Human Anatomy and Physiology

• Anatomy is the study of the structure of the body.
• Physiology is the study of how the body functions.
• Human body systems are groups of organs that work together to perform specific functions.
• The main human body systems include:
  • Integumentary system (skin, hair, nails)
  • Skeletal system (bones, cartilage, ligaments)
  • Muscular system (skeletal muscles, smooth muscles, cardiac muscle)
  • Nervous system (brain, spinal cord, nerves)
  • Endocrine system (glands that produce hormones)
  • Cardiovascular system (heart, blood vessels, blood)
  • Lymphatic system (lymph nodes, lymphatic vessels, lymph)
  • Respiratory system (lungs, airways)
  • Digestive system (mouth, esophagus, stomach, intestines, liver, pancreas)
  • Urinary system (kidneys, ureters, bladder, urethra)
  • Reproductive system (male and female reproductive organs)

Cell Structure and Function

• The cell is the basic structural and functional unit of the human body.
• Major cell structures include:
  • Plasma membrane: outer boundary of the cell, controls what enters and exits the cell.
  • Cytoplasm: the gel-like substance inside the cell, contains organelles.
  • Nucleus: the control center of the cell, contains DNA.
  • Ribosomes: synthesize proteins.
  • Endoplasmic reticulum (ER): involved in protein and lipid synthesis.
  • Golgi apparatus: modifies, sorts, and packages proteins.
  • Mitochondria: produce energy (ATP) for the cell.
  • Lysosomes: break down waste materials and cellular debris.
• Cells perform various functions, including:
  • Metabolism: chemical reactions that occur in the cell.
  • Growth: increase in size and number of cells.
  • Reproduction: production of new cells.
  • Irritability: ability to respond to stimuli.
  • Conductivity: ability to transmit electrical signals.
  • Contractility: ability to shorten and produce movement.

Musculoskeletal Anatomy

• The musculoskeletal system provides support, movement, and protection for the body.
• Bones are the organs of the skeletal system and provide a rigid framework for the body.
• Cartilage is a type of connective tissue that provides cushioning and support at the joints.
• Ligaments connect bones to bones and help to stabilize joints.
• Muscles are responsible for movement.
• Tendons connect muscles to bones.
• Types of bones:
  • Long bones (e.g., femur, humerus)
  • Short bones (e.g., carpals, tarsals)
  • Flat bones (e.g., skull, ribs)
  • Irregular bones (e.g., vertebrae)
• Types of joints:
  • Fibrous joints (immovable)
  • Cartilaginous joints (slightly movable)
  • Synovial joints (freely movable)
• Types of muscle tissue:
  • Skeletal muscle (voluntary, striated)
  • Smooth muscle (involuntary, non-striated)
  • Cardiac muscle (involuntary, striated)

Cardiovascular Physiology

• The cardiovascular system transports blood, oxygen, nutrients, and hormones throughout the body.
• The heart is the pump of the cardiovascular system.
• Blood vessels are the tubes that carry blood throughout the body.
• Blood is the fluid that transports oxygen, nutrients, and waste products.
• The heart has four chambers:
  • Right atrium: receives deoxygenated blood from the body.
  • Right ventricle: pumps deoxygenated blood to the lungs.
  • Left atrium: receives oxygenated blood from the lungs.
  • Left ventricle: pumps oxygenated blood to the body.
• Blood vessels include:
  • Arteries: carry blood away from the heart.
  • Veins: carry blood back to the heart.
  • Capillaries: tiny blood vessels that connect arteries and veins, where exchange of oxygen, nutrients, and waste products occurs.
• Blood is composed of:
  • Red blood cells (erythrocytes): carry oxygen.
  • White blood cells (leukocytes): fight infection.
  • Platelets (thrombocytes): help with blood clotting.
  • Plasma: fluid portion of blood, contains water, proteins, and other solutes.
• Blood pressure is the force of blood against the walls of the arteries.
• The cardiac cycle is the sequence of events that occurs during one heartbeat.
• The heart's electrical activity is controlled by the sinoatrial (SA) node, also known as the pacemaker.

Nervous System Pathways

• The nervous system controls and coordinates bodily functions.
• The nervous system is divided into two main divisions:
  • Central nervous system (CNS): brain and spinal cord.
  • Peripheral nervous system (PNS): nerves that connect the CNS to the rest of the body.
• Neurons are the basic units of the nervous system.
• A neuron consists of:
  • Cell body (soma): contains the nucleus.
  • Dendrites: receive signals from other neurons.
  • Axon: transmits signals to other neurons or effector cells.
  • Axon terminals: form synapses with other neurons or effector cells.
• Types of neurons:
  • Sensory neurons: transmit signals from sensory receptors to the CNS.
  • Motor neurons: transmit signals from the CNS to muscles or glands.
  • Interneurons: connect sensory and motor neurons within the CNS.
• Synapses are the junctions between neurons where signals are transmitted.
• Neurotransmitters are chemical messengers that transmit signals across synapses.
• Major neurotransmitters include:
  • Acetylcholine
  • Norepinephrine
  • Dopamine
  • Serotonin
  • GABA (gamma-aminobutyric acid)
• The spinal cord transmits signals between the brain and the rest of the body.
• The brain is the control center of the nervous system.
• Major regions of the brain include:
  • Cerebrum: responsible for higher-level functions such as thought, memory, and language.
  • Cerebellum: coordinates movement and balance.
  • Brainstem: controls basic life functions such as breathing and heart rate.
• The peripheral nervous system (PNS) is divided into:
  • Somatic nervous system: controls voluntary movements of skeletal muscles.
  • Autonomic nervous system: controls involuntary functions such as heart rate, digestion, and breathing.
    • Sympathetic nervous system: "fight-or-flight" response.
    • Parasympathetic nervous system: "rest-and-digest" response.