Musculoskeletal and Digestive Systems Overview

Components: Bones, muscles, cartilage, tendons, ligaments.
Functions:
- Provides support and shape to the body.
- Facilitates movement through muscle contractions.
- Protects vital organs (e.g., skull protects the brain).
- Stores minerals (e.g., calcium, phosphorus).
- Produces blood cells in bone marrow (hematopoiesis).
Types of Muscles:
- Skeletal Muscle: Voluntary, striated, attached to bones.
- Smooth Muscle: Involuntary, non-striated, found in walls of hollow organs (e.g., intestines).
- Cardiac Muscle: Involuntary, striated, found only in the heart.

Components: Mouth, esophagus, stomach, small intestine, large intestine, rectum, anus, liver, pancreas, gallbladder.
Functions:
- Ingestion: Taking in food.
- Digestion: Mechanical and chemical breakdown of food.
- Absorption: Nutrient uptake in the small intestine.
- Elimination: Removal of indigestible substances.
Processes:
- Mechanical Digestion: Chewing and churning of food.
- Chemical Digestion: Enzymatic breakdown of macromolecules.

Components: Nose, pharynx, larynx, trachea, bronchi, lungs, diaphragm.
Functions:
- Gas exchange: Oxygen intake and carbon dioxide removal.
- Regulation of blood pH through CO2 levels.
- Protection against pathogens and particles through mucus and cilia.
Processes:
- Inhalation: Diaphragm contracts, increasing thoracic cavity volume, air flows in.
- Exhalation: Diaphragm relaxes, decreasing thoracic cavity volume, air is expelled.

Components: Heart, blood vessels (arteries, veins, capillaries), blood.
Functions:
- Transports oxygen, nutrients, hormones, and waste products.
- Regulates body temperature and pH balance.
- Protects against disease through white blood cells and antibodies.
Heart Structure:
- Comprised of four chambers: right atrium, right ventricle, left atrium, left ventricle.
- Valves (tricuspid, pulmonary, mitral, aortic) ensure one-way blood flow.
Circulation Types:
- Pulmonary Circulation: Blood from the heart to the lungs and back.
- Systemic Circulation: Blood from the heart to the rest of the body and back.

Components include bones, muscles, cartilage, tendons, and ligaments.
Primary functions consist of support, shape, movement facilitation, organ protection, mineral storage, and blood cell production.
Types of muscles:
- Skeletal Muscle: Voluntary control, striated appearance, attached to bones, responsible for movement.
- Smooth Muscle: Involuntary, non-striated, found in hollow organ walls like intestines, regulates internal processes.
- Cardiac Muscle: Involuntary, striated, unique to the heart, responsible for pumping blood.

Comprises the mouth, esophagus, stomach, small intestine, large intestine, rectum, anus, liver, pancreas, and gallbladder.
Functions include ingestion, digestion (mechanical and chemical breakdown), nutrient absorption, and elimination of waste.
Mechanical digestion involves physical processes like chewing and churning food.
Chemical digestion utilizes enzymes to break down macromolecules for nutrient absorption.

Includes the nose, pharynx, larynx, trachea, bronchi, lungs, and diaphragm.
Main functions involve gas exchange (oxygen intake, carbon dioxide removal), regulation of blood pH, and protection from pathogens via mucus and cilia.
Inhalation occurs when the diaphragm contracts, increasing thoracic volume and allowing air to flow in.
Exhalation happens when the diaphragm relaxes, reducing thoracic volume and expelling air.

Made up of the heart, blood vessels (arteries, veins, capillaries), and blood.
Functions to transport oxygen, nutrients, hormones, and waste products, regulate body temperature, and provide disease protection through immune cells.
The heart consists of four chambers: right atrium, right ventricle, left atrium, and left ventricle; four valves (tricuspid, pulmonary, mitral, aortic) maintain one-way blood flow.
Types of circulation:
- Pulmonary Circulation: Carries blood from the heart to the lungs for oxygenation and back.
- Systemic Circulation: Distributes oxygenated blood from the heart to the body and returns deoxygenated blood.

Transports essential substances such as oxygen, nutrients, hormones, and waste products within the body.
Maintains homeostasis by regulating temperature and pH balance.
Plays a role in immune responses to defend against pathogens.

Heart:
- Comprised of four chambers: two atria (upper chambers) and two ventricles (lower chambers).
- Valves facilitate unidirectional blood flow, preventing backflow.
Blood Vessels:
- Arteries: Transport oxygenated blood away from the heart; exception includes the pulmonary artery, which carries deoxygenated blood to the lungs.
- Veins: Carry deoxygenated blood back to the heart; pulmonary veins are the exception, carrying oxygenated blood from the lungs.
- Capillaries: Microscopic vessels that enable nutrient and gas exchange between blood and tissues.
Blood Composition:
- Made up of plasma (liquid component), red blood cells (oxygen transport), white blood cells (immune response), and platelets (clotting).

Systemic Circulation: Involves blood flow from the heart to the entire body and back again.
Pulmonary Circulation: Involves blood flow from the heart to the lungs for oxygenation and back to the heart.

Heart rate is regulated by the autonomic nervous system, which has sympathetic (activates 'fight or flight' response) and parasympathetic (promotes 'rest and digest' state) divisions.
Blood pressure is influenced by cardiac output (volume of blood the heart pumps) and systemic vascular resistance (resistance of blood vessels).

Coordinates various bodily functions and processes, ensuring appropriate responses to internal and external stimuli.
Processes sensory information from the environment to shape behavior.
Regulates both voluntary (conscious) and involuntary (unconscious) actions.

Central Nervous System (CNS):
- Brain: Central organ for processing information and controlling behaviors.
- Spinal Cord: Acts as a communication conduit, transmitting signals between the brain and body.
Peripheral Nervous System (PNS):
- Somatic Nervous System: Oversees voluntary movements and actions.
- Autonomic Nervous System: Manages involuntary functions; divided into sympathetic (activates 'fight or flight') and parasympathetic (promotes 'rest and digest') pathways.
Neurons:
- Fundamental units of the nervous system, comprising dendrites (receive signals), cell body (housing nucleus), and axon (transmits signals).
Synapses:
- Communication points between neurons where signals are transmitted using neurotransmitters.
Reflex Arcs:
- Pathways for involuntary responses that bypass the brain, facilitating quick reactions to stimuli.

Maintained through feedback mechanisms within the nervous system, which regulate vital functions such as heart rate, digestion, and respiratory activities.