- Created by: CJohnstone2001
- Created on: 21-11-20 15:10
Animal structure and function
Animal structure and function
Anatomy= Structure of org.
- Cells bathed in aqueous med, allowing nut exch and waste removal (Sugar,AA,O2 and CO2)
- Dissolved sub transported across memb passively or actively.
Diffusion (SMALL)= Single celled, entire surface contacts environ/allow exchange solutes with external med.
- Specialised organs --> molecular exchange
- Digestive--> uptake nutrients
- Resp--> gas exch
- Excretory--> waste removal
- Epithelial--> Sheets packed cells lining organs.
- Connective--> Bind and support other tiss.
- Nervous--> Sense stimuli, transmit info.
- Muscle--> Contract when stimulated.
- Sheets of cells linked by tight junctions.
- Protect against injury,microbial attack and fluid loss.
Stratified columnar--> Line urethra (urine leaves body).
Simple columnar--> Line intestines/secrete mat and absorb nut.
Pseudostratified ciliated columnar--> Line tubes lungs with cilia to remove debris.
Stratified squamous--> Rapid ÷/new cells pushed to surface.
Simple squamous--> Thin and leaky/line vessels and air sacs of lungs (gas exch occ).
Cuboidal--> Specialised secretory make epithelia of kidney tubules and glands.
Binds and supports/loose organised cells + extracellular matrix with fibres(collagen) embedded in hydrophilic macromol.
Loose= Binds epithelia to other tiss/holds organs.
Fibrous= Dense/large no collagen fibres/parallel bundles inc strength (in tendons and ligaments).
Adipose= Specialised loose/stores fat/insulates.
Cartilage= Embedded in prot/carb matrix/strong but flexible/ends of bones.
Bone= Made of coll and hydroxyapatite (mineral)/bone formed by osteoblasts.
Blood= Cells in plasma/RED carry gas/WHITE immune syst.
Sense stimuli and transmit signals
Neurons/nerve cells send sig (impulses)
Skeletal/cardiac musc- Large no. myofibrils line para to cyto.
Skeletal= Attached to bones by tendons/voluntary movement function/stripy under microscope.
Cardiac= Branched cells contact eachother causes signals needed for contractions (heart beat).
Smooth= Walls of digest tract,arteries,bladder and internal org/slow contract/involuntary move function (digestion).
Tissues organised into functional units.
Vertebrates- organs suspended by connective tiss sheets (mesenteries) and surrounded by fluids.
E.g. Stomach- 4 layers
Mucosal Epithel= Lines lumen/secretes mucus and digestive juice.
Submucosa= Connective tiss/nerves and blood vessels.
Muscularis= Smooth muscle alowing contractions.
Serosa= Connective tiss and epithel tiss/encapsulates organ.
Maintaining internal environment with fluctuating external (pH,temp,blood glucose conc).
Feedback circuits- Sensor/Controller (thermostat) and Effector (heater) maintains temp at set level.
Humans= 37 degrees
Hypothalamus in brain (thermo)--> High temp nerve impulses direct inc sweating and surf blood flow. Low temp sig stop sweat glands/reduce blood flow and stimulate shivering.
Endocrine= Glands sec hormones into blood (slow act/long last)
Nervous syst= Neurons signal discrete targets (short last/limited to cells with receptors specific for signal)
+ or - Feedback-->
Temp reg is most common (-).
Baby's head pressing uterus induces contractions/contractions induce pressure causing more and inc force contract which ends in childbirth (+).