specialised animal cells/ tissues Flashcards
specialised cell
cell that has adapted to specific functions
tissue
group of interconnected cells that perform a similar function (specialised cells grouped together)
organ
different types of tissues (groups of cells) working together
adaptations of red blood cell
-flattened biconcave shape so can squeeze through narrow vessels
–no nucleus and few organelles so increased space for haemoglobin
-increased surface area for exchange
-flexible
adaptations of a white blood cell (phagocytes)
-multi-lobed (nucleus that is divided into multiple distinct lobes or segments) so easier to change shape and squeeze through small gaps
-lysosomes containing enzymes to break down pathogens
-granular cytoplasm
what is a white blood cell also known as
phagocytes known as neutrophils
what are red blood cells also known as
erythrocytes
adaptations of the sperm cell
-Manyy mitochondria to provide ATP energy for undulipodium to move
-acrosome (specialised lysosome) containing digestive enzymes so can digest zona pellucida layer on ovum to enable access for nucleus
-haploid nucleus
-locomotion (ability to swim) through liquid
diffrentiation
-start life as a single, undifferentiated cell called zygote (stem cell)
-embryo forms after many cell divisions
-embryonic cells differentiate
how do embryonic cells differentiate
-certain genes are switched off and other genes may be expressed more
examples of how a cell may differentiate
-proportion of organelles differ
-shape of cell changes
-contents of cell changes
what are epithelial cells
-a lining found on both outside and inside the body e.g. lining intestines and skin
characteristics of epithelial cells
-made up almost entirely of cells
-no blood vessels within epithelial tissue (receive nutrients from tissue fluid in underlying connective tissue)
-short cell cycles so that they can replace damaged/worn tissue
types of epithelium
-squamous (pavement) - flat, 1 cell thick, present when rapid diffusion is necessary such as across the alveoli and capillary walls
-ciliated - hair like cilia, line trachea causing mucus to be swept away from the lungs
what cells release mucus which trap pathogens and prevent entry to alveoli
goblet cells
what is cartilage an example of
a type of connective tissue
what does connective tissue consist of and whats its function
-non living extracellular matrix containing proteins (collagen and elastin) and polysaccharides
-separates living cells with tissue and enables to withstand forces such as weight
cartilage
-firm, flexible tissue made up of chondrocytes embedded in a matrix
3 types of cartilage
-hyaline (covers end of bonds)
-fibrous (discs between vertebrae and knee joint)
-elastic (outer ear and epiglottis- flap that covers larynx when swallowing)
muscle tissue adaptations
-well vascularised
-elongated
-contain special organelles called myofilaments which allow muscle tissue to contract
what are myofilaments made up of
2 proteins: actin and myosin
3 types of muscle tissue
-skeletal- when contact, causes bones to move, joined to bone by tendons
-cardiac- make up walls of heart and allow it to pump blood
-smooth- propels substances along tracts e.g. in the uterus
