Body Systems

Digestive

Mechanical and chemical digestion

An enzyme is biocatalyst. They are proteins that speed up chemical reactions.

Proteins are complex substances in all living things, (20+ amino acids). They are organ & species specific. We don’t store them, so we need them from food.

Amino acids
Organic compounds made from: carbon, hydrogen, oxygen, nitrogen.

How does food become poo?

Tongue & Esophagus

• Mechanical breakdown
• Salivary glands moisten & add amylase, enzyme, to breakdown starches to sugars.

Peristalsis

Stomach

• Mechanical - stomach churns
• Chemical - gastric juice (mucus, hydrochloric acid, enzymes) digests proteins Food is now liquid and released into small intestine.
• Mucus protects stomach lining

Small Intestine

• Enzymes continue the digestion of starches and proteins
• See bile
• Food absorbed, via villi (fractal), through epithelial tissue, into bloodstream

Liver

• Produces bile, stored in gall bladder, breaks up fats, lipids.

Large Intestine

Mechanical/Chemical digestion finished.

Absorbs water, vitamins, minerals

Unneeded stuff discarded

To Review

• Mechanical vs Chemical
• Salivary amylase enzyme
• Peristalsis
• Gastric Juice
• Small Intestine
• Villi and microvilli = SA

And

• Large intestine
• Rectum

The argument for fecal transplants

You Contain Multitudes

Your body is an archipelago of microbes!

Lack of sleep, aggression in environment, overcrowding, etc can alter a gut’s biome, the opposite is also true.

Find your microbial wonder and share it

Respiratory

Process Overview

• Rib & Diaphragm muscles contract (rips up & diaphragm down, partial vacuum = inhalation.
• Continual smaller openings where gas exchange occurs in the alveoli (air sacs)
• Exhalation = muscles relax decreasing volume and gas pushed out.
• Pathway = nose/mouth, trachea, bronchi, bronchioles, alveoli.

Gas Exchange

• Alveoli constructed of epithelial tissue.
• 1 cell thick
• Distance between capillaries containing blood and O2 in air sac quite small.
• Oxygen, via passive transport, diffuses through the epithelial tissue (high O2 alveoli to low O2 blood)
• CO2 diffuses from blood to alveoli
• Process is instantaneous, but prolonged focus has been used to illicit altered states.

Meditation Moment

• Buzzing bee
• Cooking visualization
• Others?

Respiratory Issues

• Allergies
• Asthma
• Insect bites
• Carbon Monoxide
• Pneumothorax
• Fentanyl

Circulatory

Untitled Slide

• Highway for O2, CO2, nutrients, waste
• Heart - atria and ventricles
• Arteries vs veins

Untitled Slide

• Blood = red and white cells, platelets and plasma
• Plasma is 55%

Blood flow

• Veins from body to right atrium, to right ventricle
• Right ventricle artery to lungs, vein from lungs to
• Left atrium to left ventricle to body

Arteries vs Veins

• Arteries (page 137) are thicker and have three layers - epithelial inside, muscle middle and connective tissue. Carry o2
• Veins are thinner and have valves. Carry low O2

Capillaries

• Page 139
• Between the arteries & veins are capillaries.
• Small, cell wide paths where nutrient, waste and gas exchange between circulatory system & body.

Healing

• CARE
• Check, apply pressure, raise, eval
• Scab
• Blood brings O2 and nutrients
• WBC fight infection
• (P140) platelets help stop bleeding
• Plasma moves nutrients & waste

Excretory

Untitled Slide

• Excretion is cell waste removal
• Ammonia produced
• Liver converts it to urea
• Kidneys, via nephron, filters blood producing urine - 180:1.5 a day.
• Mmmm

Formation of Urine

• Blood enters kidneys via renal artery, branches to capillaries, enters nephrons.
• Millions of nephrons remove waste.
• Blood returns to body, urine excreted.

Ureters, bladder & Urethra

• ureters - long tubes connecting kidneys to bladder
• Bladder is storage bag
• Full bladder, 1 L, muscles contract and move urine out the urethra

Skin

• Skin has 1000s of sweat glands.
• Moderate temperature & help remove excess salt from blood.

To recap

• Cell waste carried by the Plasma (mostly water) to liver & kidneys for processing.
• Blood is filtered, waste is excreted via skin and urethra
• Hu

Nervous

Neurons

• P147
• Mostly made of specialized tissue, nervous tissue.
• Special cells called neurons.

Neighbours Chat

• Neuron gets messages from neighbouring cell’s dendrites via axon. Passed to nucleus of neuron.
• Then travels to dendrites to pass to other neighbouring neurons.

CNS

• Central Nervous system - brain and spinal cord.
• Brain protected by skull
• Spinal cord protected by vertebrae

PNS

• Cranial nerves
• Spinal nerves
• Branch throughout your body.
• PNS = sensory neurons & motor neurons
• Somatic & autonomic

Sensory & Motor

• Page 148
• Sensory neurons carry information, signals, from body to CNS
• Motor neurons carry signals from CNS to muscles or organs.

Somatic & Autonomic

• Somatic is a voluntary response - listening to a sound by choosing to turn towards it.
• Autonomic is involuntary - heart rate, pupil size, blood pressure.

Brain

• 3 main sections
• Cerebrum
• Cerebellum
• Medulla

Reflex

• Page 149
• Sensory nerves are triggered and send signals to your spinal cord, inter neurons (page 148) relay to motor neurons to muscles.
• Sensory neurons send message to brain, but arm has already acted. Face response.
• Reaction time is reduced because of short cut.
• Can you encourage this action?

Uneven Touch

• Page 151 - a bit disturbing
• See question 5 to explain muscle memory.

To recap

• Central nervous system is the brain and spinal cord
• Peripheral nervous system extends throughout the body.
• PNS has sensory and motor neurons. Somatic and autonomic systems.

Theory of Disease

Theory of Disease

• Illnesses are caused by tiny organisms, such as bacteria or viruses, that invade our bodies and cause harm.
• It explains why we get sick and helps us develop ways to prevent and treat diseases.
• Previously, people believed that illnesses were caused by supernatural forces or imbalances in the body's fluids.

First Vaccine

• Smallpox use to kill up to 40% of those infected.
• Edward Jenner noticed milkmaids, who had cowpox, rarely got smallpox.

Micro-organisms

• Pasteur conducted experiments on the spoilage of beer and discovered that it was caused by the growth of microorganisms, that contaminated the beer during the brewing process.
• He used heat, beer to kill the harmful microorganisms and prevent spoilage.

Pasteurization

What is raw milk?

Byronization

Ization your name and come up with a definition.

Unpasteurized foods

Now