Exam 1 Flashcards
Hypertrophy
increase in size -changes dramatically after birth (postnatal growth), so the muscle growth is the size increase of muscle fibers postnatally
hyperplasia
increase in number -completed in prenatal growth. Fixed at birth
Bone
a mineralized connective tissue (hydroxyapatite)
Osteoblasts
bone-forming cells deposited in a matrix of collagen; once osteoblasts are trapped in their secretion
three types of bones in most animals
long bones irregular bones flat bones
two types of bone tissue
compact bone spongy bone
Skeletal muscle
attached to bones striated voluntary multi-nuclei
cardiac muscle
found in the heart striated involuntary one or two nuclei
smooth muscle
found in vessels, ducts, skin and internal organs nonstriated involuntary single nucleus
Muscle tissue can be controlled by
nerves, hormones, local chemicals, or itself depending on the type and location
What grows as muscle grows?
Connective tissue, but the percentage of connective tissue decreases because muscle fiber protein deposit at a greater rate
Factors that affect growth
Nutrition, genetic, environment, sex
Explain how nutrition alters growth
muscle fibers develop before birth, so nutrition alters muscle fiber only during prenatal development
Explain how genetics alters growth
Faster growing breeds have more muscle fibers than their slower growing counter parts
Explain how age alters growth
muscle fiber number increases rapidly during secondary muscle development. Age-related changes in muscle fiber number ocur only during early to middle phases of prenatal development and vary w/in species
determinate growth
stops once a genetically pre-determined structure has completely formed
indeterminate growth
animal grows rapidly when young and continue to grow after reaching adulthood although at a slower pace
Explain how environment alters growth
DNA mutations may lead to advantageous genetic material.
Explain how sex alters environment
androgens play a major role in increasing muscle fibers
What is development
the gradual progression in which something transforms into a different stage from a lower to a higher stage of complexity -can be quantitatively and qualitatively measured
Differentiate between growth and development
growth is the permanent increase in size and mass of an organism, while development is the increase in complexity of an organism
What are some factors affecting muscle fiber number?
Animal variation muscle type species nutrition age breed and genetic selection sex genetic “conditions”
What are the transcription factors?
Myogenin MRF-4 MyoD Myf5
Muscle regulatory factor genes
the expression of one or more of these genes will determine whether the cells become myogenic
Why does carcuss weight matter?
its an important end goal and dressing percent can affect it a lot
Explain the different paths a zygote can take
![](https://s3.amazonaws.com/brainscape-prod/system/cm/271/766/237/a_image_thumb.png?1553311822)
What are the stages of embryonic growth?
Ovum phase
embryonic phase
fetal phase
Ovum phase
the period of time from fertilization of the ovum to implantation
embryonic phase
completed when the developing organism begins to reflect its mature form
Fetal phase
from the point where species identification can be established to birth, a developing organism is considered a fetus (the main growth left to complete at this stage is the increase of existing organs and tissues in size)
What does the Ovum phase include?
Meiosis
fertilization
zona pellucida
oocyte activation
cytokinesis
cleavage
morula
Meiosis
The number of sets of chromosomes in the cell is reduced from two sets (diploid) to one set (haploid)
Fertilization
The fusion of an ovum/oocyte with a sperm. After the ovum reaches the fallopian tubes, sperm penetrates the zona pellucida and fertilize the ovum leading to the formation of a zygote (fertilized egg)
Zona pellucida
a glycoprotein membrane surrounding an ovum. This structure is important for sperm binding and allows to initiate oocyte activation/acrosome reaction
Acrosome reaction
the process that a sperm penetrates the zona pellucida and ultimately the ovum by releasing numerous enzymes
cytokinesis
the process in which the cytoplasm of a single eukaryotic cell is divided to form two daughter cells
- After fusion of ovum and sperm, the pronuclei from both ovum and sperm migrate to the center of the cell and fuse together. At this point, fertilization is complete and cytokinesis events ensues.
Cleavage
- once fertilization is complete, the fertilized egg enters cell division known as the period of cleavage.
- Increase in cell number: during the cleavage, cell numbers increase massively, but no protein synthesis during the cleavage phase. Amount of DNA increase, and cell size decreases, however, overall size of embryo has no change
Morula
- signals the end of the ovum and cleavage phases of development of fertilized egg.
- At this stage, Morula reaches the uterine lumen or cavity and zona pellucida is lost (figure 3.4). In Chicken, the liberation of a chick from a shelled egg is often referred as the process of hatching.
What are the stages of the embryonic phase?
Blastula
morphogenesis
gastrulation
neurulation
somitogenesis
limb bud formation
Blastula
a hollow sphere of cells surrounding an inner fluid-filled cavity called the blastocoele formed during an early stage of embryonic development in animals.
Morphogenesis
- After formation of the blastula, embryo enters the gastrulation phase of development. At this stage, germ layers start to form.
- Morphogenesis is a term used to refer to the collective changes of the internal and external structures in the embryo. These structural changes involve in the development of multiple cell layers.
Invagination
- Yields multiple cell layers by creating a depression in the surface of the embryo. As the depression becomes deeper, the sides of the depression come together forming multiple layers
Involution
- When new layers are formed by the inward rolling of cells along an existing membrane
Ingression
- When cells begin to replicate on the internal aspects of an existing cellular layer and form another layer