Your Brain Chapter 29.1 – 29.4

Nervous System You have 2 different major nervous systems Peripheral nervous system (PNS) Central nervous system (CNS) CNS = Brain and spinal cord PNS = All other nerves that send signals to the body from the brain and spine

Central Nervous System Is designed to process information You brain has over 100 billion neurons Fluid cushions brain so there is little injury Cerebrum (large portion) is the part of the brain that interprets signals from the body (hunger, emotion, pain) Outer layer of cerebrum is the cerebral cortex, this is where most responses are created

Green nerves are considered the peripheral nervous system Blue spine and brain are considered the central nervous system The goal is to connect these two systems so every part can communicate with each other

Neurons These are essentially the “nerve cells” that make up the nervous systems. They are complexly laid out in order to stretch and make many connections The stretched out portions are called axons These are covered in the myelin sheath and transmit signals across the nodes of Ranvier Gaps between these cells are called synapses, this is where extremely important cell communication happens

4 Major Lobes of the Brain (cerebrum) Frontal Lobe Language, Higher level thinking, motor skills Parietal Lobe Pressure, touch, pain Occipital Lobe vision Temporal Lobe Visual memories, language comprehension, emotion association, hearing

4 Major Lobes

Anatomy Cerebellum part of brain that coordinates your movements as well as: Fear/pleasure response Attention Language Balance/coordination Brain stem connects the brain to the spinal cord. Made of 3 parts: Midbrain – controls some reflexes Pons – regulates breathing Medulla oblongata – heart rate, vomiting, swallowing Corpus Callosum connects two hemispheres of the brain

The midbrain houses a lot of very basic functions for the body.

Glands in the Brain The brain features many glands that regulate many hormones in the body Pituitary = growth, hormone regulation, blood pressure Pineal = releases melatonin and regulates sleep patterns Thalamus = Helps sort information around the brain Hypothalamus = Autonomic functions around the body

Between all the glands in the brain, their job is to regulate feeling/emotions/behavior by releasing hormones into the blood stream. These can also play a huge role in digestion and growth. Regulatory processes are vitally controlled by these glands. Thalamus is a middle region of brain that helps sort through information around the brain.

Reflexes Some of your body functions are controlled by reflexes This means your Peripheral Nervous System overrides your Central Nervous System to react immediately This saves valuable time to protect you from harm

Cranial Nerves

Phineas Gage