The Nervous System Flashcards
Which receptor is stimulated by light?
Photoreceptors
Ex. Rods and Cones
Which receptor is stimulated by chemicals?
Chemoreceptors
Ex. Tastebuds
Which receptors are stimulated by pressure?
Mechanoreceptors
Ex. Hair cells inside the ear
Which receptors are stimulated by temperature?
Thermoreceptors
What is the white outer layer of connective tissue in the eye?
The Sclera
What is the Job of the cornea?
To refract light into the eye
The middle layer of the eye that contains blood vessels?
The choroid layer
What is the coloured part of the eye?
The Iris
A transparent flexible disk behind the iris that helps light focus.
The lens
A small layer of fluid in the anterior cavity of the eye which provides oxygen to the cells of the lens and cornea.
The Aqueous Humour
A fluid that fills the posterior cavity and makes up most of the volume of the eye.
The Vitreous Humour
What is the inner layer of the eye called?
The retina
What is a bipolar cell?
A cell that transfers nerve impulses to ganglion cells
What is a ganglion cell?
A cell whose axons become the optic nerve which transfers impulses to the brain.
What does a rod do?
Sees shades of black and white as well as movement.
What does a cone do?
Responsible for colour vision and can be found in the retina.
What is a blind spot in the eye?
A place where light cannot be detected. Where the optic nerve attaches to the eye.
What is it called when light focuses in front of the retina?
Near sighted
What is it called when light focuses behind the retina?
Far sighted
What is an astigmatism?
When there is an uneven curvature of the cornea.
What is a cataract?
A cloudy film which covers the lens of the eye making vision blurry.
What is the pinna and where is it located?
The pinna is located on the outer ear and it is the visible skin which directs sound waves inwards.
What is the auditory canal and where is it located?
The auditory canal is located in the outer ear and it is a tube leading to the eardrum which sits in the middle ear. Hair and ear wax are located here.
What does the tympanic membrane (Eardrum) do and where is it located?
Located in the middle ear and converts sound vibrations into mechanical vibrations.
What do the ossicles do and where are they located?
They are the 3 smallest bones in the body and they amplify sound vibrations to the oval window. All 3 bones are located in the middle ear.
Where is the oval window found and what does it do?
The oval window can be found in the middle ear and it’s job is to pass vibrations to the inner ear.
What is the Eustschian tube and where is it located?
It is a tube that leads from the middle ear to the back of the throat and it’s job is to equalize air pressure in the middle ear. The tube opens when you sneeze, swallow, or yawn.
What are the two jobs of the inner ear?
Change sound waves to nerve impulses and regulating balance.
What is the vestibule?
A shell like structure composed of the utricle and saccule and it’s main job is to regulate balance.
What is the coclea and where is it located?
The coclea contains mechanoreceptors that detect sound vibrations and transmits sound waves to the brain. The coclea is located in the inner ear and an action potential is created in a specialized part called the organ of Corti.
What is determined by the number of neutrons stimulated in the ear?
Volume
What is determined by the location of which hair cells in the ear are stimulated?
Pitch
What part of the nervous system are the brain and spinal cord?
The Central Nervous System (CNS)
What is grey matter?
Unmylintated neurons
What is white matter?
Myelinated neurons
What is the job of the spinal cord?
To carry sensory signals from the PNS to the brain and signals from the brain to the PNS.
What happens if a person sustains an injury below the first thoracic vertabre?
They would become paraplegic.
What happens if a person sustains an injury above the first thoracic vertabre?
They would become quadriplegic.
Where are the cerebrum, thalamus, hypothalamus, basal ganglia, hippocampus, and amygdala located?
The Forebrain.
Where are the pons, cerebellum, and medulla located?
The Hindbrain.
What part of the brain connects to the spinal cord as well as controls breathing, heart rate, and blood pressure?
The Medulla.
What part of the brain is involved in unconscious coordination of posture, reflexes, and muscle movement?
The Cerebellum.
What part of the brain is located between the medulla and the midbrain and is a relay centre of neurons?
The Pons.
What part of the brain is a relay centre for nerve impulses going to the cerebrum and directs sensory information?
The Thalamus.
What part of the brain is involved with temperature control, water balance, blood pressure, heart rate, hunger, thirst, and emotions, as well as regulates the pituitary gland?
The Hypothalamus.
What is the largest part of the brain which is divided into two hemispheres called?
The Cerebrum.
What are the four lobes of the cerebral cortex called?
Occipital, Temporal, Parietal, and Frontal.
What does the occipital lobe of the brain do?
Process visual information.
What does the temporal lobe of the brain do?
Process auditory information.
What does the parietal part of the brain do?
Receives sensory information from the skin.
What does the frontal lobe of the brain do?
Controls voluntary movement, language, personality, and logical thought.
What is Broca’s area responsible for?
Coordinates muscles for speaking.
What is Wernicke’s area for?
Language comprehension.
What is the somatic PNS responsible for?
Voluntary control.
What is the autonomic PNS responsible for?
Involuntary actions.
What is the job of a sensory neuron?
To detect stimuli.
Where is an interneuron found and what is its role?
Found in the CNS and processes sensory information as well as makes decisions.
What is the role of a motor neuron?
To activate muscles and glands.
What is the job of a dendrite?
To receive stimulus and transmit a signal to the cell body.
Which part of the neuron contains a nucleus?
The cell body (soma).
Which part of the neuron is the longest, reaching from the dendrites to the axon terminal?
The Axon.
What is the part of the neuron that protects/insulated the axon, and speeds up transmission called?
A Myelin Sheath.
What are the gaps between sections of myelin called and what is their job?
The nodes of ranvier are where action potentials occur to keep a signal moving down the length of the axon.
What is a neurilemma?
A delicate membrane surrounding the axon which promotes growth and regeneration.
What causes MS?
The distraction of myelin sheath, leaving scar tissue which prevents normal impulse transmission.
What does a resting membrane look like?
High concentration of potassium on the inside of the cell, low concentration or sodium and calcium and vide versa. The inside should be negatively charged.
How does a sodium/potassium pump work?
It pumps 2 potassium in and 3 sodium out using ATP.
What are the steps of Action potential?
Resting potential, depolarization, repolarization, hyper polarization, and and the refractory period.
What is saltatory conduction?
When a signal jumps between nodes of ranvier, this is much quicker to move a signal than continuous conduction which travels down the entire axon.
What kind of neuron sends a signal
A presynaptic neuron.
What kind of neuron receives a signal?
A postsynaptic neuron.
What is a synapse?
A connection between two neurons.
Regulates anterior pituitary hormones.
Hypothalamic releasing and inhibiting hormones. (Released from the hypothalamus).
Stimulates cell division, bone and muscle growth, and metabolic functions.
Human growth hormone (anterior pituitary)
Stimulates thyroid gland
Thyroid stimulating hormone (anterior pituitary)
Stimulates the adrenal cortex
Adrenocorticotropic hormone (anterior pituitary)
Stimulates production of ova and sperm
Follicle stimulating hormone (anterior pituitary)
Stimulates sex hormone production
Luteinizing hormone (anterior pituitary)
Stimulates milk production
Prolactin (anterior pituitary)
Promotes the retention of water by the kidneys
Antidiuretic hormone (posterior pituitary)
Stimulates uterine muscle contractions and the release of milk.
Oxytocin (posterior pituitary)
Increases metabolic rate and regulates growth/development
Thyroxine (thyroid)
Targets bones and kidneys to lower blood calcium by inhibiting the release of calcium from bone and reabsorption of calcium by the kidneys.
Calcitonin (thyroid)
Raises blood calcium levels by stimulating the bone cells to release calcium.
Parathyroid hormone (parathyroid)
Stimulates tissues to raise blood glucose and break down protein.
Glucocorticoids (adrenal cortex)
Promotes reabsorption of sodium and water by the kidneys
Mineralocorticoids (adrenal cortex)
Promotes secondary sexual characteristics
Gonadocorticoids (adrenal cortex)
Fight or flight hormones
Epinephrine and norepinephrine (adrenal medulla)
Lowers blood glucose levels
Insulin (pancreas)
Raises blood glucose levels
Glucagon (pancreas)
Stimulates uterine lining growth and promotes development of females secondary sexual characteristics
Estrogen (ovaries)
Promotes growth of the uterine lining and prevents muscle contractions
Progesterone (ovaries)
Promotes sperm formation and development
Testosterone (testis)
Which cells produce glucagon
Alpha cells
Which cells produce insulin
Beta cells
What does insulin do?
Makes cells permeable to glucose
What stimulates the liver to convert glucose to glycogen for temporary storage?
Insulin
Where is glycogen secreted?
In the islets of langerhan
What does glucagon do?
Promotes the breakdown of glycogen in the liver to glucose, which is then released into the blood and elevating blood sugar levels.
What is the name of the disease which makes the body unable to produce or properly use insulin?
Diabetes Mellitus
What are some short term symptoms of diabetes?
Glucose in the urine, dehydration and thirst, fatigue and low energy, and bad breath.
Long term symptoms include blindness, kidney failure, and nerve damage.
What does a negative feedback loop in the endocrine system do?
Returns the body to homeostasis, inhibiting a stimulus.
What does a positive feedback loop in the endocrine system do?
Takes the body further from homeostasis by enhancing the stimulus.
What is special about a water soluble hormone?
It cannot cross a liquid membrane and interacts with cells through binding to external receptor sites.
What is special about a fat soluble hormone?
It is able to diffuse across a liquid membrane by binding to cytoplasm.
Ex. Steroids
What are hormones?
Chemical messengers produced in glands.
Where are the adrenal glands located?
On top of the kidneys.
What is produced by the adrenal medulla?
Epinephrine and norepinephrine which are responsible for the fight or flight response.
What is produced by the adrenal cortex?
Cortisol and mineralocorticoids such as aldosterone.
What are the 3 types of neurons?
Sensory (for physical stimulation)
Motor (for brain to area for movement)
Interneuron (for sensory signals going to the brain)
What is the sympathetic nervous system?
Responsible for the autonomic fight for flight response
What is the parasympathetic nervous system responsible for?
For relaxation, digestion, and life sustaining processes.
Excitory neurotransmitter example
Epinephrine/norepinephrine
Inhibitory neurotransmitter example
GABA
Dorsal vs ventral root in the vertabre
Dorsal is sensory and ventral is motor
