Biology - Option

Nutrient

* chemical substances found in foods that are used in the human body
* some are essential others are non-essential, others are conditionally essential nutrients

Minerals

* in diet they tend to be ions
* inorganic
* deficiency disease can result if ________ is missing from diet

Vitamins

* chemically diverse carbon compounds that cannot be synthesised by body
* organic
* must be obtained from diet
* variety of roles
* required in small amounts

fat soluble vitamins

* A, E, D, K

water soluble vitamins

* B(1,2,3,5,6,7,9,12), C

Vitamin C

* contributes to formation of collagen (for tissues)
* majority of organisms can synthesise it
* mutations occur in genes that can no longer produce protein necessary for production of ________

Malnutrition

* may be caused by deficiency, imbalance or excess of nutrients in diet

essential fatty acids

omega-3 and omega-6

* growing evidence that they help lower risk of heart disease
* may protect against type 2 diabetes, alzheimers, brain-decline

amino acids

some ________ are essential as they cannot be synthesised by our bodies, and encode for a specific protein

* the other half can be made from simpler nitrogen compounds

Lack of protein

* Lack of blood plasma proteins 
* fluid retained in tissues
* Edema (swelling)
* More obvious in the abdominal
* Children may be impacted mentally and physically
* Stunted growth & development disabilities 

Hypothalamus

appetite is controlled by a centre in the _______

hypertension

* individuals who are overweight are more likely to suffer from _______ (high blood pressure)
* excess weight causes more strain on the heart to pump blood (increase in heart rate → increase in blood pressure)
* high cholesterol diets lead to atherosclerosis (narrows and hardens blood vessels) increasing blood pressure

type 2 diabetes

* individuals who are overweight are more likely to suffer from _______ (unresponsiveness to insulin)
* liver and muscle cells become unresponsive to insulin
* due to diet rich in sugars causing overstimulation of these cells by insulin

calcium

* needed for bone growth and strength, blood clotting, muscle contractions and neurons

Iron

* Needed for RBCs and many enzymes

Magnesium

* helps with heart rhythm, muscle and nerve function, bone strength

phosphorus

* helps make energy, needed for bone growth

potassium

* helps control blood pressure, makes kidney stones less likely

zinc

* supports immune system, nerve function, reproduction

PKU

* mutation to the gene encoding the enzyme *phenylalanine hydroxylase*
* build up of phenylalanine in blood and urine
* can lead to brain damage

Vitamin D deficiency (rickets)

* Body cannot properly absorb calcium and phosphorus due to lack of vitamin D, leads to bone weakness and pain

anorexia nervosa

* lack of many nutrients
* loss of appetite and loss of weight

scurvy

* lack of vitamin C
* leads to skin discolouration
* lack of collagen synthesis and connective tissue

automatic nervous system

________ controls whether digestion should be occurring in case of a fight or flight response

nerves and hormones, nervous mechanism, hormonal mechanism

_________ control secretion of digestive juice.

_________

* stimulation occurs via automatic nervous system
* occurs using nerve cells to produce a response in target cells
* releases NTs producing short and quick lived response

_________

* secreted by endocrine cells into blood stream
* transported to target cells to produce a slow, long lasting response

cephalic phase

* smell or taste of food causes brain to send nerve impulses via vagus nerve from the medulla
* occurs in brain

gastric phase

* maintains secretion of gastric juice
* enter of food stimulates medulla oblongata to send nerve impulses via vagus nerve to maintain secretions

intestinal phase

* chyme entering duodenum inhibits secretion of gastric juices
* chyme entering duodenum signals to medulla oblongata to inhibit secretions, hormones are also released to gastric gland to stop secretion

Cholera

* diarrheal illness caused by infection of intestine with vibrio cholreae bacteria
* causes diarrhea and dehydration
* treatments include rehydration, IV fluids, antibiotics

Gastrin

* stimulates secretion of acid and pepsinogen by exocrine glands
* released by G cells (endocrine cells)

secretin and Somatostatin

* inhibit gastrin secretion if pH in stomach is too low
* source duodenum (pancreas for somatostatin)

salivary glands

source of saliva

* saliva contains (amylase, lysozymes, etc.)

stomach

source of gastric juice

* gastric juice contains (HCL, pepsin, etc.)

pancreas

sources of pancreatic juice

* pancreatic juice contains (enzymes (amylase, lipase, etc.))

Endocrine glands

* secrete directly into the blood stream

exocrine glands

* secrete to the surface of the body or lumen of gut

Acinus

* identification of exocrine glands
* groups of secretory cells that surround a duct branch in lumen of the stomach

Acid, acid, denatures, hormones, bile, pancreatic, HCl, pepsin, polypeptides

* _______ secreted by parietal cell in stomach
* _______ kills bacteria, virus but also _______ proteins in fluid making it easier for the enzyme break down
* stimulates secretion of _______ that promote flow of _______ and _______ juice
* pepsinogen combines with _______ to form _______, which breaks down long _______ into shorter ones

epithelial, tightly, blood vessels, microvilli, SA, mitochondria, active transport, pinocytic

Adaptations of Villi

* _______ cells adhere _______ together assuring materials pass into the _______ lining the villi
* _______ made up brush border on the lumen side to increase _______ for absorption
* large number of _______, generate lots of ATP for _______
* many _______ vessels due to absorption by endocytosis

Apical surface

surface facing lumen

Basal Surface

surface facing blood vessels

Protective lining

* surface mucus and mucus neck cells
* prevents digestion of tissue and proteins in stomach

Ulcers

* Crater like lesion in a membrane, peptic ulcers are a result in the GI tract.

Caused by:

* H. Pylori
* hypersecretion of HCl
* inflammatory drugs such as aspirin

Cured by:

* antibiotics
* proton pump inhibitor drugs

proton pump inhibitor drugs

* low pH maintained by proton pumps in the parietal cells of the gastric pits

Dietary fibre

* indigestible plant carbohydrates (humans lack enzyme)
* cellulose
* lignin
* pectin

Insoluble fibre

* woody + structural parts of plants, skin on fruit
* speeds flow through the intestines

soluble fibre

* slows passage and decreases cholesterol

Roughage

* provides bulk in intestine
* absorbs water

materials egested as feces

* bile pigments
* human flora
* cellulose
* lignin
* epithelial cells

endothelial cell

* lines innermost layer of circulatory system
* 1 layer
* made of vimentin

Epithelial cell

* lines outermost surface of body
* varying layers
* keratin filaments

Sinusoids

* subdivided veins in the liver
* main role is exchange, they are wider than capillaries, and its wall isn’t continuously lined with cells and has increased permeability
* lined with endothelium, allows contact with hepatocytes (liver cells)
* eventually merge with hepatic artery and rejoin with hepatic vein carrying blood to vena cava

Hepatic artery

* bring oxygen rich blood from the heart branching at the aorta

hepatic vein

* brings blood back from the stomach and intestines typically with little oxygen

hepatic portal vein

most blood circulating in the liver comes from the __________ (comes from digestive system to liver)

RBCs, phagocytic macrophages

______ lack a nucleus and other organelles, therefore they cannot synthesise new components or repair damage

* therefore they are removed from circulation and destroyed by ______ (kupffer cells) in the liver

Kupffer cells

* specialised macrophage in the wall of the sinusoids, fixed in place
* destroy worn out red and white blood cells and other foreign matter
* have arm-like extensions called filopodia

kupffer cell, kupffer cell, RBCs, globin, heme, globin, amino acids, iron, heme, transferrin, ferritin, bone marrow, non-iron, bilirubin, bile, excreted

RBC life cycle - stages inside a ______


1. ______ phagocytise ruptured and worn out ______
2. ______ and ______ portions of hemoglobin are separated
3. ______ is broken down into ______ which can be used to synthesise new proteins
4. ______ is removed from ______ and associates with protein called ______


1. either iron detaches from transferrin attaches to storage moleucle called ______
2. or iron carried to ______ with transferrin for use in new RBCs
5. ______ portion of heme is converted to ______
6. bilirubin is then secreted by liver cells into ______
7. It is then ______

toxins

liver functions to remove ______ and detoxify them

jaundice

* yellow discolouration of the skin due to increased bilirubin in the blood (by product of destruction of RBCs)

Adult jaundice

* caused by liver diseases, obstruction of bile duct or pancreatic cancer
* brain condition → bilirubin encephalopathy
* treatment depends on cause

Infant jaundice

* Liver isn’t capable of processing bilirubin (also not fed properly)
* brain condition → bilirubin encephalopathy
* treatment → exposure to sunlight or exposure to UV light

glucose, glycogen, glucose, glucagon, glucose, glycogen, insulin, amino acids, lactic acid

Carbohydrate metabolism function of liver

* maintain _______ glucose levels
* if low → liver breaks down _______ to _______ by _______
* if high → liver converts _______ to _______ by _______

Liver can also convert _______ and _______ to glucose

Hepatocytes

* absorb and store nutrients
* retinol (vit A)
* glucose
* iron
* calciferol (vit D)
* stored in _______ when in excess and released when in deficit
* break down cholesterol
* produce plasma proteins

hepatocytes, bile salts

_______ break down **excess** cholesterol into _______ and use it to make bile

sources of cholesterol

1. Food
2. synthesised by hepatocytes

Contents of bile

* bile salts
* cholesterol
* bilirubin
* hydrogen carbonate ions

lipids, synthesising, breaking down, cholesterol, phospholipids, cholesterol, lipoproteins, hydrophilic, hydrophobic, chylomicrons

lipid metabolism function of liver

* liver regulates amount of circulating _______ such as cholesterol by:
* _______ as required
* _______ as required
* secreting _______ and _______ in bile
* excess saturated fat increases production of _______
* Lipids are transported in the blood in vesicles know as _______
* lipoproteins are composed of:
* _______ exterior (phospholipids, cholesterol, proteins)
* _______ core (cholesterol and fats (triglycerides))
* _______ transport lipids from intestine to the liver

hepatocytes

Production of plasma proteins

* _______ produce plasma proteins
* _______ in hepatocytes produce majority of plasma proteins such as:
* albumin
* fibrinogen
* alpha globulins
* beta globulin
* prothrombin

albumin

* helps regulate blood osmotic pressure
* is a carrier for bilirubin and some other fat soluble molecules

fibrinogen

* gets converted to fibrin to form mesh component of blood clot

alpha globulins

* transport hormones, lipids, cholesterol, copper throughout body
* serve as enzymes and carriers

beta globulins

* transport proteins through blood

prothromibin

* helps blood clotting process
* converted by clotting factors to thrombin which catalyses conversion of fibrinogen to fibrin

liver main functions

1. responsible for storage and controlled release of key nutrients
2. responsible for detoxification of potentially harmful ingested substances
3. produces plasma proteins that function to maintain sustainable osmotic conditions within the bloodstream
4. responsible for breakdown of RBCs and production of bile salts

Cardiac muscle cells

* Branching (allows for faster propagation of signal)
* Intercalated discs (binding sites of strong adhesion) (allows beating in coordinated fashion
* Gap Junction (allows diffusion of ions and small molecules between adjacent cells)
* high number of mitochondria
* Myogenic beating

striated, actin, myosin

cardiac and skeletal muscle both _______ in appearance and have similar arrangement of contractile proteins (_______ and _______)

organs, vessels, respiratory, tapered, branching, striated , slowly

Smooth muscle

* located on the wall of hollow _______, _______, _______ passageways
* _______ at each end, have _______ networks and aren’t _______
* Involuntary
* produces peristalsis
* contracts and relaxes _______; may sustain contraction

heart, branching, intercalated, striated, nucleus

cardiac muscle

* located on wall of _______
* have _______ networks, contain _______ discs , lightly _______, have single _______
* Involuntary
* pumps blood out of heart
* Myogenic but influenced by nervous system and hormones

bones, long, cylindrical, nuclei, striated, rapidly

skeletal muscle

* attached to _______
* are _______ and ______, have multiple _______ and are heavily _______
* Voluntary
* produces movement of joints
* stimulated by nervous system
* contracts and relaxes _______

shorter, wider, CM, CM, CM, CM, SM

Differences between cardiac and skeletal muscle

* CM _______ and _______ than SM
* Longer refractory period for _______
* Gap junctions exist in _______
* _______ is myogenic
* _______ is involuntary whereas _______ is voluntary

sinoatrial node, atrioventricular node

_______ initiates the contraction of cardiac muscle cells, and _______ delays movement of electrical signal by 0.12 seconds

purkinje

_______ fibres conduct the signal very rapidly to the ventricles

smaller, Na+, greater, longer, fewer, more

Specialisations in AV node


1. _______ diameter (don’t conduct as quickly)
2. reduced number of _______ channels in membrane


1. _______ resting potential
2. _______ refractory period
3. _______ gap junctions between cells of AV node (increases delay)
4. _______ non-conductive tissue present (stops depolarisation, increases delay)

fewer, bigger, more, shorter, high

Modifications to purkinje fibres


1. _______ myofibrils (function is electrical impulse not contraction)
2. _______ diameter (faster conduction)
3. _______ Na+ channels (_______ refractory period)
4. _______ number of mitochondria and glycogen stores

Stethoscope

* improved knowledge of workings of the heart
* invented by rene laennec in order to hear the heart without pressing ear to chest

veins, arteries, platelets, RBCs, fibrin

Thrombosis

* occurs when blood clots _______ or _______

2 components

* aggregated _______ and _______ form plug
* mesh of _______

Causes

* sitting or static for too long
* genetics
* obesity

Symptoms

* pain/swelling in 1 leg
* chest pain
* numbness on 1 side of body

ventricular fibrillation

abnormal heart beat rhythm

normal sinus rhythm

normal rhythm originating from the sinus node, describing characteristic rhythm of a healthy human heart

sinus tachycardia

* irregular heart beat where heart beats fast than normal

sinus bradycardia

* irregular heart beat where heart beats slower than normal

steroid hormones

* cholesterol based and lipid soluble


1. can pass through bilayer easily
2. bind to receptor to form hormone receptor complex
3. regulate gene transcription

Peptide hormones

* made from amino acids (water soluble)
* cannot pass through membrane


1. bind to receptors on plasma membrane
2. secondary messenger released into the cell
3. secondary messenger activates or inhibits enzymes

hypothalamus

* link nervous system to endocrine system
* controls pituitary gland

pituitary gland

* secretes hormones
* contains posterior (back) and anterior (front)

neurosecretory cells, portal veins

* ________ connect hypothalamus with pituitary
* ________ link capillary networks

posterior pituitary

secretes:

* ADH
* Oxytocin

Anterior Pituitary

secretes:

* TSH (thyroxin stimulating hormone)
* growth hormones
* FSH, LH
* Prolactin

FSH, LH, ovulation, sperm

_______ and _______ control reproduction

* prepare ovarian cells for _______ in females and needed for _______ production in males

GH, mitosis, growth

_______ controls growth

* stimulates _______ and organism _______ (in coordinated fashion)