Anatomy and Physiology Notes for CMA Exam (Sections 1.1–2.9)

Anatomy is the branch of science concerned with the study of the structure of organisms and their parts, while physiology deals with the functions and processes of the various systems and organs within the body. Together, these disciplines provide a comprehensive understanding of how the human body is built, and how it operates.
Anatomy includes the study of the body's organs, tissues, bones and other structures, both at the macroscopic gross anatomy and microscopic histology levels.
Physiology examines how these structures function, from cellular processes to the operations of entire systems.

The human body is organized into several levels, each more complex than the last.
Chemical level: involves atoms and molecules, which form the basic building blocks of matter.
Cellular level: Cells are the smallest functional units of life. Different types of cells perform various functions essential for life.
Tissue level: Tissues are groups of similar cells that work together to perform a specific function. There are four primary tissue types: epithelial, connective, muscle, and nervous tissues.
Organ level: Organs are structures composed of two or more tissue types that work together to perform specific complex functions.
System level: Systems consist of related organs with a common function. For example, the digestive system includes the stomach, intestines, liver and other organs involved in digestion.
Organism level: The human body as a whole is the most complex level of organization.

Homeostasis refers to the body's ability to maintain a stable internal environment, despite changes in external conditions. This balance is critical for normal body function and survival.
Key components involved in maintaining homeostasis include:
- Detect changes in the environment, internal and external.
- Control center: Often the brain, processes the information received from receptors and sends out signals to effectors.
- Organs or cells respond to the control center's signals to correct imbalances.

The integumentary system includes the skin, hair, nails, and associated glands.
It serves as a protective barrier between the body's internal environment and the external world.
Skin
- The largest organ of the body consisting of three layers: Epidermis (outermost layer), Dermis (beneath the epidermis contains tough connective tissue, hair follicles and sweat glands), and Subcutaneous tissue (deeper layer made of fat and connective tissue).
Functions: protection, regulation of body temperature, sensory reception and synthesis of vitamin D.

The skeletal system provides structure to the body, protects internal organs, and facilitates movement in conjunction with the muscular system.
Bones: there are $206$ bones in the adult human body. They provide support, protect organs, and store minerals like calcium.
Joints, where two bones meet, allowing for movement and flexibility.
Cartilage, a type of connective tissue that reduces friction and absorbs shock at joints.
Bone marrow, found within bones it produces blood cells.

The muscular system is responsible for movement, posture, and heat production.
Types of muscle tissue:
- Skeletal muscle, attached to bones and causes voluntary movements.
- Cardiac muscle, found only in the heart, responsible for pumping blood.
- Smooth muscle, found in the walls of internal organs and blood vessels controlling involuntary movements.
Functions: movement, maintaining posture and generating heat through muscle contractions.

The nervous system controls both voluntary actions, such as conscious movement, and involuntary actions, such as breathing and reflexes.
Central nervous system (CNS) consists of the brain and spinal cord. It processes information and coordinates body activities.
Peripheral nervous system (PNS) includes all the nerves outside the CNS. It transmits signals between the CNS and the rest of the body.
Neurons: The basic functional units of the nervous system, responsible for transmitting electrical signals. Sensory input, integration of data, motor output and maintaining homeostasis.

The endocrine system consists of glands that produce and secrete hormones, which regulate various body functions.
Major glands: pituitary, thyroid, parathyroid, adrenal, pineal and pancreas.
Chemical messengers that travel through the bloodstream to target organs, influencing processes such as growth, metabolism and mood.
Regulating metabolism, growth and development, tissue function, sexual function, reproduction, sleep and mood.

The cardiovascular system circulates blood throughout the body, delivering oxygen and nutrients while removing waste products.
Heart: A muscular organ that pumps blood through a network of arteries and veins.
Vessels: Include arteries, veins and capillaries.
Arteries carry blood away from the heart, veins return blood to the heart, and capillaries facilitate exchange between blood and tissues.
Blood, composed of red blood cells, white blood cells, platelets and plasma.
Transporting nutrients, oxygen and hormones to cells and removing metabolic wastes.

The lymphatic system works closely with the immune system, to defend the body against pathogens and maintain fluid balance.
Lymphatic vessels, transport lymph, a fluid containing infection fighting white blood cells.
Lymph nodes, filter lymph and house lymphocytes that respond to pathogens.
Spleen and thymus, organs involved in producing and maturing immune cells.
Returning excess tissue fluid to the bloodstream, absorbing fats from the digestive tract and defending against infection.

The respiratory system is responsible for gas exchange, supplying the blood with oxygen and removing carbon dioxide.
Nasal cavity: filters, warms and moistens air.
Pharynx and larynx: pathways for air to enter the lungs.
Wind pipe that conducts air to the bronchi.
Bronchi and branchials: branching tubes that carry air into the lungs.
Main organs of respiration where gas exchange occurs.
Tiny air sacs in the lungs where oxygen and carbon dioxide are exchanged with the blood.

The digestive system processes food into nutrients that the body can use for energy, growth and repair.
Mouth: begins mechanical digestion through chewing and chemical digestion with saliva.
Transports food to the stomach.
Secrets acid and enzymes to further break down food.