Nervous System Jr / Sr. Vet Science Mrs. Chotkowski

Nervous System Functions: Detects and processes information Formulates responses Coordinates and controls all bodily activity

Nervous System Sends and receives impulses Impulses are the electrical signals that travel through the nervous system and provide information to the brain.

Nervous System Neurons : Most highly specialized cells in the body and have no powers of regeneration.

Nervous System Neurons Cont: Have three parts: 1.Axons: efferent 2.Dendrites: afferent 3.Cyton or nerve cell

Nervous System Axon: Single Dendrite:Multiple (These refer to the processes of the cyton)

Nervous System Neurons cont: Cyton: The life center of the neuron

Nervous System Cyton Function: Maintenance of its axons and dendrites. If cyton dies then the processes die and become non functional

Nervous System Types of neurons: Sensory neurons:Carry impulses towards the brain and the spinal chord. Connecting neurons: Carry impulses from one neuron to another.

Nervous System Motor Neurons: Carry impulses away from the brain and spinal chord to the body.

Parts of a neuron: Cell Body: Often called the soma. Contains the cell nucleus. Dendrite: Branch-like, receives impulses Axon: Sends impulses away from the cells

Nervous System Synapse; Connections that link the nervous system.

Nervous System Space in between neurons: contains a chemical substance called a neurotransmitter. Helps impulses travel.

Nervous System Synapses Cont: In Parasympathetic ns and central ns, the conduction medium is: Acetylcholine

Nervous System Sympathetic ns conductor is : Noradrenaline

Nervous System Reflex Arc: Passage of a nerve impulse from:

Nervous System Receptor to sensory nerve to synapse to motor nerve to effector……..This is known as the reflex arc.

Nervous System Myelin (Sheath): Protective sheath around the neuron.

Nervous System Central: CNS (Brain and Spinal Cord) Peripheral: PNS (Cranial and Spinal nerves) Autonomic: ANS……Cont.

Nervous System Autonomic NS cont: supplying smooth muscle cardiac and glands

Nervous System I. Central Nervous System: Consists of the brain and spinal cord.

Nervous System Brain: Major Organ of the nervous system. Meninges : Three-Layered protective covering of the brain.

Nervous System Cerebrum: Largest part of the brain. It has four lobes that receive and store information and are responsible for giving signals for voluntary movement.

Cerebellum: Coordinates all muscle activity and balance.

Nervous System Brainstem: Connects the brain to the spinal cord, and contains the medulla oblongata.

Nervous System Medulla Oblongata: Dictates all life functions including:

Nervous System Medulla Oblongata Cont: Heart rate, breathing, and reflex actions.

Nervous System Thalamus: Central relay system for all nerve impulses except smell.

Nervous System Thalamus Cont: The thalamus receives the impulses and then directs them to the proper part of the brain.

Nervous System Hypothalamus: Serves as a link between the nervous system and the endocrine system.

Nervous System Pituitary Gland: Secretes hormones important for reproduction and growth.

Nervous System Spinal Cord: Pathway for all impulses going to and from the brain. Connects to the medulla oblongata.

Nervous System II. Peripheral Nervous System: Consists of nerves that relay information to and from the spinal cord.

Nervous System Sympathetic nervous system: Responsible for Emergency and stress responses: “fight or flight”

Nervous System Parasympathetic Nervous system: Seeks to maintain and restore normal body function, often called Homeostasis: a state of balance of the physiologic systems within the body.