Neural Circuits
- Reflex arc: neural circuit through the spinal cord that provides a framework for a reflex action
The Central Nervous System
- The two components of the central nervous system are the brain and the spinal cord.
- Meninges are protective membranes that surround the brain and spinal cord. The Meninges is made up of three layers; the outer membrane is the dura matter, the middle membrane is the arachnoid matter, and the inner membrane is the pia matter.
- The Cerebrospinal fluid is the cushioning fluid that circulates between the innermost and middle membranes of the brain and spinal cord; provides a connection between neural and endocrine system
- A) The spinal cord carries sensory nerve messages from receptors to the brain and relays motor nerve messages from the brain to muscles, organs and glands
C) Grey Matter consists of nonmyelinated interneurons, and white matter is composed of myelinated nerve fibres from the sensory and motor neurons.
- Parts of the brain:
| Component of Brain | Function |
| Cerebrum | Stores sensory information and initiates voluntary motor activities |
| Frontal lobe | Motor areas control movement of voluntary muscles (eg walking);
Association areas are linked to intellectual activities and personality |
| Temporal lobe | Sensory areas are associated with vision and hearing; Association areas are linked to memory and interpretation of sensory information |
| Parietal lobe | Sensory areas are associated with touch and temperature awareness;
Association areas have been linked to emotions and interpreting speech |
| Occipital lobe | Sensory areas are associated with vision;
Association areas interpret visual information |
| Corpus callosum | Nerve tract that joins the two cerebral hemispheres |
| Thalamus | Coordinates and interprets sensory information and directs it to the cerebrum |
| Hypothalamus | Co ordinates many nerve and hormone functions |
| Cerebellum | Controls limb movement, balance, and muscle tone |
| Pons | Acts as a relay station by sending nerve messages between the cerebellum and the medulla |
| Medulla Oblongata | Joins the spinal cord to the cerebellum; one of the most important sites of autonomic nerve control |
The Autonomic Nervous System
- The Autonomic Nervous System works together with the endocrine system in adjusting the body to changes in the external or internal environment. All autonomic nerves are motor nerves,
- Sympathetic- nerve cells system that prepare the body for stress
Parasympathetic- returns the body to normal levels after adjustments to stress
| Organ | Sympathetic | Parasympathetic |
| Heart | Increases heart rate | Decreases heart rate |
| Digestive | Decreases peristalsis | Increases peristalsis |
| Liver | Increases the release of glucose | Stores glucose |
| Eyes | Dilates pupils | Constricts pupils |
| Bladder | Relaxes sphincter | Restricts sphincter |
| Skin | Increases blood flow | Decreases blood flow |
| Adrenal Gland | Causes release of epinephrine | No effect |
Consult a doctor immediately….
Hi i had a car accident at one time and i hit the left side of my head hard as hell and never went to the hospital now when i start to think about anything my head hurts on the left side real bad and the rest of my head feels like a normal head ache i was just wondering on if u had an answer as to why that happens thank you