Learning Outcome Describe the structure of the brain

Learning Outcome Describe the structure of the brain, including cerebrum, cerebellum, medulla and hypothalamus. Describe the functions of the different parts of the brain.

Parts of the brain The average human brain weighs about 1, 400 grams.

The brain has two hemispheres, they are separate, but connected. The left side of your brain connects to the right side of your body, while the right brain connects to the left side. In most people, the left brain handles words and logic, and the right brain is better at art, music, and intuition.

Structure of the brain

Functions of the brain We have found out that there are five main regions of the brain: Cerebrum Cerebellum Medulla Hypothalamus Pituitary gland Each of these parts have a different function.

Cerebrum Largest part of the brain. Highly folded to give a large surface area. Involved in the control of conscious decisions, location of personality, memory and creativity.

Cerebellum The cerebellum is the area of your brain which controls balance and coordinates movements of your muscles.

Medulla The medulla connects the brain to the spinal cord, it controls the rates of breathing and heart beat.

Hypothalamus The hypothalamus is a monitoring centre, it regulates the water content of the blood and temperature of the body.

Pituitary gland The pituitary gland releases hormones into the bloodstream. For example ADH (to control water content of the blood).

Success Criteria I can describe the structure of the brain, including cerebrum, cerebellum, medulla and hypothalamus. I can describe the functions of the different parts of the brain.

Learning Outcome State that the central nervous system is composed of the brain, spinal cord and nerves. State that nerves carry impulses from the senses to the central nervous system and impulses from the central nervous system to the muscles.

Parts of the nervous system The brain and the spinal cord make up the central nervous system. The brain is protected by the skull and the spinal cord by the vertebrae.

Parts of the nervous system Nerves join the CNS. They bring messages from sensory organs which contain receptor cells. The CNS sorts the information and processes it.

Parts of the nervous system CNS sorts the information Message is sent along a nerve to the CNS Receptor cells in a sensory organ detect a stimulus CNS sends a message along nerves to an effector Effector (muscle or a gland) brings about a change

Success Criteria I can describe the structure of the brain, including cerebrum, cerebellum, medulla and hypothalamus. I can describe the functions of the different parts of the brain.

Learning Outcome Describe how a reflex action works using a simple model of a reflex arc.

Reflex responses It is important that the nervous system can make responses very quickly. Sometimes this occurs without processing the information in the brain. This type of response is called a reflex response and usually happens when the stimulus is potentially dangerous.

Reflex responses happen without you needing to think. For example if you touch something hot, your hand will pull away without conscious thought.

Neurones and rapid response A reflex arc involves neurones of the nervous system, not the brain. Usually three neurones are involved sensory, relay and motor neurones. These neurones are linked together in a scheme called a reflex arc.

Reflex arc Relay neurone Sensory neurone Video Motor neurone Effector (muscle) Receptors in skin Harmful stimulus Protective reflex response

Reflex action Sensory neurone Relay fibre Motor neurone Effector Receptors

Think – Sam Ran a Marathon Sensory neurone Relay neurone Motor neurone

Stimulus Foreign particles in nasal tract Heat from naked flame Harmful object approaching eye Response Contraction of eyelid muscle Contraction of flexor muscle Sudden contraction of chest muscles Protective Function Expulsion of unwanted particles from nose Removal of limb to safety Prevention of damage to eye

Success Criteria I can describe how a reflex action works using a simple model of a reflex arc.