Body Works

Functions of the skeleton

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)

Bones

Bones of the Skeleton

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)

Joints

A Synovial Joint – Simple Detail

A Synovial Joint – Yr10 Detail

Ridiculous detail(middle part of bone = diaphysis)

Functions of the Parts of a Synovial Joint

Tendons vs Ligaments

Tendons vs Ligaments

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.

Muscle Types

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 & Movement

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 energy and 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…

Femur

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

Skin Structure

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.[4][3]

• 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.[4] 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.

• Questions1. What happened?2. Infer an advantage of this phenomenon3. * 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:

1. What happened?2. What does this prove?3. Write the formula for cobalt chloride (Co2+ & Cl-)4. *Infer – what is 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 TaskBackground: 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: TitleAimHypothesisEquipmentVariables (independent, dependent & controlled)Method

Is your armspan your height?Aim: To find out if armspan is the same length as a person’s

heightHypothesis: I predict that armspan is roughly the same size

as height (I think that this might help the body’s balance)Equipment: ruler, test subjectsVariables: independent – the person being measured

dependent – height length and armspan lengthcontrolled: people to take shoes off

use same ruler each timeuse same measurer each timemeasure in same way (fingertip to

fingertip)

Excretion

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

Medulla: ‘collecting ducts’ from nephron meet here, carrying urine

Ureter: Takes urine to bladder

Renal Pelvis: passes urine to ureter

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)

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 odorDate:September 28, 2010Source:Monell Chemical Senses CenterSummary:Scientists have identified one of only a few known genetic contributions to the sense of smell. Most, but not all, people detect a distinct sulfurous odor 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

GainsDrinkingEatingChemical reactions (eg respiration)

LossesSweatUrineWater 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 Systemlarynx

Bronchus (pl. bronchii)

bronchioles

Alveolus (pl. alveoli)

trachea

rib

Intercostal muscle

diaphragm

heart

Right lung Left lung

Parts of the Respiratory System

Detail of Alveoli

Functions of the circulatory System