Cerebrum. The largest part of the brain; divided into two halves called.

Transcription

1 Parts of the Brain

2 The Nervous System Function: The nervous system controls and coordinates the functions throughout the body and responds to external and internal stimuli.

3 Cerebrum The largest part of the brain; divided into two halves called. hemispheres Carries out thought processes involved with learning,, memory language,, speech voluntary body movements and sensory perception. The folds and grooves increase surface area & allow more complicated thought processes. Meninges 3 layers of connective tissue to protect the brain & spinal cord. Pg. 1

4 Lobes: Frontal Lobe Functions: Motor Functions Higher Order Functions Planning Reasoning Judgment Impulse Control Memory

5 Lobes: Parietal lobe function: Cognition Information Processing Pain and Touch Sensation Spatial Orientation Speech Visual Perception

6 Lobes: Temporal Lobe Function: Auditory Perception Memory Speech Emotional Responses Visual Perception

7 Lobes: Occipital Lobe Function: Visual Perception Color Recognition

8 back balance Cerebellum Located in the of the brain. Controls, posture, &. coordination Responsible for the smooth and coordinated movement of skeletal. muscle Involved with motor skills, like playing the or riding a. piano bike Pg. 1

9 Brain Stem Connects the to the 2 regions: brain signals pons -Relays between the and the. cerebrum breathing rate Also helps control. spinal cord cerebellum Pg. 1

10 Relays signals between the brain and the. spinal cord Helps control rate, breathing rate & blood. pressure Also responsible for the, swallowing, gagging, vomiting, coughing and sneezing reflexes. Medulla oblongata heart

11 Spinal Cord Nerve column extends from the brain to the. lower back Spinal nerves extend from the spinal cord to parts of the body & connect them to the. Central nervous system Reflexes are processed by the spinal cord.

12 Thalamus Receives messages from all sensory receptors throughout body Relays info. to proper region of cerebrum for further processing Pg. 1

13 Essential for maintaining. homeostasis Hypothalamus Regulates body temperature,, thirst appetite, & water balance. Partially regulates blood, pressuresleep, aggression,, fear and sexual behavior. Coordinates activities of nervous and endocrine systems Pg. 1

14 Master Gland Pituitary gland Produces hormones that regulate other glands Produces hormone that stimulates growth

15 Neurons Cells that carry messages throughout the nervous system 3 types: - 1 st : sensory neurons- carry impulses from sense organs to brain; 2 nd : motor neurons- carry impulses from brain to muscles/glands. 3 rd : Interneuron: carry impulses between sensory and motor neurons (connects them)

16 (neurons vs. nerves)

17 Spinal cord cross-section

18 Parts of a neuron 1 st cell body: largest part, contains nucleus and most of cytoplasm most metabolic activity of cell occurs here

19 Parts of a neuron 2 nd dendrites: spread out from cell body; short, branched extensions; carry impulses toward the cell body

20 Parts of a neuron 3 rd axons: (transmit/send signals) long fiber that carries impulses away from cell body.

21 Parts of a neuron 4 th myelin sheath: (lipids) insulating membrane around axon; helps impulse travel faster & smoother 5 th Schwann cells- cells of the myelin sheath One neuron can have dozens of dendrites but only one axon.*{bonus?}*

22 (The structure of neurons can vary)

23 Nerve Impulses Messages carried by the nervous system are electrical signals called impulses. Impulse begins: neuron stimulated by environment or another neuron (impulse travels rapidly away from cell body) moves toward axon terminals and into the synapse.

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25 Synapse: the location at which a neuron can transfer an impulse to another cell

26 Neurotransmitter: chemicals used by a neuron to transmit an impulse across a synapse to another cell

27 Brian & Spinal Cord 31 pairs of Nerves Comes of the spinal cord Controls a reflex The Gas pedal The Brakes

28 The Sensory Organs Touch Response to a mechanical stimulus. The skin is the largest sensory organ. Sensory receptors detect pressure, pain, heat, cold.

29 The Sensory Organs Response to a _chemical stimulus. Sensory receptor cells are bathed in mucus and respond to different chemicals

30 The Sensory Organs Response to a _chemical_stimulus. Sensory receptors called _taste buds_ are located on the _tongue. Detect sweet, sour, salty, bitter

31 The Sensory Organs Response to a _light stimulus. Cornea Light first passes through the _cornea, a transparent, protective covering which begins _focusing the light. The light then enters a chamber filled then enters a chamber filled with watery fluid called the _aqueous humor. _Pupil - Hole that light passes through. The size of the pupil is controlled by a ring of muscles known as the _iris. _Lens - Completes focusing of the light ray. There is also a thick jelly-like substance to help maintain the shape of the chamber known as the _vitreous humor_.

32 The Sensory Organs Retina Nerve tissue at the back of the eyeball that converts light energy to an _electrical impulse_. Made up of two types of cells: Rods - Cells that detect _shape & movement; are stimulated even in _dim light. Cones - Cells that detect _color; provide a _sharp image; require _bright light for stimulation. Optic Nerve - Transmits the impulse to the _brain. Additional Structures Sclera - _ White of the eye ; continuation of the _cornea Choroid - Layer of blood vessels that _nourish the eye.

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34 The Sensory Organs Response to a mechanical stimulation - sound waves Sound waves first enter the outer ear and are funneled into the auditory canal. Causes vibrations of a membrane known as the tympanic membrane or eardrum. Vibrations are then passed to three tiny bones hammer anvil stirrup The vibrations are transferred from the stirrup to another membrane known as the oval window.

35 The Sensory Organs Finally, vibrations are converted to an electrical impulse in the cochlea, a snail-shaped sensory structure filled with fluid and tiny hairs. These hairs are pushed back & forth, producing electrical impulses. Nerve impulse is transmitted by way of the auditory nerve to the brain

36 The Sensory Organs Other parts of the Ear: The semicircular canals They play no role in hearing; they help maintain balance. The semicircular canals consist of 3 fluid-filled canals oriented at different angles to each other Eustachian Tube drainage into sinus cavities Round Window relives pressure in the ear

37 Effects of Drugs A drug is any substance, other than food, that changes the structure of function of the body Notes are filled in your binder

38 DISEASES & CONDITIONS OF THE NERVOUS SYSTEM A. Meningitis Infection of _meninges. Symptoms include severe headache, stiff neck, fever. B. Alzheimer s Disease Disease of the elderly in which there is a build-up of protein plaques on neurons in the _cerebrum. Results in progressive death of neurons. Symptoms include memory loss, confusion, emotional disturbances. C. Parkinson s Disease Disabling disease due to a decrease in _neurotransmitters which transmit impulses for movement. Results in tremors, muscle rigidity. D. Multiple Sclerosis Disease of young adults characterized by destruction of _myelin_sheaths of neurons. Normal nerve function is impaired. Symptoms include numbness, muscle weakness, muscle fatigue, vision problems.

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40 Heart Chart Veins & Arteries: Blood flow in which direction Oxygen Poor or Rich Superior Vena Cava From body to heart Pulmonary Veins Inferior vena Cava Aorta Pulmonary arteries Chambers: Either receives or pumps blood form/to???? Right Atrium Left Atrium Right Ventricle Left Ventricle Valves: Prevents blood from going back into the: Pulmonary valve Tricuspid Aortic Mitral (bicuspid)

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42 Blood Vessels Arteries carry blood from away heart carry oxygen- rich blood (except for ) pulmonary artery Have thick elastic walls surrounded by muscle smooth is Aorta the largest artery in the body

43 Blood Vessels Capillaries smallest blood vessels Walls are only 1 cell thick This is where the exchange of nutrients & wastes takes place

44 Blood Vessels Veins Collect blood and carry it towards to the heart Carry oxygen- poor blood (except for pulmonary veins) Have thinner and less elastic walls Have to valves keep blood flowing to heart and not backwards Contraction of skeletal muscles help to move blood toward the heart The is vena cava the largest vein in the body

45 Blood Vessels

46 Blood Pressure: the force of blood on the walls of the arteries relaxes Falls when the heart Heart is always under pressure in order to keep blood flowing through it Regulated by autonomic nervous system kidneys also regulate blood pressure by controlling amount of water in blood- when blood pressure is high, more water is ; removed this reduces blood volume

47 Blood Pressure Blood against the blood vessel s walls The systolic pressure refers to the pressure recorded while the ventricles pump the blood. The diastolic pressure refers to the pressure recorded as the ventricles fill with blood. A normal blood pressure is 120/80

48 Blood Pressure High blood pressure forces heart to work harder people more likely to develop heart disease obesity is one cause controlled by weight control, exercise, and diet

49 Blood Makes up 8% of body 4 to 6 liters Components of blood red 45% = blood cells, white blood cells and platelets 55% = plasma water mostly - 90% contains salts, sugars, and plasma proteins

50 What does blood contain? 50% Water 45% Erythrocytes 4% Plasma with Substances 1% Leukocytes + Platelets

51 Blood Plasma proteins Several types of proteins that fight, infection regulate osmotic pressure & help blood clotting Red blood cells- erythrocyte- RBC hemoglobin contain - iron containing protein that increases oxygen -carrying ability of RBC s produced in bone red marrow mature RBC s have no nucleus so can t divide live about 120 days when they die they are destroyed & recycled by spleen

52 Blood White blood cells leukocytes- WBC fewer in numbers than RBC produced in bone marrow live for many months or years more than 20 different types guard against, infection fight, pathogens and attack bacteria an increase in the number of WBC s is an indication the body is fighting an infection Platelets fragments of cells when blood vessel is injured, platelets become sticky; they cluster around the wound and release a series of chemicals that start a clotting reaction a protein called forms fibrin a net that traps RBCs and forms a

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54 Blood Clotting Break in Capillary Wall Blood vessels injured Clumping of Platelets Platelets clump at the site and release thromboplastin. Thromboplastin converts prothrombin into thrombin.. Clot Forms Thrombin converts fibrinogen into fibrin, which causes a clot. The clot prevents further loss of blood..

55 DISORDERS ATHEROSCLEROSIS Fatty deposits called plaque Builds up in walls of arteries Obstructs flow Also a risk if clot breaks free and blocks flow elsewhere

56 Disorders (cont) Heart Attack Atherosclerosis in coronary artery Heart muscle begins to die Symptoms Nausea Shortness of breath Severe chest pain IMMEDIATE MEDICAL ATTENTION NECESSARY

57 Disorders Continued Anemia Caused by either a deficiency of red blood cells or hemoglobin in RBCs. Less oxygen available for cells results in a lack of energy due to decreased ATP production.

58 Disorders (cont) Hypertension High blood pressure Hearts works harder than necessary Increases risk of heart attack or stroke

59 Disorders (cont) Stroke Blood clot gets stuck in blood vessels leading to brain Brain cells die due to lack of oxygen Or blood vessel burst Can lead to paralysis, loss of ability to speak death

60 THE RESPIRATORY SYSTEM The function of the respiratory system is to bring about the exchange of _O 2 and _CO 2. I. THE RESPIRATORY PASSAGEWAY A. Airway to the Lungs _Nasal Cavity - Begin the process of warming, filtering, moisturizing the air _Pharynx - Upper throat

61 THE RESPIRATORY SYSTEM Larynx - Also known as the voicebox. Bands of tissue that tighten and vibrate to create sound when air passes through. Attached to the larynx is a flap of tissue called the _epiglottis. The epiglottis closes when food is swallowed to prevent food from entering the _respiratory tract.

62 THE RESPIRATORY SYSTEM _Trachea - Airway supported by bands of _cartilage to prevent it from _collapsing when air passes in and out

63 THE RESPIRATORY SYSTEM _Bronchi - Trachea divides into two tubes leading to each _lung Trachea and bronchi are lined with _cilia and cells that secrete _mucus. The mucus traps _pathogens and other contaminants. The cilia beat _upwards to sweep contaminants toward the _pharynx.

64 THE RESPIRATORY SYSTEM Inside the Lungs _Bronchioles - Smaller branches leading from bronchi. Contain _smooth muscle tissue to facilitate air flow. _Alveoli - The bronchioles end in millions of tiny sacs called alveoli. Site for the exchange of _O 2 and _CO 2. Each alveolus is surrounded by a _capillary to allow _ O 2 to _diffuse from the lung to the blood to be delivered to cells for _cellular respiration and _ CO 2 to diffuse from the blood to the lung to be exhaled.

65 THE RESPIRATORY SYSTEM

66 THE RESPIRATORY SYSTEM Pathway of Oxygen: Pathway of Carbon Dioxide:

67 THE RESPIRATORY SYSTEM BREATHING A. Inhalation & Exhalation - Breathing is a _passive response to a change in _pressure in the chest cavity. Although there are no _muscles attached to the lungs, the change in pressure is caused by the contraction of muscles involved in breathing. Diaphragm Dome-shaped muscle located below (but not attached to!) the _lung. When the diaphragm _contracts, it flattens which _increases the volume of the chest cavity and _decreases the pressure. Air rushes into the lungs. Intercostal Muscles Also contract to further _increase volume of chest cavity As the diaphragm and intercostal muscles relax, volume of the chest cavity _decreases, and the _elasticity of the lungs help force the air back out.

68 THE RESPIRATORY SYSTEM B. Control of Breathing Breathing is controlled by the _medulla oblongata, which is monitoring the concentration of _CO 2 in the blood.

69 Disorders of Resp. System Emphysema Progressive disease in which _alveoli lose their elasticity. Affected individuals cannot fully exhale which reduces ability to inhale. O 2 and CO 2 do not diffuse properly. All _smokers eventually develop emphysema.

70 Disorders of Resp. System Asthma Allergic reaction that affects _smooth muscles of _bronchioles. They _constrict which prevents airflow into the _alveoli. Gas exchange is reduced.

71 Disorders of Resp. System Smoking Three dangerous substances found in cigarette smoke are nicotine, carbon monoxide, and tar. Nicotine stimulant that increases heart rate, constricts blood vessels; _increases blood pressure. Carbon monoxide binds to hemoglobin ; reduces oxygen-carrying capacity of _hemoglobin blood cells.

72 Disorders of Resp. System Also, combination of nicotine & CO paralyzes _cilia lining respiratory tract resulting in frequent respiratory _infections. Tar carcinogen; smokers have a much higher incidence of lung cancer.