Functions of the skeleton: • Support: The skeleton provides the framework to keep the human body in the correct shape, by supporting many internal organs and the muscles of the body. • Protection: Important and delicate organs are protected by bone. Examples include the skull protecting the brain and eyeballs, the ribs protecting the heart and lungs, and the vertebral column protecting the spinal cord. • Movement: Joints between the bones allow movement to be smooth, without friction. Muscles can only exert a pulling force so they are often arranged in pairs, one muscle producing the opposite movement of the joint to the other muscle. The bones and joints are often arranged as levers so a small contraction in the muscle produces a large movement in the bones. • Attachment: The bones of the skeleton provide an attachment surface for muscles, tendons and ligaments. Without these attachments, the movement referred to above would not occur. • Blood cell production: blood cells are produced in the red bone marrow inside the larger bones of the body…………. See cloze task (weebly)
Starter(finish by 5 min into the lesson) • Using Google, search for: skeleton klb java applet (click run if prompted) • Do the task, repeat….take a screen shot of your best time (fruit burst for fastest)
Entry Starters… • Bone names onto skeleton • (do the plant flower one….!) • !! Paper or digital name bones and then klb (coz it is missing phalanges, sacrum, coccyx)
Naming the Bones • Using Google, search for: skeleton klb. Click on the first hit returned: http://www.klbict.co.uk/interactive/science/skeleton.htm • Complete the task • Download the file “name those bones” from the questions tab of my weebly. Type in your answers, substitute cranium for skull • On the same website try the 'label dragging' version of the exercise - WHO CAN GET THE BEST TIME???!
Discuss • What are the differences between male and female skeletons? • What are the differences between child and adult skeletons?
Skeletal Differences • What are the differences between male and female skeletons? • Female pelvis is wider to: _____________________ • Female wrists and jaw bones smaller. • Male bones bigger and heavier • What are the differences between child and adult skeletons? • Baby has >300 bones, adult 206 • Movable skull plates in baby fuse together. What is the purpose of this movement? • Growth plates, areas behind end of long bones where bone material is added (disappear when fully grown) • Teeth, born with none, start to erupt from 3 months, 20 baby teeth (all replaced with 32 permanent teeth)
Muscles What is the strongest muscle in the body? - Copy the heading - Talk with the guy(s) beside you, decide on a muscle, a reason and write that down.
What is the strongest muscle? • Difficult to say because strength depends on: • physiological strength (muscle size, cross sectional area, available crossbridging, responses to training), • neurological strength (how strong or weak is the signal that tells the muscle to contract), and • mechanical strength (muscle's force angle on the lever, moment arm length, joint capabilities).
What is the strongest muscle? Some Examples • Jaw Muscle: Greatest force on external object. Record bite strength: 4340N (434kg) for 2 seconds. Advantage: works on a shorter lever than other muscles. • Quadriceps / Gluteus Maximus: Greatest force exerted by muscle onto bone. Advantage: large cross section. • Uterus: Greatest force exerted per kg of muscle. During childbirth exerts 100N to 400N per contraction (muscle weight is only 1.1kg). • Eyeball muscles: 100 times stronger than they need to be compare to weight of eyeball. They get regular exercise during facial scanning and REM sleep. • Heart: Most work during lifetime. Output of only 1-5 watts (quadriceps = 100 watts) but works continuously over a lifetime. 2.5 gigajoules of work done over 80 years • Tongue: NO! often in a list of strong muscles but for no good reason. It is actually 16 muscles.
Muscles and Movement • Almost all the movement in our bodies is controlled by muscles. • About half of our body weight is muscle. Muscles are made of lots of fibres running side by side. Muscle cells are able to convert the chemical energy contained in glucose using oxygen, into kinetic energyand heat • Muscles are the “red meat” of the body as they contain copious amounts of blood which transports the oxygen needed for aerobic respiration to occur. This is the process of releasing energy using oxygen. If Oxygen is in short supply anaerobic respiration occurs meaning muscles will function for a while but……. Eventually lactic acid will be produced which will cause pain and eventual shut down of muscular functions. • Muscles are attached to our bones by tough cords called tendons. Tendons are made of a protein called collagen. • Ligaments keep the joints that the muscles articulate in close association (tight) • Muscles cannot push only pull. When you arm bends your bicep muscle contracts and your tricep relaxes. When you open your arm the opposite occurs these are antagonistic muscles (muscles working in pairs that oppose each others motion)
Detailed muscle structure • Actin,myosin…
Skin 10 billion skin flakes are shed per day This is 2kg per year Most of household dust is skin flakes House mites feed on this – their excretions exacerbate asthma
Functions of Skin Parts • Epidermis – waterproof protective layer • Dermis – layer that cushions the body from stress and strain (has nerves, glands, hair follicle, hair muscle) , • Pigment layer – produces melanin (a pigment that protects from UV damage) • Sweat Gland – makes sweat (evaporating sweat keeps body cool) • Oil Gland – makes oil (keeps hair, skin supple) • Hairs – holds warmth (traps layer of warm air) • Hair Muscle – makes hair stand up • Fat layer – provides insulation, stores energy • Nerves – heat & touch receptors • Blood capillaries - provide nourishment and waste removal
Functions of skin • Skin performs the following functions: • Protection: an anatomical barrier from pathogens and damage between the internal and external environment in bodily defense; Langerhans cells in the skin are part of the adaptive immune system. • Sensation: contains a variety of nerve endings that react to heat and cold, touch, pressure, vibration, and tissue injury; see somatosensory system and haptics. • Heat regulation: the skin contains a blood supply far greater than its requirements which allows precise control of energy loss by radiation, convection and conduction. Dilated blood vessels increase perfusion and heat loss while constricted vessels greatly reduce cutaneous blood flow and conserve heat. Erector pili muscles are significant in animals. • Control of evaporation: the skin provides a relatively dry and semi-impermeable barrier to fluid loss. Loss of this function contributes to the massive fluid loss in burns. • Aesthetics and communication: others see our skin and can assess our mood, physical state and attractiveness. • Storage and synthesis: acts as a storage center for lipids and water, as well as a means of synthesis of vitamin D by action of UV on certain parts of the skin. • Excretion: sweat contains urea, however its concentration is 1/130th that of urine, hence excretion by sweating is at most a secondary function to temperature regulation. • Absorption: Oxygen, nitrogen and carbon dioxide can diffuse into the epidermis in small amounts, some animals using their skin for their sole respiration organ. In addition, medicine can be administered through the skin, by ointments or by means of adhesive patch, such as the nicotine patch or iontophoresis. The skin is an important site of transport in many other organisms. • Water resistance: The skin acts as a water resistant barrier so essential nutrients aren't washed out of the body.
Hair Desensitisation • What to do: • Copy title • Get a pin or match or paperclip… • Find a hair on the back of your hand • Start timer, repeatedly touch the hair until you feel the sensation stopping, record time. Repeat three times, average. Record in a results table. • Questions • What happened? • Infer an advantage of this phenomenon • * Infer what might be happening in the skin
Proving that Skin Releases H20 • What to do: • Copy title • Tape a small piece of dry cobalt chloride paper to the back of your hand • Read: Cobalt chloride paper is blue when dry and pink when wet • Questions: • What happened? • What does this prove? • Write the formula for cobalt chloride (Co2+ & Cl-) • *Infer – whatis happening chemically?
Skin Grafting What? • Skin grafting is the transplantation of skin Why? • Treating extensive wounding • Treating burns • Treating skin loss (often after infections) • Some surgery needs skin grafts for proper healing to occur Types: • Autologous: from yourself • Isogeneic: from a twin • Allogeneic: from the same species • Xenogeneic: from different species • Prosthetic: synthetic (metal, plastic, or ceramic)
Planning Task Background: It is claimed that arm span is the same length as a person’s height Develop an experimental plan to test this. Include the following: Title Aim Hypothesis Equipment Variables (independent, dependent & controlled) Method
Is your armspan your height? Aim: To find out if armspan is the same length as a person’s height Hypothesis: I predict that armspan is roughly the same size as height (I think that this might help the body’s balance) Equipment: ruler, test subjects Variables: independent – the person being measured dependent – height length and armspan length controlled: people to take shoes off use same ruler each time use same measurer each time measure in same way (fingertip to fingertip)
This area is where kidney nephrons are located. The nephrons carry out the work of the kidney (filtering out waste and returning useful material into the blood)
Capsule: covers, protects Cortex: wastes pass from blood to nephrons This area is where kidney nephrons are located. The nephrons carry out the work of the kidney (filtering out waste and returning useful material into the blood) Medulla: ‘collecting ducts’ from nephron meet here, carrying urine Renal Pelvis: passes urine to ureter Ureter: Takes urine to bladder
Urine • Composition Varies • Daily (approx) • Water 1.5 litres • Urea 30g • Salt 15g • Small amounts of other substances
Genetic differences in sense of smell identified through asparagus urine odor Date: September 28, 2010 Source: Monell Chemical Senses Center Summary: Scientists have identified one of only a few known genetic contributions to the sense of smell. Most, but not all, people detect a distinct sulfurousodor in their urine shortly after eating asparagus. Sensory testing demonstrated that some do not produce the odor while others do not smell it. DNA analyses revealed that the inability to smell the odor was linked to genetic variation within a family of olfactory receptors. http://www.sciencedaily.com/releases/2010/09/100928111231.htm
Urine Test Strips Typically Test for: • pH • Glucose • Ketones • Protein • Blood • Bilirubin • Nitrates
Water Balance Water is essential for: • Digesting food • Sweat evaporation is cooling • Dissolves substances for transport (eg glucose) • Temperature control • Gas exchange
Water balance #2 Gains Drinking Eating Chemical reactions (eg respiration) Losses Sweat Urine Water vapour (exhaled air) Faeces (egestion) Summary: The gains and losses must be balanced in order to ensure the right levels of water in your body are maintained. The kidney is the main organ that controls this balance.
Respiratory System • Organ system that delivers O2 (via air) to the blood and removes CO2 • NOT the same as (cellular) respiration which is: Glucose + O2 CO2 + H2O + energy (ATP) • Gas Exchange: exchange of gases at the lung surface (oxygen in, carbon dioxide out) • Breathing: Movements of body which result in air coming in (inhaling) and going out (exhaling)
Parts of the Respiratory System larynx trachea Bronchus (pl. bronchii) rib bronchioles Intercostal muscle Alveolus (pl. alveoli) heart Right lung Left lung diaphragm