ends of long bones and inside flat bones.

• Medullary Cavity: The central cavity of long bones, containing bone marrow.

• Bone Cells: Osteogenic cells (stem cells), osteoblasts (bone-forming), osteocytes (mature bone cells), osteoclasts (bone-resorbing).

• Ossification and Growth: Bones grow and develop through ossification, involving epiphysis (ends), diaphysis (shaft), and metaphysis (growth region).

Example: The femur contains a medullary cavity filled with yellow marrow in adults.

Chapter 9: Skeletal Muscle Tissue

Structure and Function of Skeletal Muscle

Skeletal muscle is composed of muscle fibers organized into fascicles, surrounded by connective tissue layers. It is responsible for voluntary movement.

• Connective Tissue Layers: Epimysium (outer), perimysium (fascicle), endomysium (fiber).

• Sarcolemma and Sarcoplasmic Reticulum: Sarcolemma is the muscle cell membrane; sarcoplasmic reticulum stores calcium ions.

• Myofibrils: Contain contractile proteins (actin and myosin) organized into sarcomeres.

• Transverse Tubules (T-tubules): Invaginations of the sarcolemma that transmit action potentials.

• Muscle Contraction: Involves the sliding filament theory, where actin and myosin filaments slide past each other.

• Neuromuscular Junction: The synapse between a motor neuron and a muscle fiber; acetylcholine is the neurotransmitter.

• Action Potential: Electrical signal that triggers muscle contraction.

Example: During contraction, calcium is released from the sarcoplasmic reticulum, enabling actin-myosin interaction.

Chapter 10: The Muscular System

Major Muscles of the Body

The muscular system consists of various muscles responsible for movement, posture, and heat production.

• Muscle Identification: Biceps femoris, rectus femoris, adductor longus, sartorius, deltoid, trapezius, pectoralis major, sternocleidomastoid, temporalis, semitendinosus, latissimus dorsi, rhomboids, tensor fasciae latae, gluteus.

Example: The deltoid muscle abducts the arm at the shoulder.

Chapter 11: Nervous Tissue

Organization and Function of the Nervous System

The nervous system is divided into central and peripheral components, responsible for control and communication throughout the body.

• Divisions: Central nervous system (CNS) includes brain and spinal cord; peripheral nervous system (PNS) includes nerves and ganglia.

• Somatic vs Autonomic: Somatic controls voluntary actions; autonomic controls involuntary actions (sympathetic and parasympathetic).

• Neuron Structure: Cell body, dendrites, axon.

• Neuroglia: Support cells in CNS (astrocytes, oligodendrocytes, microglia, ependymal cells) and PNS (Schwann cells, satellite cells).

• Gray vs White Matter: Gray matter contains neuron cell bodies; white matter contains myelinated axons.

• Saltatory Propagation: Action potentials jump between nodes of Ranvier in myelinated axons, increasing speed.

Example: Schwann cells myelinate axons in the PNS, enabling rapid signal transmission.

Chapter 12: The Spinal Cord, Spinal Nerves, and Spinal Reflexes

Spinal Cord Anatomy and Function

The spinal cord is a major pathway for information traveling between the brain and body. It is protected by meninges and vertebrae.

• Spinal Cord Anatomy: Posterior horns, anterior horns, posterior columns, anterior columns, spinal canal, gray commissure, lateral horns, lateral columns, anterior median fissure, dorsal root ganglion, filum terminale, cauda equina, conus medullaris.

• Spinal Nerves: 31 pairs, formed by the joining of dorsal and ventral roots.

• Meninges: Three layers—dura mater (outer), arachnoid mater (middle), pia mater (inner).

Example: The cauda equina is a bundle of spinal nerves at the lower end of the spinal cord.

Chapter 13: The Brain, Cranial Nerves, and Sensory and Motor Pathways

Brain Ventricles and Cerebrospinal Fluid

The brain contains four ventricles filled with cerebrospinal fluid (CSF), which cushions and nourishes neural tissue.

• Cerebral Ventricles: Lateral ventricles (1 & 2), third ventricle, fourth ventricle.

• CSF Production: Produced by ependymal cells in the choroid plexus.

• Meninges: Dura mater, arachnoid mater, pia mater.

Example: CSF circulates through the ventricles and subarachnoid space, providing protection and nutrient transport.

Chapter 8 & 11: Action Potentials and Synaptic Transmission

Electrical Activity in Neurons

Neurons communicate via action potentials, which are rapid changes in membrane potential.

• Depolarization: Membrane potential becomes less negative.

• Repolarization: Membrane potential returns to resting state.

• Resting Membrane Potential: Typically -70 mV, maintained by sodium-potassium pump.

• Action Potential Equation:

$V_m = V_{rest} + ext{change due to ion flux}$

• Ion Channels: Sodium and potassium channels open and close during action potentials.

• Refractory Period: Time during which a neuron cannot fire another action potential.

Example: During depolarization, sodium ions enter the cell, making the inside more positive.

HTML Table: Comparison of Bone Cells

Cell Type	Function
Osteogenic cell	Stem cell that differentiates into osteoblasts
Osteoblast	Forms new bone matrix
Osteocyte	Maintains bone tissue
Osteoclast	Resorbs bone matrix

Additional info: Table inferred from standard bone cell classification.