Unit 2-Glossary Flashcards
Active transport
Movement of substances across the cell membrane against a concentration gradient, which requires an energy supply
Adrenaline
Hormone released by adrenal glands causing a wide range of effects
Allele
One of the different forms of a gene
Anomaly scan
Ultrasound scan taken between 18-20 weeks of pregnancy,
used to identify any aspects of
physical development of the limbs and vital organs which are unusual
Artificial insemination
The placing of sperm into the reproductive tract of a female for the purpose of impregnating the
female by using means other than sexual intercourse
Atheroma
A swelling in the artery wall which consists mainly of cholesterol, calcium salts and fibrous
material; also referred to as plaques
Atherosclerosis
A condition associated with a thickening of the artery walls that is caused by a build-up of fatty
material, especially cholesterol
Atria
Upper chambers of the heart
Atrio-ventricular (AV) node
A group of modified muscle cells which initiates the contraction of the ventricles
Atrio-ventricular valves
Valves located between the atria and ventricles which prevent backflow into the atria during
ventricular systole
Autonomic nervous system
ANS - involuntary system which controls basic body functions, e.g. heart rate, digestion, and
breathing
Autosome
One of the 22 pairs of chromosomes that control the general functioning of the individual, but
which do not determine the sex
Basal metabolic rate
The daily energy use when at rest
Body Mass Index (BMI)
BMI = Mass (kg) / (Height (m) 2)
A crude measure of body fat content
BMI greater than 30 indicates obesity
Carbohydrates
Chemicals containing only carbon, hydrogen and oxygen
Carrier
An individual who is heterozygous for particular characteristic, especially applied to genetic
disorders which are caused by a recessive allele carried on an autosome or an X-chromosome
Cervix
Lower, narrow portion of the uterus where it joins with the top of the vagina
Cholesterol
A type of lipid found in the cell membrane
Conception
The fusion of sperm and egg
Contraception
The prevention of fertilisation which may be achieved by natural or artificial means
Corpus luteum
Develops from the follicle after ovulation and secretes high levels of progesterone and lower
levels of oestrogen
Cortisol
A steroid hormone produced in the adrenal gland in response to stress
Cystic fibrosis
An inherited condition which causes the production of thick mucus in the respiratory system
Dating scan
Ultrasound scan taken between 8-14 weeks of pregnancy, used to determine the age of the
foetus and hence the expected date of delivery
Deep Vein Thrombosis (DVT)
Clots forming in veins, most usually in the legs, which can form an embolus which may lodge
in the lung causing a pulmonary embolism
Density
the mass of one cm3
Diabetes
a group of diseases in which a person has chronically high blood sugar levels
Diastole
Relaxation of the heart muscle
Diploid
a cell containing two sets of chromosomes
Dominant
an allele that is expressed in the phenotype of the heterozygote
Embolus
a blood clot which has broken free in an artery and may cause a stroke or heart attack
Endometrium
inner lining of the uterus into which the blastocyst implants
Endothelium
layer of cells forming the inside of all blood vessel walls
Epididymis
narrow, coiled tube attached to the back of each testis in which sperm mature and are stored
Evolution
the process of change in a species that is driven by the selection of the best adapted genotypes as breeding stock
F1generation
the first generation produced by two parents in a cross
F2generation
the generation produced by crossing two individuals from the F1 generation
Follicle
group of cells in the ovary containing the ovum
FSH
follicle stimulating hormone, produced by the pituitary which stimulates gamete production in the testis and ovary
Gamete
sex cell: male - sperm; female - ovum/ova
Gene
a discrete region of a chromosome whose DNA codes for the production of a polypeptide or protein
Genotype
the genetic makeup of an individual with respect to a particular characteristic
Germline
cells in the body (at any stage) which could pass their genes on to the next generation, i.e.gametes or their precursors, including undifferentiated stem cells (c.f. somatic cells)
Glomerular filtrate
the liquid from the blood which passes by pressure filtration from the glomerulus into the
Glomeruli
(glomerulus) a capillary bed surrounded by the Bowman’s capsule of the kidney nephron where blood filtration occurs
Glucagon
a peptide hormone (composed of amino acids) released by the ?-cells of the islets of Langerhans in the pancreas, which stimulates the liver to convert glycogen to glucose
Gluconeogenesis
metabolic pathway located in the liver (and part of the kidney) which makes glucose from non-carbohydrate organic substrates, e.g. glycerol, lactate and certain amino acids
Glucose tolerance test
a biochemical test to establish how well a person responds to a large oral dose of is used as a diagnostic test for diabetes glucose; it
Glycogenesis
synthesis of glucose into glycogen, in the liver and the muscles
Haploid
a cell containing one set of chromosomes (gametes)
HDL/LDL ratio
the ratio of high density lipoproteins to low density lipoproteins in the blood
HDLs
high-density lipoproteins that carry cholesterol from tissues to the liver
Heterozygous/a heterozygote
an individual possessing two different alleles of a gene/individual who is heterozygous
Homologous pairs
pairs of chromosomes which carry the same genes at the same place, are the same length and have the centromere in the same place
Homozygous/a homozygote
an individual possessing two identical alleles of a gene/an individual who is homozygous
Hormone
a chemical released by a cell or gland in one part of the body which becomes attached to receptors on particular cells, triggering activity in these target cells
Hyperglycaemia
blood glucose levels above 11mmol/L, causing a wide variety of symptoms including, at worst, coma and death
Hypoglycaemia
blood glucose levels below 3mmol/L, causing a wide variety of symptoms including, at worst, coma and death
Hypothalamus
located centrally at the base of the brain, it links the nervous system to the endocrine system through the pituitary gland, produces hormones, and controls body temperature, sleep, hunger, and daily body rhythm
ICSH
interstitial cell stimulating hormone, produced by the pituitary gland, which stimulates testosterone in the interstitial cells of the testis; also known as LH (luteinising hormone) in the female
ICSI
intracytoplasmic sperm injection
Identical twins
(also called monozygotic twins) two individuals produced by the fertilisation of a single egg and the subsequent splitting of the ball of cells - they are therefore genetically identical
Incompletely dominant
an allele that is not completely masked by the dominant allele and which therefore has some effect on an individual’s phenotype
Insulin
a peptide hormone (composed of amino acids) released by the ?-cells of the islets of
Interstitial cells
also known as Leydig cells, located between the seminiferous tubules of the testis, which release testosterone in response to ICSH
Invasive
test procedures requiring the removal of tissue, e.g. amniocentesis
IVF
in vitro fertilisation
Karyotype
an image of the chromosomes of one cell arranged in homologous pairs, the karyotype, which is then analysed to identify any anomalies in terms of the numbers or structure of the chromosomes
LDLs
low-density lipoproteins that carry cholesterol from the liver to body cells
LH
luteinising hormone, produced by the pituitary gland, which triggers ovulation and also stimulates the development of the corpus luteum
Linked genes
genes carried on the same chromosome
Lipolysis
the break down of fat to fatty acids and glycerol in fat cells
Lumen
central space in a blood vessel
Luteal phase
portion of the menstrual cycle from ovulation to the end of menstruation, during which the corpus luteum develops and releases progesterone
Lymphocytes
a type of white blood cell, which includes natural killer (NK) cells, T cells and B cells
Medulla
part of the central core of the brain which regulates the basic processes of breathing, heart rate, arousal and sleep
Meiosis
process of cell division taking place in the testis or ovary which produces gametes with one of each pair of chromosomes, so half the number in other body cells
Menopause
the stage at the end of a woman’s reproductive life (typically between the ages of 45 and 55) when the ovaries cease to release ova and menstruation no longer occurs
Menstrual cycle
physiological changes which take place in women of reproductive age, consisting of three phases: follicular, ovulation, and luteal
Menstruation
shedding of the endometrium over 3-5 days
Metabolism
a term referring to all of the chemical reactions that go on in cells to keep an organism alive
Mitosis
process of cell division which gives rise to all cells in the body apart from the sex cells, which exactly copies all of the chromosomes into the daughter cells
mmol/L
millimoles per litre, i.e. the molecular weight in grams, divided by 1000; for glucose 1mmol = 0.18 g
Motile
ability to move on its own, using energy to do it
Myocardial infarction
a heart attack that is caused by the interruption of the blood supply to part of the heart muscle, leading to its death
Non-identical twins
(also called dizygotic twins) two individuals produced by the fertilisation of two eggs who are no more genetically similar than any other siblings
Non-invasive
test procedures not requiring the removal of tissue, e.g. ultrasound scans
Obesity
a condition in which fat has accumulated in the body to the extent that it begins to have an adverse effect on health
Oestrogen
steroid hormone produced mainly in the follicles of the ovary, which causes the development of female secondary sexual characteristics during puberty and the development of the endometrium during the menstrual cycle
Osmotic pressure
(OP) a measure of the tendency of a solution to take in water; if blood has a high OP because it contains a high concentration of glucose, it will tend to remove water from tissues with lower solute concentration
Ovulation
mature follicle ruptures to release the ovum into the fallopian tube
Pancreas
the organ that is located close under the stomach which supplies digestive enzymes to the small intestine and hormones into the blood
Parasympathetic
part of the autonomic nervous system which is responsible for ‘rest and digest’ functions, generally slowing processes
Pedigree chart
a diagram that shows the occurrence of the phenotypes of a particular gene from one generation to the next
Peripheral Vascular Disease (PVD)
an obstruction by atherosclerosis of large arteries other than those in the vicinity of the heart or brain
P generation
the parents at the start of any pedigree chart
Phenotype
the expression of a gene in an individual in terms of appearance, behaviour or biochemistry
Phenylketonuria
(PKU) a genetic disorder caused by a recessive mutation to the autosomal gene which produces the enzyme that converts phenylalanine to tyrosine; the build-up of phenylalanine after birth seriously slows brain development
Pituitary gland
endocrine gland, attached to the hypothalamus at the base of the brain, which releases nine hormones involved in homeostasis
Platelets
cell fragments which are formed in the bone marrow; they lack a nucleus and are involved in both blood clotting and tissue regeneration
Polysaccharide
large carbohydrate molecules consisting of repeating units, e.g. glycogen, which is made up of glucose units
Precursor
a compound that is part of the chemical reactions that produces another compound
Primates
the class of vertebrate animals to which humans belongs, which includes species ranging in size from tiny lemurs to the gorilla; humans belong to the Hominidae family along with the great apes
Progesterone
steroid hormone produced by the corpus luteum and the placenta, which promotes the
Puberty
sequence of physical changes by which the human body develops from that of a child into that of an adult capable of reproduction
Recessive
an allele that is not expressed in the phenotype of the heterozygote
Red blood cells
cells which lack a nucleus; they are formed in the red bone marrow and transport oxygen around the body in the blood, taking it in when the oxygen concentration is high and giving it out when the surrounding oxygen concentration is low
Respiratory substrates
molecules which may act as the raw materials of respiration, e.g. glucose, amino and fatty acids
Saturated fats
fat containing only fatty acids which have no double bonds
Semilunar valve
valve in the opening of the major arteries leaving the heart which prevent backflow into the ventricles during diastole
Seminal fluid
fluid released during ejaculation by the male which contains sperm, water, proteins, amino acids, acids and minerals
Seminiferous tubules
site of meiosis in the testes
Sex-chromosome
one of the pair of chromosomes which determine the sex of the individual (XX in the female and XY in the male)
Sex-linked genes
genes carried on the X-chromosome
Siblings
offspring of the same parents, although the term can also be applied children who share a single parent (half- as opposed to full-siblings)
Somatic
cells of the body other than the germline cells
Stroke
a loss of brain function resulting from an interruption of blood supply caused by a blockage (thrombosis) or a haemorrhage
Sucrose
a discaccharide sugar composed of glucose and fructose
Superovulation
the development of several follicles and ova in a single menstrual cycle as a result of the taking of fertility drugs
Sympathetic
part of the autonomic nervous system which is responsible for ‘fight or flight’ functions, generally speeding up processes
Systole
contraction of the heart muscle, atrial systole preceding ventricular
Testis
male reproductive organ
Testosterone
steroid hormone, released by the interstitial cells, which stimulates the development of secondary sexual characteristics in puberty, sperm maturation, prevention of osteoporosis and many other effects
Thrombosis
the formation of a blood clot in an artery, which may break away to form an embolus - this may block the artery, causing a stroke or heart attack
Thrombus
a blood clot
Tissue fluid
(interstitial fluid) liquid which leaves the capillaries and bathes all cells; differs from blood in lacking red blood cells and the largest protein molecules
Twins
two individuals produced in the same pregnancy
Type 1 diabetes
formerly known as juvenile diabetes, usually developing in childhood, it is caused by autoimmune destruction of the ?-cells in the pancreas which produce insulin
Type 2 diabetes
also known as non-insulin-dependent or adult-onset diabetes, it is caused by the development of insulin resistance or, less often, by failure of insulin production
Vasoconstriction
narrowing of the smaller arteries and arterioles, restricting blood supply
Vasodilation
opening up of the smaller arteries and arterioles, increasing blood supply
Ventricles
lower chambers of the heart
White blood cells
cells of various types which are formed in the bone marrow and act as part of the immune system, combatting disease
Zygote
cell formed as the result of fertilisation, the fusion of sperm and egg
