Lab 7: Life on land Part 1 Flashcards
What are the two main groups of mammals living today
Placental
Marsupial
Bear live young and wickedly their young with milk afterbirth
Compared with reptiles, mammals have a higher _______, _______, ______ and ______
Higher metabolic rate
Higher level of activity
Endothermy
More complex behaviour
Key differences between mammals and reptiles
-suckling of young with milk produced by modified skin glands called mammary glands
-evolution of a secondary palate, muscular tongue and heterodont dentition which permit mechanical breakdown of food in mouth
-shift in position of the jaw articulation from the Quadrate and articular to the dentary and squamosal and transformation of the quardrate and articular into ossicles of middle ear
-circulatory, respiratory, excretory, digestive and nervous systems have all been modified to support a higher metabolic rate
Mammalian tail function
Balancing organs, insect squatters, social signals or lost as in humans and apes
Pectoral appendage of mammals consists of what parts
Pelvic appendage consists of what parts
Brachium, antebrachium, manus
Femur, crus, pes
The medial tow of the manus (thumb equivalent) is ______ in many animals such as the cat and the ____ digit of the pes (big toe equivalent) is ____
Reduced
Lost
The mouth of mammals is bounded by fleshy lips called ___
Labia
Rhinarium
Bare, moist patch of skin on the nose which holds the Nares
Outer eye parts of mammals
Upper and lower moveable eyelids
Nictitating membranes (corner to cleanse and moisten eye)
Prominent external flap called the ______ forms the external ear and the auditory canal leads from its base to the head
The ear drum ________ is located where
Auricle
Tympanum - the base of the canal but is too deep to see externally
Mammary glands external parts
4-5 paired rows of nipples called papillae mammae or teats on the thorax of the abdomen
In females and males (remnant)
Two cloacal openings of females
Anus-dorsal opening
Urogenital sinus (vaginal vestibule)-ventral to the anus. Both the urethra and the vagina empty into the vaginal vestibule.
In the male, Urogenital ducts empty through the ____
In non-neutered males, the _______ are located in the sac shaped _____.
Penis
Testes
Scrotum
The entire area including the anus and external genitalia in both males and females is called the _________
Perineum
Claws
Where are they derived and what are they homologous to
Epidermal derivative in mammals that are homologous to primate nails and ungulate hooves
Foot pads
Integumentary structure of mammals composed of thicker stratum corneum
The head skeleton of mammals consists of…..
- Chondrocranium which encloses the brain and is composed of endodermal bone
- Dermal bone, which covered most of the chondrocranium
- Visceral skeleton which are endodermal bony remnants of the visceral arches of fish
In mammals, the nasal cavities have enlarged and the nasal capsules have ossified as the nasal __________ or ______
Conchae or turbinate bones
Increase surface area in the nose in order to clean and warm inspired air
Turbinate bones are homologous to the cartilaginous nasal capsule of primitive terrapods
What pathway allows animals to breathe while manipulating food in the mouth
Air flows dorsal to the secondary palate, through the nasopharynx, out the choanae at the back of the pharynx and into the glottis
Hard palate is formed from extensions of the following bones:
-incisive bone=premaxilla
Incisive bone bears 3 incisor teeth for nipping and cutting
-maxilla
Forms cranial part of the zygomatic arch
-paired palatine
Gives off the pterygoid process
A new jaw joint in mammals was established at the ______-_______ union
Dentary-squamosal
Quadrate and articular became involved in ________ and took up a position in the middle ear cavity as the ____ and _____
Sound transmission
Incus
Malleus
What is the squamosal portion of the temporal bone homologous to in reptiles and amphibians
What is the Petrosal portion of the temporal bone homologous to
Squamosal bone
Prootic and opisthotic bones
The hole which the ear drum fits over
The dense ring of bone surrounding this is called and is homologous to
External auditory meatus
Tympanic portion of the temporal
Angular, dermal bone
The auditory ossicles are….
Where are they housed
Malleus, incus and stapes
Within the bulla
What is the only bones in the mammalian jaw?
What is the name of the part that bears teeth
Dentary
Body
The masseter
Function
Side to side grinding movements of the jaws and teeth
Herbivores vs carnivores jaw structure
Herb: Chee by sliding the lower tooth rows over the upper tooth rows due to large masseter and smaller temporalis. Coronoid process is small or absent. Jaw joint alive teeth rows which increase leverage of the masseter muscle causing the lower teeth to approach the upper teeth perpendicularly rather than at an angle like carnivores.
Carn: bite with a chopping motion where the upper and lower tooth rows come together without lauding past each other. Due to a large tenporalis muscle and coronoid process and small masseter. Jaw joint on same line as tooth rows
What muscle helps close the jaw in a scissor like snap
Temporalis
Teeth of mammals
-deeply rooted (thecodont)
-different sizes and shapes (heterodont)
-replacement is limited
-3 incisors for nipping on each side of upper jaw
-1 canine attached to maxilla for piercing
-3 premolars for cutting and shearing attached to maxilla
-1 very small molar for grinding on maxilla
Lower jaw has 3 incisors, 1 canine, 2 premolars and one large molar
Dental formula of mammals
3.1.3.1
3.1.2.1
The last premolar of the upper jaw and the molar of the lower jaw are called the ____
Carnassial teeth
Create shearing force to cut meat from the bone
Found only in Carnivores
The vertebral types of mammals are the same as the pigeon, but there is no _____
Synsacrum
During the transition from reptiles to mammals, zygopophyses between the atlas and axis were ___—
Lost
Allowing rotational movement of the head to occur
How many ribs are in the cat
13 ribs (costae) on each side of the body
The first nine, the true ribs are joined at the sternum by costal cartilages
The teaming 4 are false ribs
The costal cartilages of the 10, 11 and 12 ribs join that of the 9th and thereby become attached to the sternum.
The thirteenth is a floating rib since it’s costal cartilage does not reach the sternum
The sternum consists of a row of _____ bones or ______ and is divided into ___ parts:
8
Sternebrae
3
Manubrium - first sternebra
Body - 2-7 sternebra
Xiphoid process - 8th sternebrae and attached to the xiphoid cartilage
Skeleton of the forelimb consists of what parts
Humerus
Radius
Ulna
Carpals
Metacarpals
Phalanages
The humerus has the following features:
-Head: Large convex smooth and hemispherical protuberance at the end of the numerous. Articulates with the glenoid fossa and scapula
-shaft: long body of the Humerus
-captiulum: rounded eminence forms the lateral parts of the distal articular surface and articulates with the ulna
-trochlea: spool-shaped medial part of the distal articular surface. Articulates with the ulna
-olecranon fossa: depression above the trochlea on the posterior surface. Receives a projection of the ulna when the forelimb is straightened
Where is the radius and what are the parts of the radius
Located on the lateral side of forearm
-Head: disc
-Neck:below head
-Shaft:body of radius
-styloid process: wedge-shaped projection extending from the medial side of radius
Ulna parts
-Olecranon process: fits into the olecranon fossa of the humerus
-Trochlear notch: articulates with the trochela and humerus
-shaft: body of ulna
-styloid process
The wrist or carpus consists of ______ bones arranged in ____ rows in cats
The metacarpus consists of _____ metacarpals set between the carpal bone and the bones of the digits
7
2
5
How many phalanges are on each digit of cats
Digit 1 (thumb) has 2 phalanges
Digits 2-5 have 3 phalanges
The pelvic girdle is made up of 2 ________
Os coxae (innominate bones)
Each os coxa consists of 3 bony parts: ilium, ischium and pubis that fuse during development at the acetabulum
Skeleton of hind limb parts
Femur, tibia and fibula, patella (knee cap), tarsals, metatarsals and phalanges
Parts of the femur
-Head: articulates at the acetabulum with the inominate bone
-Greater Trochanter
-Shaft: displays on its ventral surface a rough line called the lines aspera
-lateral and medial condyles
-intercondyloid fossa
Parts of the tibia
Larger of the two leg bones
-Lateral and medial condyles: surface of articulation with the genus
-tibial tuberosity: small bump
-medial malleolus
Parts of the fibula and where is it
Lateral side of the hind leg
-Head: Articualtes with tibia
-Shaft: slender portion
-lateral malleolus
The tarsus consists of _____ tarsal horns comprising the _____ joint
2 important tarsal bones:
7
Ankle joint
Calcaneus: forms heel bone
Talus: articulates with the tibia
The metatarsus consists of ____ metatarsal bones, the _____ of which is rudimentary.
How many phalanges on each digit
5
First
3 since first digit is lost on hind foot so the digits are numbered 2-5
What is the foot posture horses have of walking on the tip of their toe
Unguligrade
Digitigrade
Foot posture with reduced first digit and then compressed remaining toes together
Allows for speed
What type of foot posture do humans have
Plantigrade- entire foot is flat on the ground and sometimes more digits than in the other groups
Some of the hypaxial muscles in the cat are thin, antagonistic sheets in the thoracic and abdominal walls that support the body wall and function in….
Breathing movements to ventilate the lungs such as the diaphragm
Moves the volume of the chest cavity and thereby move air in and out of the lungs
The adductor Mandibular of primitive tetrapods has divided into what in mammals
Temporalis
Masseter
Muscles
Cutaneous muscles
Cutaneous Maximus: covers almost whole side of the body
Platysma: covers sides of the neck and face
These muscles allow cats to twitch and shake their skin separately from the body wall. Helps get rid of pests on fur
Back muscles of cats
-erector spinae
-multifidus spinae
Both help extend the vertebral column during movements like running
Abdominal muscles of cats
Where do these muscle tendons meet
-external oblique
-internal oblique
-transversus abdonimis
-rectus abdominis
Mid ventral line called linea alba
