Download BSc (Veterinary Biosciences) Level 2 Body Systems Physiology

BSc (Veterinary Biosciences)
Level 2
Body Systems Physiology - 2 (2009-10)
30 Credits
Course Co-ordinator: Dr I.A. Jeffcoate
Position in Course: Year 2 (both semesters)
Course prerequisites: To have achieved a minimum of Grade D in all
Level 1 courses to total 120 credits
Courses
Chemistry 1 (402B) (Chemistry)
Biology 1A (Animal biology) (KNPU) (FBLS)
Biology 1B (Cell biology) (KNMU) (FBLS)
Animal Production and Management 1 (FVM)
Basic mammalian body plan 1 (FVM)
Comparative vertebrate morphology 1 (FVM)
Body systems physiology 1 (FVM)
Credits
40
20
20
10
10
10
10
Course corequisites:
Courses
Veterinary Bioinformatics 2 (FVM)
Proteins, DNA & basic genetics 2 (FVM)
Animal Science, Behaviour and Nutrition 2 (FVM)
Other Level-2 FBLS courses (usually 6 x 10 credits)
Excluded courses or course combinations:
Credits
10
10
10
60
None
1
Aims of the Course
The aims of this course are to give participants the means of acquiring knowledge and
understanding of systems confined to mammals:
1)
temperature regulation and metabolism
2)
the digestive system and control of food intake
3)
the respiratory system and how it is regulated
4)
body fluids, blood and the cardiovascular system and how the circulation is
adjusted according to need
5)
the renal system and body fluid regulation
6)
the reproductive system and how it is regulated
Overall Intended Learning Outcomes
After completing this course you should be able to:
1)
explain the effect of body temperature on living cells
2)
describe how animals are either able to closely achieve a constant body
temperature or if not are prone to variation depending on environmental
conditions
3)
define homeothermy as opposed to poikilothermy and show metabolic rate is a
function of body size
4)
define digestion and absorption
5)
describe how food is eaten and digested
6)
describe how food components are absorbed
7)
describe that food residues are excreted
8)
explain what normally limits food intake, appetite versus satiety
9)
explain how cells require oxygen and must void carbon dioxide
10)
explain how increased body size has necessitated development of internal gas
exchange and internal gas distribution
11)
explain how gas exchange is achieved and regulated so as to maintain
homeostasis
12)
explain how impairment of gas exchange is harmful
13)
describe why cells exist in an aqueous environment and that the bulk of body
mass is water
14)
describe why the precise ionic and osmotic balance of the cellular environment is
vital to cellular viability
15)
describe the two major body water compartments, intracellular and extracellular,
which are in equilibrium
16)
define that portion of extracellular fluid comprising blood plasma
17)
describe the circulatory system and account for pressure differences between
arterial and venous circuits
18)
illustrate the structure and activity of the heart and the circulatory pattern through
pulmonary and systemic circuits
19)
describe how blood pressure is monitored and regulated in the systemic circuit
20)
explain the need for the renal system to regulate volume and composition of body
water and blood volume
21)
describe the activities of the renal nephron
22)
describe how nephronal activity is regulated to achieve body water homeostasis
23)
describe the chromosomal basis of sex determination
24)
explain the function of the male and female gonads and accessory reproductive
structures
25)
describe hormonal control of reproductive function in male and female
26)
explain the female oestrous cycle
27)
explain pregnancy establishment and the need for an altered hormonal
background
2
28)
29)
30)
explain gestational term and parturition
account for mammary development during gestation and onset of milk secretion
after parturition
account for inhibition of oestrous cycles during lactation and the effect of
weaning
Lecturing Staff - to be agreed
Teaching Methods and Hours: Body systems Physiology 2 will be taught during the first
and second semesters of Year 2 with an end of course examination. The course will comprise
three lectures per week complemented by homework and practical assignments involving
about 300h work as shown in Table 1. The FVM Moodle system will be used to communicate
these assignments and to allow a discussion forum around each topic. The course is organised
around the 6 main topics as shown above under ‘aims’. A homework essay assignment will
generally be given near the end of each topic, the marks from which will contribute towards
the course exam mark as shown in table 2. The course will also include 2 computer
simulations of laboratory experiments. Following each of these classes there will be a
summary test to be completed in the student’s own time and submitted for marking, again for
a contribution to the overall course mark as shown in Table 2.
TABLE 1
Lectures
Laboratory
Computer Lab.
Essay
Private study
TOTAL
Formal teaching (hours)
75
2x2
2x2
83
Homework (hours)
4x8
7.5h / week ( upto 25 weeks)
220
Course textbooks:
No single textbook is likely to be ideal for all students of Animal Physiology. Students are
recommended to possess one of the following:‘Textbook of Veterinary Physiology’ by J.G. Cunningham & B. Klein; fourth Edition.
‘Physiology’, by R.M. Berne and M.N. Levy; Fifth Edition, 2004.
‘Color Atlas of Physiology’ by A. Despopoulos & S. Silvernagl, Fourth Edition,
Thieme Medical Publications, 1991. New York
The following textbooks are recommended additional reading.
‘Physiology of Domestic Animals’ by Sjaastad, Hove and Sand (2003), Scandanavian
Veterinary Press, Oslo.
‘Dukes Physiology of Domestic Animals’ (12th Ed, W.O.Reece, ed). 2004
‘Neurophysiology’ by R.H.S. Carpenter, Fourth Edition, Arnold, London (2003).
In addition: Textbooks and other literature will be referenced in lectures and Students are
expected to fully consult library resources for books and journal texts Evidence of wide
reading will be required when marking assignments.
As a starting point, some references to the above texts are given under ‘study guide’
below.
3
ITEMS OF SUMMATIVE ASSESSMENT
Coursework Assessments The grades you gain from coursework will be used as 30% of your final assessment. These coursework grades will also count towards your final grade if you have to resit the end‐of‐course examination. Consequently it is vital for you to obtain a decent grade for your coursework, which means you must hand in all the required assignments. The deadlines for submission of coursework are listed in the Timetable and in the laboratory schedules. End‐of‐course Examination An end‐of‐course examination will count as 70% of your final assessment. The format will be provided in advance and you will have an opportunity to practise example questions. The examination timetables are published on the Registry website. Normally you must sit the end‐of‐course examination at the first set (diet) of examinations after the end of the course. For Body Systems Physiology 2, the first diet of end‐of‐course examinations will be held in the May / June examination period. Relative Weighting of Assessments Body Systems
physiology 2
Item of assessment
Completed during
End-of-course examination (2 hours)
May diet
Weighting
70%
Home Essay Assignment, Thermoregulation
Week 3
4%
Home Essay Assignment, Digestion
Week 6
4%
Laboratory & test, Respiration
Week 9
4%
Laboratory simulation & test, Respiration
Week 10
3%
Laboratory & test, ECG
Week 13
4%
Laboratory simulation & test, Circulation
Week 14
3%
Home essay assignment, Kidney
Week 17
4%
Home Essay Assignment, Reproduction
Week 22
4%
TOTAL
100%
Table 2. Showing value of coursework assessments and the end-of-course
examination in the overall course mark.
4
Intended learning outcomes, Lecture synopses and Study guides
Temperature regulation and metabolism
Lecture 1
Lecture 2
Effect of temperature on cell metabolism and concept of internal heat
production to achieve a constant body temperature
Basal metabolic rate is governed by body size and may be altered to maintain
stable body temperature
Intended learning outcomes:
a)
b)
c)
d)
e)
a)
b)
Explain inefficiency of metabolism and waste heat
Describe the concept of metabolic mass
Show examples where body temperature fluctuates with ambient
Explain zone of thermoneutrality and costs of keeping warm or losing heat
Active versus passive mechanisms
Explain long-term adaptations to raise heat production
Explain diverse approaches to minimising costs of maintaining constant body
temperature eg hibernation
Synopsis:
Temperature is one of the important variables affecting cell function and viability. Animals
have evolved to regulate body temperature actively by harnessing metabolic waste heat.
Poikilotherms rely on behavioural adaptations to match body and environmental temperature.
Homeotherms exibit a range of environmental temperature, the thermoneutral zone (TNZ),
over which body temperature can be kept constant by balancing basal metabolic rate with
passive adaptations such as insulation effectiveness and diurnal feeding. Above TNZ energy
is wasted in efforts to lose body heat eg panting. Below TNZ energy is wasted in efforts to
raise body temperature eg shivering. Sometimes it may be energetically more favourable to
give up the fight to maintain body temperature whereupon it will revert to environmental
temperature eg hibernation
Study Guide:
Cunningham & Klein, Chapter 53.
Berne & Levy, Page 217.
5
Intended learning outcomes, Lecture synopses and Study guides
Digestion and control of food intake, functions of gastrointestinal tract
Lecture 1
Lecture 2
Lecture 3
Lecture 4
Lecture 5
Introduction to GI tract and concept of digestion to allow absorption of
nutrients. Comparative gut design and main features.
Digestion involves mastication, maceration by muscular contraction and
mixing with digestive secretions containing enzymes in acid or alkaline
environment.
Exocrine GI glands regulated by neurohumoral reflexes
Absorption is a function of the epithelium of the small intestine and also from
the rumen and large intestine depending on species. Non absorbed
food/secretions excreted. Diarrhoea.
Food intake and appetite, roles of gut fill and neurohumoral feedback
Intended learning outcomes:
c) Describe generalised gut structure and define digestion as opposed to absorption
d) Account for movement of digesta and enzyme/fluid secretion into GI tract
e) Note gut surface area and effect on absorption and Explain absorption for each food
group and the fate of absorbed nutrients
f) Note the extent of fluid flux across gut wall and normal recovery rate and diarrhoea
g) Appetite is regulated by hypothalamus in response to afferent neural/humoral signals
Synopsis:
Food obtained by eating must be digested to make molecules accessible to the body after
absorption into the circulatory system. GI plans differ between species depending on diet,
reflecting adaptation to particular food sources. When food is swallowed it is conveyed to the
stomach and intestines where enzymes and muscular activity break it into substances of
simple chemical composition ready for absorption. This occurs across an epithelial surface
and then into the blood. Blood draining gut passes exclusively to the liver where modification
and storage of nutrients may occur.
Gut motility and exocrine secretion are controlled by neural and endocrine signals in response
to food type and also psychic signals. Large volumes of secretions are normal but recovery
rates must be high to avoid diarrhoea. Rumen and large intestine may be important as
fermentation chambers to provide microbially-derived nutrients.
Appetite may be stimulated or inhibited depending on neurohumoral traffic to the
hypothalamus.
Study Guide:
Cunningham & Klein, Chapters 27 - 31.
Berne & Levy, Chapters 31 - 33.
6
Intended learning outcomes, Lecture synopses and Study guides
Respiration and the roles of the lungs in gas exchange
Lecture 1
Lecture 2
Lecture 3
Lecture 4
Lecture 5
Lecture 6
Respiration, airways and movement of air to and from lungs and into blood
Concept of tidal volume and adequate alveolar ventilation
Brain respiratory centre and chemoreceptor regulation
Gas transport between lung and tissues, haemoglobin
Effects of exercise and lung pathology on blood gases
Lungs and acid-base balance
Intended learning outcomes:
h) Explain the need for lungs in large animals for oxygen and carbon dioxide exchange
between atmosphere and blood
i) Describe lung and airway structure and function and detail the gas exchange barrier.
How is gas transported to and from lungs?
j) Chemoreceptors monitor blood gas content and by feeding back to the medulla can
signal changes in respiration pattern
k) How does exercise stimulate breathing?
l) Explain how pulmonary and circulatory disease reduces gas exchange/transport
efficiency and can alter blood gas levels
m) Explain the involvement of the respiratory system in acid-base balance
Synopsis:
Cell metabolism requires O2 and releases CO2. Both gases must be transported in blood to
and from the lungs and the air in the lungs must be continually refreshed with atmospheric air.
Breathing movements act as bellows to move air in the lung airways. Gaseous diffusion is
responsible for gas transfer from blood to air. The gas blood barrier is so thin to allow rapid
equilibration but disease can impair the process. Chemoreceptors in blood and cerebral fluid
detect gas levels and their feedback helps regulate ventilation of the lungs to maintain
homeostasis. Respiratory changes at exercise can anticipate requirements but also rely on
other sensory inputs to the respiratory control centre. The circulation is vital for blood gas
transport and changes such as anaemia will prejudice against satisfactory cell respiration.
CO2 yields hydrogen ions in solution in plasma so the correct respiration rate is vital for
normal blood pH. Altered respiration may be able to compensate for metabolic acid-base
change.
Study Guide:
Cunningham & Klein, Chapter 53.
Berne & Levy, Chapter 25, Pages 464-468, Chapters 27 - 30.
7
Intended learning outcomes, Lecture synopses and Study guides
Body fluids and the cardiovascular system
Lecture 1
Lecture 2
Lecture 3
Lecture 4
Lecture 5
Body fluids form the bulk of body mass and most of this is located
intracellularly
Extracellular fluid is continuously formed from and reabsorbed into the blood
circulatory system. It acts to link cells to the circulatory system and is in
equilibrium with the water of the intracellular compartment
The heart structure and function – correlation of electrical and pressure cycles
Pressure gradient in the systemic circuit, feedback and autonomic control
Cardiac disease
Intended learning outcomes:
n) Appreciate the importance of body water and show differences between intra- and
extra-cellular water and their origins
o) Describe the heart and pressure and electrical
p) Describe blood pressure variation within the circulatory system and explain pressure
differences
q) Explain blood pressure feedback and control in the systemic circuit
r) What is cardiac failure and how does it affect the circulatory system and body water
content and disposition
Synopsis:
Water accounts for some 2/3 body mass of which 2/3 is contained within cells or
intracellularly. The remainder forms the fluid bathing the cells and a small fraction of this
extracellular fluid is located within the branching network of the circulatory system as blood
plasma. A powerful 2-sided pump, the heart, forces blood through the circulatory system and
also provides energy for its ultrafiltration to form the extracellular fluid. Extracellular fluid is
vital as a solvent to carry a very varied collection of substances including nutrients and
respiratory gases between blood and body cells. The heart comprises separate right and left
sides which deliver blood to the pulmonary circuit for oxygenation and systemic arterial
circuit simultaneously. The arterial circuit is through thick-walled muscular vessels under
substantial pressure which is required for tissue perfusion and to ensure venous return to the
right heart. There is great capacity for selective distribution of blood to tissue beds depending
on relative tone in the autonomic nervous system. The most marked drop in blood pressure
occurs across the great many arterioles prior to capillary and tissue distribution. The venous
system collects blood from the capillaries and is characterised by large-bore low-pressure
vessels. Extracellular fluid formation and resorption depends on these capillary pressure
differences. Certain heart and metabolic diseases can lead to increased extracellular fluid
formation.
Study Guide:
Cunningham & Klein, Section 3.
Berne & Levy, Chapters 14 - 24.
8
Intended learning outcomes, Lecture synopses and Study guides
The renal system and body fluid regulation
Lecture 1
Lecture 2
Lecture 3
Lecture 4
Lecture 5
Show the need for a system to regulate the volume and composition of body
fluids and the circulatory system
Describe the activities of the renal nephron
Explain glomerular filtration rate (GFR)
Identify sites of selective reabsorption and show mechanism
Link renal function, body fluid volume, aldosterone and ADH
Intended learning outcomes:
s)
t)
u)
v)
w)
Show suitability of renal system for the purpose of body fluid regulation
Describe the nephron, its components and activities
Explain GFR, its measurement and relevance in renal function
Show importance of reabsorption and the mechanisms involved
Explain coordination of renal body fluid regulation
Synopsis:
The fluid environment of the cell must be regulated to control exchange of materials and
preserve the fluid environment within the cell. Water is gained and must also be lost daily to
preserve this fluid homeostasis. It is the role of the kidneys to balance water gains and losses
by regulating urine volume. The kidneys take a large share of the arterial blood flow to allow
them adjust plasma water and solute content. This works because ECF and ICF are in
equilibrium with plasma. The nephron is the basic renal functional unit and its main processes
involve filtration and selective reabsorption. Quantification of these processes shows how
body fluid composition could be regulated but fine tuning of the process is vital and requires
communication between kidney and circulatory system. This is provided by endocrine means
through aldosterone and ADH.
Study Guide:
Cunningham & Klein, Section 7.
Berne & Levy, Chapters 34 - 38.
9
Intended learning outcomes, Lecture synopses and Study guides
Reproduction, maintenance of the species
Lecture 1
Lecture 2
Lecture 3
Lecture 4
Lecture 5
Lecture 6
The chromosomal basis of sex and the roles of the gonads and accessory
structures
Describe hormonal control of reproduction in male and female
Explain the purpose of the breeding season and the oestrous cycle
Explain pregnancy and parturition
Account for mammary development and onset of lactation after parturition
Account for lactational anoestrus and effect of weaning
Intended learning outcomes:
x)
y)
z)
aa)
bb)
cc)
dd)
Explain sex differences and gametogenesis
Demonstrate the endocrine hierarchy in control of reproduction
Detail the control of spermatogenesis and libido/20 sexual function in male
Explain the oestrous cycle, its follicular and luteal phases and effects of season
Explain gestation and determination of gestation length
Account for mammary development and onset and maintenance of function
Account for effects of lactation on ovulation and oestrous cycles
Synopsis:
Half of male gametes carry the male determining Y-chromosome. These and gametes
carrying X-chromosomes must be deposited in the female tract precisely when female
gametes are ready to be fertilised. This requires much synchronisation of reproductive events
in the sexes and requires a cyclic pattern of ovarian activity both to produce the hormones
necessary to both encourage sexual liaison between sexes and also to promote development of
any resulting embryos. Gestation is the prolongation of embryonic development and usually
inactivates the cyclic ovary. Gestational hormones promote mammary development but full
lactation is delayed until birth. Continued lactation requires young to suckle, which signal
usually postpones resumption of ovarian cyclicity. Termination of suckling at weaning allows
resumption of oestrous cycles.
Study Guide:
Cunningham & Klein, Section 6.
Berne & Levy, Chapter 46.
10