Human bio

What is excretion

Removal of the wastes of metabolism from the body is called excretion

Why is excretion important

Every cell producers waste products, so removing the wastes before they reach harmful concentration is extremely important

List 4 organs that process and remove waste in the excretory system

Lungs, liver, sweat glands, kidneys

Where is the liver located

In the upper abdominal cavity

What is deamination

Breaking down large amounts of protien into energy by removing the amino group from the amino acids

Where does deamination

This occurs in the liver with the aid of enzymes

What is urea

A substance formed by the breakdown of protein in the liver

Why does ammonia need to be removed from the body

Ammonia is extremely soluble in water and highly toxic to cells

How is ammonia converted to urea

The cells of the liver rapidly convert ammonia to the less toxic molecule urea

List the function of the skin

The main function of the skin are to provide a protective covering over the surface of the body and to regulate the body temp

How does the skin help with excretion

Even when there is no visible perspiration on the skin the sweat glands secrete about 500ml of water per day

What is the kidney responsible for

Filtering blood, excreting wastes and maintain homostasis

How does blood enter the kidney

Blood enters the kidney via the renal artery

What is filtrate

Blood pressure forces plasma out of the blood, through the glomerlus into the bowmans capsule

How is urine removed

Via the ureter and released via the urethra

What does the glomerul capsule look like

Resembles a pouch or sac

What do nephrons do

Filter out plasma from the blood and turn it into urine

What is reabsorption

Substances to be kept by the body

What is secretion

Substances to be removed by the body

Where is the pertibular capillaries

Surround the nephron

What are the peritubular capillaries

All substances secreted or reabsorbed involve the tubule and the capillaries

State the steps of urine formation

Glomerular filtration, tubular reabsorption, tubular secretion, excretion

What is glomerul filtration

The initial stage of urine formation, where the kidneys filter blood plasma to remove waste products and excess fluid

What is filtrate

The fluid that has passed through a filter

What is selective reabsorption

Selective reabsorption is the process where the kidneys reabsorb essential substances back into the blood stream from the filtrate produced during ultra filtration

How does surface area affect reabsorption

Increased surface area significantly enhances the rate of reabsorption across a membrane

What is tubular secretion

Tubular secretion is a process in the kidneys where substances are moved from the blood into the renal tubules

Where does filtrate change into urine

Primarily within the renal tubules specifically the proximal tubule, loop of henele and distal tubule

What is a ureters

Two narrow muscular tubes that transport urine from the kidneys to the urinary bladder

What makes the structure of the kidney well suited to urine production

The kidneys structure is well suited for urine production due to it's highly organised network of filtering units and specialized capillaries that facilitate filtration, reabsorption and secretion

What does the body need to excrete

Carbon dioxide, water, salts, urea and uric acid

How much water must be removed from the body per day

1.5 L

What can breaking down amino acids lead to

Harmful NH2 being removed

What can breaking down amino acids create

Energy

When do we break down proteins

When large stores of energy are needed

What are kidney stones

Kidney stones are formed from solid crystals that build up inside the kidneys

What is kidney failure

When the kidneys lose their ability to excrete waste and control the level of fluid in the body

What is the incidence rate of kidney failure in Australia

11%

What does kidney disease effect

Most kidney diseases effect the glomeruli, reducing their ability to filter blood

How can lifestyle measures help keep kidneys healthy

Regulating diet to maintain a health weight, don't smoke and drink alcohol in moderation

What is dalysis

A method of removing wastes from the blood when kidney failure occurs

What is pertoneal dialysis

Peritoneal dialysis occurs inside the body using the peritoneum as a membrane across which waste can be removed

What is haemodialysis

Involves passing the blood through an artificial kidney or dialysis machine

What is liver disease

When the liver is not able to function effectively, it is unable to process toxins ready for elimination

What is skeletal muscle attached to

Bones

What is the function of skeletal muscle

allow for movement, maintain posture due to the organisation of muscles to support the skeleton

How many nucleus does a skeletal muscle fiber have

More than one nucleus

What do skeletal muscles do in development

Skeletal muscle cells fuse together during development in order to form long muscle fibers

Cardiac muscle function

Provide the force needed to pump blood, so that it can be sent around the body via the blood vessels

Which direction do muscles relax

Muscles can only relax in the direction they are striated

What is the role of the permysium

A layer of connective tissue that surrounds each fascicle within a skeletal muscle providing, structural support, facilitating force transmissions and acting as a pathway for blood vessels and nerves

What is the role of empimysum

Seperates the muscle from adjacent structures and carriers blood vessels and nerves which supply the muscle tissue

What is a muscle fiber

The fundamental unit of muscle tissue, responsible for generating movement and force

What is sarcolemma

A tubular sheath that encases and defines each muscle fiber, forming a barrier between extracellular and intracellular compartments

What is the sarcoplasm

The cytoplasm off a muscle fiber

What are myofibrils

Bundles of protein filaments that contain the contractile elements of the cardiomyocyte

What are myofilaments

Protein filaments within myofibrils that are responsible for muscle contraction

What is a sacromere

Smallest and functional unit of striated muscle tissue

What is tropomyosin

Wraps around actin and covers myosin binding sites

What is toponin

Attached directly to the tropomyosin

What does tropomyosin and troponin allow

For muscle contraction to be controlled by nerve impulses

What is the first step in the sliding filament theory

Muscle contraction is initiated by a nerve impulse

What is the second step of the sliding filament theory

Sarcoplasmic reticulum is triggered to release calcium ions into muscle fiber

What is the 3rd step of the sliding filament theory

Once released calcium ions bind to troponin found an actin

What is the fourth step of the sliding theory

Calcium binding causes troponin to change shape and move slightly

What is the fifth step of the sliding theory

At rest the myosin is bound to ATP

What is the sixth step of the sliding filament theory

Phosphate is released

What is the seventh step of the sliding filament theory

ADP is released

What is the eighth step of the sliding filament theory

Myosin stays bound to actin until a new ATP molecule binds

What is a tendon

Muscles are attached to the bones of the skeleton by fibrous in elastic connective tissue called tendons

What is the origin

The end of the muscle fixed to the stationary bone called the origin

What is the belly

The fleshy portion of the muscle between the tendons of the origin and the insertion is called the belly

What is the fixator

A fixator muscle acts a stabilisers of one part of the body during movement of another parts

What is posture

A persons posture is the characteristics way they hold their body when standing or sitting

What does the axial skeleton consist of

The bones that lie around the central axis of the body

What does the axial skeleton do

It provides the main support for erect posture and protection of the central nervous system and the organs contained within the thorax

Describe the appendicular skeleton

Consists of the bones of the upper and lower limbs, pectoral girdle and pelvic girdle

What bones make up the axial skeleton

Bones from the skull, vertebral column, ribs and sternum

What bones make up the appendicular skeleton

Clavicle, scapula, humerus, femur and patella

What does the flat bone do

Protects internal organs e.g. sternum

What does the long bone do

Supports weight and allows for movement

What does the sesamoid bone do

Protects tendon e.g. patella

What does the short bone do

Provide stability and some movement

What do irregular bones do

Variable nature helps to protect different structures

Explain the structure of bones

Collagen rich fibers, minerals and hard and strong

Explain the structure of cartilage

Collagen rich fibers, no minerals and soft and flexible

Explain the structure of ligaments

Fibrous connective tissue, connect bones to other bones and found at joints

Explain how the skeletal system provides structure

Provides the structural framework which gives the body it's shape

Explain how the skeletal system provides protection

Protects soft tissue and vital organs e.g. skull surround the brain

Explain how the skeletal system is involves in movement

Provides the anchors and levers for muscles to pull

Explain how the skeletal system in mineral storage

Bones store calcium and phosphate

Describe what is stored inside yellow bones marrow

Primarily stores fats

Describe what red bone marrow is

The active tissue within bone that producers blood cells

What is spongy bone composed of

A lattice like network of small, needle like pieces of bone called trabecular

What occupies the spaces in the trabecular

Red bone marrow

What is an osteon

The cylindrical functional units of bone

What does each osteon contain

A central canal called the hewersian canal which houses blood vessels and nerve fibers

Describe bone marrow

Soft and flexible tissue, producers blood cells and stores fat

What do minerals in the matrix do

Makes the bone hard and strong

What is collagen in the matrix do

Prevents bones from being brittle