Cells & Systems 3-4 Flashcards
how do you obtain energy?
from carbohydrates, lipids, and proteins
what must your body do with energy?
process them into usable compounds
what are the 2 types of digestion?
mechanical: physical breakdown of food into smaller pieces
chemical digestion: breaks down large chemicals through chemical reactions with enzymes
how does the mouth aid in digestion?
- digestion starts in the mouth
- mechanical digestion through chewing and grinding by teeth
- chemical digestion through saliva
- water moistens and softens food making it easier to swallow
- an enzyme called salivary amylase breaks down starch molecules into sugar molecules
how does the esophagus aid in digestion?
- once thoroughly chewed you swallow your food
- a flap called the epiglottis covers your windpipe, food passes to the esophagus
- food moves down esophagus via peristalsis
what is peristalsis?
wave like muscle contractions
how does the stomach aid in digestion?
- mechanical digestion occurs as the stomach churns food back and forth
- chemical digestion occurs with secretions of gastric juice
what is gastric juice made of?
mucus: prevents gastric juice from digesting stomach
hydrochloric acid: very corrosive, low pH
water: moistening
digestive enzymes: chemically digested proteins
how does the small intestine aid in digestion?
- chemical digestion continues
- enzymes break down starches, proteins, and lipids
- 6m long
- if surface area was stretched out it would cover a classroom floor
what are villi?
- small fingerlike projections
- line the inner surface of the small intestine
- increase surface area and aid in absorbing nutrients
- covered in epithelial tissue
- molecules get absorbed into the blood stream just below the epithelial tissue
what does the pancreas do?
- produce enzymes
- enzymes are sent to the small intestine to aid in digesting starches
what does the liver do?
- produces bile
- bile is stored in the gull bladder
- gallbladder sends bile to the small intestine to digest large globules of lipid into small pieces
what does the large intestine do?
- mechanical and chemical digestion are complete
- about 1.5 m long
- absorbs water, vitamins, and minerals
- anything undigested is formed into feces
- feces are collected in the rectum and then expelled through the anus
what is the respiratory system responsible for?
supplying your blood with oxygen and removing carbon dioxide
what is breathing?
moving air in and out of your lungs
why does breathing occur?
because of diaphragm muscles
how does breathing in and out work?
breathing in: muscles contract pulling ribs up and diaphragm down - pulls air into your lungs
breathing out: muscles relax, ribs go down and diaphragm goes up - pushes air out
what is gas exchange?
- cells require oxygen to function, and need to get rid of harmful carbon dioxide
- respiratory system and circulatory system work together to exchange these gases
how does gas exchange work?
- respiratory system draws in air rich in oxygen (rich = 20% oxygen)
- air moves through tubes called bronchi to the lungs
- bronchi narrow into bronchioles and at the end there are tiny air-filled sacs called alveoli
what are alveoli?
- surrounded by capillaries with blood flowing through them
- made of specialized epithelial cells, one cell thick
- very small distance between air and blood stream
- air in alveoli has a high concentration of oxygen and the blood has a low concentration, so it diffuses into the blood
- carbon dioxides gradient is the opposite so it diffuses out of the blood
what makes up the circulatory system?
heart, veins, capillaries, and arteries
what does the circulatory system do?
- your body’s transportation network
- delivers nutrients and oxygen, helps remove waste products
what is the heart’s role in the circulatory system?
- a pump to move blood through your body
- made of muscle
- right side pumps blood to lungs
- left side receives oxygen rich blood from the lungs and pumps it to the rest of the body
- after making its way through the body it returns to the right side depleted of oxygen
how many chambers is the heart made out of?
4
what are the 4 chambers of the heart?
- the top 2 chambers are called atria
- the bottom 2 are called ventricles
- blood moves into the atria and out of the ventricles
what are arteries?
- vessels that carry blood away from your heart
- thick and muscular to deal with the pressure of blood coming towards your heart
what are veins?
- vessels that carry blood back towards your heart
- thinner with valves that make sure it doesn’t flow backwards
what are capillaries?
specialized thin layered blood vessels that allow for the exchange of gases and nutrients
what is blood and what does it consist of?
- second largest connective tissue
- consists of red blood cells, white blood cells, platelets, and plasma
what are red blood cells?
- carry oxygen
- mature red blood cells have no nuclei which makes room for more oxygen
- very flexible allowing them to bend and flex through small capillaries
what are white blood cells?
- specialized to fight infection
- some are capable at eating bacteria at the sight of infection
what do platelets do?
help stop the bleeding of cuts
what does plasma do?
transports nutrients to your cells and carries wastes away
what is the excretory system?
- removes wastes, which are poisonous to your body
- involves organs from other systems
- different organ systems interact to get rid of waste
what is the liver in the excretory system?
- an organ of the digestive system that also plays a role in the excretory system
- takes highly toxic ammonia and converts it to less harmful urea
- urea still has to be disposed of, the liver releases it into the bloodstream
what are kidneys in the excretory system?
- about 10cm long
- main organ of excretion
- strain out unwanted urea, water, and salts
- produces urine
- every drop of blood is filtered about 300 times a day
- the amount of urine you produce will depend on the amount of water you drink
where does blood enter the kidney?
the renal artery
how does urine formation occur?
- blood enters the kidney through the renal artery
- artery branches into smaller and smaller vessels (capillaries)
- these small capillaries enter the filtering units known as nephrons
- there are millions of nephrons in the kidney
what do nephrons do?
- remove wastes from blood and produce urine
- clean filtered blood returns to the body through the renal vein
- urine flows to the ureter
what is the bladder?
- muscular sac
- urine enters and the bladder expands
- bladder can store about 1L of urine
- when full the muscles contract and push the urine out and it exits the body through the urethra
how are skin and sweat related?
- sweat is salty
- your skin has thousands of sweat glands just below the surface
- produce sweat to keep you cool but also to release excess salt
what can different renal (kidney) diseases do?
- certain diseases affect kidney function
- patients with kidney failure often have protein in their urine
- people with diabetes will often have glucose in their urine
what is a dialysis machine and how does it work?
- dialysis machine performs the function of a kidney, for people whose kidneys don’t work
- patients blood flows to semi permeable tubing in the machine to filter their blood
- over 4-6 hours the patients blood is filtered and flows back into their body
what does the nervous system do?
monitors stimuli in the environment around you and reacts to stimuli if necessary
what is a stimulus?
- a change in your environment
- could be a change in pressure, heat, light, sound, or body chemistry
what is the nervous system mostly made of?
nervous tissue
what is nervous tissue made of?
neurons
what is a neuron’s job?
to send and receive messages
how do neurons work?
- small branches of the cell called dendrites receive messages
- message is passed through the cell body down the axon
- small branches carry the message to the dendrites of neighbouring cells
what is an axon?
long extension of the cell that ends in small branches
what are the 2 divisions of the nervous system?
central nervous system (CNS): the brain and the spinal cord
peripheral nervous system (PNS): these nerves travel to all parts of the body
what are the divisions of the peripheral nervous system (PNS)?
somatic nervous system: voluntary responses (ex. deciding to turn your head when you hear a sound)
autonomic nervous system: involuntary responses (ex. your body automatically changes breathing rates when needed)
how does the central nervous system (CNS) work?
- brain receives stimuli from the outside world which are gathered by the sense organs and within the body itself
- the brain reacts to stimuli and sends messages to appropriate body parts
what are the 3 main parts of the brain and where are they located?
cerebrum: main large part at front
cerebellum: smaller part at the bottom
medulla (brain stem): stem leading up to bottom of cerebellum
what is the spinal cord and what does it do?
- connects the brain to the peripheral nervous system
- highway for messages between the brain and the body
- contains interneurons
what do interneurons do?
connect sensory neurons to motor neurons
what is an example of the reflex arc?
- you touch a hot element, which gives the stimulus of heat
- sensory neurons send info to spinal cord
- interneurons relay message to motor neurons
- motor neurons quickly contract your muscles and remove your hand
- info goes to your brain, but by the time you know what happened you’ve already pulled your hand away
what does the integumentary system do?
- protect the body’s internal environment from the external environment
- senses pain, pressure, and temperature
what are the 3 layers of skin?
epidermis: top layer of skin -does not contain blood vessels but is used for protection, absorption of nutrients, and homeostatic maintenance
dermis: second layer -gives elasticity and structure to the skin, allowing for flexibility, and resisting distortion, sagging, and wrinkling
hypodermis (subcutaneous (fat)): made up of adipose (fatty) tissue
what are sweat glands?
- do not extend too deep into the dermis
- secrete a water based electrolyte complex known as sweat
- sweat acts as a coolant for the skin
- the amount of sweat in an area depends on the number of sweat glands, and the size of the surface opening
what are arrector pili?
- muscles that are attached to the hair follicles
- contraction of these muscles make the hairs stand on end, usually referred to as goosebumps
what is eczema?
characterized by areas of dry skin or rashes with symptoms such as redness and itching -scratching may result in scarring
what is acne?
characterized by bumps and discoloration of the skin, acne is most dense in areas with high oil contents, such as the face, neck, upper chest, and back
what is the structure and function of the muscular system?
structure: muscles and tendons
functions: - move bones
- move organs that contain muscle tissue (such as the heart and stomach)
what are muscles and what are the 3 types of muscles?
- soft tissue of animals
- skeletal, cardiac, smooth
what are actin and myosin?
- two filaments found in your muscles
- they slightly overlap when at rest
- when you flex, they filaments glide over each other, causing the band of muscle to flex
how does the muscular system work?
- with proper nutrition and hydration the fibres will move easily
- muscles require electrolytes
- large need of electrolytes from cardiac and skeletal muscle
what is muscle dystrophy?
- progressive weakness and wasting away of the voluntary muscles that control body movement
- muscle tissue is replaced by fatty and connective tissue
- movements of the muscle are now more rigid and difficult
- currently no cure
what is the structure and functions of the skeletal system?
structure: bones, cartilage
functions: - provide a movable support frame for the body
- protect soft tissue organs such as the heart and lungs
how are bones comprised?
- has an outer layer of hard or compact bone, it is very strong, dense, and tough
- inside this is a layer of spongy bone, which is like a honeycomb, lighter and slightly flexible
- in the middle of some bones is a jelly-like bone marrow, where cells are being produced for the blood
what are tendons?
rough, inelastic bands that hold and attach muscle to bone
what is cartilage?
- in joints
- acts as a cushion between bones, protects bones
- protects the bones from rubbing against each other and wearing down
what are ligaments?
- strong inelastic bands of connective tissue that help hold bones together at joints
- joints allow your body to move in many different ways
what is osteoarthritis?
- is a normal result of aging
- also caused by wear and tear on a joint
- cartilage breaks down and wears away, the bones rub together
- causes pain, swelling, and stiffness
- bony spurs or extra bone may form around the joint
what type of wounds were 50% lethal in the 1800s?
puncture wounds
where and when was smallpox mainly present?
in Europe in the 1600s and 1700s
what were the symptoms and death rate of smallpox?
◦ Victims broke out with puss filled
sores (pox)
◦ Presented with chills high fever
and muscle pain
◦ Up to 40% of people died
◦ Many who survived became blind
how was the first vaccine created?
◦ English country doctor Edward Jenner
noticed milkmaids who had had cowpox
rarely got smallpox
◦ Cowpox is related to smallpox but much
milder
◦ Concluded that contracting cowpox
gave them immunity to smallpox
◦ He began intentionally infecting people
with cowpox… the first vaccine!
who was Louis Pasteur?
◦ French chemist who was the first to
identify disease causing agents as
microorganisms
◦ “Germs” were too small to be seen by
the human eye!
◦ Later proved that germs were the
cause of infectious disease
◦ He was able to come up for cures of
many common diseases
who was Joseph Lister?
◦ English surgeon
◦ Many of his patients died
even though their surgeries
were successful
◦ Concluded “germs” entered
the surgical wound and
caused infection
◦ Introduced the practice of
cleanliness and sterilization
what is scurvy?
a disease often contracted by sailors that was actually a vitamin c deficiency
what is asthma?
◦ A condition where airways
become narrowed temporarily
◦ Can be triggered by many things,
dust, exercise, temperature
◦ Hundreds of years ago an asthma
attack could be fatal
◦ Developed inhalers to provide
medication and open airways
what factors affect human health?
Overall health of your cells and systems can be
determined by:
◦ Inherited diseases or conditions
◦ Sensitivity to environmental conditions
◦ How you respond to physical, emotional and
psychological stress
◦ How you treat your body in general
how many different chemicals are in cigarettes?
4000
what is tar?
◦ Dark sticky substance that forms as a cigarette burns
◦ Coat respiratory organs
◦ Tar prevents the movement of mucus out of the lung
what is carbon monoxide?
◦ Colourless odorless gas
◦ Is absorbed by blood cells instead of oxygen
◦ Smokers have less oxygen in their blood, their hearts need to beat faster
what is nicotine?
◦ A drug that speeds up the heart and raises blood pressure
◦ Highly addictive
what diseases could you get from smoking?
bronchitis, emphysema or lung cancer
what does fat turn into?
◦ Fat turns into cholesterol in your
body
◦ The more fat you eat the more
cholesterol builds up in your
arteries
what is atherosclerosis?
◦ Build up of cholesterol in arteries
◦ Pathways are narrower
◦ Heart has to pump harder to
move blood
◦ Blood lacks oxygen
◦ Could lead to heart attack
what factors affect the digestive system?
◦ Common problem: ulcers
◦ Used to believe they were due to stress
◦ Believed stress would cause a decreased
mucus production and gastric juice would
eat stomach lining
◦ Further research show it was the bacteria
H. Pylori.
◦ If the bacteria is not killed by the acid it
can break down the mucus
◦ Simple solution: Antibiotics
