Biology Grade 10 Science Reviewer - 3rd Quarter

Nervous System

• The human nervous system is a complex network that enables us to experience the world around us and respond to various stimuli.
• It involves various parts working together to send, receive, and process signals.

Brain Anatomy

• The brain is divided into three main sections: the cerebrum, the cerebellum, and the brainstem.
• The cerebrum is the largest part of the brain, controlling higher thought processes, speech, voluntary muscle movements, and interpreting sensory information.
• The cerebrum has two hemispheres that communicate with each other via the corpus callosum.
• Each hemisphere can be further divided into lobes:
  • Frontal lobe: controls reasoning
  • Parietal lobe: interprets sensory input
  • Temporal lobe: processes sound
  • Occipital lobe: associated with sight

Cerebellum

• The cerebellum sits below the brainstem and above the neck's spinal cord.
• It plays a crucial role in coordinating movement, maintaining balance, and regulating body posture.

Brainstem

• The brainstem connects the brain to the rest of the nervous system.
• It encompasses several structures, including the midbrain, pons, medulla oblongata, and reticular formation.
• The brainstem controls automatic functions like:
  • Breathing
  • Heart rate
  • Blood pressure
  • Swallowing
  • Digestion
  • Eye movements

Autonomic Nervous System

• The autonomic nervous system controls involuntary processes that occur without conscious thought.
• It has two main branches: sympathetic and parasympathetic.
• The sympathetic nervous system (also known as the fight or flight response):
  • Prepares the body for action by increasing heart rate, respiration, pupil dilation, and sweating.
  • Enables the body to respond quickly to stressful situations.
• The parasympathetic nervous system:
  • Slows the heart rate, lowers blood pressure, and increases gastric secretions.
  • Activates digestion and recovery from stress.

Peripheral Nervous System

• The peripheral nervous system is responsible for conveying information between different parts of the body.
• It consists of sensory neurons that transmit signals towards the central nervous system and motor neurons that carry signals away from it.

Somatic Nerve Fibers

• These nerve fibers provide sensation such as:
  • Touch
  • Temperature
  • Pain
  • Vibration
  • Pressure
  • Position sense
  • Muscle control
• Each somatic fiber consists of axons encased in myelin sheaths for efficient signal transmission and Schwann cells for protection and support.

Autonomic Nerve Fibers

• Unlike somatic nerves, autonomic nerves extend deep into internal organs.
• They play a vital role in controlling visceral functions like:
  • Blood flow regulation
  • Gut motility
  • Body temperature maintenance

Central Nervous System

• The central nervous system primarily consists of the brain and spinal cord.
• These organs work together to process incoming sensory information, coordinate voluntary movements, and control other essential physiological processes.

Spinal Cord

• The spinal cord runs down the back through vertebrae, acting as a bridge between the brain and the rest of the body.
• It relays messages between the brain and various regions of the body via its 31 pairs of spinal nerves.
• Injuries to the spinal cord can affect motor and sensory function depending on their location along the spine.

Prepare for your Grade 10 Biology exam with this comprehensive Science Reviewer for the 3rd Quarter. Download the document in DOCX, PDF, or TXT format to read ad-free. You can also read it online on Scribd. A valuable resource for students studying Biology in grade 10.