1、By: Christina, Sunny, & Ann,Skeletal, Muscular, Nervous, and Integumentary Systems,The Skeletal System,Animal skeletons function in support, protection, and movement,Most land animals would sag from their own weight if they had no skeleton to support them. Even an animal that lives in water would be
2、come a formless mass with no framework/skeleton to support and maintain its shape. In many animals, a hard skeleton provides protection for soft tissues. For example, the vertebrate skull protects the brain, and the ribs of terrestrial vertebrates form a cage around the heart, lungs, and other inter
3、nal organs. Skeletons also aid in the movement by giving muscles something firm to work against.,Skeletons,There are three main types of skeletons:Hydrostatic skeletons Exoskeletons Endoskeletons,Hydrostatic Skeletons,S,A Hydrostatic skeleton consists of fluid held under pressure in a closed body co
4、mpartment.,This is the main type of skeleton in most cnidarians , flatworms, nematodes, and annelids. These animals control their form and movement by using muscles to change the shape of fluid filled compartments. Among cnidarians, a hydra can elongate by closing its mouth and using contractile cel
5、ls in the body wall to constrict the central gastrovascular cavity. In planarians, the interstitial fluid is kept under pressure and functions as the main hydrostatic skeleton. The planarian movement results mainly from muscles in the body wall exerting localized forces against the hydrostatic skele
6、ton. Nematodes hold fluid in their body cavity, which is a pseudocoelom. In annelids and earthworms, the coelomic fluid functions as a hydrostatic skeleton. The coelomic cavity is divided by septa between the segments in many annelids, allowing the animal to change the shape of each segment individu
7、ally, using both circular and longitudinal muscles. These annelids use their hydrostatic skeleton for peristalsis.,Exoskeletons,E,An exoskeleton is a hard encasement deposited on the surface of an animal,As an animal grows, it enlarges the shell by adding to its outer edge. Clams close their hinged
8、shell using muscles attached to the inside of this exoskeleton. The jointed exoskeleton of arthropods is a cuticle, a non-living coat secreted by the epidermis. Muscles are attached to knobs and plates of the cuticle that extend into the interior of the body. About thirty to fifty percent of the cut
9、icle consist of chitin, a polysaccharide similar to cellulose. Fibrils of chitin are embedded in a protein matrix, forming a composite material that combines strength and flexibility. Where protection is the most important, the cuticle is hardened with organic compounds that cross link the proteins
10、of the exoskeleton. Some crustaceans, such as lobsters, harden portions of their exoskeleton even more by adding calcium salts.,Endoskeleton,An endoskeleton consists of hard supporting elements, such as bones, buried within the soft tissue of the animal.,Endoskeletons of various complexity are found
11、: chordates, and echinoderms. An endoskeleton allows the body to move and gives the body structure and shape. A true endoskeleton is derived from mesodermal tissue. Such a skeleton is present in echinoderms and chordates. Echinoderms have an endoskeleton of hard plates called ossicles beneath the sk
12、in. Chordates have an endoskeleton consisting of cartilage, bone, or some combination of these materials. The mammalian skeleton is built from more than 200 bones, some fused together and others connected at jointsby liagments that allow freedom of movement. Vertebrates have a distinctive endoskelet
13、on made up of an axial and appendicular skeleton.,Joints,Joints provide flexibility for body movements. Some examples of joints are: Ball and socket joints - Hinge joints - Pivot joints,Label the skeleton 1 17 2 18 3 19 4 20 5 21 6 22 7 23 8 24 9 25 10 26 11 12 13 14 15 16,Some Helpful Sites on the
14、Skeletal System,http:/www.mnsu.edu/emuseum/biology/humananatomy/skeletal/skeletalsystem.html http:/ http:/hes.ucfsd.org/gclaypo/skelweb/skel01.html,The Integumentary System,Integumentary system is the outer covering of a mammal;s body, including the skin, hair, and nails,Definition,Protects the body
15、s internal living tissues and organs Protects against invasion by infectious organisms Protects the body from dehydration Protects the body against abrupt changes in temperature,Functions,Functions (continued),Helps dispose of waste materialsActs as a receptor for touch, pressure, pain, heat and col
16、dStores water, fat, and vitamin D.,Epidermis,The outermost layer of skin and is composed mostly of dead epithelial cells that continually flake and fall off. New cells pushing up from lower layers replace the cells that are lost.,Dermis,Supports the epidermis and contains hair follicles, oil and swe
17、at glands, muscles, nerves, and blood vessels,Activity: True or False,1. Skin is the largest organ. 2. The integumentary system only consist of skin. 3. Part of the integumentary system job is to protect the body from dehyrdration. 4. The skin consists of five layers of skin.,Answer to Activity,True
18、2. False, the Integumentary system consists of the outer covering of a mammals body, including the skin, hair, and nails3. True4. False, the skin consist of two layers, the epidermis and dermis,To learn more about the integumentary system you can look under:,AP Biology Textbook by Campbell & ReeceWe
19、bsites such as http:/www.cancerindex.org/medterm/medtm5.htmAnd even videos: ttp:/ System,Overview,The main job of the muscular system is to provide movement for the body. There are just over 650 skeletal muscles in the whole human body. The muscular system consist of three different types of muscle
20、tissues : skeletal, cardiac, smooth, all of which have the ability to contract, allowing the body movements and functions.,Major muscles of the body,Cardiac Muscle,Cardiac muscle, called the myocardium, is found only in the heart. It is involuntary, controlled by the autonomic nervous system. The my
21、ocardium is composed of thick bundles of muscle, forming the walls of the chambers of the heart and contracts to pump blood throughout the body. Its cells are joined by intercalated disks that relay each heartbeat.,Smooth muscles are involuntary muscles found in the stomach and intestinal walls, in
22、artery and vein walls, and in various hollow organs. In a vessel or organ, smooth muscles are arranged in sheets or layers.,Smooth Muscle,Skeletal Muscle,Stabilize joints, help maintain posture, and give the body its general shape. In men, they make up about 40 percent of the bodys mass or weight an
23、d in women, about 23 percent. Are generally responsible for the voluntary movements of the body.,Structure of Muscle Cells,Within the cells are myofibrils; myofibrils contain sarcomeres, which are composed of actin and myosin. Individual muscle fibers are surrounded by endomysium. Muscle fibers are
24、bound together by perimysium into bundles called fascicles; the bundles are then grouped together to form muscle, which is enclosed in a sheath of epimysium. Muscle spindles are distributed throughout the muscles and provide sensory feedback information to the central nervous system.,Muscle Cell in
25、Detail,Movement and muscle arrangement,In skeletal muscle, contraction is stimulated by electrical impulses transmitted by the nerves, the motor nerves and motorneurons in particular. Cardiac and smooth muscle contractions are stimulated by internal pacemaker cells which regularly contract, and prop
26、agate contractions to other muscle cells they are in contact with. Muscular activity accounts for much of the bodys energy consumption. All muscle cells produce adenosine triphosphate (ATP) molecules which are used to power the movement of the myosin heads. Muscles also conserve energy in the form o
27、f creatine phosphate which is generated from ATP and can regenerate ATP when needed with creatine kinase. They keep a storage form of glucose in the form of glycogen. Glycogen can be rapidly converted to glucose when energy is required for sustained, powerful contractions.,Activity,What are muscles
28、made of? What are the 3 types of muscles? What are smooth muscles and what do they do and where are they found? What are cardiac muscles, where are they and what do they do? What are skeletal muscles what do they do? Whats the difference between voluntary and involuntary muscles? Where do facial mus
29、cles attach? What do facial muscles do? Name the muscle thats attached only at one end? List the 6 major types of muscles,Nervous System,Overview,All animals except the sponges have some type of nervous system. Nervous systems consist of circuits of neurons and supporting cells. The human brain cont
30、ains an estimated 100 billion nerve cells or neurons. Invertebrate nervous systems range in complexity from simple nerve nets to highly centralized nervous systems having complicated brains and ventral nerve cords.,The Brain,The brain is composed of three parts: the cerebrum, the cerebellum, and the
31、 medulla oblongata. The medulla oblongata is closest to the spinal cord, and is involved with the regulation of heartbeat, breathing, vasoconstriction (blood pressure), and reflex centers for vomiting, coughing, sneezing, swallowing, and hiccuping. The hypothalamus regulates homeostasis. It has regu
32、latory areas for thirst, hunger, body temperature, water balance, and blood pressure, and links the Nervous System to the Endocrine System. The midbrain and pons are also part of the unconscious brain. The thalamus serves as a central relay point for incoming nervous messages. The cerebellum is the
33、second largest part of the brain, after the cerebrum. It functions for muscle coordination and maintains normal muscle tone and posture. The cerebellum coordinates balance.,Central nervous system consists of the brain and the spinal cord,In invertebrates, the central nervous system consists of the b
34、rain and the spinal cord, which is located dorsally. Nervous systems process information in three stages: sensory input, integration, and motor output to effector cells. The three stages are illustrated by the knee jerk reflex. The CNS integrates information, while the nerves of the peripheral nervo
35、us system transmit sensory and motor signals between the CNS and the rest of the body. Sensory neurons transmit information from sensors that detect external stimuli and internal conditions. Most neurons have highly branched dendrites that receive signals from other neurons. They also typically have
36、 a single axon that transmits signals to other cells at synapses.,Nerve Cell,A basic nerve cell consists of a cell body, an axon, and many dendrites. Dendrites are thread-like branches that increase the surface area of a cell making it possible for the receiving many connections with other nerve cel
37、ls. Signals picked up by the dendrites travel through the cell and continue along the axon where they are transmitted to the next cell. Synaptic bulbs on the ends of the axons make connections with other nerve cells, via synapses.,All cells have an electrical potential difference across their plasma
38、 membrane called the membrane potential,Ions pumps and ion channels maintain the resting potential of a neuron. In neurons, the membrane potential is typically between -60 and -80 mV when the cell is not transmitting signals. The inside of the cell is negative related to the outside. The membrane po
39、tential depends on ionic gradients across its plasma membrane: the concentration of Na + is higher in the extracellular fluid than in the cytosol, while the reverse is true for K+. A neuron that is not transmitting signals contains many open K+ channels and fewer open Na + channels in its plasma mem
40、brane. The diffusion of K + and Na+ through these channels leads to separation of charges across the membrane, producing the resting potential. Gated ion channels open or close in response to membrane stretch, the binding of a specific ligand, or a change in the membrane potential. Stretch gated ion
41、 channels are found in cells that sense stretch and open when the membrane is mechanically deformed.,Somatic Nervous System,Includes all nerves controlling the muscular system and external sensory receptors.External sense organs are the receptors. Muscle fibers and gland cells are effectors. The ref
42、lex arc is an automatic, involuntary reaction to a stimulus. A reaction to the stimulus is involuntary, with the CNS being informed but not consciously controlling the response. Sensory input from the PNS is processed by the CNS and responses are sent by the PNS from the CNS to the organs of the bod
43、y. Motor neurons of the somatic system are distinct from those of the autonomic system. Inhibitory signals, cannot be sent through the motor neurons of the somatic system.,Autonomic Nervous System,Part of PNS consisting of motor neurons that control internal organs. It has two subsystems. The autono
44、mic system controls muscles in the heart, the smooth muscle in internal organs such as the intestine, bladder, and uterus. The Sympathetic Nervous System is involved in the fight or flight response. The Parasympathetic Nervous System is involved in relaxation. Each of these subsystems operates in th
45、e reverse of the other (antagonism). Motor neurons in this system do not reach their targets directly (as do those in the somatic system) but instead they just connect to a secondary motor neuron which innervates the target organ.,Crossword Activity,1. System of the nervous system that contains the
46、brain and spinal cord 2. The sensory and motor neurons that connect to the central nervous system 3. Receive and communicate information from the sensory environment 4. Makes synaptic connections with other neurons a. one of many short, branched processes of a neuron that help bring the nerve impuls
47、es toward the cell body b. A system of the nervous system that can be broken down into a sensory and a motor division c. Takes the command of the CNS and put them into action as motor outputs d. one of three divisions of the autonomic nervous system; generally enhances body activities that gain and
48、conserve energy, such as digestion and reduced heart rate e. one of three divisions of the autonomic nervous system; generally increases energy expenditure and prepares the body for action f. Longer extensions that leave from a neuron and carry impulse away from the cell body to toward target cells g. main body of the neuron,Answer to Activity,
