A&P Study Guide: Brain PDF

# A&P Study Guide: Brain ## The Brain Overview - **Parts of the Brain:** 1. **Cerebrum (largest part):** Responsible for higher functions like thinking, learning, and voluntary movements. 2. **Cerebellum (second largest):** Refines movements for fine motor skills. 3. **Diencephalon (th...

# A&P Study Guide: Brain ## The Brain Overview - **Parts of the Brain:** 1. **Cerebrum (largest part):** Responsible for higher functions like thinking, learning, and voluntary movements. 2. **Cerebellum (second largest):** Refines movements for fine motor skills. 3. **Diencephalon (thalamus, hypothalamus):** Acts as a relay station and regulates body functions like temperature and hunger. 4. **Brain Stem (midbrain, pons, medulla oblongata):** Controls basic life functions like breathing and heart rate. - **Cranial Bones:** The brain is protected by 8 cranial bones forming the cranium. - **CSF (Cerebrospinal Fluid):** - The brain floats in CSF, which cushions and lightens it. - CSF circulates in the *subarachnoid space* (between the pia and arachnoid mater). ## Layers Around the Brain (Meninges) 1. **Dura Mater (outermost):** Tough layer. 2. **Arachnoid Mater (middle):** Web-like structure. 3. **Pia Mater (innermost):** Thin layer covering the brain directly. - **Spaces:** - **Epidural:** Outside the dura mater. - **Subdural:** Between the dura and arachnoid mater. - **Subarachnoid:** Between the arachnoid and pia mater (where CSF flows). ## Cerebrum Anatomy - **Gyri:** The raised parts of the brain (bumps). - **Sulci:** The grooves between the bumps. - **Prominent Sulci:** - **Central Sulcus:** Separates the frontal and parietal lobes. - **Lateral Sulcus:** Separates the temporal lobe from the frontal and parietal lobes. - **Key Areas:** - **Precentral Gyrus (motor cortex):** Controls voluntary movements. - **Postcentral Gyrus (sensory cortex):** Processes sensory information. ## 4 Lobes of the Cerebrum 1. **Frontal Lobe:** - **Location:** At the front. - **Functions:** Responsible for thinking, planning, problem-solving, emotions, and voluntary movements. 2. **Parietal Lobe:** - **Location:** Behind the frontal lobe. - **Functions:** Processes sensory information like touch, temperature, and pain. 3. **Occipital Lobe:** - **Location:** At the back of the brain. - **Function:** Handles vision (helps you see and interpret what you're looking at). 4. **Temporal Lobe:** - **Location:** At the sides of the brain, near the ears. - **Functions:** Responsible for hearing and smell. - **Example:** Helps you hear someone's voice and recognize it. ## Other Important Brain Features 1. **Thalamus:** - A "relay station" for sensory signals. - Every sensation (except smell) goes through the thalamus before reaching the appropriate brain region. 2. **Corpus Callosum:** - A thick bundle of nerve fibers that connects the left and right hemispheres of the brain. - Ensures both sides can communicate and work together. 3. **Gray vs. White Matter:** - **In the brain:** - **Gray matter:** On the outside, contains neurons (responsible for processing information). - **White matter:** Inside, contains axons (carry signals between neurons). - **In the spinal cord:** The arrangement is reversed: white matter is on the outside, gray matter is inside. ## Cerebrospinal Fluid (CSF) - Clear fluid that surrounds the brain and spinal cord. - **Functions:** 1. Cushions the brain to protect it from injury. 2. Nourishes the brain by transporting nutrients. 3. Removes waste products. ## Ventricles Hollow cavities in the brain where CSF is produced. - 2 lateral ventricles - Third ventricle - Fourth ventricle