Lab Write-Up

1. What is the electrode measuring?An electrode measuring system comprising a measuring electrode (1) and a seat (2) co-operating with the same during the measurement, the measuring electrode comprising one or more electrode surfaces .
2. Why use leeches in neurophysiology experiments? Because they are the easiest to work with and their cells work the best under the uv light.
3. What is the difference between a sensory and a motor neuron?Sensory neurones (neurons) are unipolar neuron nerve cells within the nervous system responsible for converting external stimuli from the organism's environment into internal electrical motor reflex loops and several forms of involuntary behavior, including pain avoidance. In vertebrates, the term motor neuron (or motoneuron) classically applies to neurons located in the central nervous system (CNS) that project their axons outside the CNS and directly or indirectly control muscles.
4. Do you think a leech experiences pain? No i do not think that the leech is in pain. What is pain? PAIN is when you feel discomfort in your body due to either aches and pains or surgery.
5. What were the two most interesting things about doing this lab? It was very interesting to see how the cells changed under the uv light, and also i liked hot it walked yout through step by step.
6. Anything you found confusing or didn't like about the lab? No i really liked this lab it actually made u feel like you were in class.

Leech Lab Photos

This Photo is a picture of the dyed cell after putting the dye in it and looking at it under the uv light.

This is another photo of a different cell while dyed and viewed under the uv light.

This was the 2nd step in the leech lab. I had to cut open the leech and pin it open

This is a close up of the the cells inside the leech.

CH. 13 & 14 Review

CHAPTER 13& 14 Review

Chapter 13 Nervous System

13.1 Overview of the Nervous System
Nervous tissue is composed of two main cell types: neurons and glial cells. Neurons transmit nerve messages. Glial cells are in direct contact with neurons and often surround them. It s divided into the central nervous system and the peripheral nervous system. It has three functions, reception of input, integration of data, and generates motor output. Nervous Tissue contains two types of cells, neurons and neuroglia. These two transmit nerve impulses and nourish and support the neurons. The neuron Structure is highly specialized cells that transmit impulses within animals to cause a change in a target cell such as a muscle effectors cell or glandular cell. The cell body of a neuron, called the soma, contains the cell nucleus and the majority of the cytoplasm inclusions and organelles. Radial extensions of the soma cell membrane, called dendrites, extend to other neurons and form the interface where impulses are transmitted from neuron to neuron. One long extension of the soma, called the axon, is the primary conduit through which the neuron transmits impulses to neurons downstream in the signal chain. Axons range in length from around 0.1 millimeters to nearly a meter in length with some neurons in the sciatic nerve. Axons branch into smaller extensions at their terminal end and eventually create synapses with the target cell. The nerve impulses like other communication systems use a sequence of impulses to carry message. The nature of nerve impulses, however, differs entirely from electromagnetic waves and sound waves. In every nerve cell, there is a membrane separating the cytoplasmic fluid from the extracellular solution. The generation of action potentials is mainly due to the changes of sodium (Na+) and potassium (K+) conductances. The conductance of Na+ ions may change dramatically with the membrane potential as demonstrated by voltage clamp experiments, in which the membrane potential is displaced to a new value and maintained there. The synapse is when a neurotransmitter is released into a synaptic cleft, transmission of a nerve impulse occurs. Integration is the summing of excitatory and inhibitory signals.
13.2The Central Nervous System
The central nervous system is made up of the spinal cord and brain. The spinal cord conducts sensory information from the peripheral nervous system (both somatic and autonomic) to the brain conducts motor information from the brain to our various effectors skeletal muscles cardiac muscle , smooth muscle , glands, serves as a minor reflex center. The brain receives sensory input from the spinal cord as well as from its own nerves (e.g., olfactory and optic nerves) devotes most of its volume (and computational power) to processing its various sensory inputs and initiating appropriate — and coordinated — motor outputs.
13.3The Limbic System and Higher Mental Functions
This is a deep lying system in the brain is involved in determining emotions. The amygdale determines when a situation deserves the emotion we call fear. The hippocampus is particularly involved in storing and retrieving memories.
13.4 The Peripheral Nervous System
The PNS consists of sensory neurons running from stimulus receptors that inform the CNS of the stimuli & motor neurons running from the CNS to the muscles and glands - called effectors - that take action. The CNS consists of the spinal cord and the brain. The peripheral nervous system is subdivided into the sensory-somatic nervous system and the autonomic nervous system The Sensory-Somatic Nervous System consists of 12 pairs of cranial nerves and 31 pairs of spinal nerves. The autonomic nervous system consists of sensory neurons and motor neurons that run between the central nervous system (especially the hypothalamus and medulla oblongata) and various internal organs such as the: heart, lungs , viscera , glands (both exocrine and endocrine). It is responsible for monitoring conditions in the internal environment and bringing about appropriate changes in them. The contraction of both smooth muscle and cardiac muscle is controlled by motor neurons of the autonomic system. The preganglionic motor neurons of the sympathetic system arise in the spinal cord. They pass into sympathetic ganglia which are organized into two chains that run parallel to and on either side of the spinal cord. The preganglionic neuron may do one of three things in the sympathetic ganglion: synapse with postganglionic neurons which then reenter the spinal nerve and ultimately pass out to the sweat glands and the walls of blood vessels near the surface of the body, pass up or down the sympathetic chain and finally synapse with postganglionic neurons in a higher or lower ganglion ,leave the ganglion by way of a cord leading to special ganglia (e.g. the solar plexus) in the viscera. Here it may synapse with postganglionic sympathetic neurons running to the smooth muscular walls of the viscera. However, some of these preganglionic neurons pass right on through this second ganglion and into the adrenal medulla. Here they synapse with the highly-modified postganglionic cells that make up the secretory portion of the adrenal medulla.
13.5 Drug Abuse
Drug abuse has a wide range of definitions related to taking a psychoactive drug or performance enhancing drug for a non-therapeutic or non-medical effect. Some of the most commonly abused drugs include alcohol, amphetamines, barbiturates, benzodiazepines, cocaine, methaqualone, and opium alkaloids. Use of these drugs may lead to criminal penalty in addition to possible physical, social, and psychological harm, both strongly depending on local jurisdiction.[2] Other definitions of drug abuse fall into four main categories: public health definitions, mass communication and vernacular usage, medical definitions, and political and criminal justice definitions.
CHAPTER 14: SENSES

14.1 Sensory Receptors and Sensations
There are four types of sensory receptors chemoreceptor’s, photoreceptors, mechanoreceptors, and the thermoreceptros. Sensory receptors initiate nerve impulses that are transmitted to the spinal cord and or the brain. Sensation occurs when nerve impulses reach the cerebella cortex. Perception is an interpretation of sensations.
14.2 Proprioceptors and Cutaneous Receptors
Proprioceptors are mechanoreceptors involved in reflex actions and they help maintain equilibrium and posture. Cutaneous Receptors are found in the skin, and they are for touch, pressure, temp, and pain.
14.3 Senses of Taste & Smell
Taste and smell are due to chemoreceptor’s that are stimulated by molecules in the environment. Smell and taste problems can have a big impact on our lives. Because these senses contribute substantially to our enjoyment of life, our desire to eat, and be social, smell and taste disorders can be serious. When smell and taste are impaired, life loses some zest. We eat poorly, socialize less, and as a result, feel worse. Many older people experience this problem. Smell and taste belong to our chemical sensing system (chemo sensation). The complicated processes of smelling and tasting begin when molecules released by the substances around us stimulate special nerve cells in the nose, mouth, or throat. These cells transmit messages to the brain, where specific smells or tastes are identified. Olfactory (small nerve) cells are stimulated by the odors around us-the fragrance from a rose, the smell of bread baking. These nerve cells are found in a tiny patch of tissue high up in the nose, and they connect directly to the brain. Gustatory (taste nerve) cells react to food or drink mixed with saliva and is clustered in the taste buds of the mouth and throat. Many of the small bumps that can be seen on the tongue contain taste buds. These surface cells send taste information to nearby nerve fibers, which send messages to the brain.
14.4 Sense of Vision
Eyes are organs that detect light. Different kinds of light-sensitive organs are found in a variety of animals. The simplest eyes do nothing but detect whether the surroundings are light or dark, which is sufficient for the entrainment of circadian rhythms but can hardly be called vision. More complex eyes can distinguish shapes and colors. The visual fields of some such complex eyes largely overlap, to allow better depth perception (binocular vision), as in humans; and others are placed so as to minimize the overlap, such as in rabbits and chameleons. e structure of the mammalian eye can be divided into three main layers or tunics whose names reflect their basic functions: the fibrous tunic, the vascular tunic, and the nervous tunic. The fibrous tunic, also known as the deoxiribose cartridge, which is the main carrying point of DNA, is the outer layer of the eyeball consisting of the cornea and sclera. The sclera gives the eye most of its white color. It consists of dense connective tissue filled with the protein collagen to both protect the inner components of the eye and maintain its shape. The vascular tunic, also known as the tunica vasculosa oculi, is the middle vascularized layer which includes the iris, ciliary body, and choroid. The choroid contains blood vessels that supply the retinal cells with necessary oxygen and remove the waste products of respiration. The choroid gives the inner eye a dark color, which prevents disruptive reflections within the eye. The nervous tunic, also known as the tunica nervosa oculi, is the inner sensory which includes the retina.
14.5 Sense of Hearing
Hearing depends on the ear, the cochlear nerve, and the auditory areas of the cerebral cortex. Is one of the traditional five senses. It is the ability to perceive sound by detecting vibrations via an organ such as the ear. The inability to hear is called deafness. In humans and other vertebrates, hearing is performed primarily by the auditory system: vibrations are detected by the ear and transduced into nerve impulses that are perceived by the brain. Like touch, audition requires sensitivity to the movement of molecules in the world outside the organism. Both hearing and touch are types of mechanosensation. The middle ear, separated from the external ear by the eardrum, is an air-filled cavity (tympanic cavity) carved out of the temporal bone. It connects to the throat/nasopharynx via the Eustachian tube. This ear-throat connection makes the ear susceptible to infection (otitis media). The eustachian tube functions to equalize air pressure on both sides of the eardrum. Normally the walls of the tube are collapsed. Swallowing and chewing actions open the tube to allow air in or out, as needed for equalization. Equalizing air pressure ensures that the eardrum vibrates maximally when struck by sound waves.
The Anatomy of the Ear
Adjoining the eardrum are three linked, movable bones called "ossicles," which convert the sound waves striking the eardrum into mechanical vibrations. The smallest bones in the human body, the ossicles are named for their shape. The hammer (malleus) joins the inside of the eardrum. The anvil (incus), the middle bone, connects to the hammer and to the stirrup (stapes). The base of the stirrup, the footplate, fills the oval window which leads to the inner ear. The inner ear consists of a maze of fluid-filled tubes, running through the temporal bone of the skull. The bony tubes, the bony labyrinth, are filled with a fluid called perilymph. Within this bony labyrinth is a second series of delicate cellular tubes, called the membranous labyrinth, filled with the fluid called endolymph. This membranous labyrinth contains the actual hearing cells, the hair cells of the organ of Corti. There are three major sections of the bony labyrinth: The front portion is the snail-shaped cochlea, which functions in hearing.
The rear part, the semicircular canals, helps maintain balance.
Interconnecting the cochlea and the semicircular canals is the vestibule, containing the sense organs responsible for balance, the utricle and saccule.
14.6 Sense of Equilibrium
A sensory system located in structures of the inner ear that registers the orientation of the head.