Biology resit

• How does the horse cool itself in hot climates 


  There summer coat

  Sweating

  Vasodilation
• How does the horse heat itself in cold temperatures 


  Shivering

  Winter coat

  Vasoconstriction
• How does the summer coat help keep the horse cool in hot weather


  The horses summer coat is thinner and lays flat preventing the horse trapping an insulated layer of heat
• How does sweating keep the horse cool in hot temperatures 


  Sweating creates a layer of water that evaporates in the turn removing heat from the skin
• How does vasodilation keep the horse cool in hot temperatures 


  The horses veins dilate and this allows the blood to be closer to the surface to promote heat loss through diffusion
• How's does shivering help heat the horse in cold temperatures

  The muscles contract relatively to help produce heat
• How does the horses winter coat help keep it walm in the cold temperatures

  They grow a winter coat to allow heat to be trapped under the hair, hair stands up to cause an insulated layer
• How does vasoconstriction help heat the horse in cold temperatures

  The vains constrict to keep the blood away from the surface and closer to the internal organs to prevent heat loss
• What is the role of insulin in the body?


  Insulin is a key hormone released in the horses body

  Helps regulate blood sugar levels

  Takes glucose from the blood and into the cells

  Helps maintain homeostasis
• What are the functions if the hindbrain


  Balance/ posture

  Motor activity

  Breathing functions such as breathing intensity and frequency

  Sleep/ wakefulness

  Facial sensation and the ability to bite, chew and swallow

  Facial expressions and facial movements

  Cardiac rate, patterns and rhythms

  Breathing rhythms

  Dilation and contractions of blood vessels

  Reflex actions such as Coughing, sneezing and swallowing
• What is the function of the thalamus


  Relays sensory impulses from receptors in various parts of the body to the cerebral cortex
• What is the function of the hypothalamus 


  Overall control of the endocrine system and links to the nervous system
• What does the sympathetic nervous system do to respond to a stimulus

  Blood flow increases

  Heart beats faster

  Breathing rate increases

  Glycogen stors are broken down into glucose
• What are tendons


  A connective tissue that attaches muscle to bone

  Attaches muscles to structures such as the eye ball

  Serves to move the bone or structure
• Tendons


  Composed mostly of collagen

  Collagen structures allow for elasticity and stretch

  Made of connective tissue which connects the muscle to bone this plays a major role in helping create movement in the horse
• Tendons


  This ability enables the Tendons to function as a stretch and recoil mechanism that transmits the force generated by a muscle to the bones or joints to which the tendon is attached to

  The recoil transmits the energy of the muscle contraction to the joint and results in movement

  The elasticity snd strength of the tendon structure allows it to adapt to the stress/strain caused by movement
• Nervous systems


  Afferent (sensory nerves) respond to a stimuli (internal & external) and transmit electronic messages to the CNS in the brain

  The brain interprets the message and instructs the efferent (the motor neurons to co-ordinate the body's response and sends the messages to the body via the PNS to create a reaction in the target organ

  The PNS is responsible for relaying that information to the relevant body part
• What does the central nervous system contain

  Brain:

  Cerebrum

  Cerebellum

  Spinal cord

  Spinal cord:

  Cord

  Nerves

  Pia matter

  Arachnid matter

  Dura mater
• What does the peripheral nervous system do?

  Connects the CNS to the organs, limbs and skin

  Carries sensory and motor information to and from the CNS

  Allows the brain and spinal cord to receive and send information to other areas of the body

  Regulates involuntary body functions like heartbeat and breathing
• What does testosterone do?

  Develops the male reproductive organs and tissues

  Promotes the development of secondary sexual characteristics

  Responsible for libido

  Responsible for stallion like behaviour
• What does oestrogen do?

  Responsible for the clinical signs of oestrus in the mare

  Acts on oviducts, uterus and cervix to prepare the reproductive tract for pregnancy

  High levels of oestrogen in the blood stream cause a surge of LH to be released from the pituitary into the blood stream
• What are alveoli


  Endpoint of the Respiratory system

  Exchange oxygen and carbon dioxide in the blood stream
• Alveoli


  A large surface area - increases the amount of diffusion/gas exchange occurring

  A moist lining for dissolving gases - facilitates effective diffusion across the membrane

  Very thin walls - to facilitate the diffusion of gasses easily across the membrane

  A good blood supply - to ensure enough blood is available to carry gases to and from the lungs

  Large numbers of alveoli - to increase the amount of diffusion occurring
• What do veins do?

  Carry deoxygenated blood into the
• What do the arteries do?

  Cary oxygenated blood out of the heart at a high pressure
• What do capillaries do?

  Capillary carry blood at a low pressure and a sight of gassious exchange
• Where is the small intestine located?

  After the stomach
• What are the dimensions of the small intestine

  15- 21 meters long
• What is the capacity of the small intestine

  55 - 70 liters
• How are the alveoli structures to support diffusion

  Small round structures

  The membrane is moist to enable the effective gassious exchange

  There are numerous and creates a large surface area to facilitate diffusion

  Alveoli have very thin walls as this enabled easy diffusion across the membrane

  Alveoli have very good oxygenated blood supply
• Explain the process of selective reabsorption and ultra filtration

  Blood flows from the renal artery to the nephron under high pressure which squeezes out water, ions, sugars and urine

  Filtered into the bones casual in the nephron