The Muscular System
•An organ system consisting of over 640 muscles •Main functions – •Allows movement in the body •Maintain posture •Stabilize joints Generates heat •Each muscle is a discrete organ made of skeletal muscle tissue, blood vessels, tendons, and nerves. •Also found in the heart, digestive organs, and blood vessels •Muscles serve to move substances throughout the body. Properties of muscles •Excitable or Irritable – capable of receiving and responding to stimulation by nerves (A) •Contractible – capable of shortening (B) •Extensible – can be stretched without damage (C) •Elasticity – able to return to resting shape after being contracted or extended (D) •Adaptability – can change in response to how it’s used, get bigger or smaller (E) Muscle Movement •Voluntary – controlled consciously by a person such as speaking, walking, writing •Involuntary – controlled by the unconscious part of the brain such as heartbeat, intestine moving waste, breathing Types of Muscles •Cardiac – form the wall of the heart and controls your heartbeat – involuntary •Smooth (visceral) –Weakest of all muscle tissues found in organs and perform unique functions like grinding, churning or moving – involuntary •Skeletal – connect to the skeleton in at least one place to move parts of bones closer to each other - voluntary Location of Muscle •Named for the structure near which a muscle is found •Muscle near the Tibia = Tibialis anterior Size of Muscle •Maximus – largest –Gluteus Maximus •Medius – medium -Gluteus Medius Direction of muscle •Rectus– muscle fibers run parallel to midline •Transverse – muscle fibers run perpendicular to midline •Oblique – muscle fibers run diagonal to midline Number of origins of muscle Number of tendons of origin. Prefix determines the number. •Biceps = two •Triceps = three •Quadriceps = four Shape of muscle •Deltoid –having a triangular shape •Trapezius – having a trapezoid shape •Rhomboideus – having a diamond shape •Serratus – having a saw-toothed shape Origin and Insertion •Origin – attached to less or immovable bone •Insertion – attached to the movable bone Connective Tissue Dense layered collagen fibers •Tendons - attach muscle to bone (A) •Facia - surrounds muscles and connects muscle to muscle (B) •Nervous system (3)working with the muscular (2)and skeletal system(1) is essential to the voluntary skeletal muscles. •If nerves are severed, they will not be able to produce muscle movement. Diseases of the Muscular System •Muscular Dystrophy – genetic disease that cause damage of muscle fiber causing weakness, immobility, and imbalance •Cerebral Palsy – congenital disorder that affects the posture, balance, and motor functions •Amyotrophic Lateral Sclerosis (ALS) – Lou Gehrig’s disease – neurodegenerative disease that causes loss of control on voluntary muscles. •Tendonitis – tendons get inflamed or irritated most common in wrists, elbows, shoulders and heels causing pain and swelling Time for Payback
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WEBSITE: TYPES OF BONE IN THE BODY: https://www.visiblebody.com/learn/skeleton/types-of-bones
TYPES OF SKELTETONS: Exoskeletons •External skeletal systems made up of chitin and calcium carbonate that provides protection to creatures such as insects and crustacea Endoskeletons •Internal skeleton of an animal (vertebrates), which is comprised of bone and cartilage Skeletal System •The primary function is to form a solid framework of bones and connective tissues to support the body. •Protects the body tissues and internal organs •Anchors the skeletal muscles •The main organs are bones and joints. 5 Main Functions of the Skeletal System •Support and Protect – Supports the softer tissues, provides points of attachment for most skeletal muscles, and provides protection for many of the body’s internal organs •Movement – The skeleton works with the muscular system to allow for movement. •Production of Blood cells – Red bone marrow inside some larger bones produces blood cells as well as many other types of cells. •Storage – The interior of the bone can store minerals (calcium, phosphorus)and chemical energy (fatty acids). •Homeostasis – Bones are able to absorb or release calcium into the blood to maintain a stable environment in the body. Human Body’s Bones •The adult human skeleton is made up of 206 bones •Classified as •Long bones •Short bones •Irregular bones •Flat bones •Sesamoid bones Parts of the Skeletal System Two main divisions: •Appendicular – 126 bones of the appendages (arms and legs)and the girdles (shoulder and pelvic) that connect them with the axial skeleton and provide support and flexibility •Axial – 80 bones along the axis of the body, which protect the internal organs Bone Tissues •Compact bone – makes up the dense outer layer of bone •Spongy bone – found inside bones and is lighter and less dense than compact bone because it is porous •Bone marrow – soft connective tissue that produces blood cells, found inside the pores of spongy bone •Periosteum – tough, fibrous membrane that covers and protects the outer surface of bone Joints Holds the skeleton together and supports movement Classified by: 1.Function – range of motion (synovial) 2.Structure – material that holds the bones and joints together The skeletal system and muscular system work in conjunction to allow our body to move. •Muscles are attached to bones with tendons and ligaments. •When the muscle is contracted, the skeletal system can move. Connective Tissue Dense layered collagen fibers Ligaments •Attach bone to bone (A) Tendons •Attach muscle to bone (B) Diseases of the Skeletal System •Osteoporosis – loss of bone tissue particularly in elderly (A) •Osteomalacia – softening of bones associated with vit. D deficiency (B) •Arthritis – inflammatory disease that damages joints and surrounding tissue (C) •Scoliosis – side to side curve in the spine, becomes evident during adolescence •Bone cancers – 1% of all cancers are found in the bone •Breaks, strains, and fractures – takes 10 -6 lbs. of pressure to break an average bone
Nitrogen •Makes up about 78% of the atmosphere •Nitrogen gas is colorless, odorless, and generally inert or unreactive. •Most organisms can’t use unreactive N2. •Nitrogen compounds are vital components of foods, fertilizers, and explosives. Nitrogen Compounds •Nitrogen must be converted to more chemically available forms for plants and animals to use. •N2 – atmospheric nitrogen •N2O – nitrous oxide •NH3 – ammonia •NH4 – ammonium •NO2 – nitrites •NO3 - nitrates Nitrogen Cycle •Describes how nitrogen (N2) moves between various reservoirs: •Plants •Animals •Bacteria •Atmosphere •Soil •Describes the processes by which those reservoirs exchange N2 into usable nitrogen Vocabulary •Reservoir – A place where anything is kept or stored. •Process - A series of actions that produce something or that lead to a particular result. Processes in the Nitrogen Cycle •Fixation •Nitrification •Assimilation •Ammonification •Denitrification Nitrogen Fixation •Process where N2 molecules in the air break apart and combine with other atoms to form ammonium or NH4. •Plant nutrients are the result of nitrogen fixation. •Nitrogen gets “fixed” when it combines with oxygen or hydrogen. 3 - Ways to “fix” Nitrogen 1.Atmospheric Fixation 2.Industrial Fixation 3.Biological Fixation Atmospheric Fixation •Energy from lightning breaks N2 molecules apart. •N2 atoms combine with oxygen forming nitrogen oxides (N2O). •N2O dissolves in rain, forming Nitrates (NO3). •Nitrates are carried to the ground by rain. Industrial Fixation •Under certain conditions industrial plants combine nitrogen and hydrogen to form ammonia (NH3). •Ammonia is used as a fertilizer. Biological Fixation •Free Living Bacteria – highly specialized bacteria live in soil and combines N2 with H2. •Bacteria fixes 30% of available N2. •Produces ammonium (NH4) •This is where most nitrogen fixing is completed. •Symbiotic Relationship Bacteria - bacteria live in root nodules of pulse family plants. •Provides plants with ammonia in exchange for the plant’s carbohydrates and a protected home. •Legumes fix 70% of available N2. Nitrification •Nitrifying bacteria in the ground combine ammonia with oxygen to form nitrites (NO2). •Another group of nitrifying bacteria converts nitrites to nitrates (NO3). •Green plants absorb nitrates (assimilation),which are eaten by consumers. Assimilation •NH4 Organic N2 •Organic N2 compounds –amino acids, chlorophyll, and nucleic acid •Produced when plants take up NH4 •Organisms near top of food chain eat plants taking up biologically fixed nitrogen. Ammonification •Part of the decay process •When a plant or animal dies or leaves waste products, decomposers like fungi and bacteria turn N2 back into ammonia . •Ammonia is absorbed and stored in the soil. Denitrification •Converts nitrates (NO3) in the soil to N2 •Denitrifying bacteria live deep in swampy sediments where O2 is not easily accessible. •These bacteria take O2 from nitrates leaving the byproduct nitrogen gas (N2). •Returns nitrogen to the atmosphere to begin the cycle again Human Impact on the Nitrogen Cycle •Cause - Use of synthetic (man made) nitrogen fertilizers •Effect - Fixes more nitrogen than all natural sources combined Negative Consequences of Excess Nitrogen •Excess N2 in groundwater can lead to cancer in humans and respiratory distress in infants. •Excess N2 in surface water can lead to nutrient over-enrichment causing: • fish-kill events • algal blooms changes in species •Creates the smog-component nitric oxide (NO)and nitrous oxide (N2O) •Can result in acid rain •Allows invasion by non-native plants into ecosystems •Creates the smog-component nitric oxide (NO)and nitrous oxide (N2O) •Can result in acid rain •Allows invasion by non-native plants into ecosystems
Symbiosis
•A type of close and long-term biological interaction between two different species. •Three types of symbiosis: 1.Commensalism 2.Parasitism 3.Mutualism Commensalism •A type of symbiosis occurring between individuals of two different species •One species obtains food or other benefits from the other without either harming or benefiting the latter. Commensalism (Ex.) •Remora and zebra shark – The remora attaches itself to the shark and rides along, saving its energy. •Cattle egrets and cattle – The cattle’s movements stir up insects on which the egrets feed. •Epiphytes are plants that grow on woody plants. They get nutrients from the air, so they only use the plant for support and access to the sun. Parasitism •A type of symbiosis occurring between individuals of two species. •One organism is harmful to the other but may not kill the other organism. •The organism being harmed is called the host. Parasitism (Ex.) •Pinworm – A small, thin, white roundworm that can negatively affect people. •Head Lice – A small, wingless, blood-sucking insect that lives in the hair and feeds off the scalp. •Scabies – A skin infestation caused by a mite, which causes a rash. Mutualism •A type of symbiosis occurring between individuals of two species •Each of the organisms benefits the other. Mutualism (Ex:) •Oxpeckers and zebras or rhinos – The birds live on the animal and eat all the bugs and parasites. •Flowers and bees – Bees get food and plants are pollinated. • Sea anemones and clownfish – Clownfish have a safe place to live and anemones are protected from their predators, the butterfly fish. |
Erik E. Mason
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