Nervous System Flashcards
What does the central nervous system consist of?
Brain, Spinal Cord and relay neurons
What does the peripheral nervous system consist of?
All nervous tissue outwith the CNS. Eg. nerves and sensory receptors.
What two systems is the PNS divided into?
Autonomic (ANS) and somatic (SNS).
What is the function of the Somatic Nervous System?
Usually voluntary control of skeletal muscles. Not always, eg postural, breathing, balance are not consciously being used.
Also receives and process sensory information and respond accordingly.
What is the main function of the autonomic nervous system?
Regulates cardiac muscle, smooth muscle and glands.
What are the two divisions of the ANS?
Sympathetic nervous system and Parasympathetic nervous system.
What is the function of the sympathetic nervous system?
Increase heart rate
(fight or flight)
What is the function of the parasympathetic nervous system?
Decrease heart rate, increase rate of digestion.
(Rest and digest).
How many pairs of cranial nerves are there?
12
How many pairs of spinal nerves are there?
31
What is the function of the CNS?
Receives and processes sensory information.
Sends signals to effectors to cause muscle contractions and releases from glands.
What kind of neurons would you find in the PNS?
Sensory and motor neurons
Where in a neuron are signals from other cells recieved?
Dendrites
What is the part of the neuron that connects the cell body to the axon?
Axon hillock
True or false- myelinated neurons carry impulses faster than non myelinated neurons
true
what is the gap in between the myelin called on an axon?
Nodes of Ranvier
Where in the neuron are the neurotransmitters stored
synaptic vesicles
What is another name for sensory neurons?
Afferent
What is another name for motor neurons?
Efferent
What is the function of sensory neurons?
Conveys nerve impulses into the CNS from sensory receptors
What is the function of motor neurons?
convey nerve impulses away from the CNS to effectors (Glands and muscles)
what is the function of Glial cells?
To nourish, protect and support nervous tissue
What is the typical resting membrane potential?
-70mV
What is the threshold of a neuron?
-55mV
What flows into the cell when they are in the depolarising stage?
Na+ (Sodium)
What gate closes in the repolarising stage?
Na+ gated channels
What flows into the cell in the repolarising stage?
K+ (Potassium)
What is the period called where a nerve impulses cannot be initiated?
The refractory period
What is Saltatory conduction?
When the nerve impulse leaps from one myelinated part of the axon to the next
What is the function of the spinal cord?
Relays information to the brain from sensory neurons and from the brain to motor neurons.
Promotes homeostasis.
What is a reflex arc called that only involves one synapse?
Monosynaptic
Describe a polysynaptic reflex arc
A reflex arc that involves more than two different neurons
Describe a reflex arc.
Sensory receptor, sensory neuron, relay (inter) neuron, (spinal cord, brain), motor neurone, effector (muscle or gland).
What would you find in the diencephalon?
Thalamus, hypothalamus, posterior pituitary and the pineal gland.
What makes up the brain stem?
Medulla oblongata, mid brain and pons.
main function of the brain
To receive information, process information and respond to information
What is the pituitary gland known as and what hormones does it release?
Growth hormone, thyroid stimulating hormone, folic stimulating hormone, luteinising hormone.
Antidiuretic hormone (controls retention of water).
It is known as a master gland as it controls and regulates other hormones.
What is the gland called that controls the pituitary gland?
Hypothalamus
Where is the thyroid gland located?
inferior to the larynx (voice box)
What does the thyroid control?
Metabolism
What hormone does the thyroid produce?
Thyroid hormone (Thyroxine).
What gland is found posterior to the thyroid?
Parathyroid
What is the function of the parathyroid?
Controls levels of calcium, magnesium and phosphate in the blood.
What hormones does the pancreas release?
Glucagon and insulin.
What do glucagon and insulin do?
Glucagon raises blood sugar levels and insulin lowers blood sugar levels.
What hormones does the ovaries produce?
Estrogen and progesterone
What do estrogens and progesterone control?
regulate the female reproductive cycle.
Promotes the development and maintenance of the female secondary sex characteristics.
What hormone does the testes produce?
Testosterone
What does testosterone do?
regulates sperm production and development and maintenance of male secondary sex characteristics
Where are epinephrine and norepinephrine produced?
Adrenal (suprarenal) glands
Which hormones enhance the effects of the sympathetic part of the nervous system?
epinephrine and norepinephrine
Where are the suprarenal glands found?
Superior to the kidneys
What hormone does the pineal gland produce?
Melatonin
What does melatonin contribute to?
controlling the body clock
Where is the thymus gland found?
Posterior to the heart
What hormone does the thymus produce?
Thymosin, thymic humoral factor
What is the primary function of the thymus?
immunity
Which gland releases cortisol?
Adrenal (suprarenal)
What does cortisol do?
cortisol is released into the blood stream when you are stressed.
What is the function of the thalamus and where is it located?
The thalamus is where knowledge is stored. Relays sensory impulses to the cerebral cortex.
Located in the middle of the brain above the brain stem.
What part of the brain is responsible for intelligence, emotions and memory?
The cerebrum and it is the largest part of the brain.
where is the pineal gland located?
Middle of the brain in the epithalamus.
Where is the cerebellum located and what is it’s function?
posterior of the brain, above the brain stem.
Function is to coordinate voluntary muscle movements and to maintain balance and posture.
where is the medulla oblongata located and what is its function?
At the bottom of the brain stem.
Its function is to regulate bodily activities including breathing, swallowing, heart rhythm, blood flow.
where in the brain is the hypothalamus and what is it’s function?
above the pituitary gland.
Controls the pituitary gland. To help maintain homeostasis and regulate body temperature, hunger, thirst, emotion and memory.
Where in the brain is pons and what is its function?
Between the mid brain and the medulla. It forms part of the brain stem and bridges a connection between the mid brain and medulla.
Responsible for blinking, focus vision, tear production.
Where is the mid brain and what is its function?
Above pons, the most superior part of the brain stem.
Function is to facilitate hearing, balance, response to environmental changes.
What is the function of the spinal cord?
To relay information to and from the brain and the rest of the body.
