Dominic Luster Nervous system (Senses (sensory receptors that are…
Dominic Luster Nervous system
Classification of sensory receptors
Stimulus comes from our internal organs
Stimulus comes from our muscles, ligaments, and joints.
Stimulus comes from the enviroment located close to the skin
sensory receptors that are activated by a specific stimuli.
Responds to chemical such as: air, saliva (water), and blood (calcium, potassium, CO2, O2, sodium).
Responds to harmful stimuli that result in pain.
Stimulus that is sensitive to light.
respond to mechanical forces such as touch pressure, stretch, and vibrations
Another type of mechanoreceptor is a baroreceptor: which monitors blood pressure.
Respond to temperature change.
General sense receptor V.S. Special sense receptor.
Are localized receptors usually in the head region, are specialized receptors.
Is wide spread, and are never ending of sensory neurons that monitor touch, pressure, vibration, stretch, pain, and temperature.
Light travels through the cornea, pupil, lens, posterior segment, retina, optic nerve, optic chiasam, optic tract, mid-brain, thalamus.
3 tunics of the eye
Is a muscle that changes the shape of the lens
Colored part of the eye, intrinsic muscle/sphincter muscle.
nourishes the other layers, deeply pigmented, absorbs light preventing scattering.
White dense connective tissue, protects, anchor for muscles, and give shape to the eye.
Clear part of the eye, allows light into the eye, focusing light onto the retina.
Main areas of the
Is filled with vitreous humor, supports the retina & lens, is gel-like, and helps maintain pressure.
Anterior segment that has two different chambers and is filled with aqueous humor.
Anterior chamber, which includes from the cornea to the iris.
Posterior chamber which includes everything from the iris but not including to the posterior segment.
Other important anatomy of the eye that effect the way we see.
We have no photoreceptors here.
Precise posterior pole.
We have fewer of these and they allow us to see color, best in bright light.
Located at the center of the macula lutea, and the space of our clearest vision.
We have many of them, and they are sensitive to light.
Gustation: Sense of taste.
The three cranial nerves that have to do with gustation.
The glossopharyngeal and 9th cranial nerve which tranfers impules from the posterior 1/3 of the tongue.
Vagus and 5th cranial nerve that carries impulses from the taste bud on he epiglottis and posterior pharynx.
Facial and 7th cranial nerve that transfers impulses from the anterior 2/3 of the tongue.
Locations of the taste buds in the human body.
Tongue, inner checks, posterior wass of the pharynx, and the epiglottis.
Taste stimuli pass from one of the three sections of the tongue and pass through one of the three cranial nerves, to the medulla oblongota, thalamus, gustatory cortex that is located in the insula.
Olfactory: sense of smell.
Pathway of olfactory receptors
Olfactory receptor, olfactory sensingg neuron with in the olfactory bulb, olfactory tract, after this step the path way splits off in two directions, 1. limbic system (emotional brain) and 2. the primary olfactory cortex.
Is located on the roof of the nasal cavity, consists of pseudostratified columnar epithelium, olfactory sensory neurons.
The human ear and auditory system.
Cranial nerves involved with hearing.
Both the vestibular and the cochlear nerves pass through the internal acoustic meatus. And together they make the 8th cranial nerve the vestibulocochlear nerve.
Pathway of sound.
Auricle gathers sound waves and amplify's them to the, tympanic membrane (ear drum) to the auditory ossicles, to the cochlea (liquid filled), medulla oblongota, pons, mid brain, thalamus, primary auditory cortex, finally to the temporal lobe.
Tympanic membrane (ear drum)
Nervous system organization
Central nervous system: Brain and spinal cord, with a function to revive, process incoming signals and respond.
Neuroglial cells of the CNS
Phagocytes of the CNS, removes microbes, and damaged nerve tissue.
Simple cubodial/columnar epithelium
Lining spaces with cerebrospinal fluid.
Ventricles: Spaces filled with cerebrospinal fluid
Cillia: Keeps cerebrospinal fluid moving.
Most numerous, many processes that contact neurons and capillaries (smallest blood vessels).
Supports neurons, and helps maintain the appropriate chemical environment.
Wraps their plasma membrane around one prtion of several axons, and makes our myline sheeth.
A tract in the CNS is the same as a nerve in the PNS just in a different location.
Group or cluster of neuron cell bodies in the CNS.
Peripheral nervous system: The cranial and spinal nerves, with a function to be sensitive to stimuli and send that information toward the central nervous system.
Structurally supportive of neurons, regulates the exchange of materials in and out of a neuron cell body
Cluster to neuron cell bodies
Mostly lipid and some protein, insulates axons, allows signals to travel faster, there are gaps called myelin sheaths (not continuous).
Wraps their plasma membrane around one portion of one axon. A non-myelinated axon.
A nerve in the PNS is the same as a tract in the CNS just in a different location.
Anatomy of the central nervous system:
Sensory & Motor fibers of PNS
Input from the ventral body cavity, taste and smell.
Mainly to parts of your ventral body cavity. Smooth muscle in walls of hollow organs.
Digestive, respiratory, urinary, cardiac muscle. Arrector pili muscles of the skin, sweat glands, and blood vessel walls.
(out-put) to the skeletal muscle.
In-put from the skin, skeletal muscle, joints, limbs,(hearing, vision, and equilibrium).
Afferent & Efferent
Sensory/afferent, is sending info towards the CNS. And efferent/motor is sending info towards the PNS
White and gray matter of the CNS.
Cortex: neuron cell bodies (non-myelinated), deep gray matter of the brain/nucli.
Anatomy of a neuron
(receiving end) The body of a neuron is also a receiver.
Soma or cell body
Where signals from the dendrites or collected and passed on.
Located at the end of the soma, and controls the firing of the neuron.
Elongated fiber that transmits the neural signal.
Are located at the end of neurons and send the neural signal on to another neuron.
An extra branch of the existing tail of an axon.
Structure of a neuron
Have two processes that extend out from opposite sides of the cell body. They are in some of the special sensory organs.
Has a short single process that emerges from the cell body and divides like an inverted T. (sensory neurons)
99% of neurons in the body fall under this class, have more than two processes, have numerous dendrites and a single axon.
Motor neuron: cell bodies are in the CNS, and go on to the PNS and finally to muscles and glands.
Clusters of free ribosomes and rough ER.
Function: To renew the plasma membrane and the protein within the cystol.