Unit 3 – Key Area 1 Divisions of the nervous system and parts of the brain
KA 1: Divisions of the nervous system and parts of the brain (a) CNS Central Nervous System (f) Localisation of brain functions The Nervous System (b) PNS Peripheral Nervous System (e) Cerebral Cortex (c) Medulla and Cerebellum (d) Limbic System
The Nervous System The central nervous system (CNS) Peripheral nervous system (PNS) Brain Spinal Cord Autonomic Nervous system (ANS) Somatic Nervous system (SNS) Sympathetic Parasympathetic
The Peripheral Nervous System The Peripheral Nervous System (PNS) is made up of: Somatic nervous system (SNS) Autonomic nervous system (ANS)
Somatic Nervous System The SNS controls: Voluntary movement of skeletal muscles It is also responsible for reflex actions like the withdrawal of a limb by conduction of impulses to smooth muscle.
Autonomic Nervous System The ANS is involved in homeostasis and regulates the body’s internal environment. Homeostasis is the maintenance of the body’s internal environment within tolerable limits, despite changes to body’s external environment. This control is involuntary. Diagram from text book
Nerves of the ANS Parasympathetic nerves Sympathetic nerves The nerves of the ANS can be split into two groups and they emerge from the spinal cord to reach effectors such as: cardiac muscle, smooth muscle, glands.
The Nervous System The central nervous system (CNS) Peripheral nervous system (PNS) Brain Spinal Cord Autonomic Nervous system (ANS) Somatic Nervous system (SNS) Sympathetic Parasympathetic
Autonomic Nervous System Sympathetic Parasympathetic ‘speeds up’ Takes over when the body is active or excited. ‘fight or flight’ Increased heart rate Increased breathing rate Perspiration Redistribution of blood from digestive system to the muscles ‘slows down’ Takes over at times of rest and relaxation. ‘rest and digest’ Normal heart rate Normal breathing rate Redistribution of blood from muscles to digestive system As they have the opposite effects, the sympathetic and parasympathetic systems are said to be antagonistic
The Nervous System Use what you know about the structure of the nervous system to fill in this summary of its structure.
The Nervous System The central nervous system (CNS) Peripheral nervous system (PNS) Brain Spinal Cord Autonomic Nervous system (ANS) Somatic Nervous system (SNS) Sympathetic Parasympathetic