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Comparative Anatomy And Physiology Of Animals > Sensory Systems > Flashcards

Sensory Systems Flashcards

1
Q

Central nervous system in vertebrates

A

> 95% of 116 genes involved in brain or neural Morphogenesis were commonly shared among all vertebrates
30% of planarian nervous system-related genes are homologous sequences in Arabidopsis and yeast- which do not posses a nervous system

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2
Q

Dendrites

A

Conduct electric excitation in a directed way

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3
Q

Axon

A

A long, slender projection of a neuron that conducts electrical impulses away from the neuron’s cell body- transmit information to different neurons, muscles and glands
Myelinated axons = nerve fibres

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4
Q

Brain

A

A cluster of specialised groups of neurons
Most prominent anterior condensation of neurons

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5
Q

Nerve cord

A

Cluster of neurons
Most prominent longitudinally extending condensed part of the nervous system

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6
Q

How does the nerve cord run in invertebrates

A

Ventrally

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7
Q

How does the nerve cord run in vertebrates

A

Dorsally

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8
Q

Ganglion

A

Group of specialised neurons
Parts of CNS
Neuronal somata concentrated at the surface - forming a cell cortex
Neurites are concentrated in the centre of the ganglion to form the neuropil
Distinct unit

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9
Q

Which animals do not have a centralised nerve system

A

Animals without bilateral symmetry eg Cnidarian

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10
Q

Cephalisation

A

The process by which nervous tissue, over many generations , becomes concentrated towards one end of the organism

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11
Q

Variation of CNS in chelicerata (arachnids)

A

Exhibit maximum concentration of the nervous system
Whole series of ganglia are aggregated together and fused (into one great central brain), from where nerves radiate to all parts of the body

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12
Q

Touch (tactile) receptors in Cnidarians

A

A simple nervous system , without brain, controls homeostasis
Eg nematocyst mechanism - If touched the hair triggers the cell explosion, a harpoon-like structure which attaches to organisms that trigger it and injects a dose of venom

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13
Q

PNS. Chordotonal organ- insects and crustaceans

A

Stretched neurons that detect different stimuli
Detection of vibration, touch receptors, chemoreceptors
Each unit consists of a sensory neuron, glial cells, scolopidal cells

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14
Q

Subcuticular mechanireceptors

A

Specialised sensory organs that receive vibrations in arthropods
Important for ground-dwelling species, especially nocturnal species

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15
Q

Subgenal organ

A

Complex ciliated mechanoreceptor below the knee in insects

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16
Q

Tricoid sensilla

A

Touch receptors on bodies of anthropods

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17
Q

Johnston organ

A

Largest mechanoreceptor organ of fruit fly
Gravity and sound detection

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18
Q

In invertebrates- where do tympanic ears occur

A

Insects

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19
Q

Vertebrate senses

A

Vision
Chemoreceptors (smell and taste)
Mechanoreceptirs (sound and other vibrations)
Electroreception
Magnetoreception
Temperature sensing

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20
Q

How do eyes vary

A

Acuity
Range of wavelengths they can detect
Sensitivity in low light levels
Ability to detect motion
Whether they can discriminate colour

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21
Q

Bird eyes

A

are able to perceived a wider range of light wavelengths than we can – in effect they can see ultra-violet light.
As mammals we tend to see eyes as being spherical but avian eyes vary in shape from being rather flattened to being bowed.
They also have a blood-rich pecten that protrude from the retina and is considered as a means of maximising nutrition to the eye.

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22
Q

Field of vision in prey

A

Wide possible view
Much of the angle is only viewed by one eye - monocular vision

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23
Q

Field of vision in predators

A

Stereopsis and depth perception
Binocular vision
Blind spot

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24
Q

Rods

A

Sensitive to low light
Rhodopsin

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25
Q

Cones

A

Need brighter light
Sensitive to various wavelengths
Chromophore

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26
Q

Colour vision

A

4 cone types - tetrachromatic eg birds
2 cone types - dichromatic eg macaque
1 cone type - monochromatic - colour blind eg dolphin

3 cone types - trichromatic eg humans

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27
Q

Adaption to low light levels

A

High density of rods

A ‘tapetum lucidum’ biological reflector system that is a common feature in the eyes of vertebrates.
Functions to provide the light-sensitive retinal cells with a second opportunity for photon-photoreceptor stimulation,
Enhances visual sensitivity at low light levels.

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28
Q

Chemoreception

A

Vertebrate chemoreception consists of taste, olfaction and the vomeronasal (or Jacobson’s) organ
Olfaction involves detection of an airborne (or waterborne) molecule into a specific receptor on the surface of an olfactory sensory cell
Taste involves detection of a waterborne molecule into a specific receptor on the surface of a taste bud

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29
Q

Vomeronasal organ

A

Detects non-volatile chemical cues - Flehman’s response
Linked to hypothalamus
Used in the detection of pheromones (eg major urinary proteins in mice)
Removal of the organ impairs sexual and social behaviour in rodents

Snakes have a well developed paired Jacobson’s organs in the top of the buccal cavity. Molecules are collected by the wet tongue and then intorducted into the organ when the tongue is retracted

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30
Q

Mechanoreception

A

detects physical perturbations of the environment – the commonest are sound waves in the air (or water).
(only mammals have true pinnae that focus sound waves down the ear canal).
Sound waves going down the ear canal cause the ear drum to vibrate, which causes the ossicle bones to vibrate and transfer the sound waves to the cochlea. As the waves move through the fluid within the cochlea tiny hairs in the organ of Corti are disturbed, which generates nerve impulses which are perceived as sound.

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31
Q

Sound detection

A

The cochlea is filled with perilymph, - moves in response to the vibrations coming from the middle ear via the oval window
As the fluid moves, the cochlear partition (basilar membrane and organ of Corti) moves

Thousands of hair cells sense motion via their stereocilia, and convert that motion to electrical signals communicated via neurotransmitters to many thousands of nerve cells
Hair cells in the organ of Corti are tuned to certain sound frequencies by way of their location in the cochlea

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32
Q

Fish mechanorecpetion system

A

In fish there is an otilith which resists movement from sound waves whilst the endolymph surrounding it moves – this causes hairs to be moved and triggers a nerve response. Fish lack any outer ear structure as their whole body can absorb sound waves.

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33
Q

Amphibian mechanorecpetion system

A

In amphibians there is a tympanic membrane on the side of the head (behind the eye) and this resonates and moves the columella – a bone that connects the tympanum to the otic capsule. Amphibians lack the semi-circular canals used in perceiving position as seen in mammals, crocodilians and birds.

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34
Q

Evolution of sound detection

A

Fish
No bony structure to transmit vibrations
No Tympanum
No middle ear
Otoliths vibrate

Frogs, Reptiles, Birds
Single columella
Straight cochlea

Mammals
External pinna
Three middle ear ossicles
Coiled Cochlea (except monotremes)

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35
Q

Vibration detection - the lateral line

A

System ofmechanosensory organs found in aquatic vertebrates, mainlyfish but mostamphibianlarvaeand some fully aquatic adult amphibians posses mechanosensitive systems comparable to the lateral line
Provides information about flow patterns around animal and nearby objects Used to detect movement and vibration
Provides spatial awareness and the ability to navigate in space
Plays an essential role in orientation, foraging behaviour, andshoaling

The major unit of functionality of the lateral line is the neuromast
Superficial on surface of skin – respond to water motion
Within canals – respond to pressure variations and gradients in adjacent cells

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36
Q

Electroreception

A

Electroreception is used inelectro-location(detecting objects) and forelectro-communication
Passive – Animal senses the weakbioelectric fieldsgenerated by other animals and uses it to locate them (e.g. foraging)
Active – Animal senses its surrounding environment by generatingelectric fieldsand detecting distortions in these fields using electroreceptor organs (e.g. communication)

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37
Q

Ampullary receptors

A

located in skin
sensitive to electrical fields of low frequency - <0.1 – 25 Hz)
Found in many types of fish

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38
Q

Tuberous receptors

A

in depressions in epidermis and covered by epidermal cells
Sensitive to electrical fields of high frequency – 50 Hz – 2 kHz)
Found in species that produce their own electrical fields and most sensitive to the frequencies produced by the fish

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39
Q

Passive Electroreception

A

Animal senses the weakbioelectric fieldsgenerated by other animals and uses it to locate them (e.g. foraging)

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40
Q

Active Electroreception

A

Animal senses its surrounding environment by generatingelectric fieldsand detecting distortions in these fields using electroreceptor organs (e.g. communication)

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41
Q

Ampullae of Lorenzini

A

Electric field sensors of sharks
Detect voltage differences
Use electroreception to forage and possibly navigate

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42
Q

Weakly electric fish

A

Use electroreception for mate attraction, territorial and agonisitic displays and mimicry
Active electroreception has a range of about one body length

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43
Q

Magnetoreception

A

Allows an animal to detect amagnetic fieldto perceive direction, altitude or location.

May underlie long-distance navigation in several animal species

A method for animals to develop regional maps, e.g. of the Earth’s magnetic field

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44
Q

Infrared sensing

A

Evolved independently in several different families ofsnakes
It allows them to ‘see’ radiant heat at wavelengthsbetween 5 and 30μm
Infrared light heats up parts of a thin membrane inside the pit organ, and TRPA1 proteins embedded on that membrane detect the temperature change
Directional and sensitive

Warm-blooded animals emit heat as infrared radiation
Pit vipers can detect potential prey a meter away
Accuracy enough to target vulnerable body parts of the prey
Not only used for prey detection

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45
Q

Evolution of eyes

A

So the simplest ‘eye’ would be some photoreceptors in the epidermis (a) that sense the absence or presence of light. If the photoreceptors are then located within a depression in the epidermis (b) then the animal can determine whether light hitting the photoreceptors can come from a particular direction. If the gap through which light can travel is reduced to a ‘pin-hole’ (c) then a basic image can be projected on to the photoreceptors and offers finer directional perception. If the hole is covered by a transparent surface (d) then the space can be filled with a transparent humour. If a lens then develops next to the hole (e) then there is an ability to focus an image on the photo receptors. The final stage (f) sees the development of an iris that can actively regulate the amount of light entering the eye.

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46
Q

How does environment affect what colours of light you can see

A

ocean light penetration diminished quickly as you descend down the water column and the light wavelengths are filtered. Blue light extends furthest down and a full colour spectrum is only observable within a few metres of the surface.

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47
Q

Tapetum lucidum

A

A reflector system that provides retinal cells with a second change at light detection- increasing light sensitivity in low light level

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48
Q

Sound threshold

A

Lower thresholds = greater sensitivity to sound

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49
Q

Sound detection in alligators

A

In air- more sensitive to low frequencies but less sensitive to high frequencies
In water - more sensitive to all frequencies

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50
Q

Mechanoreception in fish

A

No bony structure to transmit vibrations
No tympanum
No kiddle ear
Otoliths vibrate

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51
Q

Mechanoreception in fish, reptiles and birds

A

Single columella
Straight cochlea

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52
Q

Mechanoreception in mammals

A

External Pinna
Three middle ear ossicles
Coiled cochlea (except monotremes)

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53
Q

Major unit of functionality of the lateral line

A

Neuromast -
- superficial on surface of skin = respond to water motion
- within canals = respond to pressure vibrations and gradients in adjacent cells

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54
Q

How do birds carry out Magnetoreception

A

Through eyes
Via iron deposits in the beak
Through ears

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55
Q

What is important for magnetoreception

A

Light
Colour of light

56
Q

Sensory transduction

A

Sensory receptor cells convert stimulus energy into an electrical signal

57
Q

Ionotropic transduction

A

Receptor binds to a neurotransmitter and opens an ion channel across a cell membrane
Ligand-gated channels

58
Q

Enlarged cell membrane of receptor cells

A

Increase surface area
Increase receptor number

59
Q

2 types of transduction

A

Ionotropic
Metabotropic

60
Q

Metabotropic transduction

A

Receptor molecule acts like a neurotransmitter to activate a metabotropic cascade
Receptor protein activates a G protein, which activates a second effector molecule in the cell that then affects ion permeability of the membrane

61
Q

Ionotropic transduction - response

A

Rapid
10-50ms

62
Q

Ionotropic transduction - latency

A

Short latency action

63
Q

Ionotropic transduction - mechanism

A

Binding site and channel combined

64
Q

Ionotropic transduction - location

A

Postsynaptic in general

65
Q

Metabotropic transduction - response

A

Slow

66
Q

Metabotropic transduction - response

A

Slow

67
Q

Metabotropic transduction - latency

A

Longer

68
Q

Metabotropic transduction - mechanism

A

Binding site not associated with channel
G-protein or 2nd messenger involvement

69
Q

Metabotropic transduction - location

A

Pre or postsynaptic

70
Q

What are commonly metabotropic systems

A

Some taste receptors
Photoreceptors

71
Q

Which mechanism of transduction are most senses

A

Ionotropic

72
Q

2 roles of sensory receptor

A

Transduction
Encoding information about the stimulus

73
Q

Labelled lines principle

A

Even though all receptors use action potentials to encode stimuli the physical destination of the sensory axons deals with each different type of sensory receptor

74
Q

Sensory receptor function- the insect bristle (sensillum)

A

Hollow shaft protrudes through exoskeleton and is attached to the end of a dendrite (nerve cell), which is supported by sheath and socket cells
Move the bristle and the distal tip of the dendrite is stretched and deformed

Deformation opens stretch-activated channels to allow cations (e.g. Na+ or K +) to move through the cell membrane generating a receptor potential across the dendrite’s plasmalemma
If a threshold for membrane depolarisation is reached then an action potential is propagated

75
Q

Insect bristle (sensillum)

A

Small bristle movement does not cause enough depolarisation to reach a threshold – bristle movement is not detected
More displacement cross the threshold and generates a train of action potentials

Further deformation increases the frequency of the action potentials
Transduction illustrated by the resting potential triggering an action potential
Encoding illustrated by the frequency of action potentials

76
Q

Rods structure

A

Lamellae form discs detached from the plasmalemma

77
Q

Cones structure

A

Lamellae are continuous with the plasmalemma

78
Q

In the dark - vertebrate eye

A

In the dark Na+ channels are relatively open and there is a flow of ‘dark’ current across a relatively depolarised (-30mV) cell membrane in the outer part of the cell

79
Q

Light stimulation

A

Metabotropic transduction
Rods contain rhodopsin- activated by light
Activated rhodopsin stimulates transducin, a G-protein to activate a phosodiesterase enzyme
Enzyme decreases cyclic guanosjne monophosphate (cGMP) concentration in the receptor cytoplasm
Decrease in cGMP closes cyclic-nucleotide-gated channels for Na+ and reduces its influx into the cytoplasm

80
Q

Response to light

A

Hyperpolarisation
Causes ion channels to close reducing the dark current

81
Q

Neuron

A

long, thin cell surrounded with plasmalemma and Schwann Cells (neurolemmocyte) and a Myelin Sheath

82
Q

Resting membrane potential

A

Sodium (Na+) and potassium (K+) ions continually diffuse across the plasmalemma
Cl- ions and large negatively charged molecules cannot cross the plasmalemma
Na+ and K+ concentrations on each side of the plasmalemma remain constant because sodium-potassium ATPase actively moves 3x Na+ out and 2x K+ in to the cytoplasm
Produces a resting potential of –70mV

83
Q

Depolarisation

A

A neuron transmits a signal as an action potential in response to a stimulus
The stimulus must of a sufficient size to cross a threshold that triggers the localised movement of ions across the plasmalemma
The threshold stimulus increases permeability to Na+ ions which all rush into the cytoplasm and neutralises the resting potential, i.e. –70 mV → 0 mV = depolarisation
The influx of Na+ ions temporarily confer a positive charge to the cytoplasm

84
Q

Repolarisation

A

Almost immediately voltage-gated Na+ channels close and voltage-gated K+ channels open and K+ ions leave the cytoplasm to build up a positive change again
This sequence of events triggers the same molecular changes in adjacent areas of the plasmalemma and the action potential moves along the axon

85
Q

Hyperpolarisation - refractory period

A

After the action potential has moved on the membrane becomes hyperpolarised (more than –70mV) because of uncontrolled movement of K+
Sodium-potassium ATPase restores the resting potential
During hyperpolarisation the membrane is insensitive to triggering another action potential
This whole process takes ~ 3 milliseconds

86
Q

Total length of action potential

A

3 ms

87
Q

All or nothing

A

exceeding the stimulus threshold does not increase the size of the action potential

88
Q

Speed of transmission

A

increased by increasing axon diameter - most vertebrate axons < 10μm
Some fish and amphibians have unmyelinated axons ~ 50μm (involved in rapid escapes)

Myelination increases transmission by Saltatory conduction from node of Ranviers

89
Q

Squid axons

A

1 mm wide and conduct an action potential at 36 m per second

90
Q

Cell bodies cluster

A

nuclei” in CNS and “ganglia” in PNS

91
Q

Types of synapses

A

Axosecretory
Axoaxonic
Axodendritic
Axoextracellular
Axosomatic
Axosynaptic

92
Q

Axosectretory

A

Axon terminal secretes directly into bloodstream

93
Q

Electrical synapses

A

between two neurons
Positively charged ions from the presynaptic end bulb directly depolarise the adjacent neuron

94
Q

Chemical synapse

A

between neuron and a range of cell types
Requires chemical agent called a neurotransmitter (e.g. acetylcholine or norepinephrine) to diffuse across the synaptic cleft

95
Q

Chemical synapse mechanism

A

An arriving action potential stimulates the free diffusion of calcium ions into the presynaptic terminal
Increased calcium ion concentration stimulates the merging of vesicles containing neurotransmitter molecules with the plasmalemma
The neurotransmitters are released into, and diffuse across, the synaptic cleft
Binding of the neurotransmitter molecules to the post-synaptic plasmalemma triggers depolarisation of the post-synaptic cell to generate an action potential

Neurotransmitter is quickly de-activated by the post-synaptic cell
Failure to deactivate would lead to continual stimulation of the cell

96
Q

Cnidarians neural networks

A

Interconnected neurons that form complex 2D nerve nets

97
Q

Polyp neural networks

A

Entire nervous system is comprised of 2 nets

98
Q

Invertebrate neural networks

A

One net lies at the base of the epidermis and the other at the base of the gastrodermis
Neurons bridge the mesoglea

Nerve impulses can move in any direction though the nets
Diffusion conduction means that a stimulus at one point on the net radiates outwards like ripples on a pond
No central control for coordinated responses

99
Q

Neural networks in swimming medusa

A

In swimming medusa, first indications of coordinated control are seen as nerve rings and ganglia are found around the margin of the bell
Associated with sensory organs – e.g. ocelli, and the swimming musculature

Ganglia are concentrations of neurons that serve as simple integration centres.
Each ganglion is associated with a sensory organ and can generate motor output
Greatest output from ganglia controls muscular activity
Contraction of the musculature must be simultaneous so neurons in the nerve ring couple with muscle cells electrically with gap junctions

100
Q

Nematoda

A

Intraepithelial nervous system
Brain is collar-like and circumpharyngeal nerve ring
2 longitudinal nerve cords

101
Q

Annelids

A

Anterior brain consisting of 2 dorsal suprapharyngeal ganglia
2 ventral longitudinal nerve cords and paired segmental ganglia

102
Q

Insecta

A

Dorsal supra-oesophageal ganglia (brain`0 in the head with 2 connectives that circle the gut linking to 2 ventral longitudinal nerve cords
Paired segmental ganglia with sensory and motor neurons
Brain has 3 parts = protocerebrum, deutocerebrum and triocerebrum

103
Q

Arachnida

A

Highly cephalised central nervous system
All segmental ganglia have coalesced in the supra-oesophageal and sub-oesophageal ganglia
2 abdominal nerves extend longitudinally along the body

104
Q

Gastropoda

A

Brain and 2 large, longitudinal nerve cords
Brain-ring of four anterior ganglia wrapped around the anterior alimentary tract
Trend towards Cephalisation and fusion of the ganglia into a brain-liege structure
Twisted configuration

105
Q

Cephalopoda

A

CNS is highly cephalised, strongly concentrated and bilaterally symmetrical, enclosed in a cartilaginous cranium
Supra-oesophageal part associated with sensory function
Sub-oesophageal part associated with motor function
Each appendage has a brachial nerve

106
Q

Squid axons

A

Squid have giant axons – 1 mm in diameter, which allow for rapid transmission of action potentials
Diameter of axons depend on length – short ones are narrow – allows for coordinated motor responses because action potentials all arrive at the same time

107
Q

Echinodermata

A

Radial symmetry- - posses nerve ring around the gut and 5 radial nerves (1 per ambulacra)
2 connected neural nets - sensory ectoneural = epidermis
Motor hyponeural = coelomic lining

108
Q

Evolution of invertebrate nervous system

A

Neural nets increasingly integrated with a localised central nervous system with different sensory and motor networks
Segmented ganglia
Increasing coalescence of nerve tissue associated with the head and often ringing the anterior gut linked to ventral longitudinal nerve cords
Nerve rings that coordinate responses to stimuli
Generalised nerve nets

109
Q

Chordata - amphioxus

A

Rudimentary hollow brain
Dorsal hollow nerve cord almost to the end of the tail
Segmental sensory nerves
Anterior neuropore that contain cilia that maintain a flow of water over and into the pore
Brain no longer wrapped around the anterior part of the alimentary tract

110
Q

Sensory (afferent) nerves

A

Visceral
Somatic

111
Q

Motor (efferent) nerves

A

Somatic nervous system
Autonomic - sympathetic, parasympathetic and enteric

112
Q

Parasympathetic nervous system

A

During relaxation

Nerves arise from the brain and sacral region of spinal cord
Long efferent nerve fibres that synapse with ganglia in vicinity of organs and short efferent neurons that extend from the ganglia to the organs
Stimulates salivary gland secretions, contracts pupils and relaxes sphincter muscles

113
Q

Sympathetic nervous system

A

division functions during “fight or flight” response
Nerve fibres originate from the thoracic and lumbar regions of spinal cord to ganglia near the spine and long efferent neurons that extend to the organs
Inhibits salivary gland secretions, dilates pupils and tightens sphincter muscles

114
Q

Enteric nervous system

A

Networks of neurons in the pancreas, gall bladder and digestive tract that control gut function
Normally regulated by the sympathetic and parasympathetic systems

115
Q

Development of nervous tissue in vertebrates

A

Nervous tissue is derived from ectoderm (outer cell layers)
All vertebrates have a mesodermal notochord during development – forms basis for vertebral column
Associated with a dorsal neural tube created by folding of ectoderm tissues

116
Q

3 layers enclosing the CNS

A

Dura matter – tough fibrous
Arachoid – delicate
Pia mater – contains small blood vessels that nourish the tissue

117
Q

Spinal cord

A

Central neural canal filled with cerebrospinal fluid
Composed of grey and white matter
Spinal nerves – number depends on degree of segmentation

118
Q

Grey matter

A

Cell bodies and dendrites (associated with reflex connections)

119
Q

Where do spinal nerves extend from

A

Grey matter

120
Q

White matter

A

Axons surrounded by myelin sheaths

121
Q

Lamprey - fish

A

No myelinated axons (no white matter)
Shape helps facilitate diffusion of nutrients and oxygen
In spinal cord

122
Q

Comparative morphology of spinal column

A

The distribution of white and grey matter differs between the various vertebrate groups.
The lamprey, being a very primitive fish, lacks any white matter.
Sharks have dorsal and ventral horns of grey matter surrounded by white matter and a sheath.
Amphibians have ventral and dorsal horns of grey matter – the latter extend to the edge of the spinal cord – within white matter.
Reptiles have grey matter surrounded by white matter
but in the spinal cords of mammals and birds the dorsal grey matter extends to the edge of the spinal cord.

123
Q

Formation of the brain

A

During early development anterior neural tube expands by accumulation of cerebrospinal fluid to form different parts that become folded and lie on top of each other
Brains have three main parts – forebrain (telencephalon and diencephalon), midbrain (mesencephalon) and hindbrain (rhombencephalon) each with different roles

124
Q

Telencephalon

A

Forebrain

Cerebrum – two hemispheres and related to sensory and motor integration
Expanded tissue and increased complexity reflects importance of the brain region
Cerebral cortex – primary sensory and motor areas
Other areas deal with processing visual or auditory perception

125
Q

Diencephalon

A

Forebrain

Thalamus – relays sensory information to higher brain centres
Hypothalamus – controls many bodily functions – body temperature, sexual drive, metabolism, hunger and thirst
Pineal gland – controls bodily rhythms
Fish – processes sensory information

126
Q

Cranial nerves

A

Fish & amphibians – 10 pairs; Reptiles, birds and mammals – 12 pairs
Sensory-only and mixed nerves – e.g. vagus has sensory neurons leading to the brain and motor neurons leading to the heart and visceral organs

127
Q

Midbrain

A

Centre for coordinating responses to visual stimuli
Evolution of mid brain – also coordinates touch and auditory processing

128
Q

Hindbrain

A

Medulla oblongata connects brain to spinal column – reflex centre for breathing, swallowing, cardiovascular function and gastric secretion
Cerebellum – outgrowth of medulla oblongata and coordinates motor activity (posture, movement, spatial orientation)
Pons connects forebrain cerebrum to cerebellum and is important in the regulation of breathing

129
Q

Medulla oblongata

A

Reflex centre for breathing, swallowing, cardiovascular function and gastric secretion

130
Q

Cerebellum

A

Coordinates motor activity (posture, movement, spatial orientation)

131
Q

Pons

A

Regulation of breathing

132
Q

Pineal gland

A

Controls bodily rhythms
Secretes melatonin

133
Q

Hypothalamus

A

Controls bodily functions- body temperature, sexual drive, metabolism, hunger and thirst

134
Q

Thalamus

A

Relays sensory information to higher brain centres

135
Q

Number of cranial nerves in fish and amphibians

A

10 pairs

136
Q

Number of cranial nerves in birds and mammals

A

12 pairs

137
Q
A

Comparative Anatomy And Physiology Of Animals (13 decks)

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