Unit 8: The Human Body- BIO Flashcards
Nutrients
-Usable parts of food
-Provide our bodies with chemicals and energy
Why do we eat?
-Nutrients
-Energy
-Flavor Satisfaction
-Social
-Bored
Nutrition
-Life activity by which your body gets food and changes it into a usable form
6 major groups of nutrients
- Carbohydrates
- Lipids
- Proteins
- Vitamins
- Minerals
- Water
Carbohydrates
-A primary source of energy
-Provides roughage- not digestible material
Lipids (Fats and Oils)
-A source of stored energy
-Yield more energy per gram than carbohydrates
Proteins
-Build and repair body tissue
-Source of energy
Vitamins
-Work as coenzymes to allow proper enzyme function
Minerals
-Build body parts
-Involved in muscle and nerve action
-Regulate body functions
Water
-Dissolve and transport materials
-Makes up approximately 65% of our body weight
Obesity
-The #2 preventable death in the world
-60% of americans are overweight/obsese
BMI
-Body Mass Index
-A number calculated from a persons weight and height
-A reliable indicator of body fatness
-A screen for weight problems that may lead to health problems
Digestion
-A process that changes food into a form that can be used by your body cells
How do we take in food?
Ingestion
Two forms of digestion
-Mechanical
-Chemical
Mechanical DIgestion
-The physical breakdown of food into smaller pieces in order to increase the surface area
Chemical DIgestion
-Chemical changes of complex food molecules into simpler molecules
Gastrointestinal Tract
-Continuous one way tube
-Starts at the mouth and ends at the anus
Peristalsis
-Slow, rhythmic muscular contractions used to move food through the GI tract
Mouth
-Teeth and jaws use mechanical digestion (mastication)
-Salvary glands produce saliva to start chemical digestion and to help moisten food
Amylases
Enzymes that break down carbs
Tongue
-Helps with the swallowing and tasting of food
Once food is swallowed it enters the..
-Esophagus
-This tube moves food from the mouth to the stomach
-Esophagus produces mucus which lubricates food so that it slides down easier
Stomach
-Mechanically churns and mashes food
Hydrochloric acid destroys bacteria and provides the proper PH for enzyme action
-Turns food into a think mixture called Chyme
Pepsin in the stomach
-Chemically digests proteins
-Gastric juices contain this
-What do glands in the stomach lining secrete?
-Gastric juice and hydrochloric acid
What 4 things does the pancreas digest?
- Pancreatic juice
- Nucleases
- Insulin
- Glucagon
Pancreatic juice
Digests carbs
Nucleases
Splits DNA and RNA into nucleotides
Insulin
-Converts excess glucose in the blood into glycogen for storage
Glucagon
-Counteracts insulin by telling the liver and the small intestines to increase blood glucose levels
Small Intestine
-Most chemical digestion takes place here
-Lined by tiny finger-like projections called villi
-Food broken down into simple molecules like monosaccharides, amino acids, fatty acids, and glycerol
Villi
-Villi line the small intestine
-Increase the surface area of the small intestine for the absorption of digested food through diffusion
The liver’s role in digestion
- Carbohydrate metabolism
- Protein metabolism
- Fat metabolism: Bile (emulsifies fat = breaking it into very small particles) stored in gallbladder
- Filters toxins
Hepatic portal vein
-Connects small intestines to Liver before going to the heart
Food travel
- Swallowed
- Mouth to stomach in 5-7 seconds
- Stomach 2-6 hours
Digestive enzyme in the mouth
Amylases- digests carbs into Maltose
Digestive enzyme in the stomach
Pepsin: Digest protein into amino acid
Lipase: Digest Lipids into fatty acids and glycerol
Small Intestine digestive enzymes
Maltase- digests maltose into glucose
Lactase- digests lactose into glucose and galactose
Sucrase: Digests sucrose into glucose and fructose
Rectum
-Lower end of the large intestine that stores undigested substances called feces
Feces is eliminated from the body through the anus in a process called …
Egestion
Feces is eliminated from the body through the anus in a process called …
Egestion
Large Intestine
-Receives indigestible foods from the small intestine
-Water and some vitamins/ minerals absorbed (sodium and potassium)
Nutrient absorption in the stomach
-Alcohol
Nutrient absorption in the small intestine
-Glucose
-Amino Acid
-Fats
-Vitamins
-Water
-Alcohol
Nutrient absorption in the large intestine
-Alcohol
-Water
-Sodium
-Potassium
Why do we excrete waste?
-By-products of reactions
-Waste products are sometimes harmful
Metabolic wastes
-Wastes produced by life activities
-Example: Carbon dioxide, water, and urea
Where are metabolic wastes excreted?
Carbon dioxide and water -> respiration
Urea -> urination
Protein/Nucleic acids turn into..
ATP and Nitrogenous wastes
-Nitrogenous wastes = ammonia, uric acid, urea
Ammonia
-Very toxic
-Must be excreted diluted
-So access to large volumes of water necessary
Uric Acid
-Insects, Reptiles
-Relatively non-toxic
-Extremely energy expensive
-Allows organisms to retain large amounts of water
Urea
-Nitrogenous waste of mammals, amphibians, sharks, marine bony fishes and turtles
-Ammonia+ carbon dioxide = urea
-Very low toxicity
Kidneys
-Bean-shaped organs that lie along the back wall of the abdomen
-Filters urea, excess water, and salts from the blood
-Excretion from kidneys called urine
Urinary System
- Blood with urea
- Kidneys (filters blood)
- Kidney excretes urine (urea and water)
- Ureter (tube connecting the kidney with the bladder)
- Bladder (stores urine temporarily)
- Urine leaves body through urethra
UTI
-A bacterial infection of the urinary system
-50-60% of adult women have at least one uti in their life
-3x more common in women than men
Kidney stones
-Solid materials that can block the excretory system
Diuretic
-A chemical substance that prevents water from being reabsorbed in the kidneys
-Coffee/tea/soda has it
Regulation
-The life process in which cells and organisms respond to changes within and around them
Hormones
-Chemical messengers, carrying instructions to regulate the activities of other cells
Endocrine system
-Hormones and their gland producing organs which bring slow, longer-lasting responses and changes
Endocrine glands
-Ductless glands: release hormones directly into the bloodstream
-Each hormone has a specific target tissue
Pituitary gland
-Base of the brain
-Growth hormone
-Stimulates the elongation of long bones
Pituitary disorders
-Oversecretion: gigantism
-Undersecretion: dwarfism
Thyroid
-In the neck
-Hormone: Thyroid
-Function: Regulates rate of metabolism, essential for mental/physical development
Thyroid disorders
Oversecretion: weight loss
Iodine Deficiency: goiter=enlargement of thyroid gland
Parathyroid
-Back of the thyroid gland
-Hormone: parathormone
Function: controls the metabolism of calcium
Parathyroid disorders
-Undersecretion: brittle bones
Adrenal Gland
-Top of each kidney
-Hormone: adrenaline
-Function: raises blood sugar levels and increases heartbeat/ breathing rates
Adrenal gland disorders
Undersecretion: inability to deal with stress
Pancreas
- Produce insulin and glucagon hormones
- Produce pancreatic juices -> digests chyme in the small intestine
Puberty
Hormones secreted by gonads (testes and ovaries) produce physical changes in the human body enabling the body to produce gametes (sex cells)
Hormone action
Hormones work like a “Lock and Key”
Specific hormones bind to specific target cells at locations called receptors
2 Major Types of Hormones:
-Protein Hormones- interact with cell membrane to cause changes inside cells (fast/short acting)
-Lipid “Steroid” Hormones- interact with structures inside the cell (slow/long acting)
What happens when the body can’t maintain homeostasis?
Failure to respond can lead to an infectious disease (illness caused by organisms/ viruses that enter and reproduce inside)
Why do we get diseases?
Inheritance (ex. genetics)
Toxic substances (ex. poisons)
Poor nutrition (ex. low protein levels)
Organ malfunction (ex. kidney malfunctions)
Personal behavior (ex. poor hygiene, lack of sleep, stress)
Types of diseases
Viruses (lifeless thing made up of genetic material inside a protein coat, reproduce inside a living cell called a host)
Bacteria
Fungi
Protozoans
Insects
PATHOGENS
virus or organism that causes an infectious disease
How does our body respond to these pathogens (non-specific defenses) ?
-Skin
-Sweat (salty and acidic) prevents growth of bacteria
-Mucus coats and traps bacteria
-Tears wash out foreign material
-Fever, slows growth of pathogen
-Coughing, Sneezing, Vomiting!
What’s an allergic reaction?
Body’s responses to usually harmless environmental substances (ex. Foods, pollen, insect bites, etc.)
Ability of the body to resist certain disease-causing organisms is called
IMMUNITY
What is our SPECIFIC defense?
White Blood Cells (Leukocyctes)
Produced in our bone marrow
Irregular in shape and have no color
Much larger than red blood cells
Types of White Blood Cells: Macrophages
consume pathogens and infected cells
Cytotoxic T cells:
attack and kill infected cells
B cells
label invaders for later destruction by macrophages
-release antibodies
Helper T cells
Activate both cytotoxic T cells and b cells to fight infection
How do white blood cells recognize invaders?
White blood cells recognize and bind to specific ANTIGENS based on similar shape
Antigens- Recognizing features on the surface of infected cells
How does an immune response work?
Macrophage engulfs pathogen
↓
Helper T cells bind to antigen presented on macrophage
↓
Helper T cells activate cytotoxic T cells and B cells
↓
B cells produce antibodies that attach to pathogen
↓
Cytotoxic T cells puncture infected cell’s cell membrane, destroying pathogen
Antibody
specialized antigen receptor proteins
1st – Antibody recognizes and binds to a certain antigen
2nd – Assists in neutralizing the antigen
How do antibodies assist?
Block viral binding sites or coat bacteria → Phagocytosis (cell eating”)
Clump viruses or bacteria → Phagocytosis
Attach and poke holes in plasma membrane → cell lysis (rupture)
What is a vaccine?
Weakened pathogen (or part of them) or mRNA (that stimulates production of foreign protein) stimulates the immune system to react
Reaction prepares the body to fight subsequent invasions by the same pathogen
Preparation and use of a weakened virus vaccine
- Obtain pathogen
- Kill/weaken it
- Inject it into organism
- Body responds by producing antibodies/wbc
- Some wbc remain and remember pathogens to protect the body in the future
- Second response to disease is faster, most of the time before the disease has a chance to develop
What is a Variant?
A mutation that occurs in a virus overtime by errors happening as the virus replicates its genome
Who is most at risk for covid?
-Elderly people
-People with cardiovascular disease, diabetes, chronic respiratory disease, cancer
-Those with dementia / other neurological conditions
-Pregnant woman
-Smokers
-People that are overweight
-Hemoglobin blood disorder patients
Where did HIV first come from?
- HIV probably came from chimpanzees in central Africa between 1915 - 1940 but was very rare
HIV
Human Immunodeficiency Virus
Damages the immune system
Leaves the body unable to deal with multiple infectious agents and cancerous cells (ex. pneumonia)
AIDS
Acquired Immunodeficiency Syndrome
How does HIV work?
-Mutation allows HIV to recognize a receptor protein called CD4 on helper T cells
-HIV attaches and enters a helper T cell
-Viral RNA is converted to complimentary single strand of DNA through reverse transcription (making HIV a Retrovirus)
-Enzymes form double-stranded DNA
-Double-stranded DNA integrated into host DNA
-When host DNA carries out transcription it makes HIV
Why is HIV so bad?
-NO CURE
Destroys helper T cells
Leaves the body susceptible to opportunistic infections, illnesses caused only in people with weakened immune systems
How can you get HIV?
-Blood
-Semen
-Pre-seminal fluid
-Rectal fluids
-Vaginal fluids
-Breast milk—from an HIV-infected person can transmit HIV!
Most HIV cases are from
Unprotected sex
Non Sterile needles
Mother-child transmission
Blood Transfusions (pre-screening)
How are you diagnosed with HIV?
Test positive for the presence of antibodies to the virus
HIV Treatment
NO CURE!!!
Treatment can minimize reproduction of the virus
Prevent binding of virus to receptors on the plasma membranes
Reverse Transcriptase inhibitors
interfere with the enzymes that control reverse transcription
Integrase inhibitors
Prevent HIV from inserting viral DNA into host DNA
Pre-Exposure Prophylaxis (PrEP)
Pre-exposure prophylaxis is medicine taken to prevent getting HIV
-Highly effective
PrEP reduces the risk of getting HIV from sex by about 99%.
PrEP reduces the risk of getting HIV from injection drug use by at least 74%.
Why can’t we come up with a vaccine for HIV?
HIV is constantly mutating with every reproduction
Anti-HIV drugs only slow the progress and are very expensive
Already some drug resistant forms of HIV have evolved
What is corona virus?
A collection of RNA viruses named for their crown-like spikes on their surfaces
-They can cause a number of respiratory, gastrointestinal, & neurological diseases in humans/animals
-There are 7 known coronaviruses known to infect humans
Long term effects of covid
Fatigue, not being able to focus, headache, loss of taste and smell, dizziness, heart beating fast, chest pain, difficulty breathing, cough, joint and muscle aches, depression, anxiety, fever, etc.
There can be long-term effects on organs, such as the heart, lungs, kidneys, skin, and the brain
Subunits of Kidneys
Nephrons
