The Nervous System Flashcards
Identify the major components of the nervous system
Nervous system:
1) Peripheral —> autonomic (controls self-regulated actions of internal organs and glands) —> sympathetic (Arousing) and parasympathetic (calming) and Somatic (conscious control) —> sensory output and motor output (controls skeletal muscles)
2) central nervous system (brain and spinal cord)
-neurones, myelinated and un-myelinated
-synapses
-receptors
Outline the functions of the brain stem
Regulating automatic functions that are essential for sustaining life, e.g. breathing.
It connects the brain to the spinal cord.
Also controls balance and coordination
What are the meninges of the brain and spinal cord
The brain and spinal cord are completely surrounded by 3 layers of tissue, the meninges.
They are: dura matter, arachnoid matter, and pia matter
Identify the origin of the CFS and its function
CSF circulates constantly from the ventricles through the subarachnoid space, around the brain and spinal cord
CSF is a clear alkaline fluid consisting of: Walter, mineral salts, glucose, plasma proteins, leukocytes, creatinine and urea.
CSF is secreted into each ventricle of the brain by choroid plexuses (vascular area, rich in blood vessels)
CSF: passes back into the blood through tiny finger-like projections of arachnoid matter called arachnoid villi
CSF movement from subarachnoid space to venous sinuses depends on difference in pressure on each side of arachnoid villi, which act as one-way valves
CSF is secreted continuously at 0.5 ml per min
Function- supports and protects the brain and spinal cord by maintaining a uniform pressure and acting as a cushion between the brain and the skull
With reference to neuronal structure briefly outline the processes of:
Action potential generation and atonal conduction
1) stimulus received
2) stimulus changes voltage such that the threshold is met
3) opening of voltage gates sodium channels
4) sodium moves into the cell
5) inside of the cell becomes more positive (depolarised)
6) changes in voltage triggers opening of voltage gated potassium channels
7) potassium leaves the cell
8) inside the cell becomes more negative (re polarised)
9) return to resting membrane potential
With reference to neuronal structure briefly outline the processes of:
Synaptic and neuromuscular transmission
1) arrival of action potential
2) opens up the voltage gated calcium channels
3) triggers vesicles to move and fuse with the nerve membrane
4) neurotransmitters diffuse across the synaptic cleft
5) act on specific receptors on post synaptic neurone
Identify how sensory information is conveyed to the CNS through activation of sensory receptors
Stimulation of the sensory receptor activates the associated affected neurone, which carries information about the stimulus to the CNS
Outline the functions of the following parts of the brain: medulla, pons, midbrain, cerebellum, hypothalamus, thalamus, cerebrum
Medulla- helps control vital processes like your heartbeat, breathing and blood pressure
Pons- relays and regulates the signals that give you the sensation of pain from anywhere in your body below your neck
Midbrain- associate with vision, motor control, sleep/wake, arousal and temp regulation
Cerebellum- helps coordinate and regulate a wide range of functions and processes in both your brain and body
Hypothalamus- keeps your body in a stable state called homeostasis
Thalamus- your body’s information relay station
Cerebrum- initiates and coordinates movement and regulates temp
Outline the production and circulation of cerebrospinal fluid (CSF) and its relation to the meninges
Describe what happens when an impulse reaches a neuromuscular junction
1) nerve impulse arrives at terminal axon
2) triggers opening of voltages gates calcium channels
3) vesicles fuse with axon membrane
4) acetylcholine is released into the synapse
5) acetylcholine acts on acetylcholine receptors- they open
6) sodium enters- if threshold is reaches an action potential is generated in the muscle, acetylcholine is broken brown
