BIOD 152 AP2 Lab 2 Exam WITH COMPLETE SOLUTION

They are essential for our intellectual functioning (EX: prisoners in solitary confinement), personality development, and for life sustaining properties (EX: pain). How do we detect changes in the environment through our body? • Sensory Receptors- 1st line of reception. They are structures specialized to detect the senses and also to convert one form of energy into another. o EX: sensory receptor gathers in information from the environment, converts that energy into a nerve signal, and then that signal is sent to the brain for processing • Sense Organs: specialized structures composed of nervous tissue and other types of tissues that work together to enhance the responses we gather from the environment and the sensory receptors. RECEPTORS • Thermoreceptors- respond to heat or cold • Photoreceptors- respond to light (found in eyes) • Chemoreceptors- respond to a chemical like an odor or taste • Nociceptor- respond to tissue injuries (pain receptors) 2 broad types of senses: • General Sense- the receptors are widely distributed through the body; muscles, joints, organs o Respond to stimuli like general touch, pain, temperature. • Special Sense- limited to the head and innervated by the cranial nerves. o The sense organs that go along with the sense organs are much more complex, o EX: vision, hearing, taste, equilibrium, and smell AUDITORY SYSTEM • Responsible for senses of hearing and equilibrium (balance). • Cranial Nerve VIII (8) vestibulocochlear nerve: responsible for the auditory system • Ear is divided into 3 sections: outer, middle, and inner o All 3 are responsible for hearing but just the inner ear is responsible for equilibrium. o Outer and inner ear are more concerned with conducting the sound waves into the inner ear where they are processed as sound. • External Ear: a funnel for collecting sound o Auricle (Pinna)- the ear lobe; its shaped and supported by a very thick skin and elastic cartilage, no bone present. (no cartilage in the ear lobe at the bottom) o External Acoustic Meatus- opening in the auricle where the sound waves enter o Auditory Canal- formed out of the temporal bone of the skull; lined with thick skin and cartilage.  Guard hairs- present to protect the ear from any debris  Sebaceous glands- secrete oil  Cerumen- earwax; mixture of oil and dead skin; they will coat the guard hairs and help them do their job o Tympanic membrane- ear drum; marks the end of the outer ear and beginning of the middle ear  The surface that faces the auditory canal is a concave shape (turns in)  The inner surface is more convex (turns out) • Middle Ear: about 2-3 mm wide (very small) o Eustachian Tube: a.k.a auditory tube  Connects the middle ear to the nasopharynx. (which allows air into the middle ear) • Disadvantage: if there is an infection in the throat region or the upper respiratory tract, it can travel through the tube and into the ear.  Also permits pressure equalization. At rest-the tube is closed. When yawning or swallowing, it will open. o Auditory ossicles- 6 (3R/3L); smallest bones found in the body; they connect the tympanic membrane to the inner ear structures. Serve as a bridge for the sound waves to travel  Malleus (hammer)- attached to the inner surface of the tympanic membrane.  Incus (anvil); connects the malleus to the stapes  Stapes- connects to the inner ear • Covers a small partition called the Oval window (one of the structures that marks the beginning of the inner ear)   Round window- another small opening that marks the beginning of the inner ear. Its covered by the 2nd tympanic membrane. • Inner Ear: in the petris portion of the temporal bone of the skull; housed in a bony tissue called a bony Labyrinth and inside of that is the membranous labyrinth (a system of meshy tubes) o Perilymph- the fluid in between the bony and membranous labyrinths o Endolymph- fluid inside the membranous labyrinth o Vestibule- beginning of the labyrinth; contains some of the organs of equilibrium.  Semicircular canals- contain endolymph; anterior (1A), posterior (1B), lateral (1C). The movement of these fluids helps us to detect acceleration, or change in the rate of motion. It provides us with our sense of balance • Saccule- (#4) another sense organ; found more anterior • Utricle- (#3) They contain hair cells that with the movement of our head, help detect what position our head is in o Cochlea- the organ of hearing; small and snail shaped organ that helps to detect auditory sensation o