Animal structure and function

Anatomy= Structure of org.

Physiology= Functions

• 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.

Diffusion (LARGE)= 

• Specialised organs --> molecular exchange
• Digestive--> uptake nutrients
• Resp--> gas exch
• Excretory--> waste removal

4 classes=

• 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)

Brain function

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.

Regulatory systems--> 

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 (+).