Nervous System and Senses (Senses (Exteroceptors- receive stimuli from…
Nervous System and Senses
Exteroceptors- receive stimuli from external environment. Cutaneous receptors- skin, responding to touch or temperature as well as sight, hearing, taste and smell. Interoceptors- respond to stimuli arising from internal organs. Proprioceptors- like interoceptors but only located in muscles, tendons, and joint capsules.
Chemoreceptors- detect presence of chemicals. Thermoreceptors- detect changes in the temperature.
Mechanoreceptors- detect mechanical forces or changes.
Photoreceptors- detect light and enable vision
Cornea, lens, retina, ciliary body, optic nerve, optic disc, aqueous humor, vitreous humor, pupil, iris. Axons enter optic nerve to optic chiasma to optic tract to thalamus to primary visual cortex.
Olfaction contain millions of bipolar olfactory sensory neurons. Go from Lamina Propria to filaments of olfactory nerve to olfactory bulb to provoke synapse with mitral cells. Mitral cells transmit signals to Limbic region then to the primary olfactory cortex.
Taste buds with the ability to regenerate and Papillae. Food dissolves on tongue and triggers gustatory receptor cells to become stimulated, impulses from receptor cells depolarizes and action potential travels to cranial nerves responsible for gustation, cranial nerves then transmit information to medulla oblongata then to the thalamus and finally to the primary gustatory cortex.
Outer Ear, Tympanic membrane, Pinna, Auditory/Ear Canals, Middle Ear, Ossicles, Cochlea, Cilia, Inner Ear. Pinna to auditory canal to ear drum to ossicles to oval window to cochlea to auditory nerve to thalamus to temporal lobe.
Anatomy of Nervous System
Glial Cells provide a supportive scaffolding for neurons and cover all non synaptic parts of the neurons, thereby insulating the neurons and keeping the electrical activities of adjacent neurons from interfering with each other. Located in both CNS and PNS.
Cable-like organs found in the PNS. Each nerve has many axons in parallel bundles. Usually contain both myelinated and non myelinated sensory and motor axons. Each axon is surrounded by a Schwann cell which are covered in loose connective tissue called Endoneurium. Groups of axons are bound together in bundles called fascicles, which are covered in Perineurium. The whole nerve is covered in a tough fibrous sheath called the Epineurium.
Cell body or "Soma" which holds nucleus, cytoplasm, and plasma membrane. A Chromatophillic substance which is rough ER which provides a dark staining. And Neurofibrils which are intermediate filaments that run between Chromatophillic substances and prevents the cell from being pulled apart from pressure. Dendrites which function as receptive sites, conduct electricity toward the body. Axons are impulse generators and conductors that transmit nerve impulses away from cell body. Synapses are the site where neurons communicate.
Multipolar Neurons- 99% of the neurons in the body, have more than two processes. Bipolar Neurons- Have two processes that extend from opposite sides of the cell body. Unipolar neurons- Have a short single process that extends from the body.
Sensory neurons- transmit impulses toward the CNS from sensory receptors in the PNS. Motor Neurons- these neurons carry signals away from the CNS to effector organs. Interneurons lie between motor and sensory neurons are confined entirely in CNS.
Nervous System Organization
Central Nervous System- Spinal Cord and Brain.Integrative and Control Center.
Peripheral Nervous System-Cranial Nerves, Spinal Nerves, and Ganglia. Communication lines between CNS and rest of body.
Somatic nervous system is somatic motor so more voluntary movement. Conducts impulses from CNS to skeletal muscles like contraction.
Autonomic nervous system is visceral motor so involuntary movement. Conducts impulses from CNS to cardiac muscles, smooth muscles, and glands.
Type of receptors based on origin
Type of receptors based on stimulus type
Visual Pathway and Components of Eye
Olfactory Pathway and Components of Smell
Gustation Pathway and Components
Ear Pathway and Components
Glial Cells Location and Brief Description
Major Components of a Neuron
Structural Types of Neurons
Functional Types of Neurons
CNS Structure and Function
PNS Structure and Function