Human Brain Structure and Functions

Cerebrum

• The largest brain part, crucial for higher functions like thinking, reasoning, and voluntary movements.
• Composed of two hemispheres (left and right) and divided into four lobes:
  • Frontal Lobe: Responsible for decision-making, problem-solving, and voluntary movement control.
  • Parietal Lobe: Processes sensory information, including touch and temperature.
  • Temporal Lobe: Handles auditory processing and memory.
  • Occipital Lobe: Responsible for visual processing.

Cerebellum

• Coordinates voluntary movements, balance, and posture.

Brainstem

• Connects the cerebrum to the spinal cord and regulates essential life functions.
• Composed of three main parts:
  • Midbrain: Manages auditory and visual reflexes.
  • Pons: Relays messages between cerebrum and cerebellum, controlling sleep and respiration functions.
  • Medulla Oblongata: Regulates vital functions such as heart rate, breathing, and blood pressure; coordinates reflexes like swallowing and coughing.

Diencephalon

• Houses the thalamus and hypothalamus, which are key for sensory perception and homeostasis.
  • Thalamus: Acts as a relay station for sensory information.
  • Hypothalamus: Regulates homeostasis, temperature, hunger, thirst, and emotional responses.

Limbic System

• Consists of structures like the hippocampus and amygdala vital for emotion, memory, and learning.
  • Hippocampus: Essential for memory formation.

Neurotransmitters

• Dopamine: Related to the brain's reward system, influencing motivation, pleasure, learning, and motor control. Imbalances are linked to Parkinson’s disease (deficits) and schizophrenia (excess).
• Serotonin: Regulates mood, emotion, sleep, and appetite. Known as the "feel-good" neurotransmitter. Imbalances contribute to depression, anxiety, and other conditions.

Nervous System

• A complex network facilitating communication between the brain, spinal cord, and body, responsible for responses to stimuli.
• Divided into:
  • Central Nervous System (CNS): Comprises the brain and spinal cord, processing sensory information and directing responses.
  • Peripheral Nervous System (PNS): Includes somatic and autonomic nervous systems.

Endocrine System

• Composed of glands producing hormones, vital chemical messengers influencing cellular functions throughout the body.
• Regulates mood, growth, metabolism, and reproductive processes.
• Major glands include:
  • Hypothalamus: Regulates the pituitary gland, maintaining homeostasis.
  • Pituitary Gland: Influences growth, metabolism, and reproduction by releasing various hormones.
  • Thyroid: Manages metabolism and energy levels.
  • Parathyroids: Control calcium levels and bone health.
  • Adrenal Glands: Produce stress, metabolism, and electrolyte balance hormones.
  • Pineal Body: Secretes melatonin for sleep-wake regulation.
  • Reproductive Glands: (Ovaries and testicles) produce reproductive hormones.
  • Pancreas: Regulates blood sugar through insulin and glucagon production.

Brain Structure

• The brain's approximate weight ranges from 1.3 to 1.4 kg and is situated within the skull.
• Grey Matter: Contains neuron cell bodies, involved in processing information.
• White Matter: Composed of nerve fibers (axons) that convey impulses to and from grey matter.
• Corpus Callosum: Thick nerve fiber band connecting the left and right hemispheres, facilitating inter-hemispheric communication.
• Ventricles: A series of interconnected, fluid-filled cavities within the brain, consisting of four main ventricles.

This quiz covers the major components of the human brain, including the cerebrum, cerebellum, and brainstem, along with their respective functions and roles. Test your knowledge on the different lobes of the cerebrum and their specific responsibilities, as well as the essential functions of the brainstem.