Anatomy workbooks Flashcards
What is the duration of pre-embryonic period?
First two weeks of prenatal development is referred to as pre-embryonic period
How do you define fetal period?
The time of prenatal development from week 9-till birth is referred to as fetal period
Define zygote
A fertilised ovum (oocyte, egg) is referred to as zygote
Define zona pellucida; what is its function?
Zona pellucida (means transparent zone) is a specialised extracellular matrix that surrounds the developing oocyte (egg, ovum). It is made up of glycoproteins; provides nutritional and mechanical support; helps in binding of sperm; promotes acrosomal reaction; prevents polyspermy
What are the outcomes of fertilisation?
- Restores the normal diploid number of chromosomes (46).
- Secondary oocyte completes meiosis.
- The sex of the embryo is established
- Initiation of cell division (cleavage)
Define the word ‘Cleavage’ in what is the outcome of ‘cleavage’?
Cleavage is the rapid mitotic division of cells in a zygote.
Zygote undergoes rapid cell divisions (cleavage) with no overall growth, producing a cluster of cells.
Different cells derived as a result of cleavage are called blastomeres resulting in a compact mass/ball of cells called morula.
What is the significance of ‘embryonic period’?
During the embryonic period most of the organ systems are established. This is the period from week 2 to week 8.
What are the normal sites of implantation of embryo?
Normal site for implantation is the upper (fundus), or posterior wall of the uterus (also may establish on side walls)
What is the outcome of implantation of embryo in fallopian (uterine) tubes?
Ectopic / tubal pregnancy, which usually results in rupture of the tube (a medical
emergency)
What are the names of the three major germ layers in an embryo?
Ectoderm, mesoderm, endoderm
What is the structural unit of:
Epithelium_________
Connective tissue___________
Muscle tissue__________
Nervous tissue_________
Epithelium_____cell_____
Connective tissue___cells, fibres, matrix_________
Muscle tissue_____muscle cell_______
Nervous tissue____neuron________
How do you define the term ‘Tissues’’? Name the four basic/main tissues of the human body.
Tissue is a group of cells that have similar structure and that function together as a unit.
Epithelium, Connective tissue, Muscle tissue, Nervous tissue-
What is the key function of each basic tissue type? (4)
Epithelium-protective linings, secretion, absorption
Connective tissue-connects/anchors, support, locomotion, repair
Muscle tissue-movement
Nervous tissue-generates, conducts nerve impulses
State the embryonic origin of each basic tissue type
Epithelium-outer linings/skin =ectoderm; inner linings endoderm Connective tissue-mesoderm Muscle tissue-mesoderm Nervous tissue-ectoderm
Define the word ‘endothelium’
‘ENDOTHELIUM’ is the inner epithelial lining of blood vessels (and lymphatic vessels)
What are the functions of the adipose tissue in the human body?
Insulation, protection (creates padding around organs e.g. eyeball)
What is the function of ‘cartilage’ in our body?
Flexible support to skeleton, framework
Why is bone tissue referred to as ‘Modified Connective Tissue’
Bone tissue referred to as ‘Modified connective tissue’ because its matrix is modified due to mineralisation i.e. mineralised
Which main body system is derived from ‘ectoderm’ germ layer?
Nervous system
Name any two surface modifications of epithelium (epithelial cells)
Cilia, microvilli
Define the term ‘gland’
A gland is a cell or group of cells modified to secrete chemical substances that are either released into its surroundings (exocrine gland) or into blood stream (endocrine gland)
Name at least three primary functions of the SKIN.
Protection, heat/thermo regulation, sensation (secretion, absorption, vit-D metabolism).
Name the two histological layers of skin?
Dermis and epidermis (also then sub-cutis)
How do the two layers of the skin differ?
Epidermis, is made of closely packed epithelial cells (stratified squamous epithelium), and
Dermis, made of dense, irregular connective tissue that houses blood vessels, hair follicles, sweat glands, etc.