Physiological and Pharmacological Aspects of CNS - 2.1 Flashcards
(37 cards)
Functions of nervous system
Recognize - Identity changes to internal and external environment
Process and Integrate - perceive changes in environment (body feels hot or cold)
React - produce response or action to change (ex. body will sweat or shiver)
Two divisions of nervous system
Central nervous system - brain and spinal cord
Peripheral nervous system - nervous system tissues outside CNS
Role of Brain
- receives and processes information
- initiates response
- memory storage
- generates thoughts and emotions
Role of Spinal Cord
- carries sensory info from skin, muscles, joints, and internal organs to brain
- controls motor outflow to muscles
- controls sensory input (pain sensation)
- controls reflex activity (breathing)
Divisions of the brain
Forebrain, midbrain, hindbrain
Parts of The Forebrain
- Cerebral cortex (cerebrum)
- Thalamus
- Hypothalamus
- Limbic System
- Pituitary
Cerebral cortex (cerebrum) - description and functions
- largest part of brain that is very rich in nerve cells
- functions include: sensory and motor coordination, mental processes, intelligence, memory, vision, judgement, thought, speech, emotions, and consciousness
- drugs can stimulate (excite) or depress (inhibit)
Thalamus - description and functions
- relay centre from which impulses are transmitted to cerebrum
- function is to coordinate and filter incoming signals
- involved in appreciation of painful sensation
Hypothalamus - description and functions
- consists of various specialized regions located near the base of skull
- functions include: control involuntary functions of body necessary for living (metabolism), controls feeding, drinking, sexual, and emotional responses
- contains neutrons that produce substances (releasing factors) that travel to pituitary and modify the gland
Limbic System - description and functions
- associated with hypothalamus
- integrates emotion, memory, and reward
- controls emotion and behaviour alongside hypothalamus
- contains dopaminergic reward centres (targets for drugs)
Pituitary
- small gland at the base of brain
- secretes hormones that travel to and act on peripheral tissues
- control of growth, behaviour, and metabolism
The Midbrain
- links forebrain to hindbrain
Relay centre for visual and auditory stimuli/signals
The Hindbrain
Pons, Medulla (the bulb), Cerebellum
Pons
- connects midbrain to medulla and cerebellum
- conduct signals from cerebral cortex to medulla and cerebellum
Medulla
- origin of many cranial nerves
- regulation of respiration, heart rate, blood pressure, and involuntary activity occurs here
What affect do drugs have on the Medulla?
Drugs depress the medulla and in turn depress respiration and blood pressure
Cerebellum
- coordination and posture
- doesn’t initiate movement
- organizer of voluntary activity
What affect do drugs have on the cerebellum?
Causes ataxia (loss of coordination)
Description of The Neuron
- functional unit of brain
- generates and transmits electrical signals
- about 90 billion neurons in brain that differ in size and shape
- generated continuously
- connection between neurons constantly reshaped (neuroplasticity)
Structure of The Neuron
- Cell Body (Soma)
- Dendrites
- Axon
Cell Body (soma)
- largest part of neuron
- contains nucleus and surrounding cytoplasm which contains abundant vesicles
Dendrites
- usually short
- highly complex branching patterns
- function as receiving antennae for incoming info and accept info through receptors located on dendritic membranes
- send electric current down neuron when info is received from another cell
Axon
- single fibre extending from cell body to synapse
- carries incoming info away from dendrites and cell body through electrical pulses to subsequent neurons
What is Synaptic Transmission?
- passage of electrical signal from one neuron to another
- very rapid and chemical process
- requires release of a substance to activate the other neuron
