biology

• The nervous system is divided into two main parts:

  • Central Nervous System (CNS): contains the brain and spinal cord, responsible for receiving, processing, and responding to sensory information
  • Peripheral Nervous System (PNS): contains nerves branching out from the spinal cord to the rest of the body, responsible for relaying information
• The brain, a complex organ, controls every process that regulates our body
• The brain is composed of three main parts:

  • Cerebrum: interprets sights, sounds, and touches, regulates emotions, reasoning, and learning
  • Cerebellum: maintains balance, posture, coordination, and fine motor skills
  • Brainstem: regulates automatic body functions, connects the brain to the spinal cord
• The brain lobes include:

  • Frontal lobes: control voluntary movement, speech, intellect, memory, intelligence, and personality
  • Temporal lobes: important for recalling words or places, recognizing people, understanding language, and interpreting emotions
  • Parietal lobes: receive and interpret signals, integrate sensory inputs to understand the environment and body state
  • Occipital lobes: interpret visual information, process shapes, colors, and movement
• The Peripheral Nervous System (PNS) consists of:

  • Autonomic: processes run automatically by the brain
  • Somatic: functions managed by conscious thought
• Neurological diseases affecting the nervous system can be classified into types such as nervous system injuries, neurodegenerative diseases, headache disorders, seizure disorders, genetic disorders, infections, cancer, neurodevelopmental disorders, and more
• Neurodegenerative diseases occur when nerve cells stop working properly or start to die off, usually worsening over time

  • Examples include Alzheimer's disease and Parkinson's disease
• Neurodevelopmental disorders are related to disruptions in the development of the nervous system

  • Examples include Autism Spectrum Disorder (ASD), Attention Deficit Hyperactivity Disorder (ADHD), and Dyslexia
• The digestive system consists of the following organs:

  • Pancreas
  • Liver
  • Small intestine
  • Large intestine
  • Anus
  • Esophagus
  • Mouth
  • Gall bladder
  • Rectum
  • Stomach
• The digestive system is one of the most complex and fascinating systems in the body
• Humans consume about 1-2 kg of food per day
• Food spends a total of 36 hours in the large intestine
• Even if upside down, the food in the digestive system will continue to move perfectly fine
• The small intestine is the longest organ, while the liver is the largest organ
• Emotions can affect your digestive system
• The digestive system has 4 main components:

  • Gastrointestinal tract: the pathway where food enters and waste is expelled
  • Gallbladder, Pancreas, and Liver
  • Enzymes, hormones, nerves, and blood
  • Mesentery: a large set of tissue that secures the intestines and other organs
• The importance of digestion is to break down food into nutrients, which the body uses for energy, growth, and cell repair
• Peristalsis, alternating waves of contraction and relaxation, moves the bolus to the esophagus
• Digestive juices produced by the Gallbladder, Pancreas, and Liver contain enzymes that break down food into different nutrients
• The mouth physically breaks down food into bits through mechanical digestion with the help of salivary glands
• The bolus, a mush or moist lump of food, is then transported to the stomach via the esophagus
• After passing through the stomach, the food turns into chyme
• The chyme goes into the small intestine where the Liver, Gallbladder, and Pancreas absorb nutrients, energy, carbohydrates, fats, proteins, vitamins, and biomolecules
• The large intestine's task is to absorb liquid, and the waste that remains after passing through is called stool, which rests in the rectum before leaving through the anus
• Four major functions/tasks of the digestive system:

  • Ingestion: the process of taking in something to the body
  • Digestion: the process of breaking down food by mechanical and chemical digestion into substances used by the body
  • Absorption: where nutrients, vitamins, and other necessary substances are absorbed into the body
  • Elimination: where any remaining waste is removed from the body
• Digestive Disorders include:

  • Celiac disease: a long-term autoimmune disorder affecting the small intestine due to gluten intolerance
  • Diverticulitis: inflammation of abnormal pouches in the wall of the large intestine
  • Heartburn: symptoms include nausea, vomiting, and intestinal cramps
  • Gastroesophageal reflux disease: stomach content flows up into the esophagus persistently
  • Colorectal cancer: cancer development in the colon or rectum