Nervous and Endocrine System Flashcards
Glial Cell
Provide neurons with structural support and nutrition. (non conducting cells)
Dendrite
Recieve information from receptors or other neurons
Axon
Longest cytoplasmic extension from cell body.
Myelin sheath
Acts as insulation/ protection and speeds up nerve impulses (it is grey matter that is not myelinated)
Schwann cells
Wrapped around axons and produce myelin sheath
Nodes of Ranvier and Saltatory conduction
Nodes- Areas between sections of myelin. Impulse thought tp jump from one node to another
Saltatory- speeds up the arrival of the impulse at the nerve terminal
Resting potential
The regular state. There are more Na+ than K+ inside and more postive ions outside the cell.
Depolarization
Na+ channels open and Na+ flow into thr negative axon
Repolarization
Na+ channels open and K+ channels open, more K+ leaves the cell than comes in. The cell loses charged ions
Hyperpolarization
Makes the cell more negative.The K+ channels stay open and release more K+. As the K+ channels close the Na-K pump works to reestablish the resting state.
Threshold Level
The critical level to which a membrane potential must be depolarized to initiate an action potential.
All or None response
Responds to a stimulus that exceeds the threshold potential or not at all.
Synapse
When a neuron communicates with a target cell.
Neurotransmitters
Chemical messengers that transmit a message from a nerve cell to a target cell.
Cholinesterase
An enzyme that breaks down acetylcholine
Norepinephrine
Compliments the actions of epinephrine ehich readies the body to respond to danger or stressful situations.
Acetylecholine
Exitatory neurotransmitter in the parasympathetic nervous system
Reflex Arc
Receptor (affector) -> Sensory Neuron (afferent) -> Interneuron (spinal cord) -> Motor Neuron (efferent) -> Effector (muscle)
Meninges
Membranes that protect the brain
Cerebrospinal Fluid
It cushions the brain and spinal cord from injury. Also serves as a delivery and waste system for the brain.
Cerebrum
Makes you YOU, control senses, memory, intelligence, language
Cerebral Cortex
A thin outer layer of grey matter that makes humans so smart
Frontal Lobe
Motor areas control movement of voluntary muscles like walking or speech. Linked to intelligence, personality etc
Pariental Lobe
Sensory areas associated with touch and temperature awarness and body position. Linked to emotions and interpreting speech
Temporal Lobe
Sensory areas associated with hearing
Occipital Lobe
Sensory areas associated with vision
Corpus Callosum
Links right and left hemispheres
Thalamus
Mostly grey matter that translates neural impulses from various receptors to the cerebral cortex
Hypothalamus
Maintains the body’s internal equilibrium
Cerebellum
The region of the brain that coordinates muscle movement and balance
Pons
The region of the brain that acts as a relay station by sending nerve messages between the cerebellum and the hindbrain
Medulla Oblongata
The hindbrain region that joins the spinal cord to the cerebellum. The site of autonomic nerve control- heart rate, blood pressure, breathing etc
Olfactory Bulbs
Located in the forebrain that recieves neural input about smell
Central Nervous System
CNS controls most functions of the body and mind. Has two parts; the brain and spinal cord. It gathers info from all over the body and coordinates activity
Peripheral Nervous System
Consists of nervous and ganglia outside the brain and spinal cord. It connects the CNS to the limbs and organs
Somatic Nerves & Sensory vs Motor
Part of the Peripheral NS and is responsible for all the functions we are aware of.
Sensory- transmits sensory info from skin, skeletal muscle to CNS. Motor transmits messages from the CNS to the muscles.
Autonomic Nerves
Acts unconsiously and regulates bodily functions such as heart rate, digestion, respiratory rate, urination
Sympathetic Nervous System
Directs the body’s rapid involuntary response to dangerous or stressful situations (fight or flight). A flash flood of hormones boosts the body’s alertness and heart rate, sending extra blood to muscles
Parasympathetic Nervous System
Responsible for the body’s rest and digestion response when the body is relaxed, resting or feeding. It decreases respiration, heart rate and increases digestion
Rods
Vision at low light levels
Cones
Higher light level, color vision
Myopia
Distant objects focused in front of retina making them appear out of focus
Hyperopia
Object focused behind the retina making objects up close out of focus
Sclera
External layer/ protects eyeball
Cornea
Bends light rays into the eye
Choroid
Intermediate layer/ absorb scattered light
Iris
Regulates the amount of light that enters they eye
Pupil
The opening for light to enter the inner eye
Ciliary Muscles
Changes the shape of the lens in order to focus
Retina
Internal layer
Fovea Centralis
Contains a high density of cones and provides acute vision
Lens
Focuses light rays onto the fovea centralis
Optic Nerve
Transmits sensory info to the brain
Optic Disc
Location where ganglion cell axons exit they eye to form the optic nerve
Vitreous Body
Clear gel that fills the space between the lens and the retina
Pinna
in the outer ear/collects sound
Auditory Canal
(ear canal) pathway running from the outer ear to middle ear
Tympanic Membrane
thin layer of connective tissue that separates the outer and middle ear (eardrum)
Ossicles
3 bones: malleus,incus and staples
who’s job is to amplify the sound waves so they can travel through the thicker fluid filled structures within the inner ear
Cochlea
fluid filled structure containing the basilar membrane & organ of corti - the site of sound waves converting into electrical impulses the brain can understand
Organ of Corti
site above the basilar membrane and contains hair cells which move and open Na+ ion channels
Auditory Nerve
connects the inner ear to the brain
Semicircular Canal
3 fluid filled canals responsible for balance. the movement of fluid stimulates cells that send an action potential to the brain
Eustachian Tube
extends from middle ear to mouth and nose - equalizes air pressure
mechanoreceptors
stimulated by pressure -touch or sound
photoreceptors
detection of light (photons) we perceive as vision
chemoreceptors
are stimulated by certain chemicals
thermoreceptors
in the skin -sense hot and cold
proprioceptors
a sensory receptor that receives stimuli from within the body, especially one that responds to body position and movement
Hypothalamus
everything starts here
HRH (acts on the pituitary gland)
ADH
Oxytocin
Anterior Pituitary
hGH- acts on the cells, bones/muscles for growth
TSH- acts on thyroid gland
FSH- production of follicles to produce egg/sperm
LH- ovulation in females and production of testosterone in males
PRL-milk production
ACTH- acts on adrenal cortex
Posterior Pituitary
Oxytocin- causes uterine contractions (child birth) and helps release milk
ADH- retains/ reabsorbs H2O (antipee)
Parathyroid
PTH- decrease Ca2+ in bones and increases Ca2+ in blood
Thyroid
Calcitonin- increases Ca2+ in bones and decrease Ca2+ in blood
Thyroxine- increases metabolism
Adrenal Cortex
Cortisol- slow stress response (protein convert to glucose in liver)
Aldosterone- increases Na+ retention and therefore H2O retention
Adrenal Medulla
Epinephrine/ Norepinephrine- fast stress response (sympathetic nervous system)
Pancreas
Insulin- decreases blood sugar
Glucagon- increases glucose levels in blood
Ovaries
Estrogen- secondary sex characteristics, growth of uterine lining
Progesterone- prevents uterine contractions
Testes
Testosterone- sperm production and secondary sex characteristics
Hyperthyroidism
overactive thyroid gland
symptoms : weight loss, mood swings
Hypothyroidism
underactive thyroid gland
symptoms: fatigue, increased sensitivity to cold
Diabetes Mellitus
in the pancreas
-does not produce enough insulin
symptoms: frequent urination, excessive thirst
Diabetes Insipidus
Stored in the pituitary gland
-ADH
symptoms: excessive amounts of urine, colorless urine
