1
Q
What are some of the functions of integument of vertebrates? (Hint:3)
A
- Protecting the organism from mechanical/ frictional stress
- Maintaining an osmotic balance between the organism and the environment
- Providing coloration
2
Q
What is one of the main characteristics of avian integument?
A
The presence of feathers.
3
Q
What can we see in the cross-section of avian integument?
A
- Developing feathers with feather follicles
4
Q
Feathers, like teeth, are dermally derived. True or False?
A
False. Feathers and feather follicles are epidermally derived.
5
Q
What are the basic types of feathers and where are they located?
A
- Contour feathers (body)
- filoplume
- semiplume
- bristle - Flight feather (wings and tail)
- Downy feathers (under contours)
6
Q
Avian skin lacks glands except for a uropygial gland at the base of the tail. True or False?
A
True.
7
Q
What is the function of a uropygial gland? Where is it found?
A
The uropygial gland produces oils that are used to waterproof the feathers. It is found at the base of the tail of birds.
8
Q
What is the function of arrector pili muscles and where are they found?
A
Arrector pili muscles –> smooth muscles in the dermis which are attached to the base of the feather follicle.
Used for heat, mating, defence. The flexion of muscle is involuntary.
9
Q
The unlayered dermis of birds lacks melanocytes. How do birds have colour?
A
Melanin, and other pigments, is injected directly into the developing feather cortex to give the feather colour.
10
Q
What are the two important parameters of wings which relate to flight? how are they calculated?
A
- Aspect ratio
Wing length/ wing width - Wing loading
body mass/ total wing area = body mass/ (wing length x wing width x 2)
11
Q
How is nitrogenous waste excreted in birds?
A
Uric acid.
12
Q
What are two special features in the digestive system of birds?
A
- The crop –> enlarged part of the esophagus used to store food
- The stomach –> consisting of the proventriculus (digestive enzymes mixed with food) and the gizzard (responsible for mechanical digestion of food)
13
Q
What are the two major components of the integument and where are they derived?
A
- Epidermis –> derived from the outermost germ layer of the embryo (ectoderm)
- Dermis –> developed from the middle layer (mesoderm)
- dermis contains connective tissue (mostly collagen fibers), nerves, smooth muscle, and blood vessels.
*Note: some vertebrates may have hypodermis beneath dermis (contains lymph or fat)
14
Q
The ________ layer of the skin is thinner across most of the body, but is thicker in the palm of the hand and the sole of the foot. This is mainly for _______.
A
The STRATUM CORNEUM layer of the skin is thinner across most of the body, but is thicker in the palm of the hand and the sole of the foot. This is mainly for PROTECTION.
15
Q
What are the layers of the epidermis, from superficial to deep? Give a description of each.
(Hint: 5)
A
- Stratum corenum –> for protection
- Stratum lucidum –> a clear area of largely keratinized cells found in thick skin
- Stratum granulosum
- Stratum spinosum –> a tough layer where the cells are linked with intercellular bridges
- Stratum germinativum –> where mitotic cell division takes place
16
Q
The dermis is composed of loose connective tissue and has finger-like projections called ______ that protrude into overlying epidermis.
A
The dermis is composed of loose connective tissue and has finger-like projections called DERMAL PAPILLAE that protrude into overlying epidermis.
17
Q
Similar to feathers, hair follicles are dermally derived. True or False?
A
False. Both feathers and hair follicles are epidermally derived.
18
Q
What are the types of glands found in mammalian integument? Give a description of each.
A
- Sebaceous glands –> appear as large clumps of large, lightly staining cells, each with a distinct nucleus.
- Associated with a hair follicle, and open into the hair follicle.
- Sebaceous secretions condition and waterproof the hair. - Sweat/ Sudoriferous glands –> highly coiled tubular grands
- Apocrine sweat glands –> open into the hair follicles in the groin and armpits (emotional stress, fatty sweat eaten by bacteria)
- Eccrine sweat glands –> open onto the surface of the skin, absent from most mammals or are restricted to the soles of the feet (thermoregulation sweat)
- Ceruminous glands –> modified sweat gland found in integument of outer ear canal of mammals.
- Product of glands is emptied into sebaceous glands and combined secretion = earwax.
19
Q
Give some examples of modifications of the mammalian integument.
A
Horns, antlers, pronghorn, whale bristles, hoof.
20
Q
What is the furcula and where is it located?
A
Furcula a.k.a wishbone is located in the front of the avian skeleton.
21
Q
What is the “Keel” and where is it located?
A
The carinate sternum, a.k.a. the keel, is the breast bone of birds.
22
Q
The avian Vertebral column is separated into 4 regions. What are they?
A
- Cervical vertebrae
- Thoracic vertebrae
- Synsacrum
- Caudal vertebrae
23
Q
Give some functions of the endoskeleton of vertebrates.
A
- Providing the rigid, hinged body segments across which muscles attach to affect locomotion.
- Protecting the delicate internal structures such as the viscera and the nerve cord.
- Acting as a storage site for minerals which can be mobilized when needed (ex. calcium)
- Aiding the ventilation of the lungs in amniotes.
24
Q
The vertebral column of mammals can be divided into 5 regions. What are they? How many of each are there?
A
- Cervical (7)
- Thoracic (13)
- Lumbar (7)
- Sacral (3, fused)
- Caudal (varies)
25
What are the special characteristics of the cervical vertebrae?
- All but 7th have transverse foramina for the passage of the vertebral artery.
- Atlas (#1) has a pair of broad, flat transverse processes and large cup-shaped facets at the anterior edge for articulation with the occipital condyles of the skull. Centrum of vertebra is greatly reduced.
- Axis (#2) is the long odontoid process (dens) that projects into the atlas and an elongated neural spine, extending over the atlas.
-Atlas & axis allow for the free head movement of reptiles, birds and mammals.
26
What do the thoracic vertebrae look like?
-Thoracic vertebrae will have facets (surfaces) for the articulation of the ribs.
27
Anterior ribs articulate ventrally with the _______, which, in the cat, is made up of small bones called ______.
Anterior ribs articulate ventrally with the STERNUM, which, in the cat, is made up of small bones called STERNEBRAE.
28
What are the cranial and caudal sternebrae? What occurs caudally to the sternebrae?
Most cranial--> manubrium
Most caudal--> xiphisternum
Caudally from the xiphisternum, is a cartilaginous projection called the xiphoid process.
*Note: Posterior ribs articulate ventrally with other ribs, but the last, floating rib, only has a vertebral attachment.
29
What are some characteristics of the lumbar vertebrae?
- They have long, anteriorly directed transverse processes.
- A small accessory process, which helps stabilize the zygapophyses, is also present, but is greatly reduced/ absent on the last 2 lumbar vertebrae.
30
What is a characteristic of the sacral vertebrae? (the sacrum)
- Serves as a point of attachment for the pelvic girdle.
31
What are some characteristics of the caudal vertebrae
- May be a pair of small hemal processes on the ventral surface of the vertebrae (in proximal region of the tail)
- Processes + Chevron bone form the hemal arch --> surrounds the caudal artery and vein
32
What is the purpose of the hemal arch and what is it made up of?
Hemal Processes + v-shaped Chevron bone
| -Protects/ supports the caudal arteries/ veins
33
Pectoral girdle of other tetrapods is reduced compared to mammals. True or False?
False. The pectoral girdle of mammals is very much reduced compared to other tetrapods.
34
The largest element of the pectoral girdle is the _______.
The largest element of the pectoral girdle is the SCAPULA.
35
What are the two regions of the scapula?
- Supraspinous fossa
| - Infraspinous fossa
36
At the ventral end of the scapula of mammals is a pit, the glenoid fossa, which will receive the head of the humerus. The orientation of the scapula allows mammalian forelimbs to be positioned directly beneath the animal's body.
What are some locomotory advantages of this shift in limb position?
- Faster, more coordinated movement
- Better range of motion
- Are able to have straight forward and backward movement rather than lateral undulation.
37
The clavicle is ______ derived, and is a component of the ______ ______ in mammals.
The clavicle is DERMALLY derived, and is a component of the PECTORAL GIRDLE in mammals.
38
The clavicle in mammals usually extends from the _____ to the ______ of the sternebrae.
The clavicle in mammals usually extends from the SCAPULA to the MANUBRIUM of the sternebrae.
39
In cats, the clavicle is reduced to a sliver of bone embedded in the shoulder musculature. True or False?
True. This is used to be able to squeeze through tight spaces, and allows less impact on the clavicle when jumping (muscles absorb shock).
40
What are features found at the proximal and distal end of the humerus?
- Proximal end --> large head
- Distal end --> trochlea (for articulation with the ulna and radius) and supracondylar foramen on the medial surface (for nerve and blood vessel passage).
41
The trochlear notch of the _____ articulates with the humerus.
The trochlear notch of the ULNA articulates with the humerus.
42
There is a small radial notch in the ridge along the distal border of the trochlear notch that allows for the articulation of the head of the radius. True or False?
True.
43
The ilium, ischium and pubis fuse to form two innominate bones which form what?
The pelvic girdle is formed by this fusion.
| *(Fusion occurs when the animal matures).
44
The pelvic girdle has a cup-like depression in the lateral wall (acetabulum) to receive what bone?
The acetabulum receives the head of the femur.
45
What does the patella ride over to connect to the femur?
The patella rides over the intercondyloid fossa on the anterior surface on the distal end of the femur.
Intercondyloid fossa --> depression between the two large condyles at the distal end of the femur.
46
What are considered to be the bones of the shank?
- Tibia
| - Fibula
47
From proximal to distal, what are the bones of the foot?
| *Hint: (start at ankle)
- tarsal bones
- Metatarsal bones
- Phalanges
48
What are the components of the vertebrate's cranial skeleton? Give a brief description of each.
1. Chondrocranium --> form the floor and lateral walls of the braincase, as well as otic and olfactory capsules.
2. Dermatocranium --> cover the dorsal aspect of the brain, and form other cranial components (*formed in dermis)
3. Splanchnocranium --> form the jaws, support the gills, tongue, larynx, and middle ear bones in tetrapods
49
why are embryological studies necessary to identify chondrocranium and dermatocranium in most mammals?
Since both these parts of the braincase ossify during development, the enchondral bone (cartilage-replacement) is indistinguishable from dermally derived bone (membranous bone).
50
What separates the respiratory passage from the alimentary passage in mammals? What is it made of?
The secondary palate separates the air and food passageways.
It consists of the bony hard palate and its posterior skin extension, the soft palate.
51
Where can elements of the splanchnocranium be found in tetrapods?
- Jaws
- Middle ear (hyomandibular is homologous to the stapes)
- Hyoid apparatus (supports tongue muscle)
- Top of trachea
52
What is the thecodont dentition?
Thecodont dentition --> the sockets in the upper and lower jaws of mammals in which teeth are rooted.
53
What is the heterodont dentition?
Heterodont dentition --> teeth that are anatomically modified to perform specific duties
54
What are the 4 types of teeth and what kind of function do they have?
1. Incisors (premaxilla) --> nipping
2. Canines (maxilla)--> Stabbing
3. Premolars (maxilla) --> Shearing
4. Molars (maxilla) --> Grinding
55
All tetrapods, mammals included, have half of their lower jaw consisting of a single dermally derived bone, the dentary. True or False?
False. Having a dentary is unique to mammals.
56
In most tetrapods, the lower jaw hinge consists of the articular and the quadrate bones. How do these two bones change in mammals?
Articular --> malleus
Quadrate -->incus
*Both moved into the middle ear
Along with the stapes, the incus and malleus form a chain of bones which now function in sound transmission.
57
What has happened to the hyoid arch and ancestral branchial arches, that used to support the gills, in mammals?
Hyoid arch and ancestral branchial arches have disappeared or have become elements of the hyoid apparatus and larynx.
58
What is the main musculature in the abdominal region of mammals?
(Hint: similar to necturus although most evidence of segmentation is lost)
The hypaxial musculature.
59
What are the oblique muscles in mammals? In which direction do they run?
- External obliques (downwards)
- Internal obliques (upwards)
- Transversus abdonimis (sideways)
60
Where is the rectus abdominus found? From where to where does it run?
- Rectus abdominus is found between the internal oblique and the transversus
- It runs from the innominate bone to the ribs.
61
Subvertebral muscles (hypaxial) have been modified in mammals and are now associated with certain pelvic muscles. True or False?
True.
62
The _______ muscles in the lumbar region are covered by a tough thoracolumbar fascia.
The EPAXIAL muscles in the lumbar region are covered by a tough thoracolumbar fascia.
63
What are the two bands of muscle located beneath the thoracolumbar fascia? Give a brief description of each.
1. Dorsal Multifidus --> attaches multi-segmentally between the neural spines of the vertebrae and acts to extend the spine.
2. Erector spinae--> extends the spine, and allows lateral twisting.
64
How are external and internal obliques modified in the thoracic region of mammals?
They become the external and internal intercostals.
| -Intercostals are located in between ribs and are involved in respiration.
65
Where is the diaphragm located?
Diaphragm --> Muscular partition between the thoracic and abdominal cavities.
*Note: It is hypaxial in origin.
66
Where are the jaw muscles and neck muscles in mammals derived from?
They are derived from the muscles which moved the visceral arches of the primitive vertebrate.
67
Where is masseter and what is its function?
Masseter --> large muscle ventral to the arch
| Function--> closes the mouth
68
What is the function of the temporalis and where is it found?
Temporalis --> mandibular arch that closes the mouth. It fills most of the temporal fossa.
69
What is the main difference between the digestive system of herbivores and carnivores?
The digestive systems are very similar. Herbivores have a longer digestive tract than carnivorous animals due to the complexity of the food.
70
What are the salivary glands that can be seen in the mink?
- Mandibular glands (pair)--> on ventral surface of the throat
- Parotid gland--> located craniodorsally to each mandibular gland.
71
Give a flowchart of the digestive system of the mink (mammal).
Food--> mouth --> Saliva/ salivary glands --> esophagus --> stomach --> pyloric sphincter --> small intestine (receives bile and enzymes from pancreatic duct --> duodenum --> jejunum --> ileum --> large intestine (colon) with vili --> rectum --> anus
*Note: Gallbladder is located in the liver lobe.
72
Rats don't have gallbladder. What does this indicate about their diet?
They will have a low-fat diet since they are unable to store bile.
73
Unlike squalus and necturus, the coelom of mammals can be divided into regions. What are these regions?
1. Thoracic cavity
- two pleural cavities (each has one of multilobed lungs)
- pericardial cavity (contains the heart)
2. Abdominal cavity
- a.k.a peritoneal cavity
- contains abdominal viscera
74
What separates the thoracic and abdominal cavities?
-The diaphragm
75
Give the flowchart of the respiratory system (airflow) in mammals.
Air --> external nares --> nasal passsages (warmed) --> nasopharynx --> glottis --> larynx -->trachea --> bronchi --> bronchioles --> alveoli
OR
Oral cavity --> oropharynx --> glottis --> larynx --> trachea --> bronchi --> bronchioles --> alveoli
*Bronchi + bronchioles = lobes of lungs
76
Arteries take blood _____ from the heart. Veins take blood ______ the heart.
Arteries take blood AWAY from the heart. Veins take blood TOWARD the heart.
77
What is the pericardial sac? Where is it found?
Pericardial sac covers the heart.
78
The aorta leaves the ______ (hint: left or right) ventricle of the heart, and curves, as the _____ __ ___ ______ toward the left side of the body.
The aorta leaves the LEFT (hint: left or right) ventricle of the heart, and curves, as the ARCH OF THE AORTA toward the left side of the body.
79
The arch of the aorta corresponds to which aortic artery of the primitive vertebrate?
Aortic arch IV.
80
What are the two main arteries that come off of the cranial portion of the arch of the aorta? Where do they lead?
1. Brachiocephalic artery (right)
- takes blood to the head and right arm
2. (left) Subclavian artery
- takes blood to the left arm
81
What gives rise to the right internal thoracic artery and where does it take blood?
The Brachiocephalic artery gives rise to the right internal thoracic artery. It takes blood to the right side of the ventral wall of the chest.
82
The brachiocephalic artery divides into three branches. What are they and where do they lead?
1. Left & Right common carotids
- supply left and right side of the head
2. Right subclavian artery
- Takes blood to right arm
83
Pulmonary arteries take blood to the lungs from the _______ (Hint: left or right) ventricle of the heart.
Pulmonary arteries take blood to the lungs from the RIGHT (Hint: left or right) ventricle of the heart.
84
What aortic arch of primitive vertebrae do the pulmonary arteries correspond to?
Aortic arch VI.
85
Blood returns to the heart from the lungs through the _______ _____ which enter the _____ atrium.
Blood returns to the heart from the lungs through the PULMONARY VEINS which enter the LEFT atrium.
86
What are the two main features of the fetal pig heart? What do they cause?
1. Ductus arteriosus --> short channel between pulmonary trunk and the aorta
- blood from right ventricle enters pulmonary turnk, and its mostly pumped into the aorta
2. Foramen ovale --> opening in the interatrial septum between the right and left atria.
- Most oxygenated blood from caudal vena cava to right atrium is diverted through the foramen ovale to the left side of the heart.
- blood then goes into the left ventricle and is pumped into the aorta and flows mainly into the arteries of the head, neck and forelimbs.
*Causes mixing of oxygenated and deoxygenated
87
The urogenital system is comprised of 2 systems. What are they? Why are they usually studied together?
1. Excretory system
2. Reproductive system
-Studied together because they are closely linked during embryological development.
88
From where do kidneys develop?
-Kidneys develop from a paired ridge of tissue (nephric ridge) which runs along the dorsal surface of the abdominal cavity.
89
Anamniotes have _______ kidneys during embryonic development, which transition to ________ kidneys in adults.
In anamniotes have PRONEPHRIC kidneys during embryonic development, which transition to OPISTHONEPHRIC kidneys in adults.
90
Amniotes have _______ kidneys during embryonic development, which transition to ________ kidneys in adults.
Amniotes have MESONEPHRIC kidneys during embryonic development, which transition to METANEPHRIC kidneys in adults.
91
The ducts which drain urine from the pronephric, mesonephric, and opisthonephric kidneys are are homologous, but the duct that drains the metanephric kidney is not. True or False?
True. These homologous ducts are sometimes called archinephric ducts.
*These are responsible for bringing waste and sperm to cloaca.
92
What is the ureter?
Ureter--> duct that drains the metanephric kidneys.
*In these males, archinephric duct is only responsible for sperm transport.
93
What is an indifferent gonad and what can it become?
Indifferent gonad --> early gonad which, depending on hormonal influence, can become either a testis or an ovary.
94
Metanephric kidneys are usually indented along their medial surface. What is this indentation called?
The indentation is called the hilus.
95
Where are the ureter, the renal artery & vein attached to the metanephric kidney?
Urether, renal vein & artery are attached to the metanephric kidney at the hilus.
96
The ureter brings urine from the kidneys to the _______.
The ureter brings urine from the kidneys to the BLADDER.
97
What drains the bladder?
The urethra.
98
What is the sac that encloses the testicles called?
The scrotum.
99
To see the testis, you need to cut through the tough _______ which covers each testicle.
To see the testis, you need to cut through the tough VAGINAL TUNIC which covers each testicle.
100
What is the flow of sperm in male mammals?
Testis --> c-shaped epididymis (storage) --> vas deferens --> urethra --> penis
101
What does the spermatic cord consist of and what is its passage through the body wall called?
```
Spermatic cord --> complex structures supplying and draining the testis
Consists of:
- Vas deferens
-testicular artery, vein
-Nerves
```
Its passage through the body wall is called the inguinal canal.
102
As sperm travels along the urethra, the products of other glands are added. What is an example of this kind of glad?
Prostate gland.
103
What is the penis bone found in minks called?
Baculum (or os penis).
104
What are the two connective tissue cavities along the base of the penis?
1. Corpora cavernosa
- Erectile when engorged with blood
2. Corpus spongiosum
- Surrounds the urethra and runs down the length of the penis
- Expands at the distal end of the penis to form the glans
105
What is the prepus?
Prepuce --> skin sheath that covers and protects the distal end of the penis.
106
Give the flowchart of the eggs in mammals.
Ovary --> follicular wall --> coelom --> infundibulum of oviduct --> oviduct --> uterine horn --> body of uterus (bicornuate) --> cervix --> vagina
107
What is the tiny bone of the vagina called?
Os clitoridis.
108
The female ______ is homologous to the male penis. (mammals)
The female CLITORIS is homologous to the male penis.
109
How does the shape of the centrum relate relate to the range of motion in the avian neck?
Ball and socket:
- Increases mobility
- longer, and more reach
110
What is the digestive flow of birds?
Mouth --> crop (storage) --> esophagus --> stomach (proventricular--> gizzard) --> small intestine, duodenum (gets enzymes from pancreas and liver) --> cecum --> colon --> cloaca
111
How do ribs connect to thoracic vertebrae in cats?
#2-#10:
- Capitulum (head) of the rib articulates to the junction of two vertebrae (at the center), called costal demifacets
- Tuberculum (shoulder) of the rib articulates with a costal facet on the transverse process of the thoracic vertebrae
```
#11-#13:
-Only the head of the rib articulates, the shoulder does not.
```
112
How does the foot posture of the cat differ from your own?
- Cats walk on toes, carpals still in the air
| - Shock absorption is important for cats to stay quiet
113
What are the functions of the secondary palate in the cat skull and what ?
Hard palate --> made of palatine bones, dermatocranium
-used for mastication
soft palate-->
-Makes food into a bolus to help with swallowing
114
How is the lower jar of cats attached to the skull?
The mandible is hinged at the junction of the dentary and squamosal.
115
How do fetal mammals obtain nutrients?
lining of uterus --> placenta (with chorioallantoic membrane) --> umbillical cord --> fetus
116
The nervous system changes a lot across vertebrate classes because it is so complex. True or False?
False. The nervous system is the most complex system in the vertebrate body but it is very conservative (changes little across vertebrate classes.
117
The nervous system is divided into 2 types. What are they and what are they comprised of?
1. Central nervous system:
- Brain
- Spinal cord
2. Peripheral nervous system:
- Cranial & spinal nerves
- Autonomic nervous system
118
The vertebrate brain can be divided into 3 basic regions. What are they and where are they located?
1. Prosencephalon (forebrain)
2. Mesencephalon (midbrain)
3. Rhombencephalon (hindbrain)
119
What are the sub-regions of the prosencephalon, and what are its components?
1. Telencephalon
- olfactory bulb, tract, lobes
- cerebral hemispheres
2. Diencephalon
- thalamus
- hypothalamus
- epithalamus
- pineal organ
- hypophysis (pituitary)
120
What are the sub-regions of the mesencephalon, and what are its components?
1. Mesencephalon
- optic lobe (superior colliculi)
- auditory lobe (inferior colliculi)
121
What are the sub-regions of the rhombencephalon, and what are its components?
1. Metencephalon
- cerebellum
- pons (birds and mammals)
2. Myelencephalon
- medulla oblongata
122
The peripheral nervous system is made up of two functionally different nerve fibers, what are they and where do these nerve fibers lead?
1. Sensory nerve fibers (afferent)
- carry impluses from receptor organs --> central nervous system
2. Motor nerve fibers (efferent)
- carry response information from central nervous system --> effector organs (usually muscles/glands
123
How are the nervous system fibers divided based on topography?
1. Somatic fibers (sensory or motor)
- innervate the skin and voluntary muscles
2. Visceral fibers (sensory or motor)
- innervate involuntary muscles and glands.
*Note: Autonomic nervous system consists only of visceral fibers
124
What are two major differences between the mammalian brain and the shark brain?
1. Enlargement of both cerebrum and cerebellum
| 2. Surface area increased due to folds (gyri and sulci)
125
What are the folds and grooves of the brain called?
Folds --> gyri
| Grooves --> sulci
126
The two cerebral hemispheres are separated from each other by a long groove called the ______ ______ ________.
The two cerebral hemispheres are separated from each other by a long groove called the LONGITUDINAL CEREBRAL FISSURE.
127
The transverse band of fibres that connects the hemispheres of the cerebrum is called the ________ ______.
The transverse band of fibres that connects the hemispheres of the cerebrum is called the CORPUS CALLOSUM.
128
Where are the olfactory bulbs located in the brain?
-The anterior end of the ventral surface of the brain
129
The hypothalamus bears the hypophysis pituitary gland) on a narrow stalked called the ___________.
The hypothalamus bears the hypophysis pituitary gland) on a narrow stalked called the INFUNDIBULUM.
130
Anterior to the pituitary gland, an X-shaped structure called the _____ ______marks the point where some nerve impulses from each eye cross over to enter the other side of the brain.
Anterior to the pituitary gland, an X-shaped structure called the OPTIC CHIASMA marks the point where some nerve impulses from each eye cross over to enter the other side of the brain.
131
What are the corpora quadrigemina, what do they do, and where are they found?
4 round swellings on the dorsal region of the brain.
1. Superior colliculi --> cranial part
- coordinates visual reflexes
2. Inferior colliculi --> posterior part
- coordinates auditory reflexes
*Both regions relay information to the telencephalon
132
The _______ forms the dorsal part of the metencephalon.
The CEREBELLUM forms the dorsal part of the metencephalon.
133
The medial portion of the cerebellum is called the _____; the lateral parts are the _________.
The medial portion of the cerebellum is called the VERMIS; the lateral parts are the HEMISPHERES.
134
What are the arbor vitae and where are they found?
Arbor vitae --> myelinated nerve fibers
| -found in the sagittal section of the cerebellum
135
Beneath the cerebellum, where is a swelling called the pons. What does it do?
The pons relays impulses between the cerebrum and the cerebellum.
136
What part of the brain is posterior to the cerebellum.
Myelencephalon is posterior to the cerebellum.
| *Note: it is largely comprised of the medulla oblongata.
137
What are the two additional nerves arising from the CNS within the skull in mammals compared to sharks?
1. The accessory nerve (XI)
| 2. The Hypoglossal nerve (XII)
138
What are 3 main differences in the function of branial nerves of mammals (amniotes) compared to other anamniotes?
1. Loss of fibers that innervate the lateral line system (amniotes dont have LLS)
2. Addition of visceral motor (autonomic) fibers to the facial & glossopharyngeal nerves
- they innervate the lacrimal and salivary glands (anamniotes don't have these glands)
139
The external nares lead into the separated _______ ______ that contain delicate, folded bones called _______ _______.
The external nares lead into the separated NASAL CAVITIES that contain delicate, folded bones called TURBINATE BONES.
140
Where are chemosensory cells found in mammals?
Found in nasal mucosa, which covers the turbinate bones.
141
Internal choanae lead air from where to where?
Internal choanae lead air from the nasal cavity into the nasopharynx.
142
What is the main difference between the Squalus eye and the mammal eye?
The eye is now protected by movable upper and lower eyelids.
*Note: some mammals (mink) have a medial nictitating membrane. (protect from dust and particles)
143
What glands are responsible for keeping the eye moist?
The lacrimal glands.
144
Mammals have a suprachoroidea layer and no optical pedicle. True or False?
False. Mammals have no suprachoroidea layer and no optical pedicle.
145
What is the lens in the eye responsible for? (What is its function?)
The lens is flexible enough to change shape in order to focus the image.
146
What is the function of the tapetum lucidum and where is it located?
The tapetum lucidum is an iridescent layer in the choroid layer of the eye. It reflects light back onto the retina.
Mammals who need to see in the dark (nocturnal) often have this layer.
ZOO 2090
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