BIOL 2401 Fundamentals of Anatomy and Physiology Mrs. Willie Grant wgrant4@alamo.edu (210) 643-8968 Chapter 17: The Special Senses Chapter 18: The Endocrine System

An Introduction to the Special Senses Learning Outcomes 17-1 Describe the sensory organs of smell, trace the olfactory pathways to their destinations in the brain, and explain the physiological basis of olfactory discrimination. 17-2 Describe the sensory organs of taste, trace the gustatory pathways to their destinations in the brain, and explain the physiological basis of gustatory discrimination. 17-3 Identify the internal and accessory structures of the eye, and explain the functions of each. 17-4 Explain color and depth perception, describe how light stimulates the production of nerve impulses, and trace the visual pathways to their destinations in the brain. 17-5 Describe the structures of the external, middle, and internal ear, explain their roles in equilibrium and hearing, and trace the pathways for equilibrium and hearing to their destinations in the brain.

An Introduction to the Endocrine System Learning Outcomes 18-1 Explain the importance of intercellular communication, describe the mechanisms involved, and compare the modes of intercellular communication that occur in the endocrine and nervous systems. 18-2 Compare the cellular components of the endocrine system with those of other systems, contrast the major structural classes of hormones, and explain the general mechanisms of hormonal action on target organs. 18-3 Describe the location, hormones, and functions of the pituitary gland, and discuss the effects of abnormal pituitary hormone production. 18-4 Describe the location, hormones, and functions of the thyroid gland, and discuss the effects of abnormal thyroid hormone production. 18-5 Describe the location, hormone, and functions of the parathyroid glands, and discuss the effects of abnormal parathyroid hormone production.

An Introduction to the Special Senses Five Special Senses Olfaction Gustation Vision Equilibrium Hearing

Figure 17-1a The Olfactory Organs Olfactory Pathway to the Cerebrum Olfactory epithelium Olfactory nerve fibers (N I) Olfactory bulb Olfactory tract Central nervous system Smell (Olfaction) Olfaction Organs provide sense of smell. They are located in nasal cavity. 1 What is the life-span of an olfactory receptor? Cribriform plate Superior nasal concha The olfactory organ on the left side of the nasal septum 5

17-2 Taste (Gustation) Taste Buds—associated with epithelial projections (lingual papillae) on superior surface of the tongue Three Types of Lingual Papillae Filiform papillae Fungiform papillae Circumvallate papillae

Figure 17-4a External Features and Accessory Structures of the Eye (Vision) Accessory Structures of the Eye (provide protection, lubrication and support) Include: The palpebrae (eyelids) and the lacrimal apparatus The palpebrae (eyelids) The lacrimal apparatus Eyelashes Pupil Lateral canthus Palpebra Sclera Palpebral fissure Medial canthus Lacrimal caruncle Corneal limbus Gross and superficial anatomy of the accessory structures 7

Muscles of the Eye

17-3 The Eye Eyeball Is hollow and divided into two cavities Large posterior cavity Smaller anterior cavity

Intermediate vascular layer Deep inner layer 17-3 The Eye Three Layers of the Eye Outer fibrous layer Intermediate vascular layer Deep inner layer 2 What are the components of the fibrous tunic and vascular tunic?

Outer layer called pigmented part Inner called neural part (retina) 17-3 The Eye The Inner Layer Outer layer called pigmented part Inner called neural part (retina) Contains visual receptors and associated neurons Rods and cones are types of photoreceptors Rods—Do not discriminate light colors/Highly sensitive to light Cones—Provide color vision Densely clustered in fovea, at center of macula 3 What the two types of photoreceptors, and how do their functions differ?

The Chambers of the Eye Aqueous Humor Vitreous boody

Light Refraction (bending of light by retina and lens) The Eye Accommodation (shape of lens changes to focus image on retina) Astigmatism Condition where light passing through cornea and lens is not refracted properly Visual image is distorted Visual acuity Clarity of vision “Normal” rating is 20/20 Light Refraction (bending of light by retina and lens)

4 What is presbyopia?

17-4 Visual Physiology The Visual Pathways Begin at photoreceptors and ends at visual cortex of cerebral hemispheres Message crosses two synapses before it heads toward brain

17-5 The Ear The External Ear Auricle—surrounds entrance to external acoustic meatus and protects opening of canal as well as provides directional sensitivity. External acoustic meatus—ends at tympanic membrane (eardrum) Tympanic membrane—is a thin, semitransparent sheet that separates external ear from middle ear Ceruminous glands—Integumentary glands along external acoustic meatus that secretes waxy material (cerumen wich keeps foreign objects out of tympanic membrane and slows growth of microorganisms in external acoustic meatus.

17-5 The Ear The Middle Ear Also called tympanic cavity Communicates with nasopharynx via auditory tube Permits equalization of pressures on either side of tympanic membrane Encloses and protects three auditory ossicles Malleus (hammer) Incus (anvil) Stapes (stirrup)

17-5 The Ear The Internal Ear Contains fluid called endolymph Bony labyrinth surrounds and protects membranous labyrinth Subdivided into: Vestibule Semicircular canals Cochlea

Figure 17-21 The Anatomy of the Ear External Ear Middle Ear Internal Ear Elastic cartilages Auditory ossicles Oval window Semicircular canals Petrous part of temporal bone Auricle Facial nerve (N VII) Vestibulocochlear nerve (N VIII) Bony labyrinth of internal ear Cochlea Tympanic cavity Auditory tube To nasopharynx External acoustic meatus Tympanic membrane Round window Vestibule 5 What structures separate the middle ear from the internal ear? 20

18 The Endocrine System

An Introduction to the Endocrine System Regulates long-term processes Growth Development Reproduction Uses chemical messengers to relay information and instructions between cells 6 What is the basic difference between endocrine glands and exocrine glands?

18-2 Hormones Classes of Hormones Hormones can be divided into three groups Amino acid derivatives Peptide hormones Lipid derivatives Secretion and Distribution of Hormones Hormones circulate freely or travel bound to special carrier proteins

18-2 Structural Classification of Hormones http://resources.mhs.vic.edu.au/science/resources/hormones.htm http://resources.mhs.vic.edu.au/science/resources/hormones.htm

18-9 Endocrine Tissues of Other Systems Many Organs of Other Body Systems Have Secondary Endocrine Functions Intestines (digestive system) Kidneys (urinary system) Heart (cardiovascular system) Thymus (lymphatic system and immunity) Gonads (reproductive system)

18-10 Hormone Interactions Hormones Interact to Produce Coordinated Physiological Responses When a cell receives instructions from two hormones at the same time, four outcomes are possible Antagonistic effects - opposing Synergistic effects - additive Permissive effects - one hormone is necessary for another to produce effect Integrative effects - hormones produce different and complementary results

18-10 Hormone Interactions Hormones Important to Growth Growth hormone (GH) Thyroid hormones Insulin PTH and calcitriol Reproductive hormones

18-10 Hormone Interactions The Hormonal Responses to Stress General Adaptation Syndrome (GAS) Also called stress response How body responds to stress-causing factors Is divided into three phases Alarm phase Resistance phase Exhaustion phase 9 What is the basic difference between the stress response and homeostasis?

18-10 Hormone Interactions The Effects of Hormones on Behavior Hormone changes Can alter intellectual capabilities, memory, learning, and emotional states Affect behavior when endocrine glands are over-secreting or under-secreting Aging and Hormone Production Causes few functional changes Decline in concentration of: Growth hormone Reproductive hormones