excretion

Name 2 layers of skin

Epidermis and dermis

What is the outer layer of skin

Epidermis

Function of malphighian layer

Mitosis

Granular layer

Produce keratin - cells to harden

Cornified layer

Mature cells form cornified layer from keratin

Melanin

Pigment that gives us our skin colour - produced by specialised cells in malphighian layer

What is the dermis made up of

Connective tissue and collagen

What does dermis contain

Sweat glands, hair follicles, sebaceous glands

Name 3 functions of skin

Protection, vitamin d production , temperature regulation

Name 2 methods of body temp regulation that happens in warm conditions

Vasodilation and sweat

Cold conditions

Piloreaction

Vasoconstriction

Shivering

Explain vasodilation

Blood vessels in the skin expand causing heat loss through skin thus cooling us down

Sweat

Salts and water released through pores onto skin . Water evaporated from surface of skin thus lowering temp of body

Piloreatcion

Erector muscles contract - hairs stand up. Layer of warm air trapped close to skin by hairs helping to reduce heat loss

Vasoconstriction

Blood vessels in skin contract when we are cold to reduce heat loss

Shivering

Brain response to cold temp is cause muscles to contact and relax rapidly to raise body temp

How kidneys work

1. Filtering blood and absorbing back into the materials it needs into the renal vein

2. Waste materials form urine - pass to bladder

Néphron

Structure in kidneys that filers blood and produces urine

Filtration

Process by which waste substances are removed from blood

Which part of body is urea is made

Liver

Where is bowman capsule located

Cortex

Ectotherm

Organism that relays on external environment to control body temp

Where does filtration occur

Cortex

Does ADH cause more or less urine to be formed

Less - enables more water to be reaborsbed back into body