Semester 2 Final Review Nervous System

Semester 2 Final Review

Nervous System • What makes up the central nervous system? – Brain and spinal cord • What makes up the peripheral nervous system? – Nerves • What is the difference between a neuron and a neuroglia? – Neurons are the conducting cells, while neuroglia are the supporting cells.

Nervous System Cont. • What are the 3 types of neurons? – Motor: • Efferent – Sensory: • Afferent – Association: • Interneuron

Types of Reflexes • Cranial Reflexes – Cranial nerves • Eyes • Head movements • Spinal Reflexes – Spinal nerves • Hand movement • Hand-eye coordination

Nervous System Cont. • Sympathetic • Mobilizes body during extreme situations (fear, exercise, rage) • “Fight-or-flight” • Prepares body to cope with some threat • Activation results in increased heart rate and blood pressure

Nervous System Cont. • Parasympathetic • “House keeper” system • In control most of the time • Maintains homeostasis by seeing that normal digestion and elimination occur and that energy is conserved

Nervous System Cont. • Nerve Conduction – Resting membrane potential – Depolarization – Refractory period

Senses • Eye – Myopia • Nearsighted – Hyperopia • Farsighted – Presbiopia • Poor vision due to age

Parts of the Eye • Cornea – Protective window of the eye • Iris – Colored part of the eye – Controls amount of light let into the eye • Lens – Focuses the image onto the retina • Retina – Layer of the eye that contains the photoreceptors

Pathway Through Eye • Cornea aqueous humor (through pupil) aqueous humor lens vitreous humor retina

Pathway Through Ear • Pinna external auditory canal tympanic membrane malleus incus stapes oval window vestibule cochlea vestibulocochlear nerve

Inner Ear • Sound = Cochlea • Equilibrium= Vestibule and semi-circular canals

Receptors • Chemoreceptors = Chemicals (Taste Buds & Olfactory Bulbs) • Mechanoreceptors = proprioceptors (Joints, Muscles, & Ligaments) • Photoreceptors (EYE) Rods = Black & White, See in dark Cones = Color, Sharper image

Receptors Cont. • Meissner’s corpuscles – fine touch – Hairless skin • Fingers, palms, soles, lips, external genitals • Krauses’s end bulbs – Like Meissner’s, but in mucous membranes of mouth • Merkel’s discs - less common – Epidermis – Light touch receptors • Pacinian corpuscles – deep pressure – Deep regions of skin, around joints and tendons, in some visceral organs • Ruffini’s corpuscles – deep & continuous pressure – Deep in dermis, hypodermis, and joint capsules

Receptors Cont. • Muscle spindles – Receptors between a tendon and a skeletal muscle – Detect when a muscle is stretched and initiates a reflex that resists that stretch – Helps maintain muscular tone and body posture

Muscular System • Sliding filaments: – Thick: myosin – Thin: actin, troponin & tropomyosin • Energy Sources: – ATP – Creatine Phosphate – Fat – Protein

Muscular • Ca+ – Breaks down ATP – Bind to troponin to move tropomyosin away from actin binding sites. • Tendon vs. Ligament – Tendon = muscle – Ligament = joint stability • Nueurotransmiter = Ach (acetylcholine)

Muscular • Origin = non moving • Insertion = moving • Tetanus Contraction: – Twitch: single contraction – Treppe: contraction after contraction with rest – Wave summation: contraction before complete relaxation – Incomplete – Complete

Blood • Transportation of oxygen • Protection of the body • Regulation: – Body temperature by absorbing and distributing heat – Acid-base balance of body fluids • Buffers neutralize harmful effects of too much CO 2, lactic acid, etc – Normal p. H in body tissues – Adequate fluid volume in the circulatory system

Blood • Formed elements – RBCs • Carries O 2 and CO 2 , Round Doughnut Shaped – WBCs • Responsible Immune System, 3 types – Platelets • Form clots • Fragments of cells

Blood • Hemoglobin : – Oxygen carrying part of the RBC • Formation: – erythropoiesis – Red Bone Marrow • Universal Donor –O • Universal Recipient – AB

Diseases of the Blood • Anemia = Low iron in the blood • Embolus = Loose blood clot • Hemophilia = Genetic bleeding disorder, low clotting ability • Leukemia = Cancer of the Bone Marrow • Polycythemia = increased RBCs • Sickle Cell Anemia = RBCs sickle shaped, O 2 • Leukopenia = WBCs • Thrombus = Blood Clot

Cardiovascular System • Parts of the Heart: – Atrium • Receives blood from vessels – Ventricle • Receives blood from atrium and pumps blood out heart – AV Valves • Separate atrium from the ventricles, prevents backflow, and causes heart sounds – SA Valves • Separates ventricles from the blood vessels, prevents backflow

CV System • Parts of the blood vessels: – Arteries • Large vessels that transport blood away from the heart – Arterioles • Smaller vessels that transport blood away from the heart – Capillaries • Smallest of all vessels, Site of gas and nutrient exchange – Venuoles • Bigger vessels that take blood to the heart – Veins • Largest vessels that take blood to the heart, contains valves to help with blood flow up towards the heart

Heart Sounds and BP • Lub – AV Valves closing • Dup – SL valves closing • Diastolic – ventricular relaxation • Systolic – ventricular contraction

Respiratory System • Sound = air vibrates strings as it travels past them. • Respiratory control center = medulla & pons • Collapsed Lung – Intrapleural pressure = outer pressure

Respiratory System • Nose pharynx larynx, trachea bronchioles alveoli reverse • Pulmonary Respiration – inspiration = breathing in – expiration = breathing out • External Respiration – Exchange of gasses between alveoli and capillaries • Internal Respiration – Exchange of gasses between capillaries and body cells

Respiratory System • Tidal volume (TV) – Normal quiet breathing moves 500 ml in and out of the lungs each breath • Inspiratory reserve volume (IRV) – Maximum amount of air that can be inhaled forcibly over the tidal volume • Expiratory reserve volume (ERV) – Maximum amount of air that can be exhaled forcibly over the tidal volume • Vital capacity (VC) – Total amount of exchangeable air – The sum of the TV + IRV + ERV

Respiratory System • Residual volume (RV) – The amount of air remaining in the lungs following a forced expiration • Total lung capacity – Total amount of air contained in the fully inflated respiratory system – The sum of the VC + RV • Dead space volume – Air that enters respiratory tract and never reaches alveoli

Respiratory System • Factors that affect breathing: – Chemicals • chemoreceptors in arteries detect levels of O 2, CO 2, and H+ in the blood – Stretch Receptors – Mental State – Physical factors • Talking, coughing, exercise