Nervous system Flashcards
State the main functions of the nervous system
The nervous system is responsible for all behaviours, memories and movements. The nervous system helps to maintain homeostasis
A nerve is a bundle of many….
neurons
State two functions of the myelin sheath
To form an insulating cover (myelin) around many neutrons which helps to increase the speed of nerve impulse conduction
Outline the events that occur at a neuromuscular junction when an impulse arrives at the axon terminal
1 - impulse arrives at axon terminal
2 - neurotransmitter (NT) is released from secretory vesicles
3 - NT crosses gap/synapse to receptors on muscle fibres
4 - muscles fibre is stimulated to contract
5 - NT is recycled back into the axon terminal
Name the mineral that is required for nerve impulse transmission
Sodium and potassium
What are the two divisions of the nervous system
1 - The central nervous system
2 - The peripheral nervous system
What does the CNS consist of
Brain and spinal cord
What does the PNS consist of
Cranial nerves and spinal nerves
How many pairs of cranial nerves and spinal nerves are there?
Cranial nerves = 12
Spinal nerves = 31
The effector for the somatic nervous system is
skeletal muscles
Effectors for the automatic nervous system are
Cardiac muscle, smooth muscle and glands
What is another word for sensory neurons?
afferent
What is another word for motor neurons?
efferent
State the function of the sensory (afferent) neuron
Conduct impulses from receptors to the CNS
State the function of the motor (efferent) neurons
Conduct nerve impulses from the CNS to muscles (to control their contraction) and to glands (to control their secretions)
What is a reflex
A reflex is a rapid, predictable sequence of involuntary actions that occur in response to a particular stimulus
List the components of a reflex arc from stimulus to response
1 - sensory (afferent) receptor
2 - sensory neuron
3 - integrating centre
4 - motor (efferent) neuron
5 - effector
State the three main regions of the brain
Cerebrum
Cerebellum
Brain stem
state the functions of the cerebrum
Sensory awareness, initiates voluntary (conscious) motor activities, Analyses information for thinking, learning etc, stores memories
State the functions of the cerebellum
Provides smooth, coordinated skeletal muscle movements.
Regulates posture and maintains balance subconsciously
State the functions of the brain stem
Has centres for control of bone activities for survival
Cardiac (heartbeat), respiratory (breathing) and vasomotor (blood vessel diameters)
Name the four main lobes of the cerebrum
Parietal
Occipital
Temporal
Frontal
State the function of the frontal lobe
Contains motor cortex for control of skeletal muscle movements
Process emotions related to personal and social interactions
Problem solving
State the function of the temporal lobe
Smell, hearing and taste
State the function of the parietal lobe
contains primary sensory cortex
Conscious awareness of sensations
State the function of the occipital lobe
Visual cortex
What is the meninges
3 membranes between the brain and skull. Protect the brain, anchor it to the skull, act as a shock absorber
What is the function to cerebrospinal fluid circulating in the meninges?
Provides physical and chemical protection
Name some infections that seriously affect the nervous system.
viral meningitis - viral
Rabies - viral
Tetanus - bacterial
Leprosy - bacterial
Fungal meningitis - fungal
Amoebic meningitis - protozoan
List three ways microbes could gain access to the nervous system
Nasal colonisation (respiratory droplet transmission)
Invasion of blood stream
Damage to the meninges (head injury, young age (neonatal))
Why are infections of the nervous system very serious?
The nervous system controls EVERYTHING
What is the link between the nervous system and the endocrine system?
The hypothalamus has both nervous and endocrine tissues.
The hypothalamus (region of the brain) influences the pituitary gland (endocrine gland) to release its hormones.
Provide an example of the anterior pituitary stimulating the hypothalamus to release its hormones
Human growth hormone (HGH) and thyroid-stimulating hormone (TSH)
Provide an example of the posterior pituitary stores releasing hormones made by the hypothalamus
Oxytocin (OT) and Antidiuretic hormone (ADH)
