Unit A Flashcards
What are the two main divisions in the human nervous system?
The Central and Peripheral Nervous System
What is the Central Nervous System(CNS)?
The body’s coordinating center for mechanical and chemical action; made up of the brain and spinal cord.
What is the Peripheral Nervous System(PNS)?
Comprised of nerves that carry information between the body and the CNS(i.e sense organs, muscles, glands, internal organs)
What are Sensory Somatic Nerves?
Specialized sensory and motor nerves designed to control the EXTERNAL environment
Are the Sensory Somatic Nerves voluntary or involuntary?
Voluntary
What part of the brain controls Sensory Somatic Nerves?
The cerebellum and the frontal lobe
What is the Autonomic Nervous System?
Specialized sensory and motor nerves designed to control the internal environment of the body
What is Sympathetic?
(prepares body for stress) Nerves arise from ribs and the small of the back
neurotransmitter -NOREPINEPINE
What is Parasympathetic?
(relaxes-reverses effects of sympathetic system) Nerves arise directly from the brain or neck and tailbone sections of spinal cord
Neurotransmitter- ACETYLCHOLINE and nitric acid
Vagus Nerves
What is the Vagus nerve(PARASYMPATHETIC)?
Controls-heart, lung, liver, pancreas, digestion
What is the name of the 2 types of cells within the nervous system?
Glial cells and Neurons
what is a Glial Cell?
non-conducting cell, nourish and support the nerve cells (protects neurons
What is a Neuron?
functional units of the nervous system, conduct impulses
What are the 3 kinds of Neurons?
Sensory (afferent) Neuron, Interneurons(association neurons), and the Motor (efferent) Neuron
What is a Sensory Neuron?
relays information about the environment to the CNS for processing
associated with receptor cells in contact with the environment
i.e touch receptors in the skin
What is an Interneuron?
form links within the body
found within the brain and spinal cord (CNS)
they integrate and interpret sensory information and connects it to the ongoing motor neurons
Whatis a Motor Neuron?
relay information from the CNS to the effectors.
Effectors could be muscles, glands or anything that cause change to happen
Are reflex voluntary or involuntary?
Involuntary
What processes situation and as a result causes reflexes?
Interneurons (association neurons)
What are the five parts of reflexes?
Receptor Sensory Neuron Association Neuron Motor Neuron Effector
What is a patellar reflex?
Knee jerk
What is a pupillary reflex?
The pupils enlarges and shrink if and increase and decrease of light
What is the Dorsal root?
Where Sensory (afferent) Neurons enter the spinal cord
What is the Ventral root?
Where Motor (efferent) leave the spinal cord
What is White matter?
(Motor and sensory) sending impulses vertically mainly
What is grey matter?
(Interneuron) connecting the front and back halves of the spinal cord
What is the 2 main function of the Spinal Cord?
- To connect the PNS to the CNS ( specifically the brain)
2. Provide neural pathway for reflex actions that don’t involve the brain
What is polarization?
It is the state of rest no stimulus
Sodium-potassium pump is still occurring
Sodium channels are closed
Potassium channels are closed but a few are open
Chlorine channels are open
More positively charged(outside the membrane)
Membrane potential of (-70mV)
What is Depolarization?
Starts when stimulates reaches threshold
Sodium and potassium pump still occurring normally
Sodium channels open
Potassium channel close
Charges flips across the membrane more negatively charged (outside the membrane)
Membrane potential of (+40mV)
What is Repolarization?
The rest
Sodium-potassium pump occurs normally
Sodium channels close
Potassium channels close but a few remain open
It creates a more positivity charged (outer) membrane
It creates a membrane potential of (-70mV)
What is threshold?
The min amount of stimulus needed to create a impulse
What is Hyperpolarzation?
When too much potassium passes through so the membrane(inner) gets too negativity charged
What is range of intensity?
Stronger stimulus more frequent impulses along more neutrons stimulated
What is rate of impulse?
The bigger the axon the faster the impulse myelined is faster then unmyelined- saltatory conduction
What is action potential?
A nerve impulse
A message or wave traveling down a nerve caused by a flip or reverse of charge across the membrane (depolarization)
What is a refractory time?
The recovery time before a neuron can produce another action potential. Impulse travel in only one direction
What is a synapse?
The area neurons or between neurons and effectors
What is presynaptic neuron?
Carries impulses to the synapse
What is postsynaptic?
Carries impulses away from synapse
What are the three layers of the eye?
Retina, Sclera and choroid
What are rode?
Photoreceptors that operate in dim light to detect light in back and white.
What are cones?
Photoreceptors that operate in bright light to identify color
What is the sclera?
It is the outermost layer. White fibrous and help maintain the eyes shape and protective layer of the eye.
What is the innermost layer of the eye? What is it and what does it do?
Retina- contains photoreceptors
The middle layer of the eye? What is it and what does it do?
Choroid layer- it contains blood vessels that nourishes retina
How are nutrients supplied to the cornea?
Through aqueous humour which is a transparent fluid in a chamber behind the cornea
What is cornea and what does it do?
Cornea is the transparent part of the sclera that protects the eye and refracts light toward the pupil of the eye
What is the iris?
Iris is found toward the front of the choroid layer which surrounds the pupil that regulates amount of light entering the eye
Is there more cones then rods?
No
160 million Rods
7-10 million cones
What are the four different layers of retina cells
Pigmented epithelium, light-sensitive cells, bipolar cells, and cells of the optic nerve
What is fovea centralis
Area at center of retina where cones are most dense and vision is sharpest
What causes the blind spot?
When there is no rod and cones in the area and absence of photosensitive cells
What is rhodopsin?
Rod that contains a light-sensitive pigment
What are the two form of the rhodopsin?
Vitamin A and Opsin
What are the two components that rhodopsin molecule divides into?
Retinene (the pigment portion) and opsin (the protein portion)
What are the three primary colours?
Green, red and blue
What is refraction?
The showing of light by a denser medium causes bending
What is accommodation?
The adjustment of the lens to objects near and far
What is Glaucoma?
Caused by a buildup of aqueous humour in the anterior chamber of the eye
What is cataract?
Prevents light from passing through and it occurs when it becomes opaque
What is astigmatism?
It’s a vision defect caused by abnormal curvature of surface of the lens or cornea
What is nearsightedness and how can it be corrected?
Occurs when the eyeball is too long and corrected by glasses that has a concave lens
(When the image is focused in front of the retina)
What is farsightedness and how can it be corrected?
Occurs when the eyeball is too short and can be corrected by a glasses that have a convex lens
(When image is focused behind the retina)
What are the two things the ear is associated with?
Hearing and equilibrium
What is the Pinna?
The outer part of the ear that acts like a funnel, taking sound from a large area and channeling it into a small canal.
What is the Auditory canal?
Carries sound waves to the eardrum
What is the Tympanic membrane?
Also known a the eardrum is a thin layer of tissue that receives sound vibrations
What are ossicles?
Tiny bones that amplify and carry sound in the middle of the ear
That are the three types of ossicles?
The Malleus, the Incus and the stapes
What is the oval window?
A oval-shaped hole in the vestibule of the inner ear, covered by a layer of thin tissue
What is the Eustachian tube?
Air-filled tube of the middle ear that equalizes pressure between the external internal ear
What is Vestibule?
It is a chamber found at the base of the semicircular canals contain two sacks the UTRICLE and SACCULE which establishes head position
(STATIC EQUILIBRIUM)
What is the semicircular canals?
Three semicircular canals, arranged at different angles and the movement of fluid help you identify body movements
(DYNAMIC EQUILIBRIUM)
What is the cochlea?
Shaped like a spiraling snail’s shell. Contains specialized hair cells that run the of the inner Canal. Hairs reaction to sound waves and convert them into nerve impulses
What is the organ of corti?
Is the primary sound receptor in the Cochlea
What is the basilar membrane?
Anchors the receptor hair cells in the Organ of Corti
What are the similarities of the nervous system and the endocrine system?
They both maintain homeostasis(balance)
Nerves secrete neurotransmitters Glands secrete hormones some nerves secrete noradrenaline and the adrenal medulla secretes noradrenaline
What are the differences of the nervous system and the endocrine system?
Mode of transmission:
Nervous system- impulse sent along the nerve
Endocrine system- hormones released in blood
Duration of effect:
Nervous system- short
Endocrine system - longer-(minutes to days)
Reaction time:
Nervous system- quick-(50ms-300mph)
Endocrine system- slower
What is the endocrine system?
Helps control body responses
Gland are scattered throughout the body- connected by the bloodstream
Chemical messengers are called hormones
What are endocrine glands ?
They release hormones directly into the bloodstream
What is homeostasis?
The body’s attempt to adjust to fluctuating environments (balance)
What is dynamic equilibrium?
It is the state of stability within fluctuating limits
What are the three functional components of all homeostatic control systems?
A receptor, a coordinating Center, and an effector. for example when running carbon dioxide levels increase, chemical receptors in the brain stem are stimulated. Nerve cells from the brain then carry impulses to effector muscles which then increase breathing levels
What is negative feedback?
It is a mechanism that makes adjustments to bring the body back to acceptable range. Pg 472
What is positive feedback?
It moves the controlled variable away from steady state. For example oxytocin
What are hormones?
They are chemical regulators produced by cells in one part of the body that affect cells in another part of the body
Work in negative feedback loops. All hormones are regulators that means they speed up or slow down body processes.
What are endocrine glands?
They secrete hormones directly into the bloodstream. They are internally secreted. Their effects can be produced throughout the body or in special target organs. For example thyroid glands
What are Exocrine glands?
secretion is through ducts. Are externally secreted. There effects are produced in regions where the duct empties. For example salivary glands
What is the difference between target hormones and nontarget hormones?
Nontarget hormones affect many cells or tissues throughout the body. For example insulin.
What is insulin?
Hormone produced by islets of Langerhan cells in the pancreas. Lowers blood sugar levels
What is human growth hormone?
A hormone produced by the pituitary gland that stimulates growth of body
When there is too much (hyper-secretion) you can get a condition called giantism in adult it’s called acromegaly. When there is too little (hypo-secretion) you can get a condition called dwarfism
What is epinephrine hormone?
It is a hormone released in times of stress by the adrenal Medulla. It accelerates heart rate and body reaction during that time
What are the two types of hormones?
Steroids hormones and protein hormones
What are steroid hormones?
They are lipids made from cholesterol. Therefore are soluble in fat and are able to pass through the membrane lipid bilayer of the cell membrane bind two receptor protein in the cytoplast
What are protein hormones?
Composed of amino acids. Therefore unable to diffuse through the lipid Bilayer. Must combine with specific receptor on cell membrane.
What is the pituitary gland?
It is often referred to as the “master gland” because it exercises control over other endocrine glands. it’s connected to the hypothalamus. The pituitary produces and stores hormones.
What is a releasing hormone?
They are peptides that stimulate the pituitary to release hormones stored
What are inhibiting factors?
Chemical that inhibits production of a hormone of the anterior pituitary gland.
What is the islets of Langerhans?
Hormone-producing cell located in pancreas
Beta and alpha
What do beta and alpha produce?
Beta produces insulin and Alpha produces glucagon
What is diabetes?
It is a chronic disease caused by insufficient production or use of insulin. There are three types pg 479 (READ ABOUT THEM)
What are the two parts of the adrenal gland?
The adrenal cortex and the adrenal medulla
What is/function of the adrenal medulla?
It produces two hormones epinephrine and norepinephrine. The hormone producing cells with in the adrenal medulla are stimulated by the sympathetic nerves in times of stress.
What is/function of the adrenal cortex?
It produces three types of steroid hormones. Glucocorticoid, mineralocorticoid and some sex hormones.
Helps body recover from stress
(READ Pg 481)
What is the adrenocorticotropic hormone?
This hormone is released by the anterior lobe of the pituitary gland to stimulate the adrenal cortex. It one of the hormones released as stress response
What is aldosterone?
It is a hormone produced by the adrenal cortex. It helps regulate water by increasing sodium intake and reabsorption of water by the kidney
What is the function of the hypothalamus?
Controls body temp, emotions, circadian rhythm( sleep rhythm) and feeling of pain, hunger, pleasure and thirst. Hypothalamus and pituitary gland=nervous and endocrine system
What is the function of the thalamus?
It directs information to the appropriate parts of the cerebrum
What is the function of the medulla oblongata?
It join the cerebellum and spinal cord together. Site of automatic nervous control: heart and breathing rate, coughing, swallowing, vomiting, dilation of blood vessels
What is the function of the cerebellum?
Controls muscle movement- complex muscle coordination balance, limb movement, posture
What is the cerebrum and what is its function?
It is the largest part of the brain. Receives and processes all sensory information. Initiates motor impulses of voluntary movement
FPOT
What is the function of the frontal lobe?
Controls voluntary movements ( ex walking and speech), memory intelligence and personality.
What is the function of the parietal lobe?
Sensory areas are associated with touch and temperature, pain, pleasure and pressure
Emotions and interpretations of speech and taste
What is the function of the Occipital lobe?
Process sensory information from the eye(vision)
What is the function of the temporal lobe?
Process sensory information for ears (hearing), smell
What is the function of the Cerebral cortex?
Folded(convoluted) outer layer of the cerebrum- function is language, reasoning and perception
What is the function of the corpus callosum?
Connects the two sides to the brain
What is the function of pons?
Relays information from the cerebellum and the medulla