1
Q
What is anatomy?
A
the structure of organs and tissues within an animal
2
Q
What is physiology?
A
the function of those organs and tissues
3
Q
What is the common integument?
A
the skin
4
Q
What are the seven function of the skin?
A
protection, immune defense, tactile sensing of the environment, thermoregulation, storage and excretion, communication and camouflage, selective permeability
5
Q
Mechanoreceptors?
A
respond to physical stimulation
6
Q
Bulbous corpuscle?
A
(Ruffini ending) sense when the skin stretches
7
Q
Bulboid corpuscle?
A
(Krause end bulb) - sense coldness
8
Q
Tactile corpuscle?
A
(Meissner corpuscle) Change in texture and slow vibrations
9
Q
Lamella corpuscle?
A
(Pacinian corpuscle) pressure and fast vibrations
10
Q
Discoid terminal free nerve ending?
A
(Merkel disc) sustained during touch and pressure
11
Q
Three types of receptors?
A
mechanoreceptors, nociceptors, thermoreceptors
12
Q
Nociceptors?
A
free nerve endings can act as nociceptors, pain
13
Q
Thermoreceptors?
A
free nerve endings, heat specific ones and cold specific ones
14
Q
What internal parameters do animals need to control?
A
temp, pH, electrolytes, water, blood gases (O2 CO2) Blood pressure and cardiovascular functions, hormonal responses etc.
15
Q
What temperatures do biological processes require?
A
optimum temps
16
Q
Endotherms?
A
derive heat from internal metabolic processes
17
Q
Homeotherms?
A
maintain internal temperature within a narrow range
18
Q
If you are an endotherm, you are also a?
A
homeotherm
19
Q
Ectotherms?
A
derive heat from external environment sources e,g. basking
20
Q
Poikilotherms?
A
variable temperature as unable to maintain internally
21
Q
Animals that are ecotherms are also?
A
poikilotherms
22
Q
Mammals and birds are what type of ‘therm’?
A
Homeotherms
23
Q
too cold?
A
HYPOthermia
24
Q
Hypothermia?
A
mild –> 32-37
moderate –> 28-32
severe –> <28
(these values are for exposure related hypothermia)
25
Too hot?
HYPERthermia
26
hyperthermia?
mild/moderate--> 39.4-41
Severe --> >41
27
hyperthermia signs?
central nervous system signs - multi organ failure - death
28
How is any complex maintained?
control centre
supply of info
communication
effectors
responses
29
effectors?
muscles/glands
30
Control centre in the body?
Hypothalamic thermoregulatory centre
(dorsal to pituitary gland)
31
What do afferent nerves do?
come to the brain
Sensory inputs from the body to the hypothalamus
32
Where do you have thermoreceptors?
In skin, in internal organs, in spinal cord, in hypothalamus itself
33
Types of thermoreceptors in skin?
hot and cold
34
Efferent nerves?
outputs from the hypothalamus to the body
35
Efferent outputs cause?
changes in behaviour, blood flow, other physiological responses, hormones
36
Thermoregulation is different but...
complementary for heat and cold stress
37
What is the autonomic nervous system made up of?
sympathetic nervous system
Primary route
Parasympathetic nervous system
38
sympathetic nervous system?
fight and flight
39
What increases or decreases the activity to different effectors?
the primary route to effectors in thermoregulation
40
parasympathetic nervous system?
rest and digest
some involvement in normal thermoregulation
41
How can an animal lose or gain heat? (blood vessels)
smooth muscle within walls of blood vessels:
Dilate - blood vessels to increase blood flow if hot
Constrict - blood vessels to decrease blood flow if cold
42
How can an animal lose or gain heat? (2) (hair)
arrector pili muscles (smooth)
- contract to lift hairs/feathers
-relax to lower hairs/feathers
43
How can an animal lose or gain heat? (3) (glands)
Sweat gland activation
- increase secretions to skin surface for evaporation
44
How can an animal lose or gain heat? (4) (breath)
Panting - change in breathing pattern to increase airflow over moist mucosal surfaces for evaporation - no gas exchange occurs here
45
How can an animal lose or gain heat? (5) GIVE 2 (movements)
shivering
behavioural changes (e.g. huddling together)
46
What information does the hypothalamus receive (and where from) about the temperature?
receives sensory information about temperature from skin surface, internal organs and itself
47
If temperature increases?
physiology does what it can to reduce it again
48
If temp decreases?
physiology does what it can to increase it again
49
How does the hypothalamus maintain its temperature set point?
through sensory and hormonal outputs
50
What is thermoregulation?
a negative feedback mechanism
51
Fever or pyrexia?
a reset of the hypothalamic set point to a higher temperature
52
What does fever/pyrexia enhance?
it enhances leucocyte (white blood cell) function to help fight infection
53
The hypothalamus has a heat loss centre - what does this do?
detects higher than set points - so starts process of heat loss
54
When temperature is corrected, what happens?
the heat loss centre switches off and in the opposite case, the heat conservation centre switches off
55
The hypothalamus has a heat conservation centre, what does this do?
it detects lower than set point so starts process of conserving/generating heat
56
What is a by-product of all metabolic processes?
heat
57
eventually all food energy is converted into...
heat, either directly or via exercise, eating and muscle contraction
58
how does exercise produce heat?
work done converted to heat energy
59
how does eating produce heat?
supply of energy, but also digestion is work
60
how does muscle contraction produce heat? (shivering)
as a means of increasing metabolic heat in response to a drop in temp where antagonistic muscles produce no useful work
61
hormones -->
longer term, chronic
62
Brown adipose tissue?
a form of non-shivering thermogenesis
63
muscle contraction is:
shivering thermogenesis
64
non shivering thermogenesis?
produces more body heat from metabolic sources of energy
65
what is the special type of fat in neonatal mammals?
brown adipose
66
using fat reserves?
rewatcj lecture
67
thyroxine?
lecture
68
what animal does not have brown adipose tissue?
PIGS
69
what gene did pigs lose meaning that they don't have brown adipose tissue?
lots the UCP1 gene - 20 million years ago
70
What is brown adipose tissue predominantly in?
neonates
71
describe neonates SA:V ratio?
larger surface area to volume ratio
72
Describe which animals have brown adipose tissue?
in small hibernating mammals in adulthood
73
Why does brown adipose tissue have a darker colour?
due to higher density of mitochindria with cytochrome (iron-containing) pigments
74
what does brown adipose tissue contain?
smaller numerous lipid droplets
75
where is brown adipose tissue located?
located in subcutaneous region between scapulae and around kidneys and myocardium
76
What does the presence of lipids in close proximity to many mitochondria allow in brown adipose tissue?
facilitates rapid transfer of stored energy into heat energy
77
What is brown adipose tissue stimulated by?
both circulating catecholaminbes and norepinephrine secreted by sympathetic nerve endings
78
HOW DO ANIMALS LOSE HEAT?
radiation, conduction and convection, evaporation,
79
Where is most body heat produced?
in metabolically active organs and tissues: liver and muscles
80
What part of the body are good insulators?
tissues - so they hold onto heat and the heat needs to be taken away
81
Where is heat carried?
in the warm blood
82
Why do blood vessels dilate?
to allow more blood to flow through and release more heat
83
Why do blood vessels constrict?
to reduce blood flow and retain more heat
84
What nervous system regulates heat loss? (via blood vessels)
sympathetic nervous system
85
Blood supply to skin?
Triple plexuses (superficial, middle, deep)
Immense surface area
86
piloerection?
hair is standing up on end - more insulation and is regulated by sympathetic nervous system
87
how do you retain heat and increase the insulation?
via piloerection with use of the arrector pili muscles
88
Describe dogs and cats sweat glands?
poorly developed
89
apocrine sweat glands?
proteinaceous sweat
90
eccrine sweat glands?
watery sweat
91
where are sweat glands predominantly localised in domestic species?
paws
92
Describe how panting cools the animal down?
evaproationm, moisture from mucosal surfaces in upper resp tract
increased salivation, local vasodilation to increase blood flow and dissipation of heat
differentr breat5hing patterns using nose/mouth and dead space breathing where there is no gas exchange
93
what is dead space breathing?
no gas exchange
94
local vasodilation?
heat energy from warm blood evaporates the moisture cooling the blood
95
when is core body maintained?
in cool and warm environmental temperatures
96
How do animals prevent cold blood from extremities from cooling the core?
contstriction of blood vessels in extremities to reduce heat loss
Results in cooler extremities with cooler blood
Need to avoid cooling the core so the returning blood needs to be warmed
97
counter current exchange
more blood goes deeper than superficial so more cool blood goiong into the deep vessels
heat from artery warms blood up in the deep vein
exchange of heat - warm blood going to core and restrict heat loss going to the environment
98
carotid rete?
expansion of a vein, with coold blood in it which has come from nasal muscosum area, the mesh from the carotid artery, heat radiatyes out of arterial vessels into cool blood in the sinus then the mesh of vessels all comes back together and it is much cooler and this cooler blood can then go to the brain coming from the carotid - cats, pigs and chickens, cattle and sheep horses/primates do not have it
99
selective carotid rete?
the facial vein dilates and the angularis oculi vein contricts so the blood can avoid the cavernous sinus as much as possible
100
tmj
tempero mandibure joint
101
what is rudimentary in dogs?
carotid rete
102
what are the functions of skin?
protection
immune defence
tactile sensing of the environment
thermoregulation
storage and excretion
communication and camouflage
selective permeability
103
what mechanoreceptors does the skin have?
bulbous corpuscle
bulboid corpuscle
tactile corpuscle
lamellar corpuscle
discoid terminal free nerve ending
104
what nociceptors does the skin contain?
free nerve endings can act as nociceptors - detect pain
105
what thermoreceptors does the skin contain?
free nerve endings can also act as thermoreceptors - you can have heat and cold specific ones
106
what is the 'textbook' definition of homeostasis?
maintenance of constant conditions within the body's internal environment in face of disturbances
107
what is an ectotherm?
they derive heat from external environmental sources (e.g. basking)
108
what is the temperature range for mammals?
36.5-39.5 degrees - there is species variation
109
what is the temp range for birds?
38-43 degrees (ofc there is species variation)
110
what is the control centre for homeostasis?
the hypothalamic thermoregulatory centre
111
how do sensory inputs make it from the body to the hypothalamus?
through afferent nerves
112
how does thermoregulation occur - where are there thermoreceptors?
in the skin (hot or cold)
in internal organs
in spinal cord
in hypothalamus itself
113
where do the outputs from the hypothalamus to the body go through?
through efferent nerves (and/or hormones, these are slower release)
114
what are the effectors for thermoregulation?
changes in behaviour
changes in blood flow
(+ other physiological responses)
hormones
115
what are the key points to managing temp?
there is a normal temp range
then hypothalamus receives sensory info about temp from skin surface/internal organs and itself
the hypothalamus has a temp set point that it maintains through sensory and hormonal outputs
effectors are adjusted to produce more heat if cold, or lose more heat if warm
116
what does fever do?
it changes the 'set point' (the speed limit - analogy)
117
what is heat a by-product of?
of all metabolic processes
118
how do animals produce heat?
by-product of all metabolic processes
exercise
eating
muscle contraction
brown adipose tissue (only certain species and age of animals e.g. neonates)
119
what is brown adipose tissue an example of?
non shivering thermogenesis
120
give examples of non shivering thermogenesis?
using fat reserves
special type of fat in neonatal mammals
also
can adjust basal metabolic rate in response to chronic cold conditions
121
what is the special type of fat that is an example of non-shivering thermogenesis?
brown adipose
122
what is non-shivering thermogenesis?
where you're producing more body heat from metabolic sources of energy
123
what is using fat reserves (an example of non-shivering thermogenesis) mediated by?
mediated by sympathetic ANS (noradrenaline)
and by catecholamines (Adrenaline and noradrenaline) - the hormonal aspect = longer term
124
adjusting basal metabolic rate in response to chronic cold conditions is an example of non-shivering thermogenesis - what is this mediated by?
by thyroxine (T4) levels
Higher = higher metabolic rate
Low = lower metabolic rate
125
what is brown adipose tissue specific to?
to mammals (it is not present in other vertebrate species including birds)
126
which mammal can you not find brown adipose tissue in and why?
pigs - they lost a gene (UCP1) 20 mill yrs ago
so are much less tolerant to cold conditions than other domestic species
127
where is brown adipose tissue predominantly found?
neonates (larger body surface to volume ratio)
also
present in small hibernating mammals in adulthood (as they maintain it into adulthood
128
what does brown adipose tissue look like?
darker in colour due to a higher density of mitochondria with cytochrome (iron-containing) pigments
129
describe the lipid droplets in brown adipose tissue:
they are smaller and more (numerous) lipid droplets
130
where is brown adipose tissue located?
in subcut region between scapulae and around kidneys + myocardium
131
what does the presence of lipids being in close proximity to mitochondria within brown adipose tissue?
it facilitates rapid transfer of stored energy into heat energy
132
what is brown adipose tissue stimulated by?
by both circulating catecholamines and norepinephrine secreted from sympathetic nerve endings
133
how does radiation help an animal lose heat?
when body is warmer than environment - it loses heat by emission of infra-red radiation
134
how do animals lose heat via conduction or convection?
lose heat directly from body surface to cooler objects in contact with the animal
there is a transfer of heat by warm air to cooler air
135
how do animals lose heat by evporation?
it is the only form of heat loss when ambient temp equals or is greater than body temp
via panting, sweating
(evaporation of 1L of water requires 2.43kJ)
136
which organs/tissues is most heat produced in?
most heat produced in metabolically active organs/tissues: liver + muscles
137
how do you lose heat via blood?
the blood vessels dilate to allow more blood to flow through and release more heat
138
how can you retain heat in your blood?
the blood vessels constrict to reduce blood flow and retain more heat
139
heat loss by radiation, conduction and convection (dilation + constriction of blood vessels etc.) is regulated by what?
by the sympathetic nervous system
140
where are sweat glands found predominantly in cats/dogs?
predominantly localised to paws
141
do many animals use sweating a major cooling mechanism?
in most domestic species, sweating is not a major cooling mechanism
(e.g. cats and dogs have few and poorly developed sweat glands over their bodies)
142
what are the more important means of cooling in horses and cattle?
apocrine sweat glands (proteinaceous sweat)
- also in sheep, but less effective under wool, can be useful in breeds with open fleeces)
143
what is the primary means of cooling in primates (incl. humans)?
sweating (evaporation)
via eccrine sweat glands (watery sweat)
144
describe how panting helps with heat loss?
moisture from mucosal surfaces in upper resp tract evaporates
increased salivation
local vasodilation to increase blood flow and dissipation of heat - the heat energy from warm blood evaporates the moisture cooling the blood
SHALLOW BREATHING (dead space breathing - so no gas exchange)
145
how do animals prevent the cold blood from the extremities from cooling the core temp?
constriction of blood vessels in extremities to reduce heat loss
results in cooler extremities within cooler blood
must avoid cooling the core - so returning blood needs to be warmed
146
how do you warm the 'returning' blood that is going towards the core - in order to maintain a hot core?
counter-current exchange:
peripheral blood vessels are constricted
resistance is high (as vessel is narrow)
blood flows through deep capillaries - to reduce transfer of heat to the environment
the heat from warm blood in arteries (coming from core) is transferred to the cooler blood in the deep veins (coming from periphery)
Opposite directions - hence countercurrent
Blood returning to core is warmed up before reaching core
147
how do you cool the 'returning blood' to cool down the hot core?
peripheral blood vessels are dilated
resistance is low
blood flows through superficial capillaries to transfer heat to the environment
148
apart from the counter-current cooling system - what other vascular arrangements for thermoregulation is there?
brain cooling in cloven-hoofed (artiodactyls) animals
in artiodactyls there is the carotid rete (rete mirabile)
149
mirabile is a...
mesh
150
what is the carotid rete best developed in?
cattle and sheep
151
where else is the carotid rete seen (not just in cattle and sheep)?
cats, pigs and chickens
and it is rudimentary in dogs
horses/humans don't carry this at all
152
what is the carotid rete?
you have an expansion of a vein (angularis occuli vessel)
(w/ cool blood in it - come from the nasal mucosa area which has cooled the environment - so you have this cool blood in the cavernous sinus)
mesh of vessels that comes from the carotid artery - the vessels work their way through cavernous sinus, no mixing of blood - vessels maintain structure + integrity - the mesh of vessels sit inside the cavernous sinus
The heat radiates out of the arterial vessels into the cool blood of the venous sinus - then the mesh vessels come back together again into a vessel coming out the other side which then goes to feed the brain - so NO HOT blood is going to the brain
153
how is the carotid rete selective?
if temp gets a bit cooler and you don't want to cool the blood as much you can constrict the angularis oculi vein + dilate facial vein so you can bypass that sinus so don't get significant cooling affect - sympathetic nervous system
154
how do horses cool their brain without the carotid rete?
guttural pouch
155
what is the guttural pouch present in?
in perissodactyla (odd toed nonruminant ungulates) e.g. horses, tapirs, rhinos
156
explain the guttural pouch:
auditory tube diverticula containing air
arteries pass through and can dissipate heat into the air-filled space
157
what is the auditory tube full of?
it's an outpouching which is full of air
found at the caudo-ventral aspect of the skull
158
look at cases...
STRUC+FUNC 2 (vet)
flashcards
Decks in class (30)
# Cards
-
Intro to Vet Anatomy57
-
Intro to Histology85
-
The Common Integument141
-
HAIR104
-
GLANDS133
-
footpads, claws, hooves, horns and antlers147
-
Integument Physiology158
-
Development of the Integument40
-
Scales25
-
THE SKIN9
-
Oral Anatomy - Tongue81
-
Oral Anatomy - Salivary Glands79
-
Oral Cavity Anatomy - Teeth160
-
Digestive System GIT - Canine127
-
Digestive System GIT - Ruminants47
-
Horse, Pig, Rabbit GIT15
-
GI Physiology63
-
Digestive system comparative anatomy of the liver and pancreas113
-
Gastric Function61
-
Pancreas and Liver Physiology124
-
Function of the small and large intestine78
-
Control of the digestive system91
-
Horse GIT91
-
Comparative Guts147
-
The Rumen Complex13
-
Exotics GIT37
-
Equine Hindgut Microbiome14
-
GIT Behaviour17
-
Development Gastrointestinal System39
-
GI Physiology - Pancreas and Liver119
