Cytology, Congenital Disorders, Histology

1
Cytology, Congenital Disorders, Histology

• Medical Terminology

2
Cytology

• Cells are the basic structural unit of the body.
• Cytology is the study of the formation, structure
  and function of cells
• Cyt/o (cell) -ology (study of)

3
Structure of a Cell

• Cell membrane surrounds and protects the cell
• Cytoplasm material within membrane that is not
  part of nucleus (-plasm means formative material
  of cells)

4
Structure of a Cell

• Nucleus surrounded by nuclear membrane, has two
  functions
• Controls the activities of the cell
• Helps the cell divide

5
Chromosomes

• The nucleus of each cell contains 46 chromosomes
  in 23 pairs.
• There are 22 identical pairs and one single pair
  (XX or XY) that determines gender of child.
• Gametes (sperm and ovum) are the only cells that
  dont have 46 chromosomes.

6
Gametes

• Each gamete has 23 single chromosomes.
• When a sperm and ovum join to form new life, the
  embryo receives half of his/her chromosomes from
  each parent.

7
DNA and Genes

• Deoxyribonucleic Acid
• Long coiled molecules of DNA form chromosomes.
• Genes (functional units of heredity) are a
  segment of DNA that is located on a specific site
  on a chromosome.
• Each chromosome contains about 100,000 genes.

8
Terms Related to Genetics

• Genetics the study of how genes are transferred
  from parents to their children
• Geneticist specialist in the field of genetics
• Genetic engineering research to identify
  defective genes and to develop gene therapy to
  treat or replace them

9
Terms Related to Genetics

• Genetic mutation changes that occur within
  genes
• Somatic cell mutation change within the cells
  of a body, cant be transmitted to the next
  generation
• Gametic cell mutation change within the genes
  found in the gamenes, can be transmitted to next
  generation

10
Genetic Disorders

• Also known as hereditary disorders
• Caused by a defective gene
• Transmitted by parents
• Disorder may be manifested at any time in life
• There are more than 2,000 known genetic disorders

11
Genetic Counseling

• Transmission of genetic disorders is a game of
  chance
• Genetic counseling is a valuable tool for people
  concerned about genetic disorders

12
Congenital Disorders

• An abnormal condition that exists at birth
• May be caused
• By a developmental disorder before birth
• Prenatal influences
• Premature birth
• Injuries during birth

13
Congenital Disorders

• Developmental Disorders
• May result in an anomaly such as the absence of a
  limb
• Anomaly the deviation from what is regarded as
  normal
• Prenatal Influences
• Fetal Alcohol Syndrome
• Birth Injuries
• Cerebral Palsy

14
Histology

• The study of the structure, composition and
  function of tissues
• Hyst/o (tissue) -ology (a study of)
• Histologist a specialist in the study of cells
  and microscopic tissues

15
Stem Cells

• Precursor cells have the ability to divide
  without limit and to give rise to specialized
  cells
• Abundant in fetus and cord blood of a newborn
• Present in limited quantities in adults

16
Stem Cells

• Each type of tissue has its own stem cells
• Can regenerate the full range of cell types
• Research goal is to discover how to use stem
  cells as a source for organ and tissue
  regeneration
• Already used in bone marrow transplants

17
Types of Tissues

• Epithelial form a protective covering for all
  internal and external surfaces of the body
• Connective support and connect organs and
  tissues
• Muscle contain cells with the special ability
  to contract and relax
• Nerve contain cells with the special ability to
  react to stimuli and conduct electrical impulses

18
Glands

• Specialized epithelial cells that form secretions
• Secretion is the substance produced by by a gland
• Two types of glands
• Exocrine
• Endocrine

19
Glands

• Exocrine
• Secrete their chemical substances into ducts and
  then to other organs or out of the body
• Ex/o (out of) -crine (to secrete)
• Endocrine
• Secrete hormones
• Do not have ducts
• End/o (within) -crine (to secrete)
• Secretions flow directly into blood stream