A&P Flashcards
(525 cards)
1
Q
What is homeostasis?
A
The maintenance of stable living conditions
2
Q
Components of a feedback system
A
Stimulus, Controlled condition, Receptor, Control Centre, Effectors, Response
3
Q
What does a negative feedback system do?
A
Reverses an effect
4
Q
What does a positive feedback system do?
A
Enhances an effect
5
Q
What are the different methods of measuring body temperature?
A
Oral, axillary, tympanic and rectal
6
Q
What is core temperature?
A
The temperature of the deep tissues of the body.
7
Q
Average core temperature
A
36.5-37.5°C
8
Q
What is peripheral temperature?
A
The temperature of the blood flow through the vessels under the skin
9
Q
Average peripheral temperature
A
18-36°C
10
Q
Cyclic variations in normal temperature
A
0.25-0.5°C
11
Q
Axillary temperature
A
Armpit. Usually 1°C lower than oral and up to 2°C lower than rectal. Least accurate.
12
Q
Rectal temperature
A
Usually most accurate - especially best for infants.
13
Q
Role of hypothalamus in regulating temperature
A
The hypothalamus checks our current temperature and compares it with the normal temperature of about 37°C. If our temperature is too low, the hypothalamus makes sure that the body generates and maintains heat.
14
Q
Signs of a temperature
A
Increased heart rate, red face due to increased blood flow.
15
Q
Tissue repair - normal vs. scar
A
New cells originate via cell division from the stroma, or the parenchyma. If parenchymal cells accomplish the repair, tissue regeneration is possible. However, if fibroblasts need to come in, then they synthesise materials that aggregate to form scar tissue, through a process called fibrosis.
16
Q
Why is the endocrine system ductless?
A
It is quicker to dump hormones directly into the bloodstream
17
Q
Technical term for generating heat
A
Thermogenesis
18
Q
What do goosebumps do?
A
Trap air
19
Q
Flow chart of temperature regulation
A
Stimulus decreases body temp –> Thermoreceptors –> Hypothalamus and anterior pituitary –> Vasoconstriction decreases heat loss through skin, Adrenal medulla releases hormones that increase cellular metabolism, skeletal muscles contract and cause shivering, thyroid gland release thyroid hormones which increases metabolic rate –> Response
20
Q
What is heat?
A
A form of energy measured in calories
21
Q
What is a calorie?
A
The amount of energy required to raise the temperature of 1g of water by 1°C.
22
Q
Metabolic rate definition
A
The rate at which heat is produced from the catabolism of food
23
Q
4 principle routes of heat loss
A
- Radiation
- Conduction
- Convection
- Evaporation
24
Q
BMR
A
Basal Metabolic Rate
25
Where are baroreceptors located?
In the carotid sinus and its aortic arch.
26
How do baroreceptors detect pressure changes?
By responding to changes in the tension of the arterial wall
27
Flow chart of an injury
Injury --> Platelets release growth factors --> Neutrophils and macrophages engulf bacteria --> Epithelial + endothelial cells and fibroblasts produce growth factors --> Synthesis of extracellular matrix and new capillaries --> Fibroblasts orchestrate remodelling of scar by producing ECM, MMPs and TIMPs --> Mature scar
28
Which part of the brain connects the endocrine and the nervous system?
The hypothalamus
29
What is the response of the effector to the stimulus in a negative feedback system?
It inhibits the original stimulus
30
What does the adrenal medulla respond to?
Neural stimuli, not ACTH
31
What does innate immunity include?
External physical and chemical barriers provided by skin and mucous membranes. Also includes various internal defences such as antimicrobial substances, NK cells, phagocytes, inflammation and fever
32
First line of defence against pathogens?
Skin and mucous membranes.
33
Second line of defence against pathogens?
Internal defences
34
What does telomerase do?
maintains chromosome ends
35
4 main types of antimicrobial substances
interferons, complement system, iron binding proteins and antimicrobial proteins
36
What is inflammation?
Defensive response to tissue damage
37
Impact of fever
Intensifies effects of interferons, inhibits growth of some microbes and speeds up body reactions that aid repair
38
5 cardinal signs
Pain, redness, swelling, heat, loss of function
39
2 examples of commensal bacteria and their location
Staphylococcus aureus - mouth
| Escherichia coli - gut
40
Flow diagram for inflammation
Tissue injury --> microbes enter --> release chemicals which are recognised by body --> initiates release of phagocytes --> blood vessels leak fluid into tissues, causing swelling
41
Difference between granular and agranular leukocytes
Granular contain granules that are visible under a light microscope after staining
42
Why don't red blood cells contain a nucleus?
to increase surface area, allowing space for haemoglobin
43
What does the T in T cells mean?
Thymus
44
What does the B in B cells mean?
Bursa
45
Which cells are formed from a myeloid stem cell?
Erythrocytes, platelets, leukocytes
46
Which cells are formed from lymphoid stem cells?
T, B and NK cells
47
What does adaptive immunity mean?
The production of specific types of cells or antibodies to destroy a particular antigen. Involves B and T cells.
48
Two types of adaptive immunity
Cell mediated and antibody mediated
49
Cell mediated immunity
Doesn't use antibodies. Cytotoxic T cells directly attack invading antigens and phagocytes are activated.
50
Antibody mediated immunity/humoral
B cells transform into plasma cells, then secrete antibodies
51
Clonal selection
Lymphocyte proliferates and differentiates in response to specific antigen, forming a clone of cells that can recognise the same antigen.
52
What is an antigen?
Any substance the body recognises as foreign
53
Which 2 types of cells does clonal selection lead to?
Effector and memory
54
Effector cells
carry out immune responses that result in the destruction/inactivation of the antigen.
55
Memory cells
do not participate in initial immune response, but if antigen reappears in future, will quickly respond by proliferating and differentiating into more effector and memory cells.
56
Effector cells include...
active helper T cells, active cytotoxic T cells and plasma cells
57
Memory cells include...
memory helper T cells, memory cytotoxic T cells and memory B cells.
58
Naturally acquired active immunity
After exposure to microbe, antigen is recognised by B cells and T cells and costimulation leads to the antibody secreting plasma cells, cytotoxic T cells and B and T memory cells
59
Naturally acquired passive immunity
Transfer of IgG antiboies from mother to foetus aross placenta or of IgA antibodies via breastmilk.
60
Artificially acquired active immunity
antigens introduced during vaccination stimulate cell mediated and antibody mediated immune responses, leading to the production of memory cells. Antigens pretreated to be immunogenic but not pathogenic, meaning they will trigger an immune response but not cause illness.
61
Artificially acquired passive immunity
IV injection of immunoglobulins
62
What are interferons?
a group of signalling proteins made and released by cells in response to the presence of viruses
63
What do interferons do?
Boost immune response and regulate the action of several genes which control the secretion of cellular proteins affecting growth
64
What does the complement system do?
enhances the ability of antibodies and phagocytic cells to clear microbes, promote inflammation and attack the pathogen's cell membrane
65
Iron binding proteins
carrier proteins needed for the proliferation and maturation of immune cells
66
Antimicrobial proteins
contain sites that target specific microbial macromolecules.
67
What do the smaller antimicrobial proteins do?
disrupt structure and function of microbial cell membranes
68
What is chemotaxis
the movement of an organism in response to a chemical stimulus
69
What do immune cells use chemotaxis for?
to circulate between vascular and lymphatic systems and to migrate from the blood to the site of infection
70
IgA - where is it? what does it protect against?
Found in mucous, saliva, tears and breast milk. Protects against pathogens
71
IgD - where is it? what does it do?
part of B cell receptor, activates basophils and mast cells
72
IgE - what does it do?
protects against parasitic worms and responsible for allergic reactions
73
IgG - how does it travel?
secreted by plasma cells in blood, crosses from mother to foetus via placenta
74
IgM - where is it? what does it do?
may be attached to surface of B cell or secreted into blood. Responsible for early stages of immunity.
75
What is a mast cell?
a cell filled with basophil granules
76
Frank-Starling law
the greater the force of contraction during systole, the more forcefully it will contract
77
How does ANS affect force of contraction?
Stimulation increases force, inhibition decreases force
78
Effect of increased nerve impulses from vagus nerves (parasympathetic)
decreased heart rate
79
Effect of increased nerve impulses from cardiac accelerator nerves (sympathetic)
increased heart rate and contractility
80
Effect of increased nerve impulses from vasomotor nerves (sympathetic)
vasoconstriction
81
Perfusion definition
the passage of fluid through the circulatory system or lymphatic system to an organ or a tissue, usually referring to the delivery of blood to a capillary bed in tissue
82
Signs and symptoms of altered perfusion
dyspnoea, cough, chest pain, tachycardia, hypotension, cyanosis, changes in arterial blood gases, changes in ECG and biochemistry, confusion and anxiety, oedema, finger clubbing
83
How does the movement of fluids and solutes out of capillaries into the interstitial fluid occur?
via filtration which is driven by blood hydrostatic pressure
84
What assists the return of venous blood from the foot to the right atrium?
a system of valves within the veins
85
What percentage of the fluids in the body are extracellular?
33%
86
What percentage of the fluids in the body are intracellular?
67%
87
What percentage of extracellular fluid is made up of interstitial?
80%
88
What percentage of extracellular fluid is made up of plasma?
20%
89
Components of average daily water gain and their amounts
Metabolic water - 200mL
Ingested foods - 700mL
Ingested liquids - 1600mL
90
Components of average daily water loss and their amounts
GI tract - 100mL
Lungs - 300mL
Skin - 600mL
Kidneys - 1500mL
91
Dehydration pathway - decreased flow of saliva
Dehydration --> decreased flow of saliva --> dry mouth and pharynx --> stimulates thirst centre in hypothalamus --> increases thirst --> increases water intake --> increases body water to normal level and decreases thirst
92
Dehydration pathway - Increased blood osmotic pressure
Dehydration --> increased blood osmotic pressure --> stimulates osmoreceptors in hypothalamus --> stimulates thirst centre in hypothalamus --> increases thirst --> increases water intake --> increases body water to normal level and decreases thirst
93
Dehydration pathway - decreased blood volume
Dehydration --> decreased blood volume --> decreased blood pressure --> increased renin release by kidneys --> increased angiotensin ll formation --> stimulates thirst centre in hypothalamus --> increases thirst --> increases water intake --> increases body water to normal level and decreases thirst
94
Mechanism and effect of thirst centre in hypothalamus
Stimulates desire to drink leading towater gain if thirst is quenched
95
Mechanism and effect of angiotensin ll
stimulates secretion of aldosterone which reduces loss of water in urine
96
Mechanism and effect of aldosterone
By promoting urine reabsorption of Na+ and Cl- ions, increases water reabsorption via osmosis
97
Mechanism and effect of ANP
promotes natriuresis, elevated urine excretion of Na+, Cl- ions with water
98
Mechanism and effect of ADH
promotes insertion of water channel proteins into plasma membranes of cells in collecting ducts of kidneys, causing water permeability to increased and more water to be absorbed
99
Order of layers of artery from inside out
Endothelium, basement membrane, internal elastic lamina, smooth muscle, outer layer
100
Order of layers of vein from inside out
Endothelium, basement membrane, smooth muscle, outer layer
101
Layers of capillary
Endothelium and basement membrane
102
Filtration in capillary exchange
Fluid moves from high pressure in capillary bed to low pressure in tissues
103
Reabsorption in capillary exchange
Fluid moves from high pressure in tissues to low pressure in capillary bed
104
Two types of pressure involved in capillary exchange
Hydrostatic and osmotic
105
Blood hydrostatic pressure
force exerted by blood confined in blood vessels and heart chambers
106
Capillary hydrostatic pressure
force of blood on capillary walls --> drives fluid out of capillaries into tissue fluid
107
How does fluid move out of the capillary into ISF?
As fluid leaves capillary, hydrostatic pressure in ISF rises. Capillary hydrostatic pressure is higher than IFHP so fluid moves from capillary to ISF.
108
How is fluid drawn from tissue back into capillary?
Plasma proteins in blood can't move across semi permeable capillary cell membrane so they remain in the plasma, meaning blood has a higher colloidal concentration and lower water concentration than tissue fluid so attracts water. Blood colloidal osmotic pressure is higher than IFCOP.
109
Capillary exchange
Net filtration occurs near the arterial end of the capillary since capillary hydrostatic pressure (CHP) is greater than blood colloidal osmotic pressure (BCOP). There is no net movement of fluid near the midpoint since CHP = BCOP. Net reabsorption occurs near the venous end since BCOP is greater than CHP.
110
4 functions of electrolytes broken into ions
1. control osmosis of water between fluid compartments
2. help maintain acid-base balance
3. carry electrical current
4. serve as cofactors for optimal activity of enzymes
111
Sodium ions in fluid
most abundant extracellular ions. Involved in action potentials, muscle contraction and fluid and electrolyte balance`
112
What is Na+ balance controlled by?
aldosterone, ADH, ANP
113
Chloride ions in fluid
major extracellular anions. Play role in regulating osmotic pressure, and forming HCl in gastric juice
114
What is Cl- balance controlled by?
processes that increase or decrease kidney reabsorption of Na+
115
Potassium ions in fluid
most abundant cations in intracellular fluid. Play key role in establishing the resting membrane potential in neurons and muscle fibres, contribute to regulation of pH
116
What is K+ balance controlled by?
aldosterone
117
Calcium ions in fluid
principally extracelllular cations. function in blood clotting, neurotransmitter release and muscle contraction.
118
What is Ca2+ balance controlled by?
parathyroid hormone and calcitriol
119
Oedema - what is it? Causes?
accumulation of excess interstitial fluid. Caused by heart failure, kidney disease, inadequate lymphatic systems or weakness/damage in leg veins
120
Renin-angiotensin-aldosterone system
kidneys convert prorenin to renin and secrete it into bloodstream. Plasma renin converts angiotensinogen to angiotensin, which is then converted to angiotensin ll. This causes vasoconstriction, leading to increased BP. Also stimulates aldosterone which causes renal tubules to increase reabsorption of sodium and water into blood while causing excretion of K+. This increases volume of ECF and increases BP.
121
Pressure of breathing at rest
diaphragm relaxed, so alveolar pressure = atmospheric pressure and there is no air flow
122
Pressure changes during inhalation
diaphragm contracts, chest cavity expands and alveolar pressure drops below atmospheric pressure.
123
Pressure changes during exhalation
diaphragm and external intercostals relax. Chest and lungs recoil, chest cavity contracts and alveolar pressure increases above atmospheric.
124
Negative feedback of breathing
stimulus --> controlled condition decreases pH --> central chemoreceptors in medulla / preipheral chemoreceptors in aorticand carotid bodies --> dorsal respiratory group in medulla oblongata --> muscles of inhalation + exhalation contract more forcefully and frequently --> response
125
Blood pressure formula
Cardiac Output x Peripheral Resistance
126
Cardiovascular disorders that can alter perfusion
```
Hypertension (In CYP causes may include renal disease, congenital cardiac disease)
Diseases of the heart
CYP -Congenital Heart Disease (CHD)
Coronary Heart Disease (CHD)
Heart failure (acute or chronic)
Myocardial infarction (Ischaemic heart disease)
Valve insufficiencies
Cardiogenic shock
Pericarditis
Sinus Node Dysfunction
```
127
Cardiovascular disorders that can alter perfusion
```
Hypertension (In CYP causes may include renal disease, congenital cardiac disease)
Diseases of the heart
CYP -Congenital Heart Disease (CHD)
Coronary Heart Disease (CHD)
Heart failure (acute or chronic)
Myocardial infarction (Ischaemic heart disease)
Valve insufficiencies
Cardiogenic shock
Pericarditis
Sinus Node Dysfunction
```
128
Cause for abrupt increase in ventilation at start of exercise
due to neural changes that send excitatory impulses to inspiratory area of medulla oblongata
129
Cause for more gradual increase in ventilation during moderate exercise
due to chemical and physical changes in bloodstream
130
Haemoptysis
coughing up blood
131
Lung compliance
a measure of the lung's ability to stretch and expand
132
Compliance is affected by...
the amount of elastic tissue in the lung and the amount of surfactant
133
What is lymphatic tissue a specialised form of?
reticular connective tissue
134
What do lymph nodes do?
filter all fluids that pass through them and filter into the thoracic duct
135
Where is the thoracic duct located?
along the aorta
136
3 functions of immune system
1. drains excess interstitial fluid
2. transports dietary lipids
3. carries out immune responses
137
role of lymphatic capillaries
absorb ISF and pass lymph to affarent vessels
138
role of affarent lymph vessels
carry lymph from lymph capillaries to lymph nodes
139
role of efferent lymp vessels
carry lymph from nodes to ducts
140
When is interstitial fluid called lymph?
After it passes into the lymphatic vessels
141
What is the spleen and where is it located?
the largest single mass of lymphatic tissue in the body. Located between the stomach and the diaphragm.
142
What types of tissue does the spleen contain?
white pulp and red pulp
143
White pulp
lymphatic tissue where B and T cells carry out immune responses
144
Red pulp
blood filled sinuses where worn out blood cells and platelets are removed - red blood cells broken down into biliverdin and bilirubin
145
Splenectomy
removal of spleen
146
What cells does a lymph node contain?
B cells, T cells, plasma cells, dendritic cells, macrophages
147
Lymphatic nodules
egg shaped masses of lymphatic tissue that are not surrounded by a capsule
148
How does lymph flow around the body?
Lymphatic capillaries merge to form large lymphatic vessels which drain into the thoracic duct and the right lymphatic duct. Thoracic duct empties fluid into left internal jugular and left subclavian veins, right lymphatic duct empties into right internal jugular and right subclavian veins, then back to blood.
149
Flow diagram of lymphatic filtration
Extra fluid in body tissues --> lymphatic capillaries absorb fluid and pass on to --> affarent lymphatic vessels which pass to --> lymph nodes which contain lymphocytes that attack and break down pathogens --> lymp fluid carries waste through efferent lymphatic vessels to --> blood stream --> liver or kidneys remove waste from blood --> passed out of body
150
Biliverdin
green bile pigment responsible for greenish colour in bruising. Converted to bilirubin via chemical reduction
151
BIlirubin
orange-yellow substance in bile. Higher levels can indicate a liver problem (can cause jaundice). Oxidised back to biliverdin.
152
How does photo therapy work?
Light waves are absorbed by the skin and blood. Oxides bilirubin so that is can easily dissolve in water.
153
How does fluid move from the blood system to the lymphatic system?
Fluid accumulates in interstitial space is tissues after leaking through the cardiovascular capillaries, then leaks through mini valves at the junction of the endothelium into lymph capillaries.
154
What are the major lymphoid tissues?
Primary - thymus and bone marrow
| Secondary - lymph nodes, tonsils, and spleen
155
What are primary lymphoid organs?
where lymphocytes are formed and mature.
156
What are secondary lymphoid organs?
sites where lymphocytes interact with each other and nonlymphoid cells to generate immune responses to antigens.
157
Where are the major lymph nodes?
tonsils, adenoids, armpits, neck, groin and mediastinum.
158
Parts of the urinary system top to bottom
kidney, ureter, ovary, bladder, uterus, urethra
159
Functions of the kidneys
- regulate ion levels in blood
- regulate blood volume and BP
- regulate blood pH
- produce hormones
- excrete wastes
160
Path of blood flow in kidneys
renal artery --> segmental arteries --> interlobal arteries --> arcuate arteries--> cortical radiate arteries --> afferent arterioles --> peritubular capillaries --> cortical radiate veins --> arcuate veins --> interlobar veins --> renal vein
161
Flow of fluid through a cortical nephron
Glomerular capsule --> proximal convoluted tubule --> descending limb of nephron loop --> ascending limb of nephron loop --> distal convoluted tubule (drains into collecting duct)
162
Glomerular filtration
In glomerulus, blood plasma and dissolved substances get filtered into glomerular capsule
163
Tubular reabsorption
all along renal tubule and collecting duct, water, ions and other substances get reabsorbed from the renal tubule into peritubular capillaries and into the blood
164
Tubular secretion
all along renal tubule and collecting duct, waste substances get secreted from peritubular capillaries into the renal tubule and go onto form urine
165
Transportation of urine
Urine produced by nephrons drains into minor calyces, which join to become major calyces that unite to form the renal pelvis. From here, urine drains first into the ureters and then into the bladder where it is discharged from the body though the urethra
166
How many layers do the ureter walls consist of? What are they?
3 - transitional mucosa on inside, smooth muscle in middle and an outer layer of areolar connective tissue
167
Urinary bladder - what is it? What does it do?
hollow muscular organ in pelvic cavity posterior to pubic symphysis. Stores urine prior to mictuition
168
Mictuition
urinating
169
Describe the walls of the bladder
Mucosa contains transitional epithelium and rugae. Muscular layer consists of 3 layers of smooth muscle called detrusor muscle. Outer coat is a fibrous covering.
170
What is responsible for the yellow/amber colour of urine?
Urochrome and urobilin
171
What is urochrome?
a pigment produced from the breakdown of bile
172
What is urobilin?
a pigment produced from the breakdown of haemoglobin
173
What diets affect the pH of urine?
High protein increases acidity, vegetarian increases alkalinity
174
What does albumin in urine indicate?
increase in permeability of filtering membranes
175
What does glucose in urine indicate?
diabetes
176
What do red blood cells in urine indicate?
acute inflammation of urinary organs
177
What do white blood cells in urine indicate?
infection in the kidneys or other urinary organs
178
What do ketone bodies in urine indicate?
diabetes or anorexia due to too few carbohydrates
179
What does bilirubin in urine indicate?
liver damage or disorder
180
What does urobilinogen in urine indicate?
anemia, hepatitis, jaundice
181
What do ureters do?
transport urine from kidneys to bladder. As bladder fills, it expands and compresses the ureters to prevent backflow
182
What do rugae in kidneys do?
allow bladder to expand as it fills
183
What does the peritonum in kidneys do?
helps hold bladder in place
184
What does the internal urethral sphincter do?
it is an involuntary smooth muscle - opens and closes urethra
185
What does the external urethral sphincter do?
It is a voluntary skeletal muscle - opens and closes urethra
186
What is the external urethral orifice?
the opening of the urethra to the outside
187
What is the urethra?
a small tube leading from the bladder to the outside
188
What does urine consist of?
95% water, urea (ammonia and CO2), chloride, sodium, potassium and creatinine
189
pH of gastric juice
1.2-3
190
pH of vaginal fluid
3.5-4.5
191
pH of urine
4.6-8.0
192
pH of saliva
6.4-6.9
193
pH of semen
7.2-7.6
194
pH of cerebrospinal fluid
7.4
195
pH of bile
7.6-8.6
196
pH of blood
7.35-7.45
197
Why is the pH of blood so tightly controlled?
as proteins are sensitive to pH
198
What do buffer systems do?
temporarily bind H+, removing the highly reactive, excess H+ ions from solution but not from the body
199
3 types of buffer systems in the body
protein buffer system
carbonic acid-bicarbonate buffer system
phosphate buffer system
200
Kidney excretion of H+
slowest but only way for most acids.
| cells of renal tubules secrete H+ which is then excreted in the urine.
201
What is H+ usually replaced with when excreted via kidneys?
Potassium which organs are very sensitive to
202
Acidosis and CNS
causes depression of CNS
203
Alkalosis and CNS
causes overexcitability of CNS
204
Protein buffer system
Proteins are made up of amino acids, which contain positively charged amino groups and negatively charged carboxyl groups. The charged regions of these molecules can bind hydrogen and hydroxyl ions, and thus function as buffers.
205
Carbonic acid-bicarbonate buffer system
CO2+H20H2CO3H+ + HCO3-
206
Phosphate buffer system
It consists of dihydrogen phosphate ions as the hydrogen ion donor ( acid ) and hydrogen phosphate ion as the ion acceptor ( base ) . If additional hydroxide ions enter the cellular fluid, they are neutralised by the dihydrogen phosphate ion
207
Effects of ageing on fluid and electrolyte balance
impaired thirst perception; decreased glomerular filtration rate; alterations in hormone levels, including ADH, ANP and aldosterone; decreased urinary concentrating ability; and limitations in excretion of water, electrolytes and acid.
208
What is the role of the somatic nervous system?
voluntary control of body movements via skeletal muscles
209
What is the role of the autonomic nervous system?
mostly involuntary and regulates bodily functions e.g. HR, digestion, RR. Sympathetic controls fight or flight response.
210
What is the role of the enteric nervous system?
governs functions of GI tract
211
What neurons does the somatic nervous system contain?
sensory neurons that conduct impulses from somatic and special sense receptors to the CNS and motor neurons from CNS to skeletal muscles
212
What neurons does the autonomic nervous system contain?
sensory neurons from visceral organs and motor neurons that carry impulses from CNS to smooth muscle tissue, cardiac muscle tissue and glands.
213
What are the divisions of the motor part of the autonomic nervous system and what do they do?
Sympathetic - supports exercise and emergency actions
| Parasympathetic- rest and digest activities
214
What neurons does the enteric nervous system contain?
neurons in enteric plexuses in GI tract that function somewhat independently of ANS and CNS.
215
3 basic functions of nervous system
- SENSORY detecting stimuli
- INTEGRATIVE analysing, integrating and storing sensory information
- MOTOR responding to integrative decisions
216
two types of cells in nervous tissue
neurons and neuroglia
217
What is a neuron?
a cell specialised for nerve impulse conduction. Enables sensing, thinking, remembering and controlling muscle activity.
218
What do neuroglia do?
support, nourish and protect neurons and maintain homeostasis in ISF.
219
3 parts of a neuron
Dendrite - main receiving or input region
Cell body - where integration occurs
Axon - output part, conducts nerve impulse towards another neuron, muscle fibre or gland cell.
220
Classifications of neurons
Sensory - carry sensory info to CNS
Motor - carry info out of CNS into effectors
Inter - within CNS between sensory and motor
221
Names of neuroglia in CNS
astrocytes, oligodendrocytes, microglia and ependymal
222
Names of neuroglia in PNS
schwann cells and satellite cells
223
Which neuroglia produce myelin sheaths?
oligodendrocytes and schwann cells
224
What does white matter consist of?
primarily myelinated axons
225
What does grey matter consist of?
neuronal cell bodies, dendrites and axon terminals of neurons, unmyelinated axons and neuroglia.
226
Ganglion definition
cluster of neuronal cell bodies located in PNS
227
Nucleus definition (CNS)`
cluster of neuronal cell bodies which relays info
228
Nerve definition
bundle of axons located in PNS
229
Tract definition
bundle of nerves located in CNS. Interconnect neurons in brain and spinal cord
230
What nerves connect brain to periphery?
cranial
231
What nerves connect spinal cord to periphery?
spinal
232
How does the myelin sheath increase the speed of transmission?
due to saltatory conduction where the impulse jumps from one node of Ranvier to another.
233
What is a bouton?
button like structures of axon terminals
234
What is the resting membrane potential?
-70mV
235
How does a resting membrane potential aris?
due to an unequal distribution of ions on either side the plasma membrane and a higher membrane permeability to K+ than to Na+
236
What is the all or none principle?
It says that if a stimulus is strong enough to generate an AP, the impulse generated is of a constant size
237
What makes an axon conduct impulses faster?
If they have a larger diameter or if they are myelinated
238
What happens during the generation of an action potential?
Generation depends on existence of a membrane potential and the presence of voltage gated channels for Na+ and K+. These channels open in sequence - opening of the Na+ channels results in depolarisation whereas opening of K+ channels results in repolarisation, causing membrane potential to return to resting.
239
What is continuous conduction?
When nerve impulse conduction occurs by a step by step process along an unmyelinated axon
240
What are meninges?
highly vascular structures that support the brain
241
Three types of meninges
Pia (innermost)
Arachnoid (middle)
Dura (outermost)
242
How does synaptic transmission occur?
At a synapse, a neurotransmitter is released from a presynaptic neuron into the synaptic cleft and then binds to receptors on the plasma membrane of the postsynaptic neuron.
243
What does an excitatory neurotransmitter do?
depolarises the post synaptic neuron's membrane, brings membrane potential closer to threshold and increases chance that one or more APs will rise
244
What does an inhibitory neurotransmitter do?
hyperpolarises the membrane of the post synaptic neuron, thereby inhibiting AP generation.
245
How is a neurotransmitter removed?
3 ways:
| diffusion, enzymatic destruction or reuptake by neuron and neuroglia.
246
Examples of neurotransmitters
acetyl choline, glutamate, aspartate, gammaaminobutyric acid, glycine, norepinephrine, dopamine, serotonin, neuropeptides and nitric oxide
247
How do vesicles fuse?
An action potential must be converted into a chemical signal, a rise in the Ca2+ concentration in the cytosol. The arrival of the action potential causes depolarisation and opens the voltage gated Ca2+ channels, allowing Ca2+ ions to enter the cytosol from the extracellular fluid. This raises the level of Ca2+ near the synaptic vesicles and the ions bind to proteins that connect the synaptic vesicle to the plasma membrane, inducing membrane fusion and then causing exocytosis of the neurotransmitter. The extra Ca2+ ions are rapidly pumped out of the cell by Ca2+ ATPases, lowering the cytosolic Ca2+ level and preparing the terminal to respond again to an action potential.
248
afferent definition
information towards
249
efferent definition
information away from
250
How many pairs of spinal nerves are there?
32
251
Cranial nerve I
Olfactory nerve - SENSORY allows smell
252
Cranial nerve II
Opic nerve - SENSORY allows vision
253
Cranial nerve III
Oculomotor nerve - MOTOR allows movement of upper eyelid and eyeball, alters shape of lens for near vision and constricts pupil
254
Cranial nerve IV
Trochlear nerve - MOTOR allows movement of eyeball
255
Cranial nerve V
Trigeminal nerve (face) - SENSORY senses touch, pain and temperature sensations, muscle sense MOTOR chewing
256
Cranial nerve VI
Abducens nerve - MOTOR movement of eyeball
257
Cranial nerve VII
Facial nerve - SENSORY taste, muscle sense, touch, pain and temperature sensations MOTOR facial expressions, secretion of tears and saliva
258
Cranial nerve VIII
Vestibulocochlear nerve - VESTIBULAR SENSORY equilibrium COCHLEAR SENSORY hearing
259
Cranial nerve IX
Glossopharyngeal nerve - SENSORY taste, somatic sensations, monitor BP, O2 and CO2 in blood MOTOR swallowing, speech, secretion of saliva
260
Cranial nerve X
Vagus nerve - SENSORY taste and somatic sensations from pharynx and epiglottis, monitor BP, monitor O2 and CO2 in blood MOTOR swallow, cough, voice production, smooth muscle contraction and relaxation in GI tract, slowing of HR
261
Cranial nerve XI
Accessory nerve - MOTOR movement of head and shoulders
262
Cranial nerve XII
Hypoglossal nerve - MOTOR movement of tongue during speech and swallowing
263
Remembering cranial nerves
Nerves - OOOTTAFVGVAH
| Sensory/Motor/Both - SSMMBMBSBBMM
264
What is the myelin sheath?
a fatty insulating layer
265
What is a neurotransmitter?
a chemical released by a nerve that causes a response
266
Other name for sympathetic division of ANS
thoracolumbar region because outflow of sympathetic nerve impulses come from the thoracic and lumbar segments of spinal cord
267
How are sympathetic ganglia classified?
sympathetic trunk ganglia (lateral to vertebral column)
OR
prevertebral ganglia (anterior to vertebral column)
268
Once an axon of a preganglionic neuron of sympathetic trunk enters a sympathetic trunk ganglion, what 4 paths may it follow?
1. It may synapse with postganglionic neurons in the sympathetic trunk ganglion it first reaches
2. It may ascend/descend to a higher/lower sympathetic trunk ganglion before synapsing with postganglionic neurons.
3. It may continue. without synapsing, through the sympathetic trunk ganglion to end and synapse with postganglionic neurons there
4. It may terminate in the adrenal medulla
269
Another name for the parasympathetic division of the ANS
Craniosacral division because the outflow of parasympathetic nerve impulses come from cranial nerve nuclei and sacral segments of the spinal cord.
270
Alternate name for parasympathetic ganglia
terminal ganglia and are locaated near or within autonomic effectors.
271
Which ANS neurons release acetylcholine?
all sympathetic and parasympathetic preganglionic neurons, all parasympathetic postganglionic neurons and a few sympathetic postganglionic neurons
272
Where does cerebrospinal fluid circulate?
in the subarachnoid space (between arachnoid and pia mater)
273
What are the roots of the spinal cord called?
cauda equina
274
Which nerves does the cervical enlargement contain?
nerves that supply the upper limbs
275
Which nerves does the lumbar enlargement contain?
nerves that supply lower limbs
276
How long is the spinal cord?
42-45cm
277
Division of grey matter in spinal cord
divided on each side into regions called horns. Posterior grey horns contain cell bodies of incoming sensory neurons and anterior grey horns contain cell bodies of somatic motor neurons
278
How is white matter organised?
into white columns
279
How are spinal nerves wrapped?
Individual axons are wrapped in endoneurium, which are then arranged in bundles called fascicles, which are each wrapped in perineurium. The superficial covering over the entire nerve is called the epineurium.
280
What are the basic components of a reflex?
1) sensory receptor
2) sensory neuron
3) integrating center
4) motor neuron
5) effector
281
4 major parts of the brain
brain stem, diencephalon, cerebrum and cerebellum
282
What does the brain stem contain?
medulla oblongata, pons and midbrain
283
Where is CSF produced?
choroid plexuses
284
Where is the midbrain?
connects pons to diencephalon.
285
What does the diencephalon include?
thalamus, hypothalamus and pineal gland
286
What is the thalamus responsible for?
main relay station for most sensory impulses that reach the cerebral cortex from the spinal cord and brain stem.
287
What does the pineal gland do?
secretes melatonin
288
Function of frontal lobe
controls important cognitive skills in humans, such as emotional expression, problem solving, memory, language, judgement, and sexual behaviours.
289
Effects of damage to the frontal lobe
Damage can affect an individual's abilities to make good choices and recognise consequences are often impaired. Damage to the frontal lobe can cause increased irritability, which may include a change in mood and an inability to regulate behaviour.
290
Function of parietal lobe
processes sensory information regarding the location of parts of the body as well as interpreting visual information and processing language and mathematics.
291
Effect of damage to parietal lobe
Damage can result in what is called "Gerstmann's Syndrome." It includes right-left confusion, difficulty with writing (agraphia) and difficulty with mathematics (acalculia).
292
Function of temporal lobe
involved in vision, memory, sensory input, language, emotion, and comprehension.
293
Effect of damage to temporal lobe
Right temporal damage can cause a loss of inhibition of talking. Left temporal lesions result in impaired memory for verbal material.
294
Function of occipital lobe
participates in vision processing. It processes and interprets everything we see. It is also responsible for analysing contents and drawing conclusions about the images we see.
295
Effect of damage to occipital lobe
Damage can cause loss of vision with exactly the same "field cut" in both eyes. Hallucinations can also occur.
296
Function of cerebellum
receives information from the sensory systems, the spinal cord, and other parts of the brain and then regulates motor movements.
297
Effect of damage to cerebellum
Damage to the cerebellum can result is a loss of coordination, inability to judge distance, movement tremors or staggering.
298
3 main uses of food molecules
provide energy, serve as building blocks and as storage for future use
299
What are essential nutrients?
nutrients that the body cannot make so must be obtained from the diet
300
How many calories is 1g of protein or carbs?
4
301
How many calories is 1g of fat?
9
302
What elements do carbohydrates contain?
carbon, hydrogen and oxygen
303
What elements do proteins contain?
carbon, hydrogen, oxygen, nitrogen and sulphur
304
What elements do lipids contain?
carbon, hydrogen, oxygen, phosphorus and nitrogen
305
Where are sugars stored?
in the muscles in the liver
306
What is glycogenesis?
the synthesis of glycogen from glucose
307
What is glycogenelysis?
the breakdown of glycogen to glucose
308
Glycolysis pathway
Glucose --> G3P --> Pyrovate --> Lactic acid (if not enough oxygen) or Acetyl co enzyme A --> KREBS cycle --> ATP
309
Types of lipids
fatty acids
triglycerides (fats)
sterols (cholesterol)
phospholipids
310
What are some potential deficiencies with vegetarianism?
iron, energy, calcium + other minerals, Vitamin B12 and D
311
2 sources of blood cholesterol
foods or synthesised by the liver
312
How can fatty foods that don't contain cholesterol increase blood cholesterol?
1) Increase in dietary fat stimulates reabsorption of cholesterol containing bile back into the blood so less is lost in faeces
2) When saturated fats are broken down in the body, liver cells use some of the breakdown products to make cholesterol
313
What does a lipid profile do?
Measures total cholesterol, HDL cholesterol, and VDLs (triglycerides)
314
What is HDL cholesterol?
High density lipoprotein cholesterol (good cholesterol)
315
How can we predict coronary heart disease risk?
Total cholesterol to HDL cholesterol ratio
316
What does nephrotoxic mean?
toxic to the kidneys
317
What is haematuria?
the presence of blood in the urine
318
What is apnoea?
temporary stopping of breathing
319
What is dysuria?
painful or difficult urination
320
What is polyuria?
excessive production of urine
321
What is anuria?
failure of the kidneys to produce urine
322
Components of the vascular system of the kidney?
renal, segmental, interlobar, arcuate and interlobular arteries, efferent and afferent arterioles, glomerulus, peritubular capillaries plus veins
323
Order of anatomical structures in kidney?
Glomerulus, proximal tubule, descending loop of Henle, ascending loop of Henle, distal tubule
324
Where does the ureter leave the kidney?
renal hilium
325
Where are the renal pyramids located?
renal medulla
326
ADH alters the permeability of...
the collecting duct
327
Which substance usually remains in the glomerulus during filtration?
albumin
328
Which of the following is secreted by the juxtaglomerular cells?
urea
329
What are the first line of defence in any immune response?
anatomical and chemical barriers
330
Which immune response is the inflammatory response part of?
non-specific
331
What is autoimmunity?
An abnormal immune response to an individual's own body tissues
332
What are the gaps between myelinated segments of an axon called?
nodes of Ranvier
333
What is metabolism?
all chemical reactions in the body
334
What is anabolism?
reactions that combine simple substances into more complex molecules
335
What is catabolism?
reactions that break down complex organic compounds into simple ones
336
Explain carbohydrate metabolism
During digestion, polysaccharide and disaccharide carbs are converted to glucose.
337
How does glucose move into cells and what is this facilitated by?
facilitated diffusion, stimulated by insulin
338
What is cellular respiration?
the catabolism of glucose to produce ATP
339
Which reactions does the complete catabolism of glucose to ATP involve?
glycolysis, Krebs cycle, and the electron transport chain
340
Where does glycolysis occur?
in the cytosol
341
Where does the Krebs cycle occur?
in the mitochondria
342
What does glycolysis yield?
2ATP + 2NADH + 2H+
343
What happens with the energy in the Krebs cycle?
energy contained in glucose, pyruvic acid and acetyl CoA is transferred to coenzymes NADH and FADH2.
344
What is the elctron transport chain?
series of reactions in the mitochondria where energy in reduced coenzymes is transferred to ATP.
345
Simple flow diagram of cellular respiration
Glucose --> Pyruvic acid --> acetyl CoA --> Krebs cycle --> electron transport chain where ATP is released
346
Explain lipid metabolism
Muscle, liver and adipose cells routinely catabolise fatty acids from triglycerides to produce ATP.
1. Triglycerides are split into glycerol and fatty acids via lipolysis.
2. Liver converts some acetyl CoA into ketone bodies, which leave liver to enter body cells, where they are broken down into acetyl CoA, which then enters the Krebs cycle.
347
Which hormones enhance lipid metabolism?
epinephrine, norepinephrine, and cortisol
348
Explain protein metabolism
Their amino acids are either oxidised to produce ATP or used to synthesise new proteins for growth and repair of body tissues. Excess amino acids are converted to glucose or triglycerides.
349
What is the active transport of amino acids into body cell stimulated by?
insulin like growth factors and insulin
350
Gluconeogenesis
glucose formation from pyruvate
351
Glycogenolysis
breakdown of glucose to form glucose-1-phosphate and glycogen
352
Osteomalacia
softening of bones
353
Atherosclerosis
plaque build up in arteries
354
Role of calcium
formation of bones and teeth, blood clotting, normal muscle and nerve activity
355
Role of phosphorus
Formation of bones and teeth, buffer system in body, muscle contraction and nerve activity
356
Role of potassium
generation and conduction of action potentials in neurons and muscle fibres
357
Role of sulphur
needed for ATP production in electron transport chain, component of many hormones and vitamins
358
Role of sodium
distribution of water in osmosis, bicarbonate buffer system
359
Role of chloride
acid base balance, water balance, formation of HCl in stomach
360
Role of magnesium
normal functioning of muscle and nervous tissue, participate sin bone formation, component of many coenzymes
361
Role of Iron
component of haemoglobin, binds to O2
362
Role of iodide
required by thyroid gland to synthesise thyroid hormones
363
Role of manganese
activates several enzymes, needed for haemoglobin synthesis, lactation, urea formation
364
Fat soluble vitamins
A, B, E, K
365
Water soluble vitamins
B1, B2, Niacin, B8, B12, pantothenic acid, folic acid, biotin, C
366
Symptoms of Vitamin A deficiency
night blindness, slow development of bones and teeth, dry skin and hair, increased risk of infection
367
Symptoms of Vitamin D deficiency
rickets and osteomalacia.
368
Symptoms of Vitamin E deficiency
hemolytic anemia. abnormal structure and function of cell components (mitochondria, plasma membrane, lyosomes)
369
Symptoms of Vitamin K deficiency
delayed clotting time leading to excessive blood loss
370
Symptoms of Vitamin B1 deficiency
build up of pyruvic and lactic acids, and insufficient production of ATP leads to beri beri and polyneuritis
371
What is beri beri?
partial paralysis of muscle, can cause heart problems
372
What is polyneuritis?
affects peripheral nerves
373
Symptoms of Vitamin B2 deficiency
blurred vision, cataracts, dermatitis, cracking of skin, anemia
374
Symptoms of Niacin deficiency
Pellagra, characterised by dermatitis and diarrhoea.
375
Symptoms of Vitamin B3 deficiency
dermatitis, retarded growth, nausea
376
Symptoms of Vitamin B12 deficiency
anemia, impaired activity of osteoblasts, neuropsychiatric abnormalities
377
Symptoms of Pantothenic acid deficiency
fatigue, muscle spasms, vomiting, insomnia
378
Symptoms of Folic acid deficiency
production of abnormally large red blood cells, higher risk of neural tube defects in newborns
379
Symptoms of Biotin deficiency
mental depression, muscular pain, dermatitis, fatigue and nausea
380
Symptoms of Vitamin C deficiency
scurvy, anemia
381
What is reticular formation?
the net like arrangement of the brain stem consisting of small clusters of grey matter with small bundles of white matter
382
order of stages in sleep cycle
1, 2-4, 2, REM
383
Stages of NREM
1) falling asleep, sense of falling, eye movements slow down, muscle tone relaxes, hypnic jerks, micro sleeps
2) eye movements reduced, muscle tone further reduced, arousal threshold decreased
3+4) eye movements stop, muscle activity reduces, disorientated if woken
384
What happens during REM sleep?
rapid eye movements, RR increases, loss of muscle tone except around extraocular, diaphragm and penile erections, deep sleep.
385
How long does each sleep cycle last and how many times is it repeated?
60-120 minutes, repeats 4-6 times a night
386
Thalamo-cortical arousal branch role in waking
Wakefulness and REM sleep
387
Hypothalamic-aminergic arousal branch role in waking
Chemicals (dopamine, noradrenalin, serotoninc, histamine)
| Active during waking, suppressed during NREM and inactive during REM
388
Effect of a deficiency of dopamine on sleep
sleep movement disorders
389
Effect of noradrenalin on sleep
if aroused causes wakefulness
| if deficient causes reduced wakefulness
390
Effect of histamine on sleep
if aroused, causes wakefulness
391
Effects of serotonin on sleep
reduces REM sleep
392
Effects of cholinesterase inhibitors on sleep
increase REM sleep
393
Effects of anticholinergic and antimuscarine drugs on sleep
reduce REM sleep
394
Role of suprachiasmic nucleus in sleep
internal clock, circadian rhythm, regulates wakefulness and sleep cycle
395
Role of melatonin
hormone regulated by circadian clock, peaks at night
396
What is the reticular activating system?
short, pencil sized piece of the brain located just above where the spinal cord is attached to the brain. Acts as the gatekeeper of information between most sensory systems and the conscious mind. Filters out unnecessary information so important stuff gets through.
397
Early stage of dying
sleeping more, eating and drinking less, social withdrawal, talking less, loss of mobility, pain, confusion
398
Middle stage of dying
change in mental state - only briefly awake
noisy, rattily breathing
oral secretions, loss of swallow reflex
399
Late stage of dying
coma, changes in vital signs, mottled/cyanosis, changing body temperature, breathing problems
400
Biological effects of dying
organs gradually slow and stop working - lose control of bowel and bladder
Sleep increases to conserve energy
Col arms and legs - body is conserving blood volume to vital organs to maintain stroke volume
401
DNA
contains genetic information
402
Chromosomes
dense structures of tightly coiled DNA that becomes visible during division
403
Gene
sequence of DNA that functions as a unit of genetic information. Provides instructions for making proteins out of individual aminoacids in the order specified by the sequence of base pairs
404
Phenotype
Outward characteristics
405
Genotype
what we are made of
406
Karyotype
homologous pairs of chromosomes
407
Which chromosomes do females contain?
XX
408
Which chromosomes do males contain?
XY
409
3 components of nucleotides
nitrogenous base (AGTC)
five carbon sugar
phosphate group
410
Pairings of nucleotide bases in DNA
Adenine + Thymine
| Guanine + Cytosine
411
Pairings of nucleotide bases in RNA
Adenine + Uracil
| Guanine + Cytosine
412
Phenylketonuria
cannot produce phenylalanine hydroxylase. Heel prick test at 5 days.
413
Codon
AKA triplet. Set of 3 bases which make up genetic code - each codon codes for a single amino acid.
414
Synthesis of proteins - transcription + translation
Info in specific region of DNA is transcribed to produce molecule of RNA.
RNA attaches to ribosome and is translated into a corresponding specific sequence of amino acids to form a new protein molecule.
415
Co-dominance
share phenotype between alleles (e.g. AB blood type)
416
Genetic imprinting
sex specific process of chemical modification to the genes so that the alleles are unequally expressed depending on the sex of the parent
417
Polygenic
several genes responsible for a trait e.g. skin colour
418
Multifactorial
involve a complex interaction of the genes with environment e.g. sunlight - skin cancer
419
Epigenetics definition
study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself. e.g. adding molecules
420
Mutation definition
change in genetic material
421
Mutations in somatic cells
usually repaired or cells destroyed. Cannot be passed to next generation, may result in uncontrolled growth.
422
Mutations in germ cells (gametes)
can be passed down
423
Point mutation
exchange of single nucleotide for another e.g. A for G
424
Insertions
add extra nucleotides into DNA
425
Deletions
delete nucleotides from DNA
426
Example of autosomal recessive disorder
Phenylketonuria
427
Example of autosomal dominant disorder
Marfan's syndrome
428
Marfan's syndrome
genetically inherited disease of skeletal and muscle tissue that causes heart and eye problems. Arm span is longer than height
429
Example of sex linked condition
colour blindness, hemophilia, duchenne muscular dystrophy
430
Numerical aberrations
failure in chromosome division results in gamtes with an extra chromosome or a deficiency
431
Structural aberrations
rearrangement in location or loss of genetic material
432
Diploid
paired chromosomes
433
Haploid
single unpaired chromosome
434
Allele definition
pair of genes that determine hereditary characteristics
435
Locus definition
fixed position on chromosome where a particular gene is located
436
Autosomes
22 number chromosomes
437
What type of chromosomes are X and Y?
sex chromosomes
438
Trisomy definition
The presence of an extra chromosome in a diploid cell
439
Where does meiosis occur?
In the reproductive organs
440
Ducts in male reproductive system
epididymis,ductus deferens, ejaculatory ducts and urethra
441
Accessory sex glands in male reproductive system
seminal vesicles, prostate, bulboerethral glands
442
What do the testes contain?
seminiferous tubules, sustentacular/sertoli cells, leydig/interstitial cells
443
role of seminiferous tubules
where sperm cells develop
444
role of sustentacular/sertoli cells
nourish sperm cells and release hormone inhibin
445
role of leydig/interstitial cells
produce testosterone
446
Process of spermatogenesis
primordial germ cell --> spermatogonial stem cell (diploid) --> spermatogonium (diploid) --> primary spermatocyte (diploid) --> secondary spermatocyte (haploid) --> spermatids (haploid) --> sperm cells
447
Role of leutanizing hormone in male reproductive system
stimulates leydig cells to produce testosterone
448
Role of FSH and testosterone in male resproductive system
stimulate spermatogenesis
449
Role of inhibin in male reproductive system
inhibits FSH, helping to regulate the rate of spermatogenesis
450
How is sperm transported?
out of testes into epididymis, where their motility increases. The ductus deferens stores sperm and propels them into the urethra during ejaculation.
451
How are the ejaculatory ducts formed?
by the union of the ducts from the seminal vesicles and vas deferens
452
Role of ejaculatory ducts
eject sperm into urethra
453
Components of sperm cells
acrosome, nucleus, mitochondria
454
What do bulboerethral glands do?
secrete mucus for lubrication and an alkaline substance that neutralises acid
455
3 parts of the penis
root, body and glans penis
456
What is caused by the expansion of penis' blood sinuses?
erection
457
What are the male gonads?
testes
458
Components of the female reproductive system
ovaries, uterine/fallopian tubes, uterus, vagina, vulva + mammary glands
459
What are the female gonads?
ovaries
460
What is oogenesis?
production of haploid secondary oocytes
461
Where is the usual site of fertilization?
uterine tubes
462
Functions of uterus (womb)
part of pathway for sperm to reach uterine tubes, functions in menstruation, implantation of a fertilized ovum, development of foetus during pregnancy and labour
463
What is the endometrium?
inner layer of uterine wall
464
Process of oogenesis
oogonium --> primary oocyte --> secondary oocyte and first polar body --> sperm cells fertilizes secondary oocyte --> ovum and second polar body --> zygote
465
`What is the role of the vagina?
passage for menstrual flow, receptacle for penis during sexual intercourse, lower portion of birth canal
466
What is the vulva and what are its components?
the external genitals of the female. Consists of mons pubis, labia majora, labia minora, clitoris, vestibule, vaginal and urethral orifices, paraurethral glands and greater vestibular glands
467
Where do the breasts lie?
over pectoralis major and serratus anterior muscles and are attached to them by a layer of connective tissue
468
What is milk ejection stimulated by?
oxytocin
469
What is the function of the ovarian cycle?
development of secondary oocyte
470
What is the function of the uterine cycle?
preparation of endometrium each month to receive a fertilized egg
471
What are the ovarian and uterine cycles controlled by?
GnRH from hypothalamus which stimulates release of FSH and LH by the anterior pituitary
472
Role of oestrogens in females
stimulate growth, development and maintenance of female reproductive structures, development of secondary sex characteristics and protein synthesis
473
Role of progestrone in females
works with estrogens to prepare the endometrium for implantation and mammary glands for milk synthesis
474
Role of relaxin in females
increases flexibility of pubic symphysis and helps dilate the uterine cervix to ease delivery of baby
475
What happens during menstrual phase?
part of endometrium is shed, discharging blood and tissue cells
476
What happens during preovulatory phase?
a group of follicles in the ovaries begins to undergo maturation. One follicle outgrows others and becomes dominant while others die. At same time, endometrial repair occurs inuterus.
477
Which are the dominant hormones during the preovulatory phase?
estrogens
478
What happens during ovulation?
the rupture of the dominant mature (Graafian) follicl and the release of a secondary oocyte in the pelvic cavity.
479
How is ovulation brought on?
by a surge of LH
480
What happens during the postovulatory phase?
both presterones and estrogens are secreted in large quantity by corpus luteum of ovary and the endometrium thickens in readiness for implantation. The fertilization and implantation do not occur, corpus luteum degenerates and the resulting low levels of hormones allow the discharge of the endometrium.
481
What does RU 486 do?
can induce abortion by blocking action of progesterone
482
Where are immunoglobulins produced?
by plasma cells
483
Where are leukocytes produced?
in the bone marrow
484
What is anuresis?
retention of urine in the bladder
485
What is nephritis?
inflammation of the kidneys
486
What is cystitis?
inflammation of the bladder or other parts of the urinary system
487
What is haemodialysis?
purifying the blood of someone whose kidneys are not working
488
What do chylomicrons do?
transport dietary lipids through lymph and blood
489
What is myoglobin?
oxygen and iron binding protein
490
What is the role of the human chorionic gonadotrophin hormone and where is it produced?
Produced in placenta and maintains corpus luteum during pregnancy
491
Role of prostaglandin
promotes uterine contractions during childbirth
492
Role of phrenic nerve
controls diaphragm so controls breathing
493
Two types of macrophages
fixed and wandering
494
shape of antibodies
Y
495
Where are podocytes?
line the glomerulus, providing structure
496
Role of juxtaglomerular cells?
renin release
497
Where are the affarent arterioles located?
renal artery
498
What does the loop of henle reabsorb?
magnesium
499
How does information enter the spinal cord?
via the dorsal roots
500
What is penetration of the zona pellucida facilitated by?
enzymes in the sperm's acrosome
501
Path of sperm cell in fertilization
corona radiata --> zona pellucida --> plasma membrane of secondary oocyte --> cytoplasm of secondary oocyte
502
morula definition
sphere of cells produced by cleavage
503
cleavage definition
early, rapid cell division of zygote
504
blastula definition
animal embryo at early stage of development when it is a hollow ball of cells
505
Fraternal twins
two eggs fertilized
506
Identical twins
one cell divides
507
What happens during first week of gestation?
1) fertilization
2) cleavage - first completed 30 hrs after fertilization
3) morula - 3-4 days after
4) blastocyst - 5 days after
5) Implantation - 6 days after
508
Chorionic villi
connect to the embryonic heart so that maternal and fetal blood vessels are brought into close proximity, to allow exchange of nutrients and wastes
509
What happens during 4th week of development?
formation of body organs and systems
510
What happens by end of 4th week of development?
upper and lower limb buds
511
What happens by end of 8th week of development?
embryo has clear human features
512
Teratogens
any agent that is able to cause developmental defects in embryo. Most common is alcohol
513
Amniocentesis
removing some amniotic fluid surrounding the developing fetus and analysing it for abnormalities. Done at 14-18 weeks. Guided by ultrasound to prevent harm.
514
Chorionic villi sampling
from 8 weeks of gestation. Guided by ultrasound; catheter inserted through vagina and cervix to collect a tissue sample from chorionic villi.
515
True labour
when uterine contractions occur at regular intervals
516
False labour
irregular contractions and no show (discharge of blood with mucus)
517
3 stages of true labour
1) dilation
2) expulsion
3) placental
518
adjustments of infant at birth
- lungs able to exchange gases due to surfactant that began to develop by end of 6th month
- RR at birth is 45 bpm, reduces to 12 within 2 weeks
519
When does the fetal period begin?
9th week after gestation
520
What is parturition?
childbirth
521
Explain initial development after fertilization until implantation
Morula enters uterine cavity and is nourished by uterine milk. Rearranged into a large, fluid filled blastocyst. As blastocyst forms, 2 cell populations develop: inner embryoblast which will develop into embry and outer trophoblast which will develop into the outer chorionic sac. Blastocyst remains in uterine cavity for 2 days until it implants in the fundus or uterus.
522
2 layers of embryoblast and what do their cells form?
hypoblast and epiblast - form flat disc called the bilaminar embryonic disc.
523
What is fetal ultrasonography used for?
to confirm pregnancy, identify position, fetal age and multiple pregnancies.
524
What does surge in LH trigger?
ovulation
525
Which duct contributes most semen?
seminal vesicles
